mirror of
https://github.com/borgbackup/borg.git
synced 2024-12-26 01:37:20 +00:00
107 lines
3.3 KiB
Python
107 lines
3.3 KiB
Python
import hashlib
|
|
import logging
|
|
import msgpack
|
|
import os
|
|
import zlib
|
|
|
|
NS_ARCHIVES = 'A'
|
|
NS_CHUNKS = 'C'
|
|
|
|
|
|
class Cache(object):
|
|
"""Client Side cache
|
|
"""
|
|
|
|
def __init__(self, store):
|
|
self.store = store
|
|
self.path = os.path.join(os.path.expanduser('~'), '.dedupestore', 'cache',
|
|
'%s.cache' % self.store.uuid)
|
|
self.tid = -1
|
|
self.open()
|
|
if self.tid != self.store.tid:
|
|
self.init()
|
|
|
|
def open(self):
|
|
if not os.path.exists(self.path):
|
|
return
|
|
data = open(self.path, 'rb').read()
|
|
id = data[:32]
|
|
data = data[32:]
|
|
if hashlib.sha256(data).digest() != id:
|
|
raise Exception('Cache hash did not match')
|
|
data = msgpack.unpackb(zlib.decompress(data))
|
|
version = data.get('version')
|
|
if version != 1:
|
|
logging.error('Unsupported cache version %r' % version)
|
|
return
|
|
if data['store'] != self.store.uuid:
|
|
raise Exception('Cache UUID mismatch')
|
|
self.chunkmap = data['chunkmap']
|
|
self.archives = data['archives']
|
|
self.tid = data['tid']
|
|
|
|
def init(self):
|
|
"""Initializes cache by fetching and reading all archive indicies
|
|
"""
|
|
logging.info('Initialzing cache...')
|
|
self.chunkmap = {}
|
|
self.archives = {}
|
|
self.tid = self.store.tid
|
|
if self.store.tid == 0:
|
|
return
|
|
for id in list(self.store.list(NS_ARCHIVES)):
|
|
data = self.store.get(NS_ARCHIVES, id)
|
|
if hashlib.sha256(data).digest() != id:
|
|
raise Exception('Archive hash did not match')
|
|
archive = msgpack.unpackb(zlib.decompress(data))
|
|
self.archives[archive['name']] = id
|
|
for id, size in archive['chunks']:
|
|
try:
|
|
count, size = self.chunkmap[id]
|
|
self.chunkmap[id] = count + 1, size
|
|
except KeyError:
|
|
self.chunkmap[id] = 1, size
|
|
self.save()
|
|
|
|
def save(self):
|
|
assert self.store.state == self.store.OPEN
|
|
data = {'version': 1,
|
|
'store': self.store.uuid,
|
|
'chunkmap': self.chunkmap,
|
|
'tid': self.store.tid, 'archives': self.archives}
|
|
cachedir = os.path.dirname(self.path)
|
|
if not os.path.exists(cachedir):
|
|
os.makedirs(cachedir)
|
|
with open(self.path, 'wb') as fd:
|
|
data = zlib.compress(msgpack.packb(data))
|
|
id = hashlib.sha256(data).digest()
|
|
fd.write(id + data)
|
|
|
|
def add_chunk(self, id, data):
|
|
if self.seen_chunk(id):
|
|
return self.chunk_incref(id)
|
|
data = zlib.compress(data)
|
|
data = hashlib.sha256(data).digest() + data
|
|
csize = len(data)
|
|
self.store.put(NS_CHUNKS, id, data)
|
|
self.chunkmap[id] = (1, csize)
|
|
return csize
|
|
|
|
def seen_chunk(self, id):
|
|
count, size = self.chunkmap.get(id, (0, 0))
|
|
return count
|
|
|
|
def chunk_incref(self, id):
|
|
count, size = self.chunkmap[id]
|
|
self.chunkmap[id] = (count + 1, size)
|
|
return size
|
|
|
|
def chunk_decref(self, id):
|
|
count, size = self.chunkmap[id]
|
|
if count == 1:
|
|
del self.chunkmap[id]
|
|
self.store.delete(NS_CHUNKS, id)
|
|
else:
|
|
self.chunkmap[id] = (count - 1, size)
|
|
|
|
|