def storeLink(self, fileName):
'''Pricate specialization function
Links are stored much like directories. Their type is link
'''
assert os.path.islink(fileName)
md = self.getMetadata(fileName)
md['type'] = u'link'
md['target'] = os.readlink(fileName)
digest = sha1(fileName)
metadataFileName = os.path.join(self.storagePath, 'tree', digest[:2], u'%s.json' % digest)
metadata.appendMeta(metadataFileName, md)
def storeDirectory(self, fileName):
'''Private specialization function
Directories are stored by using the path to the file as input for the hash function.
All the hashed files are placed in a special directory called "tree" because
they only describe parts of the file system tree.
'''
assert os.path.isdir(fileName)
md = self.getMetadata(fileName)
md['type'] = u'directory'
digest = sha1(fileName)
metadataFileName = os.path.join(self.storagePath, 'tree', digest[:2], u'%s.json' % digest)
metadata.appendMeta(metadataFileName, md)
def storeFile(self, fileName):
'''Private specialization function'''
i = file(fileName)
chunkSums = []
completeDigest = hashlib.sha1()
while True:
read = i.read(self.CHUNK_SIZE)
h = hashlib.sha1()
h.update(read)
completeDigest.update(read)
digest = unicode(h.hexdigest())
chunkSums.append(digest)
#Store chunk
chunkFileName = os.path.join(self.storagePath, 'data', digest[:2], digest)
#Only write if not existing
if not os.path.exists(chunkFileName):
outputDir = os.path.dirname(chunkFileName)
if not os.path.exists(outputDir):
os.makedirs(outputDir)
file(chunkFileName, 'w').write(read)
del outputDir
else:
#If the file does exist, do some sanity checks
if not os.path.getsize(chunkFileName) == len(read):
raise Exception('Chunk with name %s already exists but it does not have the same size as the chunk I just read (with the same name) %i on disk, %i read' % (chunkFileName, os.path.getsize(chunkFileName), len(read)))
#detect EOF
if len(read) < self.CHUNK_SIZE:
break
del read
md = self.getMetadata(fileName)
md['type'] = u'file'
md['chunks'] = chunkSums
md['digest'] = unicode(completeDigest.hexdigest())
metadataFileName = os.path.join(self.storagePath, 'meta', digest[:2], u'%s.json' % digest)
metadata.appendMeta(metadataFileName, md)
