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• Computer Networks UNISA - Chap 10 &ndash; In Depth TCP/IP Networking

  - by MarkPearl

  After reading this section you should be able to Understand methods of network design unique to TCP/IP networks, including subnetting, CIDR, and address translation Explain the differences between public and private TCP/IP networks Describe protocols used between mail clients and mail servers, including SMTP, POP3, and IMAP4 Employ multiple TCP/IP utilities for network discovery and troubleshooting Designing TCP/IP-Based Networks The following sections explain how network and host information in an IPv4 address can be manipulated to subdivide networks into smaller segments. Subnetting Subnetting separates a network into multiple logically defined segments, or subnets. Networks are commonly subnetted according to geographic locations, departmental boundaries, or technology types. A network administrator might separate traffic to accomplish the following… Enhance security Improve performance Simplify troubleshooting The challenges of Classful Addressing in IPv4 (No subnetting) The simplest type of IPv4 is known as classful addressing (which was the Class A, Class B & Class C network addresses). Classful addressing has the following limitations. Restriction in the number of usable IPv4 addresses (class C would be limited to 254 addresses) Difficult to separate traffic from various parts of a network Because of the above reasons, subnetting was introduced. IPv4 Subnet Masks Subnetting depends on the use of subnet masks to identify how a network is subdivided. A subnet mask indicates where network information is located in an IPv4 address. The 1 in a subnet mask indicates that corresponding bits in the IPv4 address contain network information (likewise 0 indicates the opposite) Each network class is associated with a default subnet mask… Class A = 255.0.0.0 Class B = 255.255.0.0 Class C = 255.255.255.0 An example of calculating  the network ID for a particular device with a subnet mask is shown below.. IP Address = 199.34.89.127 Subnet Mask = 255.255.255.0 Resultant Network ID = 199.34.89.0 IPv4 Subnetting Techniques Subnetting breaks the rules of classful IPv4 addressing. Read page 490 for a detailed explanation Calculating IPv4 Subnets Read page 491 – 494 for an explanation Important… Subnetting only applies to the devices internal to your network. Everything external looks at the class of the IP address instead of the subnet network ID. This way, traffic directed to your network externally still knows where to go, and once it has entered your internal network it can then be prioritized and segmented. CIDR (classless Interdomain Routing) CIDR is also known as classless routing or supernetting. In CIDR conventional network class distinctions do not exist, a subnet boundary can move to the left, therefore generating more usable IP addresses on your network. A subnet created by moving the subnet boundary to the left is known as a supernet. With CIDR also came new shorthand for denoting the position of subnet boundaries known as CIDR notation or slash notation. CIDR notation takes the form of the network ID followed by a forward slash (/) followed by the number of bits that are used for the extended network prefix. To take advantage of classless routing, your networks routers must be able to interpret IP addresses that don;t adhere to conventional network class parameters. Routers that rely on older routing protocols (i.e. RIP) are not capable of interpreting classless IP addresses. Internet Gateways Gateways are a combination of software and hardware that enable two different network segments to exchange data. A gateway facilitates communication between different networks or subnets. Because on device cannot send data directly to a device on another subnet, a gateway must intercede and hand off the information. Every device on a TCP/IP based network has a default gateway (a gateway that first interprets its outbound requests to other subnets, and then interprets its inbound requests from other subnets). The internet contains a vast number of routers and gateways. If each gateway had to track addressing information for every other gateway on the Internet, it would be overtaxed. Instead, each handles only a relatively small amount of addressing information, which it uses to forward data to another gateway that knows more about the data’s destination. The gateways that make up the internet backbone are called core gateways. Address Translation An organizations default gateway can also be used to “hide” the organizations internal IP addresses and keep them from being recognized on a public network. A public network is one that any user may access with little or no restrictions. On private networks, hiding IP addresses allows network managers more flexibility in assigning addresses. Clients behind a gateway may use any IP addressing scheme, regardless of whether it is recognized as legitimate by the Internet authorities but as soon as those devices need to go on the internet, they must have legitimate IP addresses to exchange data. When a clients transmission reaches the default gateway, the gateway opens the IP datagram and replaces the client’s private IP address with an Internet recognized IP address. This process is known as NAT (Network Address Translation). TCP/IP Mail Services All Internet mail services rely on the same principles of mail delivery, storage, and pickup, though they may use different types of software to accomplish these functions. Email servers and clients communicate through special TCP/IP application layer protocols. These protocols, all of which operate on a variety of operating systems are discussed below… SMTP (Simple Mail transfer Protocol) The protocol responsible for moving messages from one mail server to another over TCP/IP based networks. SMTP belongs to the application layer of the ODI model and relies on TCP as its transport protocol. Operates from port 25 on the SMTP server Simple sub-protocol, incapable of doing anything more than transporting mail or holding it in a queue MIME (Multipurpose Internet Mail Extensions) The standard message format specified by SMTP allows for lines that contain no more than 1000 ascii characters meaning if you relied solely on SMTP you would have very short messages and nothing like pictures included in an email. MIME us a standard for encoding and interpreting binary files, images, video, and non-ascii character sets within an email message. MIME identifies each element of a mail message according to content type. MIME does not replace SMTP but works in conjunction with it. Most modern email clients and servers support MIME POP (Post Office Protocol) POP is an application layer protocol used to retrieve messages from a mail server POP3 relies on TCP and operates over port 110 With POP3 mail is delivered and stored on a mail server until it is downloaded by a user Disadvantage of POP3 is that it typically does not allow users to save their messages on the server because of this IMAP is sometimes used IMAP (Internet Message Access Protocol) IMAP is a retrieval protocol that was developed as a more sophisticated alternative to POP3 The single biggest advantage IMAP4 has over POP3 is that users can store messages on the mail server, rather than having to continually download them Users can retrieve all or only a portion of any mail message Users can review their messages and delete them while the messages remain on the server Users can create sophisticated methods of organizing messages on the server Users can share a mailbox in a central location Disadvantages of IMAP are typically related to the fact that it requires more storage space on the server. Additional TCP/IP Utilities Nearly all TCP/IP utilities can be accessed from the command prompt on any type of server or client running TCP/IP. The syntaxt may differ depending on the OS of the client. Below is a list of additional TCP/IP utilities – research their use on your own! Ipconfig (Windows) & Ifconfig (Linux) Netstat Nbtstat Hostname, Host & Nslookup Dig (Linux) Whois (Linux) Traceroute (Tracert) Mtr (my traceroute) Route

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• Blogging locally and globally–my experience

  - by DigiMortal

  In Baltic MVP Summit 2011 there was discussion about having two blogs - one for local and another for global audience – and how to publish once written information in these blogs. There are many ways how to optimize your blogging activities if you have more than one audience and here you can find my experiences, best practices and advices about this topic. My two blogs I have to working blogs: this one here technology and programming blog for local market My local blog is almost five years old and it makes it one of the oldest company blogs in Estonia. It is still active and I write there as much as I have time for it. This blog here is active since September 2007, so it is about 3.5 years old right now. Both of these blogs are  my major hits in my MVP carrier and they have very good web statistics too. My local blog My local blog is about programming, web and technology. It has way wider target audience then this blog here has. By example, in my local blog I blog also about local events, cool new concept phones, different webs providing some interesting services etc. But local guys can find there also my postings about how to solve one or another programming problem and postings about Microsoft technologies I am playing with. This far my local blog has a lot of readers for such a small country that Estonia is. This blog has made me a lot of cool contacts and I have had there a lot of interesting discussions about different technical topics. Why I started this blog? Living in small country is different than living in big country. In small country you have less people and therefore smaller audience so you have to target more than one technical topic to find enough readers. In a same time you are still interested in your main topics and you want to reach to more people who are sharing same interests with you. Practically one day y will grow out from local market and you go global. This is how this blog was born. Was it worth to create, promote and mess with it? Every second I have put on my time to this blog has been worth of it. Thanks to this blog I have found new good friends and without them I think it is more boring to work on different problems and solutions. Defining target audiences One thing you should always do when having more than one blog is defining target audiences. If you are just technomaniac interested in sharing your stuff and make some new friends and have something to write to your MVP nomination form then you don’t have to go through complex targeting process. You can do it simple way and same effectively. Here is how I defined target audiences to my blogs: local blog – reader of my local blog is IT professional, software developer, technology innovator or just some guy who is interested in technology,   this blog – reader of this blog is experienced professional software developer who works on Microsoft technologies or software developer who is open minded and open to new technologies and interesting solutions to development problems. You can see how local blog – due to small market with less people – has wider definition for audience while this blog is heavily targeted to Microsoft technologies and specially to software development. On practical side these decisions are also made well I think because it is very hard to build up popular common IT blog. On global level it is better to target some specific niche and find readers who are professionals on your favorite topics. Thanks to this blog I have found new friends who are professional developers and I am very happy about all the discussions I have had with them. Publishing content to different blogs My local blog and this blog have some overlapping topics like .NET, databases and SEO. Due to this overlapping there is question: when I write posting to my local blog then should I have to publish same thing in my global blog? And if I write something to my global blog then should I publish same thing also in my local blog? Well, it really depends on the definition of your target audiences. If they match then of course it is good idea to translate you post and publish it also to another blog. But if you have different audiences then you may need to modify your posting before publishing it. The questions you have to answer are: is target audience interested in this topic? is target audience expecting more specific and deeper handling of this topic or are they expecting more general handling of topic? is the problem you are discussing actual for target audience or not? You have to answer these questions and after that make your decision. If you need to modify your original posting then take some time and do it. Provide quality to all your readers because they will respect you if you respect them. Cross-posting and referencing It is tempting to save time that preparing some blog post takes and if you have are done with posting in one blog it may seem like good idea to make short posting to another blog and add reference to first one where topic is discussed longer. Well, don’t do it – all your readers expect good quality content from you and jumping from one blog post to another is disturbing for them. Of course, there is problem with differences between target audiences. You may have wider target audience and some people may be interested in more specific handling of topic. In this case feel free to refer your blog you are writing in english. This is not working very well in opposite direction because almost all my global blog readers understand english but not estonian. By example, estonian language is complex one and online translating tools make very poor translations from estonian language. This is why I don’t even plan to publish postings here that refer to my local blog for more information. I am keeping these two blogs as two different worlds and if there is posting that fits well to both blogs I will write my posting to one blog and then answer previous three questions before posting same thing to another blog. Conclusion Growing out of your local market is not anything mysterious if you are living in small country. As it is harder to find people there who are interested in same topics with you then sooner or later you will start finding these new contacts from global audience. Global audience is bigger and to be visible there you must provide high quality content to your audience. It is something you will learn over time and you will learn every day something new when you are posting to your global blog. You may ask: if global blog is much more complex thing to do then is it worth to do at all? My answer is: yes, do it for sure. It is not easy thing to do when you start but if you work on your global blog and improve it over time you will get over all obstacles pretty soon. Just don’t forget one thing – content is king and your readers expect high quality from you.

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• C#/.NET Little Wonders: Interlocked Read() and Exchange()

  - by James Michael Hare

  Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. Last time we discussed the Interlocked class and its Add(), Increment(), and Decrement() methods which are all useful for updating a value atomically by adding (or subtracting).  However, this begs the question of how do we set and read those values atomically as well? Read() – Read a value atomically Let’s begin by examining the following code: 1: public class Incrementor 2: { 3: private long _value = 0; 4:  5: public long Value { get { return _value; } } 6:  7: public void Increment() 8: { 9: Interlocked.Increment(ref _value); 10: } 11: } 12:  It uses an interlocked increment, as we discuss in my previous post (here), so we know that the increment will be thread-safe.  But, to realize what’s potentially wrong we have to know a bit about how atomic reads are in 32 bit and 64 bit .NET environments. When you are dealing with an item smaller or equal to the system word size (such as an int on a 32 bit system or a long on a 64 bit system) then the read is generally atomic, because it can grab all of the bits needed at once.  However, when dealing with something larger than the system word size (reading a long on a 32 bit system for example), it cannot grab the whole value at once, which can lead to some problems since this read isn’t atomic. For example, this means that on a 32 bit system we may read one half of the long before another thread increments the value, and the other half of it after the increment.  To protect us from reading an invalid value in this manner, we can do an Interlocked.Read() to force the read to be atomic (of course, you’d want to make sure any writes or increments are atomic also): 1: public class Incrementor 2: { 3: private long _value = 0; 4:  5: public long Value 6: { 7: get { return Interlocked.Read(ref _value); } 8: } 9:  10: public void Increment() 11: { 12: Interlocked.Increment(ref _value); 13: } 14: } Now we are guaranteed that we will read the 64 bit value atomically on a 32 bit system, thus ensuring our thread safety (assuming all other reads, writes, increments, etc. are likewise protected).  Note that as stated before, and according to the MSDN (here), it isn’t strictly necessary to use Interlocked.Read() for reading 64 bit values on 64 bit systems, but for those still working in 32 bit environments, it comes in handy when dealing with long atomically. Exchange() – Exchanges two values atomically Exchange() lets us store a new value in the given location (the ref parameter) and return the old value as a result. So just as Read() allows us to read atomically, one use of Exchange() is to write values atomically.  For example, if we wanted to add a Reset() method to our Incrementor, we could do something like this: 1: public void Reset() 2: { 3: _value = 0; 4: } But the assignment wouldn’t be atomic on 32 bit systems, since the word size is 32 bits and the variable is a long (64 bits).  Thus our assignment could have only set half the value when a threaded read or increment happens, which would put us in a bad state. So instead, we could write Reset() like this: 1: public void Reset() 2: { 3: Interlocked.Exchange(ref _value, 0); 4: } And we’d be safe again on a 32 bit system. But this isn’t the only reason Exchange() is valuable.  The key comes in realizing that Exchange() doesn’t just set a new value, it returns the old as well in an atomic step.  Hence the name “exchange”: you are swapping the value to set with the stored value. So why would we want to do this?  Well, anytime you want to set a value and take action based on the previous value.  An example of this might be a scheme where you have several tasks, and during every so often, each of the tasks may nominate themselves to do some administrative chore.  Perhaps you don’t want to make this thread dedicated for whatever reason, but want to be robust enough to let any of the threads that isn’t currently occupied nominate itself for the job.  An easy and lightweight way to do this would be to have a long representing whether someone has acquired the “election” or not.  So a 0 would indicate no one has been elected and 1 would indicate someone has been elected. We could then base our nomination strategy as follows: every so often, a thread will attempt an Interlocked.Exchange() on the long and with a value of 1.  The first thread to do so will set it to a 1 and return back the old value of 0.  We can use this to show that they were the first to nominate and be chosen are thus “in charge”.  Anyone who nominates after that will attempt the same Exchange() but will get back a value of 1, which indicates that someone already had set it to a 1 before them, thus they are not elected. Then, the only other step we need take is to remember to release the election flag once the elected thread accomplishes its task, which we’d do by setting the value back to 0.  In this way, the next thread to nominate with Exchange() will get back the 0 letting them know they are the new elected nominee. Such code might look like this: 1: public class Nominator 2: { 3: private long _nomination = 0; 4: public bool Elect() 5: { 6: return Interlocked.Exchange(ref _nomination, 1) == 0; 7: } 8: public bool Release() 9: { 10: return Interlocked.Exchange(ref _nomination, 0) == 1; 11: } 12: } There’s many ways to do this, of course, but you get the idea.  Running 5 threads doing some “sleep” work might look like this: 1: var nominator = new Nominator(); 2: var random = new Random(); 3: Parallel.For(0, 5, i => 4: { 5:  6: for (int j = 0; j < _iterations; ++j) 7: { 8: if (nominator.Elect()) 9: { 10: // elected 11: Console.WriteLine("Elected nominee " + i); 12: Thread.Sleep(random.Next(100, 5000)); 13: nominator.Release(); 14: } 15: else 16: { 17: // not elected 18: Console.WriteLine("Did not elect nominee " + i); 19: } 20: // sleep before check again 21: Thread.Sleep(1000); 22: } 23: }); And would spit out results like: 1: Elected nominee 0 2: Did not elect nominee 2 3: Did not elect nominee 1 4: Did not elect nominee 4 5: Did not elect nominee 3 6: Did not elect nominee 3 7: Did not elect nominee 1 8: Did not elect nominee 2 9: Did not elect nominee 4 10: Elected nominee 3 11: Did not elect nominee 2 12: Did not elect nominee 1 13: Did not elect nominee 4 14: Elected nominee 0 15: Did not elect nominee 2 16: Did not elect nominee 4 17: ... Another nice thing about the Interlocked.Exchange() is it can be used to thread-safely set pretty much anything 64 bits or less in size including references, pointers (in unsafe mode), floats, doubles, etc.  Summary So, now we’ve seen two more things we can do with Interlocked: reading and exchanging a value atomically.  Read() and Exchange() are especially valuable for reading/writing 64 bit values atomically in a 32 bit system.  Exchange() has value even beyond simply atomic writes by using the Exchange() to your advantage, since it reads and set the value atomically, which allows you to do lightweight nomination systems. There’s still a few more goodies in the Interlocked class which we’ll explore next time! Technorati Tags: C#,CSharp,.NET,Little Wonders,Interlocked

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• Bouncing off a circular Boundary with multiple balls?

  - by Anarkie

  I am making a game like this : Yellow Smiley has to escape from red smileys, when yellow smiley hits the boundary game is over, when red smileys hit the boundary they should bounce back with the same angle they came, like shown below: Every 10 seconds a new red smiley comes in the big circle, when red smiley hits yellow, game is over, speed and starting angle of red smileys should be random. I control the yellow smiley with arrow keys. The biggest problem I have reflecting the red smileys from the boundary with the angle they came. I don't know how I can give a starting angle to a red smiley and bouncing it with the angle it came. I would be glad for any tips! My js source code : var canvas = document.getElementById("mycanvas"); var ctx = canvas.getContext("2d"); // Object containing some global Smiley properties. var SmileyApp = { radius: 15, xspeed: 0, yspeed: 0, xpos:200, // x-position of smiley ypos: 200 // y-position of smiley }; var SmileyRed = { radius: 15, xspeed: 0, yspeed: 0, xpos:350, // x-position of smiley ypos: 65 // y-position of smiley }; var SmileyReds = new Array(); for (var i=0; i<5; i++){ SmileyReds[i] = { radius: 15, xspeed: 0, yspeed: 0, xpos:350, // x-position of smiley ypos: 67 // y-position of smiley }; SmileyReds[i].xspeed = Math.floor((Math.random()*50)+1); SmileyReds[i].yspeed = Math.floor((Math.random()*50)+1); } function drawBigCircle() { var centerX = canvas.width / 2; var centerY = canvas.height / 2; var radiusBig = 300; ctx.beginPath(); ctx.arc(centerX, centerY, radiusBig, 0, 2 * Math.PI, false); // context.fillStyle = 'green'; // context.fill(); ctx.lineWidth = 5; // context.strokeStyle = '#003300'; // green ctx.stroke(); } function lineDistance( positionx, positiony ) { var xs = 0; var ys = 0; xs = positionx - 350; xs = xs * xs; ys = positiony - 350; ys = ys * ys; return Math.sqrt( xs + ys ); } function drawSmiley(x,y,r) { // outer border ctx.lineWidth = 3; ctx.beginPath(); ctx.arc(x,y,r, 0, 2*Math.PI); //red ctx.fillStyle="rgba(255,0,0, 0.5)"; ctx.fillStyle="rgba(255,255,0, 0.5)"; ctx.fill(); ctx.stroke(); // mouth ctx.beginPath(); ctx.moveTo(x+0.7*r, y); ctx.arc(x,y,0.7*r, 0, Math.PI, false); // eyes var reye = r/10; var f = 0.4; ctx.moveTo(x+f*r, y-f*r); ctx.arc(x+f*r-reye, y-f*r, reye, 0, 2*Math.PI); ctx.moveTo(x-f*r, y-f*r); ctx.arc(x-f*r+reye, y-f*r, reye, -Math.PI, Math.PI); // nose ctx.moveTo(x,y); ctx.lineTo(x, y-r/2); ctx.lineWidth = 1; ctx.stroke(); } function drawSmileyRed(x,y,r) { // outer border ctx.lineWidth = 3; ctx.beginPath(); ctx.arc(x,y,r, 0, 2*Math.PI); //red ctx.fillStyle="rgba(255,0,0, 0.5)"; //yellow ctx.fillStyle="rgba(255,255,0, 0.5)"; ctx.fill(); ctx.stroke(); // mouth ctx.beginPath(); ctx.moveTo(x+0.4*r, y+10); ctx.arc(x,y+10,0.4*r, 0, Math.PI, true); // eyes var reye = r/10; var f = 0.4; ctx.moveTo(x+f*r, y-f*r); ctx.arc(x+f*r-reye, y-f*r, reye, 0, 2*Math.PI); ctx.moveTo(x-f*r, y-f*r); ctx.arc(x-f*r+reye, y-f*r, reye, -Math.PI, Math.PI); // nose ctx.moveTo(x,y); ctx.lineTo(x, y-r/2); ctx.lineWidth = 1; ctx.stroke(); } // --- Animation of smiley moving with constant speed and bounce back at edges of canvas --- var tprev = 0; // this is used to calculate the time step between two successive calls of run function run(t) { requestAnimationFrame(run); if (t === undefined) { t=0; } var h = t - tprev; // time step tprev = t; SmileyApp.xpos += SmileyApp.xspeed * h/1000; // update position according to constant speed SmileyApp.ypos += SmileyApp.yspeed * h/1000; // update position according to constant speed for (var i=0; i<SmileyReds.length; i++){ SmileyReds[i].xpos += SmileyReds[i].xspeed * h/1000; // update position according to constant speed SmileyReds[i].ypos += SmileyReds[i].yspeed * h/1000; // update position according to constant speed } // change speed direction if smiley hits canvas edges if (lineDistance(SmileyApp.xpos, SmileyApp.ypos) + SmileyApp.radius > 300) { alert("Game Over"); } // redraw smiley at new position ctx.clearRect(0,0,canvas.height, canvas.width); drawBigCircle(); drawSmiley(SmileyApp.xpos, SmileyApp.ypos, SmileyApp.radius); for (var i=0; i<SmileyReds.length; i++){ drawSmileyRed(SmileyReds[i].xpos, SmileyReds[i].ypos, SmileyReds[i].radius); } } // uncomment these two lines to get every going // SmileyApp.speed = 100; run(); // --- Control smiley motion with left/right arrow keys function arrowkeyCB(event) { event.preventDefault(); if (event.keyCode === 37) { // left arrow SmileyApp.xspeed = -100; SmileyApp.yspeed = 0; } else if (event.keyCode === 39) { // right arrow SmileyApp.xspeed = 100; SmileyApp.yspeed = 0; } else if (event.keyCode === 38) { // up arrow SmileyApp.yspeed = -100; SmileyApp.xspeed = 0; } else if (event.keyCode === 40) { // right arrow SmileyApp.yspeed = 100; SmileyApp.xspeed = 0; } } document.addEventListener('keydown', arrowkeyCB, true); JSFiddle : http://jsfiddle.net/gj4Q7/

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• Online ALTER TABLE in MySQL 5.6

  - by Marko Mäkelä

  This is the low-level view of data dictionary language (DDL) operations in the InnoDB storage engine in MySQL 5.6. John Russell gave a more high-level view in his blog post April 2012 Labs Release – Online DDL Improvements. MySQL before the InnoDB Plugin Traditionally, the MySQL storage engine interface has taken a minimalistic approach to data definition language. The only natively supported operations were CREATE TABLE, DROP TABLE and RENAME TABLE. Consider the following example: CREATE TABLE t(a INT); INSERT INTO t VALUES (1),(2),(3); CREATE INDEX a ON t(a); DROP TABLE t; The CREATE INDEX statement would be executed roughly as follows: CREATE TABLE temp(a INT, INDEX(a)); INSERT INTO temp SELECT * FROM t; RENAME TABLE t TO temp2; RENAME TABLE temp TO t; DROP TABLE temp2; You could imagine that the database could crash when copying all rows from the original table to the new one. For example, it could run out of file space. Then, on restart, InnoDB would roll back the huge INSERT transaction. To fix things a little, a hack was added to ha_innobase::write_row for committing the transaction every 10,000 rows. Still, it was frustrating that even a simple DROP INDEX would make the table unavailable for modifications for a long time. Fast Index Creation in the InnoDB Plugin of MySQL 5.1 MySQL 5.1 introduced a new interface for CREATE INDEX and DROP INDEX. The old table-copying approach can still be forced by SET old_alter_table=0. This interface is used in MySQL 5.5 and in the InnoDB Plugin for MySQL 5.1. Apart from the ability to do a quick DROP INDEX, the main advantage is that InnoDB will execute a merge-sort algorithm before inserting the index records into each index that is being created. This should speed up the insert into the secondary index B-trees and potentially result in a better B-tree fill factor. The 5.1 ALTER TABLE interface was not perfect. For example, DROP FOREIGN KEY still invoked the table copy. Renaming columns could conflict with InnoDB foreign key constraints. Combining ADD KEY and DROP KEY in ALTER TABLE was problematic and not atomic inside the storage engine. The ALTER TABLE interface in MySQL 5.6 The ALTER TABLE storage engine interface was completely rewritten in MySQL 5.6. Instead of introducing a method call for every conceivable operation, MySQL 5.6 introduced a handful of methods, and data structures that keep track of the requested changes. In MySQL 5.6, online ALTER TABLE operation can be requested by specifying LOCK=NONE. Also LOCK=SHARED and LOCK=EXCLUSIVE are available. The old-style table copying can be requested by ALGORITHM=COPY. That one will require at least LOCK=SHARED. From the InnoDB point of view, anything that is possible with LOCK=EXCLUSIVE is also possible with LOCK=SHARED. Most ALGORITHM=INPLACE operations inside InnoDB can be executed online (LOCK=NONE). InnoDB will always require an exclusive table lock in two phases of the operation. The execution phases are tied to a number of methods: handler::check_if_supported_inplace_alter Checks if the storage engine can perform all requested operations, and if so, what kind of locking is needed. handler::prepare_inplace_alter_table InnoDB uses this method to set up the data dictionary cache for upcoming CREATE INDEX operation. We need stubs for the new indexes, so that we can keep track of changes to the table during online index creation. Also, crash recovery would drop any indexes that were incomplete at the time of the crash. handler::inplace_alter_table In InnoDB, this method is used for creating secondary indexes or for rebuilding the table. This is the ‘main’ phase that can be executed online (with concurrent writes to the table). handler::commit_inplace_alter_table This is where the operation is committed or rolled back. Here, InnoDB would drop any indexes, rename any columns, drop or add foreign keys, and finalize a table rebuild or index creation. It would also discard any logs that were set up for online index creation or table rebuild. The prepare and commit phases require an exclusive lock, blocking all access to the table. If MySQL times out while upgrading the table meta-data lock for the commit phase, it will roll back the ALTER TABLE operation. In MySQL 5.6, data definition language operations are still not fully atomic, because the data dictionary is split. Part of it is inside InnoDB data dictionary tables. Part of the information is only available in the *.frm file, which is not covered by any crash recovery log. But, there is a single commit phase inside the storage engine. Online Secondary Index Creation It may occur that an index needs to be created on a new column to speed up queries. But, it may be unacceptable to block modifications on the table while creating the index. It turns out that it is conceptually not so hard to support online index creation. All we need is some more execution phases: Set up a stub for the index, for logging changes. Scan the table for index records. Sort the index records. Bulk load the index records. Apply the logged changes. Replace the stub with the actual index. Threads that modify the table will log the operations to the logs of each index that is being created. Errors, such as log overflow or uniqueness violations, will only be flagged by the ALTER TABLE thread. The log is conceptually similar to the InnoDB change buffer. The bulk load of index records will bypass record locking. We still generate redo log for writing the index pages. It would suffice to log page allocations only, and to flush the index pages from the buffer pool to the file system upon completion. Native ALTER TABLE Starting with MySQL 5.6, InnoDB supports most ALTER TABLE operations natively. The notable exceptions are changes to the column type, ADD FOREIGN KEY except when foreign_key_checks=0, and changes to tables that contain FULLTEXT indexes. The keyword ALGORITHM=INPLACE is somewhat misleading, because certain operations cannot be performed in-place. For example, changing the ROW_FORMAT of a table requires a rebuild. Online operation (LOCK=NONE) is not allowed in the following cases: when adding an AUTO_INCREMENT column, when the table contains FULLTEXT indexes or a hidden FTS_DOC_ID column, or when there are FOREIGN KEY constraints referring to the table, with ON…CASCADE or ON…SET NULL option. The FOREIGN KEY limitations are needed, because MySQL does not acquire meta-data locks on the child or parent tables when executing SQL statements. Theoretically, InnoDB could support operations like ADD COLUMN and DROP COLUMN in-place, by lazily converting the table to a newer format. This would require that the data dictionary keep multiple versions of the table definition. For simplicity, we will copy the entire table, even for DROP COLUMN. The bulk copying of the table will bypass record locking and undo logging. For facilitating online operation, a temporary log will be associated with the clustered index of table. Threads that modify the table will also write the changes to the log. When altering the table, we skip all records that have been marked for deletion. In this way, we can simply discard any undo log records that were not yet purged from the original table. Off-page columns, or BLOBs, are an important consideration. We suspend the purge of delete-marked records if it would free any off-page columns from the old table. This is because the BLOBs can be needed when applying changes from the log. We have special logging for handling the ROLLBACK of an INSERT that inserted new off-page columns. This is because the columns will be freed at rollback.

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• Notes on implementing Visual Studio 2010 Navigate To

  - by cyberycon

  One of the many neat functions added to Visual Studio in VS 2010 was the Navigate To feature. You can find it by clicking Edit, Navigate To, or by using the keyboard shortcut Ctrl, (yes, that's control plus the comma key). This pops up the Navigate To dialog that looks like this: As you type, Navigate To starts searching through a number of different search providers for your term. The entries in the list change as you type, with most providers doing some kind of fuzzy or at least substring matching. If you have C#, C++ or Visual Basic projects in your solution, all symbols defined in those projects are searched. There's also a file search provider, which displays all matching filenames from projects in the current solution as well. And, if you have a Visual Studio package of your own, you can implement a provider too. Micro Focus (where I work) provide the Visual COBOL language inside Visual Studio (http://visualstudiogallery.msdn.microsoft.com/ef9bc810-c133-4581-9429-b01420a9ea40 ), and we wanted to provide this functionality too. This post provides some notes on the things I discovered mainly through trial and error, but also with some kind help from devs inside Microsoft. The expectation of Navigate To is that it searches across the whole solution, not just the current project. So in our case, we wanted to search for all COBOL symbols inside all of our Visual COBOL projects inside the solution. So first of all, here's the Microsoft documentation on Navigate To: http://msdn.microsoft.com/en-us/library/ee844862.aspx . It's the reference information on the Microsoft.VisualStudio.Language.NavigateTo.Interfaces Namespace, and it lists all the interfaces you will need to implement to create your own Navigate To provider. Navigate To uses Visual Studio's latest mechanism for integrating external functionality and services, Managed Extensibility Framework (MEF). MEF components don't require any registration with COM or any other registry entries to be found by Visual Studio. Visual Studio looks in several well-known locations for manifest files (extension.vsixmanifest). It then uses reflection to scan for MEF attributes on classes in the assembly to determine which functionality the assembly provides. MEF itself is actually part of the .NET framework, and you can learn more about it here: http://mef.codeplex.com/. To get started with Visual Studio and MEF you could do worse than look at some of the editor examples on the VSX page http://archive.msdn.microsoft.com/vsx . I've also written a small application to help with switching between development and production MEF assemblies, which you can find on Codeproject: http://www.codeproject.com/KB/miscctrl/MEF_Switch.aspx. The Navigate To interfaces Back to Navigate To, and summarizing the MSDN reference documentation, you need to implement the following interfaces: INavigateToItemProviderFactoryThis is Visual Studio's entry point to your Navigate To implementation, and you must decorate your implementation with the following MEF export attribute: [Export(typeof(INavigateToItemProviderFactory))]  INavigateToItemProvider Your INavigateToItemProviderFactory needs to return your implementation of INavigateToItemProvider. This class implements StartSearch() and StopSearch(). StartSearch() is the guts of your provider, and we'll come back to it in a minute. This object also needs to implement IDisposeable(). INavigateToItemDisplayFactory Your INavigateToItemProvider hands back NavigateToItems to the NavigateTo framework. But to give you good control over what appears in the NavigateTo dialog box, these items will be handed back to your INavigateToItemDisplayFactory, which must create objects implementing INavigateToItemDisplay  INavigateToItemDisplay Each of these objects represents one result in the Navigate To dialog box. As well as providing the description and name of the item, this object also has a NavigateTo() method that should be capable of displaying the item in an editor when invoked. Carrying out the search The lifecycle of your INavigateToItemProvider is the same as that of the Navigate To dialog. This dialog is modal, which makes your implementation a little easier because you know that the user can't be changing things in editors and the IDE while this dialog is up. But the Navigate To dialog DOES NOT run on the main UI thread of the IDE – so you need to be aware of that if you want to interact with editors or other parts of the IDE UI. When the user invokes the Navigate To dialog, your INavigateToItemProvider gets sent a TryCreateNavigateToItemProvider() message. Instantiate your INavigateToItemProvider and hand this back. The sequence diagram below shows what happens next. Your INavigateToItemProvider will get called with StartSearch(), and passed an INavigateToCallback. StartSearch() is an asynchronous request – you must return from this method as soon as possible, and conduct your search on a separate thread. For each match to the search term, instantiate a NavigateToItem object and send it to INavigateToCallback.AddItem(). But as the user types in the Search Terms field, NavigateTo will invoke your StartSearch() method repeatedly with the changing search term. When you receive the next StartSearch() message, you have to abandon your current search, and start a new one. You can't rely on receiving a StopSearch() message every time. Finally, when the Navigate To dialog box is closed by the user, you will get a Dispose() message – that's your cue to abandon any uncompleted searches, and dispose any resources you might be using as part of your search. While you conduct your search invoke INavigateToCallback.ReportProgress() occasionally to provide feedback about how close you are to completing the search. There does not appear to be any particular requirement to how often you invoke ReportProgress(), and you report your progress as the ratio of two integers. In my implementation I report progress in terms of the number of symbols I've searched over the total number of symbols in my dictionary, and send a progress report every 16 symbols. Displaying the Results The Navigate to framework invokes INavigateToItemDisplayProvider.CreateItemDisplay() once for each result you passed to the INavigateToCallback. CreateItemDisplay() is passed the NavigateToItem you handed to the callback, and must return an INavigateToItemDisplay object. NavigateToItem is a sealed class which has a few properties, including the name of the symbol. It also has a Tag property, of type object. This enables you to stash away all the information you will need to create your INavigateToItemDisplay, which must implement an INavigateTo() method to display a symbol in an editor IDE when the user double-clicks an entry in the Navigate To dialog box. Since the tag is of type object, it is up to you, the implementor, to decide what kind of object you store in here, and how it enables the retrieval of other information which is not included in the NavigateToItem properties. Some of the INavigateToItemDisplay properties are self-explanatory, but a couple of them are less obvious: Additional informationThe string you return here is displayed inside brackets on the same line as the Name property. In English locales, Visual Studio includes the preposition "of". If you look at the first line in the Navigate To screenshot at the top of this article, Book_WebRole.Default is the additional information for textBookAuthor, and is the namespace qualified type name the symbol appears in. For procedural COBOL code we display the Program Id as the additional information DescriptionItemsYou can use this property to return any textual description you want about the item currently selected. You return a collection of DescriptionItem objects, each of which has a category and description collection of DescriptionRun objects. A DescriptionRun enables you to specify some text, and optional formatting, so you have some control over the appearance of the displayed text. The DescriptionItems property is displayed at the bottom of the Navigate To dialog box, with the Categories on the left and the Descriptions on the right. The Visual COBOL implementation uses it to display more information about the location of an item, making it easier for the user to know disambiguate duplicate names (something there can be a lot of in large COBOL applications). Summary I hope this article is useful for anyone implementing Navigate To. It is a fantastic navigation feature that Microsoft have added to Visual Studio, but at the moment there still don't seem to be any examples on how to implement it, and the reference information on MSDN is a little brief for anyone attempting an implementation.

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• SSIS - Range lookups

  - by Repieter

    When developing an ETL solution in SSIS we sometimes need to do range lookups in SSIS. Several solutions for this can be found on the internet, but now we have built another solution which I would like to share, since it's pretty easy to implement and the performance is fast.   You can download the sample package to see how it works. Make sure you have the AdventureWorks2008R2 and AdventureWorksDW2008R2 databases installed. (Apologies for the layout of this blog, I don't do this too often :))   To give a little bit more information about the example, this is basically what is does: we load a facttable and do an SCD type 2 lookup operation of the Product dimension. This is done with a script component.   First we query the Data warehouse to create the lookup dataset. The query that is used for that is:   SELECT     [ProductKey]     ,[ProductAlternateKey]     ,[StartDate]     ,ISNULL([EndDate], '9999-01-01') AS EndDate FROM [DimProduct]     The output of this query is stored in a DataTable:     string lookupQuery = @"                         SELECT                             [ProductKey]                             ,[ProductAlternateKey]                             ,[StartDate]                             ,ISNULL([EndDate], '9999-01-01') AS EndDate                         FROM [DimProduct]";           OleDbCommand oleDbCommand = new OleDbCommand(lookupQuery, _oleDbConnection);         OleDbDataAdapter adapter = new OleDbDataAdapter(oleDbCommand);           _dataTable = new DataTable();         adapter.Fill(_dataTable);     Now that the dimension data is stored in the DataTable we use the following method to do the actual lookup:   public int RangeLookup(string businessKey, DateTime lookupDate)     {         // set default return value (Unknown)         int result = -1;           DataRow[] filteredRows;         filteredRows = _dataTable.Select(string.Format("ProductAlternateKey = '{0}'", businessKey));           for (int i = 0; i < filteredRows.Length; i++)         {             // check if the lookupdate is found between the startdate and enddate of any of the records             if (lookupDate >= (DateTime)filteredRows[i][2] && lookupDate < (DateTime)filteredRows[i][3])             {                 result = (filteredRows[i][0] == null) ? -1 : (int)filteredRows[i][0];                 break;             }         }           filteredRows = null;           return result;     }       This method is executed for every row that passes the script component. This is implemented in the ProcessInputRow method   public override void Input0_ProcessInputRow(Input0Buffer Row)     {         // Perform the lookup operation on the current row and put the value in the Surrogate Key Attribute         Row.ProductKey = RangeLookup(Row.ProductNumber, Row.OrderDate);     }   Now what actually happens?!   1. Every record passes the business key and the orderdate to the RangeLookup method. 2. The DataTable is then filtered on the business key of the current record. The output is stored in a DataRow [] object. 3. We loop over the DataRow[] object to see where the orderdate meets the following expression: (lookupDate >= (DateTime)filteredRows[i][2] && lookupDate < (DateTime)filteredRows[i][3]) 4. When the expression returns true (so where the data is between the Startdate and the EndDate), the surrogate key of the dimension record is returned   We have done some testing with this solution and it works great for us. Hope others can use this example to do their range lookups.

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• Restructuring a large Chrome Extension/WebApp

  - by A.M.K

  I have a very complex Chrome Extension that has gotten too large to maintain in its current format. I'd like to restructure it, but I'm 15 and this is the first webapp or extension of it's type I've built so I have no idea how to do it. TL;DR: I have a large/complex webapp I'd like to restructure and I don't know how to do it. Should I follow my current restructure plan (below)? Does that sound like a good starting point, or is there a different approach that I'm missing? Should I not do any of the things I listed? While it isn't relevant to the question, the actual code is on Github and the extension is on the webstore. The basic structure is as follows: index.html <html> <head> <link href="css/style.css" rel="stylesheet" /> <!-- This holds the main app styles --> <link href="css/widgets.css" rel="stylesheet" /> <!-- And this one holds widget styles --> </head> <body class="unloaded"> <!-- Low-level base elements are "hardcoded" here, the unloaded class is used for transitions and is removed on load. i.e: --> <div class="tab-container" tabindex="-1"> <!-- Tab nav --> </div> <!-- Templates for all parts of the application and widgets are stored as elements here. I plan on changing these to <script> elements during the restructure since <template>'s need valid HTML. --> <template id="template.toolbar"> <!-- Template content --> </template> <!-- Templates end --> <!-- Plugins --> <script type="text/javascript" src="js/plugins.js"></script> <!-- This contains the code for all widgets, I plan on moving this online and downloading as necessary soon. --> <script type="text/javascript" src="js/widgets.js"></script> <!-- This contains the main application JS. --> <script type="text/javascript" src="js/script.js"></script> </body> </html> widgets.js (initLog || (window.initLog = [])).push([new Date().getTime(), "A log is kept during page load so performance can be analyzed and errors pinpointed"]); // Widgets are stored in an object and extended (with jQuery, but I'll probably switch to underscore if using Backbone) as necessary var Widgets = { 1: { // Widget ID, this is set here so widgets can be retreived by ID id: 1, // Widget ID again, this is used after the widget object is duplicated and detached size: 3, // Default size, medium in this case order: 1, // Order shown in "store" name: "Weather", // Widget name interval: 300000, // Refresh interval nicename: "weather", // HTML and JS safe widget name sizes: ["tiny", "small", "medium"], // Available widget sizes desc: "Short widget description", settings: [ { // Widget setting specifications stored as an array of objects. These are used to dynamically generate widget setting popups. type: "list", nicename: "location", label: "Location(s)", placeholder: "Enter a location and press Enter" } ], config: { // Widget settings as stored in the tabs object (see script.js for storage information) size: "medium", location: ["San Francisco, CA"] }, data: {}, // Cached widget data stored locally, this lets it work offline customFunc: function(cb) {}, // Widgets can optionally define custom functions in any part of their object refresh: function() {}, // This fetches data from the web and caches it locally in data, then calls render. It gets called after the page is loaded for faster loads render: function() {} // This renders the widget only using information from data, it's called on page load. } }; script.js (initLog || (window.initLog = [])).push([new Date().getTime(), "These are also at the end of every file"]); // Plugins, extends and globals go here. i.e. Number.prototype.pad = .... var iChrome = function(refresh) { // The main iChrome init, called with refresh when refreshing to not re-run libs iChrome.Status.log("Starting page generation"); // From now on iChrome.Status.log is defined, it's used in place of the initLog iChrome.CSS(); // Dynamically generate CSS based on settings iChrome.Tabs(); // This takes the tabs stored in the storage (see fetching below) and renders all columns and widgets as necessary iChrome.Status.log("Tabs rendered"); // These will be omitted further along in this excerpt, but they're used everywhere // Checks for justInstalled => show getting started are run here /* The main init runs the bare minimum required to display the page, this sets all non-visible or instantly need things (such as widget dragging) on a timeout */ iChrome.deferredTimeout = setTimeout(function() { iChrome.deferred(refresh); // Pass refresh along, see above }, 200); }; iChrome.deferred = function(refresh) {}; // This calls modules one after the next in the appropriate order to finish rendering the page iChrome.Search = function() {}; // Modules have a base init function and are camel-cased and capitalized iChrome.Search.submit = function(val) {}; // Methods within modules are camel-cased and not capitalized /* Extension storage is async and fetched at the beginning of plugins.js, it's then stored in a variable that iChrome.Storage processes. The fetcher checks to see if processStorage is defined, if it is it gets called, otherwise settings are left in iChromeConfig */ var processStorage = function() { iChrome.Storage(function() { iChrome.Templates(); // Templates are read from their elements and held in a cache iChrome(); // Init is called }); }; if (typeof iChromeConfig == "object") { processStorage(); } Objectives of the restructure Memory usage: Chrome apparently has a memory leak in extensions, they're trying to fix it but memory still keeps on getting increased every time the page is loaded. The app also uses a lot on its own. Code readability: At this point I can't follow what's being called in the code. While rewriting the code I plan on properly commenting everything. Module interdependence: Right now modules call each other a lot, AFAIK that's not good at all since any change you make to one module could affect countless others. Fault tolerance: There's very little fault tolerance or error handling right now. If a widget is causing the rest of the page to stop rendering the user should at least be able to remove it. Speed is currently not an issue and I'd like to keep it that way. How I think I should do it The restructure should be done using Backbone.js and events that call modules (i.e. on storage.loaded = init). Modules should each go in their own file, I'm thinking there should be a set of core files that all modules can rely on and call directly and everything else should be event based. Widget structure should be kept largely the same, but maybe they should also be split into their own files. AFAIK you can't load all templates in a folder, therefore they need to stay inline. Grunt should be used to merge all modules, plugins and widgets into one file. Templates should also all be precompiled. Question: Should I follow my current restructure plan? Does that sound like a good starting point, or is there a different approach that I'm missing? Should I not do any of the things I listed? Do applications written with Backbone tend to be more intensive (memory and speed) than ones written in Vanilla JS? Also, can I expect to improve this with a proper restructure or is my current code about as good as can be expected?

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• Make a lives display in HUD, Flash AS3 (not text!)

  - by user40404

  I've been searching the internet all day and I can't find the answer I'm looking for. In my HUD I want to use orange dots to represent lives. The user starts off with 5 lives and every time they die, I want a dot to be removed. Pretty straight forward. So far my idea is to make a movie clip that has the five dots in a line. There would be 5 frames on the timeline (because after the last life it goes to a game over screen right away). I would have a variable set up to store the number of lives and a function to keep track of lives. So every hit of an obstacle would result in livesCounter--;. Then I would set up something like this: switch(livesCounter){ case 5: livesDisplay.gotoAndPlay(1); break; case 4: livesDisplay.gotoAndPlay(2); break; case 3: livesDisplay.gotoAndPlay(3); break; case 2: livesDisplay.gotoAndPlay(4); break; case 1: livesDisplay.gotoAndPlay(5); break; } I feel like there has to be an easier way to do this where I could just have a movie clip of a single orange dot that I could replicate across an x value based on the number of lives. Maybe the dots would be stored in an array? When the user loses a life, a dot on the right end of the line is removed. So in the end the counter would look like this: * * * * * * * * * * * * * * * (last life lost results in the end game screen) EDIT: code based on suggestions by Zhafur and Arthur Wolf White package { import flash.display.MovieClip; import flash.events.*; import flash.ui.Multitouch; import flash.ui.MultitouchInputMode; import flash.display.Sprite; import flash.text.*; import flash.utils.getTimer; public class CollisionMouse extends MovieClip{ public var mySprite:Sprite = new Sprite(); Multitouch.inputMode = MultitouchInputMode.TOUCH_POINT; public var replacement:newSprite = new newSprite; public var score:int = 0; public var obstScore:int = -50; public var targetScore:int = 200; public var startTime:uint = 0; public var gameTime:uint; public var pauseScreen:PauseScreen = new PauseScreen(); public var hitTarget:Boolean = false; public var hitObj:Boolean = false; public var currLevel:Number = 1; public var heroLives:int = 5; public var life:Sprite; public function CollisionMouse() { mySprite.graphics.beginFill(0xff0000); mySprite.graphics.drawRect(0,0,40,40); addChild(mySprite); mySprite.x = 200; mySprite.y = 200; pauseScreen.x = stage.width/2; pauseScreen.y = stage.height/2; life = new Sprite(); life.x = 210; stage.addEventListener(MouseEvent.MOUSE_MOVE,followMouse); /*mySprite.addEventListener(TouchEvent.TOUCH_END, onTouchEnd);*/ //checkLevel(); timeCheck(); trackLives(); } public function timeCheck(){ addEventListener(Event.ENTER_FRAME, showTime); } public function showTime(e:Event) { gameTime = getTimer()-startTime; rm1_mc.timeDisplay.text = clockTime(gameTime); rm1_mc.livesDisplay.text = String(heroLives); } public function clockTime(ms:int) { var seconds:int = Math.floor(ms/1000); var minutes:int = Math.floor(seconds/60); seconds -= minutes*60; var timeString:String = minutes+":"+String(seconds+100).substr(1,2); return timeString; } public function trackLives(){ for(var i:int=0; i<heroLives; i++){ life.graphics.lineStyle(1, 0xff9900); life.graphics.beginFill(0xff9900, 1); life.graphics.drawCircle(i*15, 45, 6); life.graphics.endFill(); addChild(life); } } function followMouse(e:MouseEvent){ mySprite.x=mouseX; mySprite.y=mouseY; trackCollisions(); } function trackCollisions(){ if(mySprite.hitTestObject(rm1_mc.obst1) || mySprite.hitTestObject(rm1_mc.obst2)){ hitObjects(); } else if(mySprite.hitTestObject(rm1_mc.target_mc)){ hitTarg(); } } function hitObjects(){ addChild(replacement); mySprite.x ^= replacement.x; replacement.x ^= mySprite.x; mySprite.x ^= replacement.x; mySprite.y ^= replacement.y; replacement.y ^= mySprite.y; mySprite.y ^= replacement.y; stage.removeEventListener(MouseEvent.MOUSE_MOVE, followMouse); removeChild(mySprite); hitObj = true; checkScore(); } function hitTarg(){ addChild(replacement); mySprite.x ^= replacement.x; replacement.x ^= mySprite.x; mySprite.x ^= replacement.x; mySprite.y ^= replacement.y; replacement.y ^= mySprite.y; mySprite.y ^= replacement.y; stage.removeEventListener(MouseEvent.MOUSE_MOVE, followMouse); removeEventListener(Event.ENTER_FRAME, showTime); removeChild(mySprite); hitTarget = true; currLevel++; checkScore(); } function checkScore(){ if(hitObj){ score += obstScore; heroLives--; removeChild(life); } else if(hitTarget){ score += targetScore; } rm1_mc.scoreDisplay.text = String(score); rm1_mc.livesDisplay.text = String(heroLives); trackLives(); } } }

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• How to trace a function array argument in DTrace

  - by uejio

  I still use dtrace just about every day in my job and found that I had to print an argument to a function which was an array of strings.  The array was variable length up to about 10 items.  I'm not sure if the is the right way to do it, but it seems to work and is not too painful if the array size is small.Here's an example.  Suppose in your application, you have the following function, where n is number of item in the array s.void arraytest(int n, char **s){    /* Loop thru s[0] to s[n-1] */}How do you use DTrace to print out the values of s[i] or of s[0] to s[n-1]?  DTrace does not have if-then blocks or for loops, so you can't do something like:    for i=0; i<arg0; i++        trace arg1[i]; It turns out that you can use probe ordering as a kind of iterator. Probes with the same name will fire in the order that they appear in the script, so I can save the value of "n" in the first probe and then use it as part of the predicate of the next probe to determine if the other probe should fire or not.  So the first probe for tracing the arraytest function is:pid$target::arraytest:entry{    self->n = arg0;}Then, if I want to print out the first few items of the array, I first check the value of n.  If it's greater than the index that I want to print out, then I can print that index.  For example, if I want to print out the 3rd element of the array, I would do something like:pid$target::arraytest:entry/self->n > 2/{    printf("%s",stringof(arg1 + 2 * sizeof(pointer)));}Actually, that doesn't quite work because arg1 is a pointer to an array of pointers and needs to be copied twice from the user process space to the kernel space (which is where dtrace is). Also, the sizeof(char *) is 8, but for some reason, I have to use 4 which is the sizeof(uint32_t). (I still don't know how that works.)  So, the script that prints the 3rd element of the array should look like:pid$target::arraytest:entry{    /* first, save the size of the array so that we don't get            invalid address errors when indexing arg1+n. */    self->n = arg0;}pid$target::arraytest:entry/self->n > 2/{    /* print the 3rd element (index = 2) of the second arg. */    i = 2;    size = 4;    self->a_t = copyin(arg1+size*i,size);    printf("%s: a[%d]=%s",probefunc,i,copyinstr(*(uint32_t *)self->a_t));}If your array is large, then it's quite painful since you have to write one probe for every array index.  For example, here's the full script for printing the first 5 elements of the array:#!/usr/sbin/dtrace -spid$target::arraytest:entry{        /* first, save the size of the array so that we don't get           invalid address errors when indexing arg1+n. */        self->n = arg0;}pid$target::arraytest:entry/self->n > 0/{        i = 0;        size = sizeof(uint32_t);        self->a_t = copyin(arg1+size*i,size);        printf("%s: a[%d]=%s",probefunc,i,copyinstr(*(uint32_t *)self->a_t));}pid$target::arraytest:entry/self->n > 1/{        i = 1;        size = sizeof(uint32_t);        self->a_t = copyin(arg1+size*i,size);        printf("%s: a[%d]=%s",probefunc,i,copyinstr(*(uint32_t *)self->a_t));}pid$target::arraytest:entry/self->n > 2/{        i = 2;        size = sizeof(uint32_t);        self->a_t = copyin(arg1+size*i,size);        printf("%s: a[%d]=%s",probefunc,i,copyinstr(*(uint32_t *)self->a_t));}pid$target::arraytest:entry/self->n > 3/{        i = 3;        size = sizeof(uint32_t);        self->a_t = copyin(arg1+size*i,size);        printf("%s: a[%d]=%s",probefunc,i,copyinstr(*(uint32_t *)self->a_t));}pid$target::arraytest:entry/self->n > 4/{        i = 4;        size = sizeof(uint32_t);        self->a_t = copyin(arg1+size*i,size);        printf("%s: a[%d]=%s",probefunc,i,copyinstr(*(uint32_t *)self->a_t));} If the array is large, then your script will also have to be very long to print out all values of the array.

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• Inheritance of templates in WPF

  - by Alxandr

  I'm trying to make sure that every child of a given element (MPF.MWindow) gets custom templates. For instance, the button should get the template defined in resMButton.xaml. As of now I'm using the following code on: (resMWindow.xaml) <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:MPF"> <Style x:Key="SystemKeyAnimations" TargetType="{x:Type Button}"> <Setter Property="Opacity" Value="0.5" /> <Setter Property="Background" Value="Transparent" /> <Style.Triggers> <EventTrigger RoutedEvent="Mouse.MouseEnter"> <BeginStoryboard> <Storyboard> <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="Opacity"> <SplineDoubleKeyFrame KeyTime="00:00:00.2" Value="1.0" /> </DoubleAnimationUsingKeyFrames> </Storyboard> </BeginStoryboard> </EventTrigger> <EventTrigger RoutedEvent="Mouse.MouseLeave"> <BeginStoryboard> <Storyboard> <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="Opacity"> <SplineDoubleKeyFrame KeyTime="00:00:00.2" Value="0.5" /> </DoubleAnimationUsingKeyFrames> </Storyboard> </BeginStoryboard> </EventTrigger> </Style.Triggers> </Style> <Style TargetType="{x:Type local:MWindow}"> <!-- Remove default frame appearance --> <Setter Property="WindowStyle" Value="None" /> <Setter Property="AllowsTransparency" Value="True" /> <Setter Property="Background" Value="Transparent" /> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type local:MWindow}"> <Border Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" x:Name="ChromeBorder"> <Grid> <Grid.ColumnDefinitions> <ColumnDefinition Width="4" /> <ColumnDefinition /> <ColumnDefinition Width="4" /> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition Height="4" /> <RowDefinition /> <RowDefinition Height="4" /> </Grid.RowDefinitions> <Thumb Grid.Row="0" Grid.Column="1" x:Name="TopThumb" Cursor="SizeNS" BorderThickness="4" BorderBrush="Transparent" /> <Thumb Grid.Row="2" Grid.Column="1" x:Name="BottomThumb" Cursor="SizeNS" BorderThickness="4" BorderBrush="Transparent" /> <Thumb Grid.Row="1" Grid.Column="0" x:Name="LeftThumb" Cursor="SizeWE" BorderThickness="4" BorderBrush="Transparent" /> <Thumb Grid.Row="1" Grid.Column="2" x:Name="RightThumb" Cursor="SizeWE" BorderThickness="4" BorderBrush="Transparent" /> <Thumb Grid.Row="0" Grid.Column="0" x:Name="TopLeftThumb" Cursor="SizeNWSE" BorderThickness="5" BorderBrush="Transparent" /> <Thumb Grid.Row="0" Grid.Column="2" x:Name="TopRightThumb" Cursor="SizeNESW" BorderThickness="5" BorderBrush="Transparent" /> <Thumb Grid.Row="2" Grid.Column="0" x:Name="BottomLeftThumb" Cursor="SizeNESW" BorderThickness="5" BorderBrush="Transparent" /> <Thumb Grid.Row="2" Grid.Column="2" x:Name="BottomRightThumb" Cursor="SizeNWSE" BorderThickness="5" BorderBrush="Transparent" /> <Grid Grid.Row="1" Grid.Column="1"> <Grid.RowDefinitions> <RowDefinition Height="20" /> <RowDefinition /> </Grid.RowDefinitions> <Grid> <Grid.ColumnDefinitions> <ColumnDefinition /> <ColumnDefinition Width="Auto" /> </Grid.ColumnDefinitions> <StackPanel Orientation="Horizontal" Grid.Column="1"> <Button Command="local:WindowCommands.Minimize" Style="{StaticResource ResourceKey=SystemKeyAnimations}"> <Button.Template> <ControlTemplate> <Canvas Width="10" Height="10" Margin="5" Background="Transparent"> <Line X1="0" X2="10" Y1="5" Y2="5" Stroke="White" StrokeThickness="2" /> </Canvas> </ControlTemplate> </Button.Template> </Button> <Button Command="local:WindowCommands.Maximize" x:Name="MaximizeButton" Style="{StaticResource ResourceKey=SystemKeyAnimations}"> <Button.Template> <ControlTemplate> <Canvas Width="10" Height="10" Margin="5" Background="Transparent"> <Rectangle Width="10" Height="10" Stroke="White" StrokeThickness="2" /> </Canvas> </ControlTemplate> </Button.Template> </Button> <Button Command="ApplicationCommands.Close" Style="{StaticResource ResourceKey=SystemKeyAnimations}"> <Button.Template> <ControlTemplate> <Canvas Width="10" Height="10" Margin="5" Background="Transparent"> <Line X1="0" X2="10" Y1="0" Y2="10" Stroke="White" StrokeThickness="2" /> <Line X1="10" X2="0" Y1="0" Y2="10" Stroke="White" StrokeThickness="2" /> </Canvas> </ControlTemplate> </Button.Template> </Button> </StackPanel> <ContentControl x:Name="TitleContentControl"> <TextBlock Text="{TemplateBinding Title}" Foreground="DarkGray" Margin="5,0" /> </ContentControl> </Grid> <ContentPresenter Content="{TemplateBinding Content}" Grid.Row="1"> <ContentPresenter.Resources> <ResourceDictionary> <ResourceDictionary.MergedDictionaries> <ResourceDictionary Source="/MPF;component/Themes/resMWindowContent.xaml" /> </ResourceDictionary.MergedDictionaries> </ResourceDictionary> </ContentPresenter.Resources> </ContentPresenter> </Grid> </Grid> </Border> </ControlTemplate> </Setter.Value> </Setter> </Style> </ResourceDictionary> As you can see during the ContentPresenter which gets the content of the window I merge in a dicrionary called resMWindowContent.xaml. The resMWindowContent.xaml looks as following: <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:MPF"> <ResourceDictionary.MergedDictionaries> <ResourceDictionary Source="/MPF;component/Themes/resMButton.xaml" /> </ResourceDictionary.MergedDictionaries> </ResourceDictionary> It simply merges in the resMButton.xaml dictionary (this is done because in the feature I will have MTextBox, mList... and I want to separate them). The resMButton.xaml looks as following: <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:MPF"> <Style TargetType="{x:Type Button}"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type Button}"> <Grid Background="Transparent"> <Rectangle Stroke="{TemplateBinding BorderBrush}" StrokeThickness="{TemplateBinding BorderThickness}" Fill="{TemplateBinding Background}" /> <ContentPresenter Content="{TemplateBinding Content}" Margin="3" /> </Grid> </ControlTemplate> </Setter.Value> </Setter> </Style> </ResourceDictionary> A simple template drawing a square button. However, it isn't applied at all. My buttons remain normal, and I don't understand what I'm doing wrong. I just want every button inside the MWindow to get a special style (and in time every textbox and so forth). How do I achieve this? One note though: It's important that the styles doesn't apply to elements outside an MWindow.

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• OpenVPN - Windows 8 to Windows 2008 Server, not connecting

  - by niico

  I have followed this tutorial about setting up an OpenVPN Server on Windows Server - and a client on Windows (in this case Windows 8). The server appears to be running fine - but it is not connecting with this error: Mon Jul 22 19:09:04 2013 Warning: cannot open --log file: C:\Program Files\OpenVPN\log\my-laptop.log: Access is denied. (errno=5) Mon Jul 22 19:09:04 2013 OpenVPN 2.3.2 x86_64-w64-mingw32 [SSL (OpenSSL)] [LZO] [PKCS11] [eurephia] [IPv6] built on Jun 3 2013 Mon Jul 22 19:09:04 2013 MANAGEMENT: TCP Socket listening on [AF_INET]127.0.0.1:25340 Mon Jul 22 19:09:04 2013 Need hold release from management interface, waiting... Mon Jul 22 19:09:05 2013 MANAGEMENT: Client connected from [AF_INET]127.0.0.1:25340 Mon Jul 22 19:09:05 2013 MANAGEMENT: CMD 'state on' Mon Jul 22 19:09:05 2013 MANAGEMENT: CMD 'log all on' Mon Jul 22 19:09:05 2013 MANAGEMENT: CMD 'hold off' Mon Jul 22 19:09:05 2013 MANAGEMENT: CMD 'hold release' Mon Jul 22 19:09:05 2013 Socket Buffers: R=[65536->65536] S=[65536->65536] Mon Jul 22 19:09:05 2013 UDPv4 link local: [undef] Mon Jul 22 19:09:05 2013 UDPv4 link remote: [AF_INET]66.666.66.666:9999 Mon Jul 22 19:09:05 2013 MANAGEMENT: >STATE:1374494945,WAIT,,, Mon Jul 22 19:10:05 2013 TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity) Mon Jul 22 19:10:05 2013 TLS Error: TLS handshake failed Mon Jul 22 19:10:05 2013 SIGUSR1[soft,tls-error] received, process restarting Mon Jul 22 19:10:05 2013 MANAGEMENT: >STATE:1374495005,RECONNECTING,tls-error,, Mon Jul 22 19:10:05 2013 Restart pause, 2 second(s) Note I have changed the IP and port no (it uses a non-standard port for security reasons). That port is open on the hardware firewall. The server logs are showing a connection attempt from my client: TLS: Initial packet from [AF_INET]118.68.xx.xx:65011, sid=081af4ed xxxxxxxx Mon Jul 22 14:19:15 2013 118.68.xx.xx:65011 TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity) How can I problem solve this & find the problem? Thx Update - Client config file: ############################################## # Sample client-side OpenVPN 2.0 config file # # for connecting to multi-client server. # # # # This configuration can be used by multiple # # clients, however each client should have # # its own cert and key files. # # # # On Windows, you might want to rename this # # file so it has a .ovpn extension # ############################################## # Specify that we are a client and that we # will be pulling certain config file directives # from the server. client # Use the same setting as you are using on # the server. # On most systems, the VPN will not function # unless you partially or fully disable # the firewall for the TUN/TAP interface. ;dev tap dev tun # Windows needs the TAP-Win32 adapter name # from the Network Connections panel # if you have more than one. On XP SP2, # you may need to disable the firewall # for the TAP adapter. ;dev-node MyTap # Are we connecting to a TCP or # UDP server? Use the same setting as # on the server. ;proto tcp proto udp # The hostname/IP and port of the server. # You can have multiple remote entries # to load balance between the servers. remote 00.00.00.00 1194 ;remote 00.00.00.00 9999 ;remote my-server-2 1194 # Choose a random host from the remote # list for load-balancing. Otherwise # try hosts in the order specified. ;remote-random # Keep trying indefinitely to resolve the # host name of the OpenVPN server. Very useful # on machines which are not permanently connected # to the internet such as laptops. resolv-retry infinite # Most clients don't need to bind to # a specific local port number. nobind # Downgrade privileges after initialization (non-Windows only) ;user nobody ;group nobody # Try to preserve some state across restarts. persist-key persist-tun # If you are connecting through an # HTTP proxy to reach the actual OpenVPN # server, put the proxy server/IP and # port number here. See the man page # if your proxy server requires # authentication. ;http-proxy-retry # retry on connection failures ;http-proxy [proxy server] [proxy port #] # Wireless networks often produce a lot # of duplicate packets. Set this flag # to silence duplicate packet warnings. ;mute-replay-warnings # SSL/TLS parms. # See the server config file for more # description. It's best to use # a separate .crt/.key file pair # for each client. A single ca # file can be used for all clients. ca "C:\\Program Files\\OpenVPN\\config\\ca.crt" cert "C:\\Program Files\\OpenVPN\\config\\my-laptop.crt" key "C:\\Program Files\\OpenVPN\\config\\my-laptop.key" # Verify server certificate by checking # that the certicate has the nsCertType # field set to "server". This is an # important precaution to protect against # a potential attack discussed here: # http://openvpn.net/howto.html#mitm # # To use this feature, you will need to generate # your server certificates with the nsCertType # field set to "server". The build-key-server # script in the easy-rsa folder will do this. ns-cert-type server # If a tls-auth key is used on the server # then every client must also have the key. ;tls-auth ta.key 1 # Select a cryptographic cipher. # If the cipher option is used on the server # then you must also specify it here. ;cipher x # Enable compression on the VPN link. # Don't enable this unless it is also # enabled in the server config file. comp-lzo # Set log file verbosity. verb 3 # Silence repeating messages ;mute 20 Server config file: ################################################# # Sample OpenVPN 2.0 config file for # # multi-client server. # # # # This file is for the server side # # of a many-clients <-> one-server # # OpenVPN configuration. # # # # OpenVPN also supports # # single-machine <-> single-machine # # configurations (See the Examples page # # on the web site for more info). # # # # This config should work on Windows # # or Linux/BSD systems. Remember on # # Windows to quote pathnames and use # # double backslashes, e.g.: # # "C:\\Program Files\\OpenVPN\\config\\foo.key" # # # # Comments are preceded with '#' or ';' # ################################################# # Which local IP address should OpenVPN # listen on? (optional) ;local 00.00.00.00 # Which TCP/UDP port should OpenVPN listen on? # If you want to run multiple OpenVPN instances # on the same machine, use a different port # number for each one. You will need to # open up this port on your firewall. std 1194 port 1194 # TCP or UDP server? ;proto tcp proto udp # "dev tun" will create a routed IP tunnel, # "dev tap" will create an ethernet tunnel. # Use "dev tap0" if you are ethernet bridging # and have precreated a tap0 virtual interface # and bridged it with your ethernet interface. # If you want to control access policies # over the VPN, you must create firewall # rules for the the TUN/TAP interface. # On non-Windows systems, you can give # an explicit unit number, such as tun0. # On Windows, use "dev-node" for this. # On most systems, the VPN will not function # unless you partially or fully disable # the firewall for the TUN/TAP interface. ;dev tap dev tun # Windows needs the TAP-Win32 adapter name # from the Network Connections panel if you # have more than one. On XP SP2 or higher, # you may need to selectively disable the # Windows firewall for the TAP adapter. # Non-Windows systems usually don't need this. ;dev-node MyTap # SSL/TLS root certificate (ca), certificate # (cert), and private key (key). Each client # and the server must have their own cert and # key file. The server and all clients will # use the same ca file. # # See the "easy-rsa" directory for a series # of scripts for generating RSA certificates # and private keys. Remember to use # a unique Common Name for the server # and each of the client certificates. # # Any X509 key management system can be used. # OpenVPN can also use a PKCS #12 formatted key file # (see "pkcs12" directive in man page). ca "C:\\Program Files\\OpenVPN\\config\\ca.crt" cert "C:\\Program Files\\OpenVPN\\config\\server.crt" key "C:\\Program Files\\OpenVPN\\config\\server.key" # Diffie hellman parameters. # Generate your own with: # openssl dhparam -out dh1024.pem 1024 # Substitute 2048 for 1024 if you are using # 2048 bit keys. dh "C:\\Program Files\\OpenVPN\\config\\dh2048.pem" # Configure server mode and supply a VPN subnet # for OpenVPN to draw client addresses from. # The server will take 10.8.0.1 for itself, # the rest will be made available to clients. # Each client will be able to reach the server # on 10.8.0.1. Comment this line out if you are # ethernet bridging. See the man page for more info. server 10.8.0.0 255.255.255.0 # Maintain a record of client <-> virtual IP address # associations in this file. If OpenVPN goes down or # is restarted, reconnecting clients can be assigned # the same virtual IP address from the pool that was # previously assigned. ifconfig-pool-persist ipp.txt # Configure server mode for ethernet bridging. # You must first use your OS's bridging capability # to bridge the TAP interface with the ethernet # NIC interface. Then you must manually set the # IP/netmask on the bridge interface, here we # assume 10.8.0.4/255.255.255.0. Finally we # must set aside an IP range in this subnet # (start=10.8.0.50 end=10.8.0.100) to allocate # to connecting clients. Leave this line commented # out unless you are ethernet bridging. ;server-bridge 10.8.0.4 255.255.255.0 10.8.0.50 10.8.0.100 # Configure server mode for ethernet bridging # using a DHCP-proxy, where clients talk # to the OpenVPN server-side DHCP server # to receive their IP address allocation # and DNS server addresses. You must first use # your OS's bridging capability to bridge the TAP # interface with the ethernet NIC interface. # Note: this mode only works on clients (such as # Windows), where the client-side TAP adapter is # bound to a DHCP client. ;server-bridge # Push routes to the client to allow it # to reach other private subnets behind # the server. Remember that these # private subnets will also need # to know to route the OpenVPN client # address pool (10.8.0.0/255.255.255.0) # back to the OpenVPN server. ;push "route 192.168.10.0 255.255.255.0" ;push "route 192.168.20.0 255.255.255.0" # To assign specific IP addresses to specific # clients or if a connecting client has a private # subnet behind it that should also have VPN access, # use the subdirectory "ccd" for client-specific # configuration files (see man page for more info). # EXAMPLE: Suppose the client # having the certificate common name "Thelonious" # also has a small subnet behind his connecting # machine, such as 192.168.40.128/255.255.255.248. # First, uncomment out these lines: ;client-config-dir ccd ;route 192.168.40.128 255.255.255.248 # Then create a file ccd/Thelonious with this line: # iroute 192.168.40.128 255.255.255.248 # This will allow Thelonious' private subnet to # access the VPN. This example will only work # if you are routing, not bridging, i.e. you are # using "dev tun" and "server" directives. # EXAMPLE: Suppose you want to give # Thelonious a fixed VPN IP address of 10.9.0.1. # First uncomment out these lines: ;client-config-dir ccd ;route 10.9.0.0 255.255.255.252 # Then add this line to ccd/Thelonious: # ifconfig-push 10.9.0.1 10.9.0.2 # Suppose that you want to enable different # firewall access policies for different groups # of clients. There are two methods: # (1) Run multiple OpenVPN daemons, one for each # group, and firewall the TUN/TAP interface # for each group/daemon appropriately. # (2) (Advanced) Create a script to dynamically # modify the firewall in response to access # from different clients. See man # page for more info on learn-address script. ;learn-address ./script # If enabled, this directive will configure # all clients to redirect their default # network gateway through the VPN, causing # all IP traffic such as web browsing and # and DNS lookups to go through the VPN # (The OpenVPN server machine may need to NAT # or bridge the TUN/TAP interface to the internet # in order for this to work properly). ;push "redirect-gateway def1 bypass-dhcp" # Certain Windows-specific network settings # can be pushed to clients, such as DNS # or WINS server addresses. CAVEAT: # http://openvpn.net/faq.html#dhcpcaveats # The addresses below refer to the public # DNS servers provided by opendns.com. ;push "dhcp-option DNS 208.67.222.222" ;push "dhcp-option DNS 208.67.220.220" # Uncomment this directive to allow differenta # clients to be able to "see" each other. # By default, clients will only see the server. # To force clients to only see the server, you # will also need to appropriately firewall the # server's TUN/TAP interface. ;client-to-client # Uncomment this directive if multiple clients # might connect with the same certificate/key # files or common names. This is recommended # only for testing purposes. For production use, # each client should have its own certificate/key # pair. # # IF YOU HAVE NOT GENERATED INDIVIDUAL # CERTIFICATE/KEY PAIRS FOR EACH CLIENT, # EACH HAVING ITS OWN UNIQUE "COMMON NAME", # UNCOMMENT THIS LINE OUT. ;duplicate-cn # The keepalive directive causes ping-like # messages to be sent back and forth over # the link so that each side knows when # the other side has gone down. # Ping every 10 seconds, assume that remote # peer is down if no ping received during # a 120 second time period. keepalive 10 120 # For extra security beyond that provided # by SSL/TLS, create an "HMAC firewall" # to help block DoS attacks and UDP port flooding. # # Generate with: # openvpn --genkey --secret ta.key # # The server and each client must have # a copy of this key. # The second parameter should be '0' # on the server and '1' on the clients. ;tls-auth ta.key 0 # This file is secret # Select a cryptographic cipher. # This config item must be copied to # the client config file as well. ;cipher BF-CBC # Blowfish (default) ;cipher AES-128-CBC # AES ;cipher DES-EDE3-CBC # Triple-DES # Enable compression on the VPN link. # If you enable it here, you must also # enable it in the client config file. comp-lzo # The maximum number of concurrently connected # clients we want to allow. ;max-clients 100 # It's a good idea to reduce the OpenVPN # daemon's privileges after initialization. # # You can uncomment this out on # non-Windows systems. ;user nobody ;group nobody # The persist options will try to avoid # accessing certain resources on restart # that may no longer be accessible because # of the privilege downgrade. persist-key persist-tun # Output a short status file showing # current connections, truncated # and rewritten every minute. status openvpn-status.log # By default, log messages will go to the syslog (or # on Windows, if running as a service, they will go to # the "\Program Files\OpenVPN\log" directory). # Use log or log-append to override this default. # "log" will truncate the log file on OpenVPN startup, # while "log-append" will append to it. Use one # or the other (but not both). ;log openvpn.log ;log-append openvpn.log # Set the appropriate level of log # file verbosity. # # 0 is silent, except for fatal errors # 4 is reasonable for general usage # 5 and 6 can help to debug connection problems # 9 is extremely verbose verb 3 # Silence repeating messages. At most 20 # sequential messages of the same message # category will be output to the log. ;mute 20 I have changed IP's for security

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• Get to know what HTML-button is clicked with PHP, no Name of value available

  - by koko

  I have a wizard with 4 steps and in one of the steps, you can add items. By default, there are 3 time 5 empty input-fields listed. When you click a button, there have to be added some more. The 3 times 5 fields are added by a loop. How can I determine where I have to add some fields (in the first 5 field of the second or the third). I can't use another name for every button, because sometimes there can be more then 3 groups of 5 fields. In my code (PHP), I use the name of the button to know what happened in the form, so the name can't be different for the button in every group ... Further, the whole step is 1 form, so the post can't go to another script ... The value of the button has to be the same for every group. I've been thinking on possible solutions and these came up: On click a javascript adds a value to the post (in a hidden field?) But is this posted with the form? Could it be possible to get the ID of the clicked button? This might be different :-) I need a refresh after the click, so pure javascript isn't a solution either ... It is a very specific question, but I hope someone can give me some direction. Here is the code I'm talking about: <h3><label class="list_list:table_title">Eten</label></h3> <table id="eten"> <thead> <tr> <th>Naam item</th> <th>Aantal</th> </tr> </thead> <tbody> <tr> <td class="item"><input type="text" name="item_1_1" value="" class="inputText" maxlength="64" size="46" tabindex="11"/></td> <td class="amount"><input type="text" name="amount_1_1" value="" class="inputText" maxlength="64" size="10" tabindex="11"/></td> </tr> <tr> <td class="item"><input type="text" name="item_1_2" value="" class="inputText" maxlength="64" size="46" tabindex="12"/></td> <td class="amount"><input type="text" name="amount_1_2" value="" class="inputText" maxlength="64" size="10" tabindex="12"/></td> </tr> <tr> <td class="item"><input type="text" name="item_1_3" value="" class="inputText" maxlength="64" size="46" tabindex="13"/></td> <td class="amount"><input type="text" name="amount_1_3" value="" class="inputText" maxlength="64" size="10" tabindex="13"/></td> </tr> <tr> <td class="item"><input type="text" name="item_1_4" value="" class="inputText" maxlength="64" size="46" tabindex="14"/></td> <td class="amount"><input type="text" name="amount_1_4" value="" class="inputText" maxlength="64" size="10" tabindex="14"/></td> </tr> <tr> <td class="item"><input type="text" name="item_1_5" value="" class="inputText" maxlength="64" size="46" tabindex="15"/></td> <td class="amount"><input type="text" name="amount_1_5" value="" class="inputText" maxlength="64" size="10" tabindex="15"/></td> </tr> </tbody> </table> <input id="list_list:add" type="submit" name="list_list:add" value="voeg extra items toe" class="add" /> <div class="spacer"></div> <h3><label class="list_list:table_title">Drinken</label></h3> <table id="drinken"> <thead> <tr> <th>Naam item</th> <th>Aantal</th> </tr> </thead> <tbody> <tr> <td class="item"><input type="text" name="item_2_1" value="" class="inputText" maxlength="64" size="46" tabindex="21"/></td> <td class="amount"><input type="text" name="amount_2_1" value="" class="inputText" maxlength="64" size="10" tabindex="21"/></td> </tr> <tr> <td class="item"><input type="text" name="item_2_2" value="" class="inputText" maxlength="64" size="46" tabindex="22"/></td> <td class="amount"><input type="text" name="amount_2_2" value="" class="inputText" maxlength="64" size="10" tabindex="22"/></td> </tr> <tr> <td class="item"><input type="text" name="item_2_3" value="" class="inputText" maxlength="64" size="46" tabindex="23"/></td> <td class="amount"><input type="text" name="amount_2_3" value="" class="inputText" maxlength="64" size="10" tabindex="23"/></td> </tr> <tr> <td class="item"><input type="text" name="item_2_4" value="" class="inputText" maxlength="64" size="46" tabindex="24"/></td> <td class="amount"><input type="text" name="amount_2_4" value="" class="inputText" maxlength="64" size="10" tabindex="24"/></td> </tr> <tr> <td class="item"><input type="text" name="item_2_5" value="" class="inputText" maxlength="64" size="46" tabindex="25"/></td> <td class="amount"><input type="text" name="amount_2_5" value="" class="inputText" maxlength="64" size="10" tabindex="25"/></td> </tr> </tbody> </table> <input id="list_list:add" type="submit" name="list_list:add" value="voeg extra items toe" class="add" /> <div class="spacer"></div> <h3><label class="list_list:table_title">Varia</label></h3> <table id="varia"> <thead> <tr> <th>Naam item</th> <th>Aantal</th> </tr> </thead> <tbody> <tr> <td class="item"><input type="text" name="item_3_1" value="" class="inputText" maxlength="64" size="46" tabindex="31"/></td> <td class="amount"><input type="text" name="amount_3_1" value="" class="inputText" maxlength="64" size="10" tabindex="31"/></td> </tr> <tr> <td class="item"><input type="text" name="item_3_2" value="" class="inputText" maxlength="64" size="46" tabindex="32"/></td> <td class="amount"><input type="text" name="amount_3_2" value="" class="inputText" maxlength="64" size="10" tabindex="32"/></td> </tr> <tr> <td class="item"><input type="text" name="item_3_3" value="" class="inputText" maxlength="64" size="46" tabindex="33"/></td> <td class="amount"><input type="text" name="amount_3_3" value="" class="inputText" maxlength="64" size="10" tabindex="33"/></td> </tr> <tr> <td class="item"><input type="text" name="item_3_4" value="" class="inputText" maxlength="64" size="46" tabindex="34"/></td> <td class="amount"><input type="text" name="amount_3_4" value="" class="inputText" maxlength="64" size="10" tabindex="34"/></td> </tr> <tr> <td class="item"><input type="text" name="item_3_5" value="" class="inputText" maxlength="64" size="46" tabindex="35"/></td> <td class="amount"><input type="text" name="amount_3_5" value="" class="inputText" maxlength="64" size="10" tabindex="35"/></td> </tr> </tbody> </table> <input id="list_list:add" type="submit" name="list_list:add" value="voeg extra items toe" class="add" /> <div class="spacer"></div> </div> <div id="formButtons"> <input id="list_info:back" type="submit" name="list_info:back" value="<< Terug" tabindex="11" class="back" /> <input id="list_info:next" type="submit" name="list_info:next" value="Volgende >>" tabindex="12" class="next" /> <input id="list_info:options" type="submit" name="list_info:options" value="Opties" tabindex="13" class="options" /> <input id="list_info:finish" type="submit" name="list_info:finish" value="Voltooien" tabindex="14" disabled="disabled" class="finish" /> </div>

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• Help Optimizing MySQL Table (~ 500,000 records) and PHP Code.

  - by Pyrite

  I have a MySQL table that collects player data from various game servers (Urban Terror). The bot that collects the data runs 24/7, and currently the table is up to about 475,000+ records. Because of this, querying this table from PHP has become quite slow. I wonder what I can do on the database side of things to make it as optomized as possible, then I can focus on the application to query the database. The table is as follows: CREATE TABLE IF NOT EXISTS `people` ( `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(40) NOT NULL, `ip` int(4) unsigned NOT NULL, `guid` varchar(32) NOT NULL, `server` int(4) unsigned NOT NULL, `date` int(11) NOT NULL, PRIMARY KEY (`id`), UNIQUE KEY `Person` (`name`,`ip`,`guid`), KEY `server` (`server`), KEY `date` (`date`), KEY `PlayerName` (`name`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 COMMENT='People that Play on Servers' AUTO_INCREMENT=475843 ; I'm storying the IPv4 (ip and server) as 4 byte integers, and using the MySQL functions NTOA(), etc to encode and decode, I heard that this way is faster, rather than varchar(15). The guid is a md5sum, 32 char hex. Date is stored as unix timestamp. I have a unique key on name, ip and guid, as to avoid duplicates of the same player. Do I have my keys setup right? Is the way I'm storing data efficient? Here is the code to query this table. You search for a name, ip, or guid, and it grabs the results of the query and cross references other records that match the name, ip, or guid from the results of the first query, and does it for each field. This is kind of hard to explain. But basically, if I search for one player by name, I'll see every other name he has used, every IP he has used and every GUID he has used. <form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post"> Search: <input type="text" name="query" id="query" /><input type="submit" name="btnSubmit" value="Submit" /> </form> <?php if (!empty($_POST['query'])) { ?> <table cellspacing="1" id="1up_people" class="tablesorter" width="300"> <thead> <tr> <th>ID</th> <th>Player Name</th> <th>Player IP</th> <th>Player GUID</th> <th>Server</th> <th>Date</th> </tr> </thead> <tbody> <?php function super_unique($array) { $result = array_map("unserialize", array_unique(array_map("serialize", $array))); foreach ($result as $key => $value) { if ( is_array($value) ) { $result[$key] = super_unique($value); } } return $result; } if (!empty($_POST['query'])) { $query = trim($_POST['query']); $count = 0; $people = array(); $link = mysql_connect('localhost', 'mysqluser', 'yea right!'); if (!$link) { die('Could not connect: ' . mysql_error()); } mysql_select_db("1up"); $sql = "SELECT id, name, INET_NTOA(ip) AS ip, guid, INET_NTOA(server) AS server, date FROM 1up_people WHERE (name LIKE \"%$query%\" OR INET_NTOA(ip) LIKE \"%$query%\" OR guid LIKE \"%$query%\")"; $result = mysql_query($sql, $link); if (!$result) { die(mysql_error()); } // Now take the initial results and parse each column into its own array while ($row = mysql_fetch_array($result, MYSQL_NUM)) { $name = htmlspecialchars($row[1]); $people[] = array( 'id' => $row[0], 'name' => $name, 'ip' => $row[2], 'guid' => $row[3], 'server' => $row[4], 'date' => $row[5] ); } // now for each name, ip, guid in results, find additonal records $people2 = array(); foreach ($people AS $person) { $ip = $person['ip']; $sql = "SELECT id, name, INET_NTOA(ip) AS ip, guid, INET_NTOA(server) AS server, date FROM 1up_people WHERE (ip = \"$ip\")"; $result = mysql_query($sql, $link); while ($row = mysql_fetch_array($result, MYSQL_NUM)) { $name = htmlspecialchars($row[1]); $people2[] = array( 'id' => $row[0], 'name' => $name, 'ip' => $row[2], 'guid' => $row[3], 'server' => $row[4], 'date' => $row[5] ); } } $people3 = array(); foreach ($people AS $person) { $guid = $person['guid']; $sql = "SELECT id, name, INET_NTOA(ip) AS ip, guid, INET_NTOA(server) AS server, date FROM 1up_people WHERE (guid = \"$guid\")"; $result = mysql_query($sql, $link); while ($row = mysql_fetch_array($result, MYSQL_NUM)) { $name = htmlspecialchars($row[1]); $people3[] = array( 'id' => $row[0], 'name' => $name, 'ip' => $row[2], 'guid' => $row[3], 'server' => $row[4], 'date' => $row[5] ); } } $people4 = array(); foreach ($people AS $person) { $name = $person['name']; $sql = "SELECT id, name, INET_NTOA(ip) AS ip, guid, INET_NTOA(server) AS server, date FROM 1up_people WHERE (name = \"$name\")"; $result = mysql_query($sql, $link); while ($row = mysql_fetch_array($result, MYSQL_NUM)) { $name = htmlspecialchars($row[1]); $people4[] = array( 'id' => $row[0], 'name' => $name, 'ip' => $row[2], 'guid' => $row[3], 'server' => $row[4], 'date' => $row[5] ); } } // Combine people and people2 into just people $people = array_merge($people, $people2); $people = array_merge($people, $people3); $people = array_merge($people, $people4); $people = super_unique($people); foreach ($people AS $person) { $date = ($person['date']) ? date("M d, Y", $person['date']) : 'Before 8/1/10'; echo "<tr>\n"; echo "<td>".$person['id']."</td>"; echo "<td>".$person['name']."</td>"; echo "<td>".$person['ip']."</td>"; echo "<td>".$person['guid']."</td>"; echo "<td>".$person['server']."</td>"; echo "<td>".$date."</td>"; echo "</tr>\n"; $count++; } // Find Total Records //$result = mysql_query("SELECT id FROM 1up_people", $link); //$total = mysql_num_rows($result); mysql_close($link); } ?> </tbody> </table> <p> <?php echo $count." Records Found for \"".$_POST['query']."\" out of $total"; ?> </p> <?php } $time_stop = microtime(true); print("Done (ran for ".round($time_stop-$time_start)." seconds)."); ?> Any help at all is appreciated! Thank you.

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• Delphi: EInvalidOp in neural network class (TD-lambda)

  - by user89818

  I have the following draft for a neural network class. This neural network should learn with TD-lambda. It is started by calling the getRating() function. But unfortunately, there is an EInvalidOp (invalid floading point operation) error after about 1000 iterations in the following lines: neuronsHidden[j] := neuronsHidden[j]+neuronsInput[t][i]*weightsInput[i][j]; // input -> hidden weightsHidden[j][k] := weightsHidden[j][k]+LEARNING_RATE_HIDDEN*tdError[k]*eligibilityTraceOutput[j][k]; // adjust hidden->output weights according to TD-lambda Why is this error? I can't find the mistake in my code :( Can you help me? Thank you very much in advance! unit uNeuronalesNetz; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, ExtCtrls, StdCtrls, Grids, Menus, Math; const NEURONS_INPUT = 43; // number of neurons in the input layer NEURONS_HIDDEN = 60; // number of neurons in the hidden layer NEURONS_OUTPUT = 1; // number of neurons in the output layer NEURONS_TOTAL = NEURONS_INPUT+NEURONS_HIDDEN+NEURONS_OUTPUT; // total number of neurons in the network MAX_TIMESTEPS = 42; // maximum number of timesteps possible (after 42 moves: board is full) LEARNING_RATE_INPUT = 0.25; // in ideal case: decrease gradually in course of training LEARNING_RATE_HIDDEN = 0.15; // in ideal case: decrease gradually in course of training GAMMA = 0.9; LAMBDA = 0.7; // decay parameter for eligibility traces type TFeatureVector = Array[1..43] of SmallInt; // definition of the array type TFeatureVector TArtificialNeuralNetwork = class // definition of the class TArtificialNeuralNetwork private // GENERAL SETTINGS START learningMode: Boolean; // does the network learn and change its weights? // GENERAL SETTINGS END // NETWORK CONFIGURATION START neuronsInput: Array[1..MAX_TIMESTEPS] of Array[1..NEURONS_INPUT] of Extended; // array of all input neurons (their values) for every timestep neuronsHidden: Array[1..NEURONS_HIDDEN] of Extended; // array of all hidden neurons (their values) neuronsOutput: Array[1..NEURONS_OUTPUT] of Extended; // array of output neurons (their values) weightsInput: Array[1..NEURONS_INPUT] of Array[1..NEURONS_HIDDEN] of Extended; // array of weights: input->hidden weightsHidden: Array[1..NEURONS_HIDDEN] of Array[1..NEURONS_OUTPUT] of Extended; // array of weights: hidden->output // NETWORK CONFIGURATION END // LEARNING SETTINGS START outputBefore: Array[1..NEURONS_OUTPUT] of Extended; // the network's output value in the last timestep (the one before) eligibilityTraceHidden: Array[1..NEURONS_INPUT] of Array[1..NEURONS_HIDDEN] of Array[1..NEURONS_OUTPUT] of Extended; // array of eligibility traces: hidden layer eligibilityTraceOutput: Array[1..NEURONS_TOTAL] of Array[1..NEURONS_TOTAL] of Extended; // array of eligibility traces: output layer reward: Array[1..MAX_TIMESTEPS] of Array[1..NEURONS_OUTPUT] of Extended; // the reward value for all output neurons in every timestep tdError: Array[1..NEURONS_OUTPUT] of Extended; // the network's error value for every single output neuron t: Byte; // current timestep cyclesTrained: Integer; // number of cycles trained so far (learning rates could be decreased accordingly) last50errors: Array[1..50] of Extended; // LEARNING SETTINGS END public constructor Create; // create the network object and do the initialization procedure UpdateEligibilityTraces; // update the eligibility traces for the hidden and output layer procedure tdLearning; // learning algorithm: adjust the network's weights procedure ForwardPropagation; // propagate the input values through the network to the output layer function getRating(state: TFeatureVector; explorative: Boolean): Extended; // get the rating for a given state (feature vector) function HyperbolicTangent(x: Extended): Extended; // calculate the hyperbolic tangent [-1;1] procedure StartNewCycle; // start a new cycle with everything set to default except for the weights procedure setLearningMode(activated: Boolean=TRUE); // switch the learning mode on/off procedure setInputs(state: TFeatureVector); // transfer the given feature vector to the input layer (set input neurons' values) procedure setReward(currentReward: SmallInt); // set the reward for the current timestep (with learning then or without) procedure nextTimeStep; // increase timestep t function getCyclesTrained(): Integer; // get the number of cycles trained so far procedure Visualize(imgHidden: Pointer); // visualize the neural network's hidden layer end; implementation procedure TArtificialNeuralNetwork.UpdateEligibilityTraces; var i, j, k: Integer; begin // how worthy is a weight to be adjusted? for j := 1 to NEURONS_HIDDEN do begin for k := 1 to NEURONS_OUTPUT do begin eligibilityTraceOutput[j][k] := LAMBDA*eligibilityTraceOutput[j][k]+(neuronsOutput[k]*(1-neuronsOutput[k]))*neuronsHidden[j]; for i := 1 to NEURONS_INPUT do begin eligibilityTraceHidden[i][j][k] := LAMBDA*eligibilityTraceHidden[i][j][k]+(neuronsOutput[k]*(1-neuronsOutput[k]))*weightsHidden[j][k]*neuronsHidden[j]*(1-neuronsHidden[j])*neuronsInput[t][i]; end; end; end; end; procedure TArtificialNeuralNetwork.setReward; VAR i: Integer; begin for i := 1 to NEURONS_OUTPUT do begin // +1 = player A wins // 0 = draw // -1 = player B wins reward[t][i] := currentReward; end; end; procedure TArtificialNeuralNetwork.tdLearning; var i, j, k: Integer; begin if learningMode then begin for k := 1 to NEURONS_OUTPUT do begin if reward[t][k] = 0 then begin tdError[k] := GAMMA*neuronsOutput[k]-outputBefore[k]; // network's error value when reward is 0 end else begin tdError[k] := reward[t][k]-outputBefore[k]; // network's error value in the final state (reward received) end; for j := 1 to NEURONS_HIDDEN do begin weightsHidden[j][k] := weightsHidden[j][k]+LEARNING_RATE_HIDDEN*tdError[k]*eligibilityTraceOutput[j][k]; // adjust hidden->output weights according to TD-lambda for i := 1 to NEURONS_INPUT do begin weightsInput[i][j] := weightsInput[i][j]+LEARNING_RATE_INPUT*tdError[k]*eligibilityTraceHidden[i][j][k]; // adjust input->hidden weights according to TD-lambda end; end; end; end; end; procedure TArtificialNeuralNetwork.ForwardPropagation; var i, j, k: Integer; begin for j := 1 to NEURONS_HIDDEN do begin neuronsHidden[j] := 0; for i := 1 to NEURONS_INPUT do begin neuronsHidden[j] := neuronsHidden[j]+neuronsInput[t][i]*weightsInput[i][j]; // input -> hidden end; neuronsHidden[j] := HyperbolicTangent(neuronsHidden[j]); // activation of hidden neuron j end; for k := 1 to NEURONS_OUTPUT do begin neuronsOutput[k] := 0; for j := 1 to NEURONS_HIDDEN do begin neuronsOutput[k] := neuronsOutput[k]+neuronsHidden[j]*weightsHidden[j][k]; // hidden -> output end; neuronsOutput[k] := HyperbolicTangent(neuronsOutput[k]); // activation of output neuron k end; end; procedure TArtificialNeuralNetwork.setLearningMode; begin learningMode := activated; end; constructor TArtificialNeuralNetwork.Create; var i, j, k: Integer; begin inherited Create; Randomize; // initialize random numbers generator learningMode := TRUE; cyclesTrained := -2; // only set to -2 because it will be increased twice in the beginning StartNewCycle; for j := 1 to NEURONS_HIDDEN do begin for k := 1 to NEURONS_OUTPUT do begin weightsHidden[j][k] := abs(Random-0.5); // initialize weights: 0 <= random < 0.5 end; for i := 1 to NEURONS_INPUT do begin weightsInput[i][j] := abs(Random-0.5); // initialize weights: 0 <= random < 0.5 end; end; for i := 1 to 50 do begin last50errors[i] := 0; end; end; procedure TArtificialNeuralNetwork.nextTimeStep; begin t := t+1; end; procedure TArtificialNeuralNetwork.StartNewCycle; var i, j, k, m: Integer; begin t := 1; // start in timestep 1 cyclesTrained := cyclesTrained+1; // increase the number of cycles trained so far for j := 1 to NEURONS_HIDDEN do begin neuronsHidden[j] := 0; for k := 1 to NEURONS_OUTPUT do begin eligibilityTraceOutput[j][k] := 0; outputBefore[k] := 0; neuronsOutput[k] := 0; for m := 1 to MAX_TIMESTEPS do begin reward[m][k] := 0; end; end; for i := 1 to NEURONS_INPUT do begin for k := 1 to NEURONS_OUTPUT do begin eligibilityTraceHidden[i][j][k] := 0; end; end; end; end; function TArtificialNeuralNetwork.getCyclesTrained; begin result := cyclesTrained; end; procedure TArtificialNeuralNetwork.setInputs; var k: Integer; begin for k := 1 to NEURONS_INPUT do begin neuronsInput[t][k] := state[k]; end; end; function TArtificialNeuralNetwork.getRating; begin setInputs(state); ForwardPropagation; result := neuronsOutput[1]; if not explorative then begin tdLearning; // adjust the weights according to TD-lambda ForwardPropagation; // calculate the network's output again outputBefore[1] := neuronsOutput[1]; // set outputBefore which will then be used in the next timestep UpdateEligibilityTraces; // update the eligibility traces for the next timestep nextTimeStep; // go to the next timestep end; end; function TArtificialNeuralNetwork.HyperbolicTangent; begin if x > 5500 then // prevent overflow result := 1 else result := (Exp(2*x)-1)/(Exp(2*x)+1); end; end.

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• Help Optimizing MySQL Table (~ 500,000 records).

  - by Pyrite

  I have a MySQL table that collects player data from various game servers (Urban Terror). The bot that collects the data runs 24/7, and currently the table is up to about 475,000+ records. Because of this, querying this table from PHP has become quite slow. I wonder what I can do on the database side of things to make it as optomized as possible, then I can focus on the application to query the database. The table is as follows: CREATE TABLE IF NOT EXISTS `people` ( `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(40) NOT NULL, `ip` int(4) unsigned NOT NULL, `guid` varchar(32) NOT NULL, `server` int(4) unsigned NOT NULL, `date` int(11) NOT NULL, PRIMARY KEY (`id`), UNIQUE KEY `Person` (`name`,`ip`,`guid`), KEY `server` (`server`), KEY `date` (`date`), KEY `PlayerName` (`name`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 COMMENT='People that Play on Servers' AUTO_INCREMENT=475843 ; I'm storying the IPv4 (ip and server) as 4 byte integers, and using the MySQL functions NTOA(), etc to encode and decode, I heard that this way is faster, rather than varchar(15). The guid is a md5sum, 32 char hex. Date is stored as unix timestamp. I have a unique key on name, ip and guid, as to avoid duplicates of the same player. Do I have my keys setup right? Is the way I'm storing data efficient? Here is the code to query this table. You search for a name, ip, or guid, and it grabs the results of the query and cross references other records that match the name, ip, or guid from the results of the first query, and does it for each field. This is kind of hard to explain. But basically, if I search for one player by name, I'll see every other name he has used, every IP he has used and every GUID he has used. <form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post"> Search: <input type="text" name="query" id="query" /><input type="submit" name="btnSubmit" value="Submit" /> </form> <?php if (!empty($_POST['query'])) { ?> <table cellspacing="1" id="1up_people" class="tablesorter" width="300"> <thead> <tr> <th>ID</th> <th>Player Name</th> <th>Player IP</th> <th>Player GUID</th> <th>Server</th> <th>Date</th> </tr> </thead> <tbody> <?php function super_unique($array) { $result = array_map("unserialize", array_unique(array_map("serialize", $array))); foreach ($result as $key => $value) { if ( is_array($value) ) { $result[$key] = super_unique($value); } } return $result; } if (!empty($_POST['query'])) { $query = trim($_POST['query']); $count = 0; $people = array(); $link = mysql_connect('localhost', 'mysqluser', 'yea right!'); if (!$link) { die('Could not connect: ' . mysql_error()); } mysql_select_db("1up"); $sql = "SELECT id, name, INET_NTOA(ip) AS ip, guid, INET_NTOA(server) AS server, date FROM 1up_people WHERE (name LIKE \"%$query%\" OR INET_NTOA(ip) LIKE \"%$query%\" OR guid LIKE \"%$query%\")"; $result = mysql_query($sql, $link); if (!$result) { die(mysql_error()); } // Now take the initial results and parse each column into its own array while ($row = mysql_fetch_array($result, MYSQL_NUM)) { $name = htmlspecialchars($row[1]); $people[] = array( 'id' => $row[0], 'name' => $name, 'ip' => $row[2], 'guid' => $row[3], 'server' => $row[4], 'date' => $row[5] ); } // now for each name, ip, guid in results, find additonal records $people2 = array(); foreach ($people AS $person) { $ip = $person['ip']; $sql = "SELECT id, name, INET_NTOA(ip) AS ip, guid, INET_NTOA(server) AS server, date FROM 1up_people WHERE (ip = \"$ip\")"; $result = mysql_query($sql, $link); while ($row = mysql_fetch_array($result, MYSQL_NUM)) { $name = htmlspecialchars($row[1]); $people2[] = array( 'id' => $row[0], 'name' => $name, 'ip' => $row[2], 'guid' => $row[3], 'server' => $row[4], 'date' => $row[5] ); } } $people3 = array(); foreach ($people AS $person) { $guid = $person['guid']; $sql = "SELECT id, name, INET_NTOA(ip) AS ip, guid, INET_NTOA(server) AS server, date FROM 1up_people WHERE (guid = \"$guid\")"; $result = mysql_query($sql, $link); while ($row = mysql_fetch_array($result, MYSQL_NUM)) { $name = htmlspecialchars($row[1]); $people3[] = array( 'id' => $row[0], 'name' => $name, 'ip' => $row[2], 'guid' => $row[3], 'server' => $row[4], 'date' => $row[5] ); } } $people4 = array(); foreach ($people AS $person) { $name = $person['name']; $sql = "SELECT id, name, INET_NTOA(ip) AS ip, guid, INET_NTOA(server) AS server, date FROM 1up_people WHERE (name = \"$name\")"; $result = mysql_query($sql, $link); while ($row = mysql_fetch_array($result, MYSQL_NUM)) { $name = htmlspecialchars($row[1]); $people4[] = array( 'id' => $row[0], 'name' => $name, 'ip' => $row[2], 'guid' => $row[3], 'server' => $row[4], 'date' => $row[5] ); } } // Combine people and people2 into just people $people = array_merge($people, $people2); $people = array_merge($people, $people3); $people = array_merge($people, $people4); $people = super_unique($people); foreach ($people AS $person) { $date = ($person['date']) ? date("M d, Y", $person['date']) : 'Before 8/1/10'; echo "<tr>\n"; echo "<td>".$person['id']."</td>"; echo "<td>".$person['name']."</td>"; echo "<td>".$person['ip']."</td>"; echo "<td>".$person['guid']."</td>"; echo "<td>".$person['server']."</td>"; echo "<td>".$date."</td>"; echo "</tr>\n"; $count++; } // Find Total Records //$result = mysql_query("SELECT id FROM 1up_people", $link); //$total = mysql_num_rows($result); mysql_close($link); } ?> </tbody> </table> <p> <?php echo $count." Records Found for \"".$_POST['query']."\" out of $total"; ?> </p> <?php } $time_stop = microtime(true); print("Done (ran for ".round($time_stop-$time_start)." seconds)."); ?> Any help at all is appreciated! Thank you.

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• Android chess development design [on hold]

  - by Plejo

  I want to develop human vs human android chess game and I have bunch of new questions. I would like to have screen where online players are shown(nickname, rating) and when player challenge antoher player and he accpet it game begins. These are my questions: When player install application, does he have to create account/login or does every instance of installed application have some kind of ID so I can recognize it on server side? I want to have also ratings of players saved in my DB so login procedure will probably be necessary. When player connects to server server updates online players list. When he challenge another player and he accept server exchange ip`s(and ports? which port to use?) between players. Then they connect to each other and game begins. What is best practice for connection between server-android and android-android? Probably sockets, right? Is there any library for handling lost connection etc.? Which server do you recommend?

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• HTTP Error 403.18 - Forbidden - asp.net mvc web api

  - by CoffeeCode

  I have deployed the default asp.net mvc 4 web api project to my windows server 2008 RC and am experiensing some issues with calling the web api actions. I'm quite new in the server/iis configuration part. I can open the home page, but the API part doesnt work. I'm getting such an error: HTTP Error 403.18 - Forbidden The specified request cannot be processed in the application pool that is configured for this resource on the Web server Module IIS Web Core Notification BeginRequest Handler StaticFile Error Code 0x00000000 Requested URL http://server.com:80/index.php?p=MvcApplication2_deploy/api/values/ Physical Path C:\Inetpub\vhosts\server.com\Webservice\index.php Logon Method Not yet determined Logon User Not yet determined I have checked Url Rewrite it is empty, have disabled WebDAV and also checked the Handler Mappings every thing seems to be ok there. Could any one give me some hints what could be wrong? Thanks!!!

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• DVR_PLAYER.exe reports Remote200.ocx is missing?

  - by Kalamane

  I have a program called DVR_PLAYER that is downloaded from a home security camera web interface. The web interface saves surveillance footage in the form of proprietary .drv files. I am unable to use the program to view the files on the cd on any machine that isn't the original machine I downloaded the files from. Every time I try to open it up it says, " Remote200.ocx not installed or it couldn't be installed. Please check user privilege." I need other machines to be able to open and view the footage I've downloaded using this program so that I can hand it in to the local police. Any ideas?

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• modprobe vboxguest failed

  - by Andrew123321

  I am running an Ubuntu Server (12.0.4-beta2; kernel 3.2.0) in VirtualBox (host is Win7) and I want to use shared folders. I've followed the manual to set up vbox guest additions http://www.virtualbox.org/manual/ch04.html#idp5801200 but this error occurs with every startup: Starting the VirtualBox Guest Additions ...fail! (modprobe vboxguest failed) Starting VirtualBox Guest Addition service VirtualBox Additions module not loaded! When I try it myself: $ modprobe vboxguest FATAL: Module vboxguest not found. Did I do something wrong, what do I need to fix it? Thanks for help.

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• Cisco ASA log error "regular translation creation failed for icmp ..."

  - by Martijn Heemels

  Every few seconds our new Cisco ASA 5505 firewall is logging errors that I can't figure out with my limited Cisco experience. Severity Date Time Syslog ID Source IP Destination IP Description 3 Mar 25 2010 17:21:14 305006 8.8.8.8 regular translation creation failed for icmp src inside:10.10.0.200 dst outside:8.8.8.8 (type 3, code 3) 3 Mar 25 2010 17:18:37 305006 8.8.4.4 regular translation creation failed for icmp src inside:10.10.0.200 dst outside:8.8.4.4 (type 3, code 3) The logged inside IP is our internal DNS resolver, and the outside IP's are Google's public DNS servers. ICMP Type 3 Code 3 means "Port Unreachable" Our "outside" interface has a fixed IP and our "inside" interface is in the 10.10.0.0/16 subnet. The 'Inspect DNS' Service Policy is enabled, with the preset DNS inspection map. Furthermore there's an ACL that allows all inbound ICMP on the "outside" interface. I've spent hours trying to figure this one out, so any and all advice is welcome!

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• Java applet needs permission but doesn't ask for it!

  - by Karl Jóhann

  I'm trying to connect a VPN connection (on Mac OS X 10.6.6) through a Check point java applet. The first time it ran I chose NOT to give it access to my files and such and now every time I try to lunch the applet it tells me too "Please confirm the use of this Java applet and then refresh or reopen the window." But I don't know how to confirm it nor delete the applet. How can I change the permissions afterwards and where can I find java applets installed on my computer? Update: This turns out to be a problem in Firefox. Cleared cookies, Java cache and certificate in Safari and it seems to work.

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• "getpt failed: No such file or directory" when opening a terminal through VNC

  - by Michael

  I am running Debian Wheezy on my server, and have just installed a VNC server and Xfce. I have come across a problem: whenever I open a terminal emulator through VNC, I get an error box with this message: Failed to execute child. getpt failed: No such file or directory. This happens with every terminal I try to run. I can still run commands through SSH, however. It's just the terminal that won't open. Does anyone have any suggestions? /etc/fstab: proc /proc proc defaults 0 0 none /dev/pts devpts rw 0 0

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• Proxy cache zone static is unknown

  - by AnApprentice

  I'm working to setup a reverse proxy cache. In nginx.conf I added the following: location /blog { # Reverse Proxy # Cache the Blog Pages from Heroku proxy_cache STATIC; proxy_cache_valid 200 10m; proxy_cache_valid 404 1m; proxy_cache_use_stale error timeout invalid_header updating http_500 http_502 http_503 http_504; rewrite ^/blog$ /; rewrite ^/blog/(.*)$ /$1; proxy_pass http://whispering-retreat-1.herokuapp.com; break; } However when trying to restart nginx I received the following error: $ /opt/nginx/sbin/nginx -s stop nginx: [emerg] "proxy_cache" zone "STATIC" is unknown in /opt/nginx/conf/nginx.conf:182 Any ideas what's the problem is with using STATIC? I just want to cache the blog pages so it doesn't hit heroku every time which is horribly slow. Thanks

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• (Solved) ERROR: Packet source 'wlan0' failed to set channel 2: mac80211_setchannel() in Kismet and Ubuntu 12.10

  - by M. Cunille

  I have installed Ubuntu 12.10 in my computer with an Atheros AR5007 wireless card. I want to use Kismet but when I run it it starts displaying the message: ERROR: Packet source 'wlan0' failed to set channel X: mac80211_setchannel() It keeps displaying the same for every channel except channel 1. I have installed the compat-wireless-3.6.6-1 drivers and patched them with the following patch in order to use them with aircrack-ng. I have installed the latest version of Kismet in the git repository and I even tried with the svn but it keeps displaying the same error. I also have set the kismet.conf file with the nsource=wlan0 as it is the name of my wireless interface according to iwconfig : lo no wireless extensions. wlan0 IEEE 802.11bg ESSID:"XXXX" Mode:Managed Frequency:2.412 GHz Access Point: XX:XX:XX:XX:XX:XX Bit Rate=18 Mb/s Tx-Power=20 dBm Retry long limit:7 RTS thr:off Fragment thr:off Power Management:off Link Quality=28/70 Signal level=-82 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:282 Missed beacon:0 I haven't found any answer since similar errors are supposed to be fixed with the latest Kismet release but this isn't my case. Any help will be appreciated. Thank you!

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