def buildPackIndex(self):
pos = 4
# We make the initial assumption that the database has been
# packed before and set unpacked to True only after seeing the
# first record with a status == " ". If we get to the packtime
# and unpacked is still False, we need to watch for a redundant
# pack.
unpacked = False
while pos < self.eof:
th = self._read_txn_header(pos)
if th.tid > self.packtime:
break
self.checkTxn(th, pos)
if th.status != "p":
unpacked = True
tpos = pos
end = pos + th.tlen
pos += th.headerlen()
while pos < end:
dh = self._read_data_header(pos)
self.checkData(th, tpos, dh, pos)
if dh.plen or dh.back:
self.oid2curpos[dh.oid] = pos
else:
if dh.oid in self.oid2curpos:
del self.oid2curpos[dh.oid]
pos += dh.recordlen()
tlen = self._read_num(pos)
if tlen != th.tlen:
self.fail(
pos, "redundant transaction length does not "
"match initial transaction length: %d != %d", tlen,
th.tlen)
pos += 8
self.packpos = pos
if unpacked:
return
# check for a redundant pack. If the first record following
# the newly computed packpos has status 'p', then it was
# packed earlier and the current pack is redudant.
try:
th = self._read_txn_header(pos)
except CorruptedDataError as err:
if err.buf != b"":
raise
if th.status == 'p':
# Delayed import to cope with circular imports.
# TODO: put exceptions in a separate module.
from ZODB.FileStorage.FileStorage import RedundantPackWarning
raise RedundantPackWarning(
"The database has already been packed to a later time"
" or no changes have been made since the last pack")
class GC(FileStorageFormatter):
def __init__(self, file, eof, packtime, gc, referencesf):
self._file = file
self._name = file.name
self.eof = eof
self.packtime = packtime
self.gc = gc
# packpos: position of first txn header after pack time
self.packpos = None
# {oid -> current data record position}:
self.oid2curpos = ZODB.fsIndex.fsIndex()
# The set of reachable revisions of each object.
#
# This set as managed using two data structures. The first is
# an fsIndex mapping oids to one data record pos. Since only
# a few objects will have more than one revision, we use this
# efficient data structure to handle the common case. The
# second is a dictionary mapping objects to lists of
# positions; it is used to handle the same number of objects
# for which we must keep multiple revisions.
self.reachable = ZODB.fsIndex.fsIndex()
self.reach_ex = {}
# keep ltid for consistency checks during initial scan
self.ltid = z64
self.referencesf = referencesf
def isReachable(self, oid, pos):
"""Return 1 if revision of `oid` at `pos` is reachable."""
rpos = self.reachable.get(oid)
if rpos is None:
return 0
if rpos == pos:
return 1
return pos in self.reach_ex.get(oid, [])
def findReachable(self):
self.buildPackIndex()
if self.gc:
self.findReachableAtPacktime([z64])
self.findReachableFromFuture()
# These mappings are no longer needed and may consume a lot of
# space.
del self.oid2curpos
else:
self.reachable = self.oid2curpos
def buildPackIndex(self):
pos = 4L
# We make the initial assumption that the database has been
# packed before and set unpacked to True only after seeing the
# first record with a status == " ". If we get to the packtime
# and unpacked is still False, we need to watch for a redundant
# pack.
unpacked = False
while pos < self.eof:
th = self._read_txn_header(pos)
if th.tid > self.packtime:
break
self.checkTxn(th, pos)
if th.status != "p":
unpacked = True
tpos = pos
end = pos + th.tlen
pos += th.headerlen()
while pos < end:
dh = self._read_data_header(pos)
self.checkData(th, tpos, dh, pos)
if dh.plen or dh.back:
self.oid2curpos[dh.oid] = pos
else:
if dh.oid in self.oid2curpos:
del self.oid2curpos[dh.oid]
pos += dh.recordlen()
tlen = self._read_num(pos)
if tlen != th.tlen:
self.fail(
pos, "redundant transaction length does not "
"match initial transaction length: %d != %d", tlen,
th.tlen)
pos += 8
self.packpos = pos
if unpacked:
return
# check for a redundant pack. If the first record following
# the newly computed packpos has status 'p', then it was
# packed earlier and the current pack is redudant.
try:
th = self._read_txn_header(pos)
except CorruptedDataError, err:
if err.buf != "":
raise
if th.status == 'p':
# Delayed import to cope with circular imports.
# TODO: put exceptions in a separate module.
from ZODB.FileStorage.FileStorage import RedundantPackWarning
raise RedundantPackWarning(
"The database has already been packed to a later time"
" or no changes have been made since the last pack")