D-LAN

h1. Prototypes

Prototypes are locate in the '/prototypes' directory in the repository. The goal is to write some code to try to resolve a particular problem which we don't know exactly how to solve.

# [[SHA-1 prototype]] : Creating SHA-1 hash for each part of a file. See [[Libraries]] for the list of SHA-1 lib. We must find the quickest library. The reference in term of speed is _sha1sum_ from the openssl package. The speed is approximately 150Mo/s for a cached file for an Intel 1.8 GHz Core2 CPU.

# [[UTF8 prototype]] : Reading and writing files with UTF8 characters in theirs filename. Must be tested for the three platforms : Linux, Windows and MacOSX.

# [[Search prototype]] : Searching into a large set of files and directories with a glob string or a range of size. Measure the average time for about 50'000 files, it should be below one minute for the first search and below 3 seconds for the next searches.

# [[UDP prototype]] : Multicast UDP and periodically signal emitting.

# [[Protobuf prototype]] : Serializing and exchanging message with _Protocol Buffers_.

# [[Concurrent prototype]] : Defining and testing the concurrent model for downloading and uploading. Reading and writing the same file from different threads.

# [[Watcher prototype]] : Observing the modifications of the files structure to hash new added files and remove hash from the cache when a file is deleted. See the class "QFileSystemWatcher":http://doc.trolltech.com/4.5/qfilesystemwatcher.html.