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.

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

# Searching into a large set of files and directories with a glob string or a range of size, see the chapter 8 and 9 of RWH. 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.

# Observing the modifications of the files structure to hash new added files and remove hash from the cache when a file is deleted.

# Efficient of the file transfer over TCP/IP with Haskell. It includes reading from the disk, streaming and writing to the disk. Comparisons with SMB and NFS.

# Multicast UDP and periodically signal emitting.

# Serializing and exchanging message with _Protocol Buffers_ in Haskell. see http://hackage.haskell.org/cgi-bin/hackage-scripts/package/protocol-buffers.

# Defining and testing the concurrent model for downloading and uploading.

## Reading and writing the same file from different threads.