Store more chunk metadata in the archive.

This commit is contained in:
Jonas Borgström 2010-03-15 21:23:34 +01:00
parent 98f738fe7f
commit 42ff0a850b
2 changed files with 82 additions and 77 deletions

View File

@ -15,15 +15,28 @@ class Archive(object):
def __init__(self, store, name=None):
self.store = store
self.items = []
self.chunks = []
self.chunk_idx = {}
if name:
self.open(name)
def add_chunk(self, id, sum, csize, osize):
try:
return self.chunk_idx[id]
except KeyError:
idx = len(self.chunks)
self.chunks.append((id, sum, csize, osize))
self.chunk_idx[id] = idx
return idx
def open(self, name):
archive = cPickle.loads(zlib.decompress(self.store.get(NS_ARCHIVES, name)))
self.items = archive['items']
for i, (id, sum, csize, osize) in enumerate(archive['chunks']):
self.chunk_idx[i] = id
def save(self, name):
archive = {'name': name, 'items': self.items}
archive = {'name': name, 'items': self.items, 'chunks': self.chunks}
self.store.put(NS_ARCHIVES, name, zlib.compress(cPickle.dumps(archive)))
self.store.commit()
@ -39,10 +52,14 @@ class Archive(object):
if not os.path.exists(item['path']):
os.makedirs(item['path'])
if item['type'] == 'FILE':
path = item['path']
if not os.path.exists(os.path.dirname(path)):
os.makedirs(os.path.dirname(path))
with open(item['path'], 'wb') as fd:
for chunk in item['chunks']:
data = self.store.get(NS_CHUNKS, chunk)
if hashlib.sha1(data).digest() != chunk[4:]:
id = self.chunk_idx[chunk]
data = self.store.get(NS_CHUNKS, id)
if hashlib.sha1(data).digest() != id:
raise Exception('Invalid chunk checksum')
fd.write(zlib.decompress(data))
@ -50,9 +67,11 @@ class Archive(object):
for item in self.items:
if item['type'] == 'FILE':
print item['path'], '...',
print self.chunk_idx[0].encode('hex')
for chunk in item['chunks']:
data = self.store.get(NS_CHUNKS, chunk)
if hashlib.sha1(data).digest() != chunk[4:]:
id = self.chunk_idx[chunk]
data = self.store.get(NS_CHUNKS, id)
if hashlib.sha1(data).digest() != id:
print 'ERROR'
break
else:
@ -68,28 +87,39 @@ class Archive(object):
cache.archives.remove(self.name)
cache.save()
class Archiver(object):
def create_archive(self, archive_name, paths):
try:
self.store.get(NS_ARCHIVES, archive_name)
except Store.DoesNotExist:
pass
else:
raise Exception('Archive "%s" already exists' % archive_name)
archive = Archive(self.store)
def create(self, name, paths, cache):
for path in paths:
for root, dirs, files in os.walk(path):
for d in dirs:
name = os.path.join(root, d)
archive.items.append(self.process_dir(name, self.cache))
p = os.path.join(root, d)
self.items.append(self.process_dir(p, cache))
for f in files:
name = os.path.join(root, f)
archive.items.append(self.process_file(name, self.cache))
archive.save(archive_name)
self.cache.archives.append(archive_name)
self.cache.save()
p = os.path.join(root, f)
self.items.append(self.process_file(p, cache))
self.save(name)
cache.archives.append(name)
cache.save()
def process_dir(self, path, cache):
path = path.lstrip('/\\:')
print 'Directory: %s' % (path)
return {'type': 'DIR', 'path': path}
def process_file(self, path, cache):
with open(path, 'rb') as fd:
path = path.lstrip('/\\:')
print 'Adding: %s...' % path
chunks = []
for chunk in chunkify(fd, CHUNK_SIZE, cache.summap):
chunks.append(self.add_chunk(*cache.add_chunk(chunk)))
return {'type': 'FILE', 'path': path, 'chunks': chunks}
class Archiver(object):
def create_archive(self, name, paths):
archive = Archive(self.store)
archive.create(name, paths, self.cache)
def delete_archive(self, archive_name):
archive = Archive(self.store, archive_name)
@ -112,28 +142,6 @@ class Archiver(object):
archive = Archive(self.store, archive_name)
archive.extract()
def process_dir(self, path, cache):
path = path.lstrip('/\\:')
print 'Directory: %s' % (path)
return {'type': 'DIR', 'path': path}
def process_file(self, path, cache):
with open(path, 'rb') as fd:
path = path.lstrip('/\\:')
print 'Adding: %s...' % path,
sys.stdout.flush()
origsize = 0
compsize = 0
chunks = []
for chunk in chunkify(fd, CHUNK_SIZE, self.cache.summap):
origsize += len(chunk)
id, size = cache.add_chunk(chunk)
compsize += size
chunks.append(id)
ratio = origsize and compsize * 100 / origsize or 0
print '(%d chunks: %d%%)' % (len(chunks), ratio)
return {'type': 'FILE', 'path': path, 'size': origsize, 'chunks': chunks}
def run(self):
parser = OptionParser()
parser.add_option("-s", "--store", dest="store",

View File

@ -2,7 +2,6 @@ import cPickle
import hashlib
import os
import sys
import struct
import zlib
from chunkifier import checksum
@ -49,10 +48,11 @@ class Cache(object):
for id in self.store.list(NS_ARCHIVES):
archive = cPickle.loads(zlib.decompress(self.store.get(NS_ARCHIVES, id)))
self.archives.append(archive['name'])
for item in archive['items']:
if item['type'] == 'FILE':
for c in item['chunks']:
self.chunk_incref(c)
for id, sum, csize, osize in archive['chunks']:
if self.seen_chunk(id):
self.chunk_incref(id)
else:
self.init_chunk(id, sum, csize, osize)
print 'done'
def save(self):
@ -71,42 +71,39 @@ class Cache(object):
def add_chunk(self, data):
sum = checksum(data)
osize = len(data)
data = zlib.compress(data)
#print 'chunk %d: %d' % (len(data), sum)
id = struct.pack('I', sum) + hashlib.sha1(data).digest()
if not self.seen_chunk(id):
size = len(data)
self.store.put(NS_CHUNKS, id, data)
else:
size = 0
#print 'seen chunk', hash.encode('hex')
self.chunk_incref(id)
return id, size
id = hashlib.sha1(data).digest()
if self.seen_chunk(id):
return self.chunk_incref(id)
csize = len(data)
self.store.put(NS_CHUNKS, id, data)
return self.init_chunk(id, sum, csize, osize)
def seen_chunk(self, hash):
return self.chunkmap.get(hash, 0) > 0
def init_chunk(self, id, sum, csize, osize):
self.chunkmap[id] = (1, sum, osize, csize)
self.summap.setdefault(sum, 1)
return id, sum, csize, osize
def seen_chunk(self, id):
return id in self.chunkmap
def chunk_incref(self, id):
sum = struct.unpack('I', id[:4])[0]
self.chunkmap.setdefault(id, 0)
self.summap.setdefault(sum, 0)
self.chunkmap[id] += 1
count, sum, csize, osize = self.chunkmap[id]
self.chunkmap[id] = (count + 1, sum, osize, csize)
self.summap[sum] += 1
return id, sum, csize, osize
def chunk_decref(self, id):
sum = struct.unpack('I', id[:4])[0]
sumcount = self.summap[sum] - 1
count = self.chunkmap[id] - 1
assert sumcount >= 0
assert count >= 0
if sumcount:
self.summap[sum] = sumcount
else:
count, sum, csize, osize = self.chunkmap[id]
sumcount = self.summap[sum]
if sumcount == 1:
del self.summap[sum]
if count:
self.chunkmap[id] = count
else:
self.summap[sum] = sumcount - 1
if count == 1:
del self.chunkmap[id]
print 'deleting chunk: ', id.encode('hex')
self.store.delete(NS_CHUNKS, id)
return count
else:
self.chunkmap[id] = (count - 1, sum, csize, osize)