Search Results

Search found 5180 results on 208 pages for 'binary serialization'.

Page 158/208 | < Previous Page | 154 155 156 157 158 159 160 161 162 163 164 165  | Next Page >

• Which are the most useful techniques for faster Bluetooth?

  - by Mike Howard

  Hi. I'm adding peer-to-peer bluetooth using GameKit to an iPhone shoot-em-up, so speed is vital. I'm sending about 40 messages a second each way, most of them with the faster GKSendDataUnreliable, all serializing with NSCoding. In testing between a 3G and 3GS, this is slowing the 3G down a lot more than I'd like. I'm wondering where I should concentrate my efforts to speed it up. How much slower is GKSendDataReliable? For the few packets that have to get there, would it be faster to send a GKSendDataUnreliable and have the peer send an acknowledgement so I can send again if I don't get the Ack within, say, 100ms? How much faster would it be to create the NSData instance using a regular C array rather than archiving with the NSCoding protocol? Is this serialization process (for about a dozen floats) just as slow as you'd expect from an object creation/deallocation overhead, or is something particularly slow happening? I heard that (for example) sending four seperate sets of data is much, much slower, than sending one piece of data four times the size. Would I make a significant saving by sending separate packets of data that wouldn't always go together in the same packet when they happen at the same time? Are there any other bluetooth performance secrets I've missed? Thanks for your help.

  Read the article

• iPhone: Which are the most useful techniques for faster Bluetooth?

  - by Mike Howard

  Hi. I'm adding peer-to-peer bluetooth using GameKit to an iPhone shoot-em-up, so speed is vital. I'm sending about 40 messages a second each way, most of them with the faster GKSendDataUnreliable, all serializing with NSCoding. In testing between a 3G and 3GS, this is slowing the 3G down a lot more than I'd like. I'm wondering where I should concentrate my efforts to speed it up. How much slower is GKSendDataReliable? For the few packets that have to get there, would it be faster to send a GKSendDataUnreliable and have the peer send an acknowledgement so I can send again if I don't get the Ack within, say, 100ms? How much faster would it be to create the NSData instance using a regular C array rather than archiving with the NSCoding protocol? Is this serialization process (for about a dozen floats) just as slow as you'd expect from an object creation/deallocation overhead, or is something particularly slow happening? I heard that (for example) sending four seperate sets of data is much, much slower, than sending one piece of data four times the size. Would I make a significant saving by sending separate packets of data that wouldn't always go together in the same packet when they happen at the same time? Are there any other bluetooth performance secrets I've missed? Thanks for your help.

  Read the article

• C++ Boost bind value type

  - by aaa

  hello. I look in documentation and source code but cannot figure out how to get return value type of boost bind functor. I am trying to accomplish following: 35 template<typename T,size_t N, class F> 36 boost::array<typename F::value_type, N> make_array(T (&input)[N], F unary) { 37 boost::array<typename F::value_type, N> array; 38 std::transform(input, input + N, array.begin(), unary); 39 return array; 40 } where F can be bind functor. the above does not work because functor does not have value_type. for that matter, is there standard interface for unary/binary functor as far as return value. Thanks

  Read the article

• Reading bytes from JavaScript string

  - by Jan

  I have a string containing binary data in JS. Now I want to read, for example, an integer from it. So I get the first 4 characters, use charCodeAt, do some shifting etc. to get an integer. Problem is that strings in JS are UTF-16 (instead of ASCII) and charCodeAt often returns values higher than 256. The Mozilla reference states that "The first 128 Unicode code points are a direct match of the ASCII character encoding." (what about ASCII values 128?) How can I convert the result of charCodeAt to an ASCII value? Or is there a better way to convert a string of four characters to a 4 byte integer?

  Read the article

• Why can't we have an immutable version of operator[] for map

  - by Yan Cheng CHEOK

  The following code works fine : std::map<int, int>& m = std::map<int, int>(); int i = m[0]; But not the following code : // error C2678: binary '[' : no operator... const std::map<int, int>& m = std::map<int, int>(); int i = m[0]; Most of the time, I prefer to make most of my stuff to become immutable, due to reason : http://www.javapractices.com/topic/TopicAction.do?Id=29 I look at map source code. It has mapped_type& operator[](const key_type& _Keyval) Is there any reason, why std::map unable to provide const mapped_type& operator[](const key_type& _Keyval) const

  Read the article

• Creating and parsing huge strings with javascript?

  - by user246114

  Hi, I have a simple piece of data that I'm storing on a server, as a plain string. It is kind of ridiculous, but it looks like this: name|date|grade|description|name|date|grade|description|repeat for a long time this string can be up to 1.4mb in size. The idea is that it's a bunch of student records, just strung together with a simple pipe delimeter. It's a very poor serialization method. Once this massive string is pushed to the client, it is split along the pipes into student records again, using javascript. I've been timing how long it takes to create, and split, these strings on the client side. The times are actually quite good, the slowest run I've seen on a few different machines is 0.2 seconds for 10,000 'student records', which has a final string size of ~1.4mb. I realize this is quite bizarre, just wondering if there are any inherent problems with creating and splitting such large strings using javascript? I don't know how different browsers implement their javascript engines. I've tried this on the 'major' browsers, but don't know how this would perform on earlier versions of each. Yeah looking for any comments on this, this is more for fun than anything else! Thanks

  Read the article

• sqlite use in tcl script over nfs (or.. how to make standalone sqlite3 which can be run over nfs)

  - by wom

  Hello. I want to use an embed an sqlite database into an existing tcl application (Migrate from flat-file). Currently; our tcl interpreter is run from a network location; /bin/tclsh8.3 I do have an nfs $PATH for executables set for all users already; I am assuming I can place a standalone sqlite3 executible there; though I have been not found an easy way to compile a local lib independent sqlite yet... (all linux clients, running anything from red hat 9 to ubuntu 10.04) Anyone able to poke me in the right direction in building an sqlite3 standalone binary I can use in my nfs tcl install? Thanks, Chris

  Read the article

• Why isn't my favicon appearing in IE7/8?

  - by X3Maverick

  Page of interest: https://www.gsb-yourbank.com/test/ ICO file: https://www.gsb-yourbank.com/test/favicon.ico My favicon is a 16x16 resolution, 16-color ICO file. It will not appear in IE 7/8 no matter what I do! I've tried everything I can think of, including: generating the ICO with a variety of different utilities, changing the syntax of the favicon link elements in the document head, using absolute, relative, and root-relative URLs in the favicon link elements, using a PNG instead of an ICO file, ensuring that I am uploading the file via FTP in binary mode, As a longtime web developer/programmer, I can't believe that this is tripping me up. Any help would be greatly appreciated.

  Read the article

• How should i be handling string Interning on deserialization?

  - by DayOne

  In the example below I am interning the string in the constructor which is fine. However when i deserialise the object from the binary formatter I don't think the string will be interned as the constructor should be called. How should I be ensuring the _name string is interned? ... or will it be interned ok? Thanks [Serializable] class City { private readonly string _name; public City(string t) { _name = string.Intern(t); } public string Name { get { return _name; } } public override string ToString() { return _name; } }

  Read the article

• Why does the right-shift operator produce a zero instead of a one?

  - by mrt181

  Hi, i am teaching myself java and i work through the exercises in Thinking in Java. On page 116, exercise 11, you should right-shift an integer through all its binary positions and display each position with Integer.toBinaryString. public static void main(String[] args) { int i = 8; System.out.println(Integer.toBinaryString(i)); int maxIterations = Integer.toBinaryString(i).length(); int j; for (j = 1; j < maxIterations; j++) { i >>= 1; System.out.println(Integer.toBinaryString(i)); } In the solution guide the output looks like this: 1000 1100 1110 1111 When i run this code i get this: 1000 100 10 1 What is going on here. Are the digits cut off? I am using jdk1.6.0_20 64bit. The book uses jdk1.5 32bit.

  Read the article

• Fundamentals of Deserialization in .NET?

  - by Codehelp

  I have been working with XML for past couple of months with .NET Basically all the work I do involve XML in oneway of another so I thought it would be good to learn the serialization and deserialization part of the game. My work mostly involves the 'Deserialization' part of it. Almost every time I have an XML file which has to be used by the application that I write. An object form of the XML is the best way to use. Now initially the XML was very straight forward, just a couple of tags which would translate into a class very easily using XSD.exe tool. Things grew a bit complex with nesting of tags and I found Xsd2Code gen tool work fine. During this whole process I have been able to do my work with a lot of help from Stackoverflow community, thanks for that, but I think I have missed the forest for the trees. I need to know how Deserialization works in .NET Fundamentally, I would like to know what happens behind the scenes in taking a XML and converting it into a usable object. Code samples have helped me in the past, and as mentioned earlier the problem get's solved but the learning does not happen. So, if anyone can guide to resources that can get me started on the Deserialization part of the game, I would be thankful to them. Regards.

  Read the article

• Fastest reliable way for Clojure (Java) and Ruby apps to communicate

  - by jkndrkn

  Hi There, We have cloud-hosted (RackSpace cloud) Ruby and Java apps that will interact as follows: Ruby app sends a request to Java app. Request consists of map structure containing strings, integers, other maps, and lists (analogous to JSON). Java app analyzes data and sends reply to Ruby App. We are interested in evaluating both messaging formats (JSON, Buffer Protocols, Thrift, etc.) as well as message transmission channels/techniques (sockets, message queues, RPC, REST, SOAP, etc.) Our criteria: Short round-trip time. Low round-trip-time standard deviation. (We understand that garbage collection pauses and network usage spikes can affect this value). High availability. Scalability (we may want to have multiple instances of Ruby and Java app exchanging point-to-point messages in the future). Ease of debugging and profiling. Good documentation and community support. Bonus points for Clojure support. What combination of message format and transmission method would you recommend? Why? I've gathered here some materials we have already collected for review: Comparison of various java serialization options Comparison of Thrift and Protocol Buffers (old) Comparison of various data interchange formats Comparison of Thrift and Protocol Buffers Fallacies of Protocol Buffers RPC features Discussion of RPC in the context of AMQP (Message-Queueing) Comparison of RPC and message-passing in distributed systems (pdf) Criticism of RPC from perspective of message-passing fan Overview of Avro from Ruby programmer perspective

  Read the article

• TFS 2008 and Common libraries folder structure.

  - by Doerr

  TFS 2008 and Common Libraries I have created a Team Project called "Common Library" that will host code used in numerous different Team Projects throughout TFS. For sake of argument, lets say we have 2 distinct Librarys under the "Common Library" Team Projects, MailProject and LoggingProject. Other projects throughout TFS will be using the binary representation of these projects via branching and not the actual source code. What is the best way to set up the folder structure for this Team Project? Do I add the project to the "Common Library" and simply "include" the bin/release folder as part of the project? I have seen some examples of people creating a seperate "Deploy" folder. I assume this is synonamous with the bin/release folder?

  Read the article

• Eclipse is not importing jar dependencies between two projects in the same workspace

  - by jax

  Here is the situation. I have a java project "LicenseGenerator" in eclipse that depends on commons-codec. I have therefore added the commons-codec jar file to the build path. I have Junit tests and everything is working fine. I have made a different project in the same workspace - which happens to be an Android project - that needs to use my LicenseGenerator classes. I added LicenseGenerator to the "projects" tab in the build path - the classes were recognized and I was able to use them. Everything compiled and ran. However, when the part of the LicenseGenerator that used the commons-codec was called from my Android project I got the following error. Could not find method org.apache.commons.codec.binary.Base64.encodeBase64URLSafeString, referenced from method This basically tells me that the commons-codec was not packaged which the Android project, so I added the commons-codec to the android project as well but the same error appears. how do I fix this?

  Read the article

• Eclipse is not importing jar dependencies between two projects in the same workspace

  - by jax

  Here is the situation. I have a java project "LicenseGenerator" in eclipse that depends on commons-codec. I have therefore added the commons-codec jar file to the build path. I have Junit tests and everything is working fine. I have made a different project in the same workspace - which happens to be an Android project - that needs to use my LicenseGenerator classes. I added LicenseGenerator to the "projects" tab in the build path - the classes were recognized and I was able to use them. Everything compiled and ran. However, when the part of the LicenseGenerator that used the commons-codec was called from my Android project I got the following error. Could not find method org.apache.commons.codec.binary.Base64.encodeBase64URLSafeString, referenced from method This basically tells me that the commons-codec was not packaged which the Android project, so I added the commons-codec to the android project as well but the same error appears. how do I fix this?

  Read the article

• convert the key in MIME encoded form in python

  - by jaysh

  this is the code : f = urllib.urlopen('http://pool.sks-keyservers.net:11371/pks/lookup?op=get&search= 0x58e9390daf8c5bf3') #Retrieve the public key from PKS data = f.read() decoded_bytes = base64.b64decode(data) print decoded_bytes i need to convert the key in MIME encoded form which is presently comes in (ascii armored) radix 64 format.for that i have to get this radix64 format in its binary form and also need to remove its header and checksum than coversion in MIME format but i didnt find any method which can do this conversion. i used the base64.b64decode method and its give me error: Traceback (most recent call last): File "RetEnc.py", line 12, in ? decoded_bytes = base64.b64decode(data) File "/usr/lib/python2.4/base64.py", line 76, in b64decode raise TypeError(msg) TypeError: Incorrect padding what to do i'didnt getting .can anybody suggest me something related to this...... thanks!!!!

  Read the article

• Performance improvement to a big if clause in SQL Server function

  - by Miles D

  I am maintaining a function in SQL Server 2005, that based on an integer input parameter needs to call different functions e.g. IF @rule_id = 1 -- execute function 1 ELSE IF @rule_id = 2 -- execute function 2 ELSE IF @rule_id = 3 ... etc The problem is that there are a fair few rules (about 100), and although the above is fairly readable, its performance isn't great. At the moment it's implemented as a series of IF's that do a binary-chop, which is much faster, but becomes fairly unpleasant to read and maintain. Any alternative ideas for something that performs well and is fairly maintainable?

  Read the article

• How to find the number of inversions in an array ?

  - by Michael

  This is an phone interview question: "Find the number of inversions in an array". I guess they mean O(N*log N) solution since O(N^2) is trivial. I guess it cannot be better than O(N*log N) since sorting is O(N*log N) I have checked a similar question from SO and can summarize the answers as follows: Calculate half the distance the elements should be moved to sort the array : copy the array and sort the copy. For each element of the original array a[i] find it's position j in the sorted copy (binary search) and sum abs(i - j)/2. Modify merge sort : modify merge to count inversions between two sorted arrays (it takes O(N)) and run merge sort with the modified merge. Does it make sense ? Are there other (maybe simpler) solution ? Isn't it too hard for a phone interview ?

  Read the article

• Database for Large number of 1kB data chunks (MySQL?)

  - by The Unknown

  I have a very large dataset, each item in the dataset being roughly 1kB in size. The data needs to be queried rapidly by many applications distributed over a network. The dataset has more than a million items (so 500 million+ 1kB data chunks). What would be the best method to storing this dataset (need to allow adding more items, and reading them rapidly, but never modifying already added data)? Would using a MySQL DB using the binary blob format be appropriate? Or should each of these be stored as files on a file system? edit: the number is 1 million items now, but needs to be able to scale to well over 500 million items easily.

  Read the article

• Please suggest other ways of communicating between server & client.

  - by Geo

  I'm writing a TCP chat server ( programming language does not mather ). It's a school project for my nephew, so it won't be released, and all questions I'm asking are just for my knowledge :). . Some of the things it will support: chatting between users ( doh ), it will be multithreaded sending each other files I know I could easily get away with all the stuff above if I go with serialization, and just send objects from client to server and back. But, if I do that, it will be limited to a specific programming language ( meaning clients written in other programming languages may not be able to deserialize the objects ). What would be the way to go so that other clients written in other languages could be supported? One way to go, off the top of my head, would be to go in this direction: the server & the client communicate by sending messages & chunks ( in lieu of other names ). Here's what I mean by this: every time the client/server wants to send something ( text message or file ) it will first send a simple text message ( newline terminated ) with the number of the chunks it will send. Example: command 4,20,30,40,50 Where command would be something like instant-message or file,4 would be the number of chunks to be sent, 20 would be the size in bytes of the first chunk, 30 of the 2nd, and so forth. after the message was sent, the client/server will start sending chunks ( of sizes mentioned in the sent message ). What do you think about implementing the client/server communication this way? What better options are there?

  Read the article

• What is the fastest method to calculate substring

  - by Misha Moroshko

  I have a huge "binary" string, like: 1110 0010 1000 1111 0000 1100 1010 0111.... It's length is 0 modulo 4, and may reach 500,000. I have also a corresponding array: {14, 2, 8, 15, 0, 12, 10, 7, ...} (every number in the array corresponds to 4 bits in the string) Given this string, this array, and a number N, I need to calculate the following substring string.substr(4*N, 4), i.e.: for N=0 the result should be 1110 for N=1 the result should be 0010 I need to perform this task many many times, and my question is what would be the fastest method to calculate this substring ? One method is to calculate the substring straight forward: string.substr(4*N, 4). I'm afraid this one is not efficient for such huge strings. Another method is to use array[N].toString(2) and then wrap the result with zeros if needed. I'm not sure how fast is this. May be you have any other ideas ?

  Read the article

• C: Reading file with a starting point

  - by Shinka

  A simple question but I can't find the answer in my book. I want to read a binary file to seed a random number generator, but I don't want to seed my generator with the same seed each time I call the function, so I will need to keep a variable for my position in the file (not a problem) and I would need to know how to read a file starting a specific point in the file (no idea how). The code: void rng_init(RNG* rng) { // ... FILE *input = fopen("random.bin", "rb"); unsigned int seed[32]; fread(seed, sizeof(unsigned int), 32, input); // seed 'rng'... fclose(input); }

  Read the article

• Tiny C Compiler and Virus warnings...

  - by NoMoreZealots

  I wanted to try out the TCC and got the Win32 Binary zip file from the website. upon decompressing it I tried to compile the "hello_win.c" source from the example directory. As soon as the compiler tried to write to the disk McAfee Popped up a dialog box and identified a Trojan named "Generic.dx." Has anyone else experience this? Dropping a virus into a compiler would be a sneaky, but brilliant, delivery mechanizism. I just want to know if this is a legit threat.

  Read the article

• Coldfusion 8 and HTTP PUT - is there a way to PUT an object?

  - by ciaranarcher

  Hi all We are using EHCache with CF 8 to cache stuff on a central server using a RESTful interface over HTTP. I am trying to cache a cfquery object to the cache server. I can get this to work if I call EHCache direct (i.e. store it in a local cache) but if I try to cache on a remote server over HTTP I am running into problems. The code I am using is as follows: <cfhttp url="http://localhost:8080/myCache/myKey" method="put" result="r" timeout="2" throwonerror="true" > <cfhttpparam type="body" value="#ARGUMENTS.item#" /> </cfhttp> CF doesn't like this reference to #ARGUMENTS.item# and it complains Complex object types cannot be converted to simple values. Can anyone give me an example of how to put an object over http using CF? If this is not possible with CF then a Java example would be the next best thing. Many thanks in advance! PS: I do not want to use serialization to text/JSON etc. as this approach has issues with data integrity and most importantly it's not fast enough.

  Read the article

• Passing the Class<T> in java of a generic list?

  - by Rob Stevenson-Leggett

  I have a method for reading JSON from a service, I'm using Gson to do my serialization and have written the following method using type parameters. public T getDeserializedJSON(Class<T> aClass,String url) { Reader r = getJSONDataAsReader(url); Gson gson = new Gson(); return gson.fromJson(r, aClass); } I'm consuming json which returns just an array of a type e.g. [ { "prop":"value" } { "prop":"value" } ] I have a java class which maps to this object let's call it MyClass. However to use my method I need to do this: RestClient<ArrayList<MyClass>> restClient = new RestClient<ArrayList<MyClass>>(); ArrayList<MyClass> results = restClient.getDeserializedJSON(ArrayList<MyClass>.class, url); However, I can't figure out the syntax to do it. Passing just ArrayList.class doesn't work. So is there a way I can get rid of the Class parameter or how do I get the class of the ArrayList of MyClass?

  Read the article

< Previous Page | 154 155 156 157 158 159 160 161 162 163 164 165  | Next Page >