Trap OSError when deleting env vars
On the other OS, it seems that case insensitivity for
environment vars can bite users when using some unknown
combination of python 2.4.1 and win2kSP4+minsys (and
probably other vversions of these softwares).
The best way to avoid problems in those weird cases is to
ignore OSError exception during env var deletion.
# revlog.py - storage back-end for mercurial
#
# This provides efficient delta storage with O(1) retrieve and append
# and O(changes) merge between branches
#
# Copyright 2005 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.
import zlib, struct, sha, binascii, heapq
from mercurial import mdiff
def hex(node): return binascii.hexlify(node)
def bin(node): return binascii.unhexlify(node)
def short(node): return hex(node[:6])
def compress(text):
if not text: return text
if len(text) < 44:
if text[0] == '\0': return text
return 'u' + text
bin = zlib.compress(text)
if len(bin) > len(text):
if text[0] == '\0': return text
return 'u' + text
return bin
def decompress(bin):
if not bin: return bin
t = bin[0]
if t == '\0': return bin
if t == 'x': return zlib.decompress(bin)
if t == 'u': return bin[1:]
raise "unknown compression type %s" % t
def hash(text, p1, p2):
l = [p1, p2]
l.sort()
s = sha.new(l[0])
s.update(l[1])
s.update(text)
return s.digest()
nullid = "\0" * 20
indexformat = ">4l20s20s20s"
class lazyparser:
def __init__(self, data, revlog):
self.data = data
self.s = struct.calcsize(indexformat)
self.l = len(data)/self.s
self.index = [None] * self.l
self.map = {nullid: -1}
self.all = 0
self.revlog = revlog
def load(self, pos=None):
if self.all: return
if pos is not None:
block = pos / 1000
i = block * 1000
end = min(self.l, i + 1000)
else:
self.all = 1
i = 0
end = self.l
self.revlog.index = self.index
self.revlog.nodemap = self.map
while i < end:
d = self.data[i * self.s: (i + 1) * self.s]
e = struct.unpack(indexformat, d)
self.index[i] = e
self.map[e[6]] = i
i += 1
class lazyindex:
def __init__(self, parser):
self.p = parser
def __len__(self):
return len(self.p.index)
def load(self, pos):
self.p.load(pos)
return self.p.index[pos]
def __getitem__(self, pos):
return self.p.index[pos] or self.load(pos)
def append(self, e):
self.p.index.append(e)
class lazymap:
def __init__(self, parser):
self.p = parser
def load(self, key):
if self.p.all: return
n = self.p.data.find(key)
if n < 0: raise KeyError("node " + hex(key))
pos = n / self.p.s
self.p.load(pos)
def __contains__(self, key):
self.p.load()
return key in self.p.map
def __iter__(self):
yield nullid
for i in xrange(self.p.l):
try:
yield self.p.index[i][6]
except:
self.p.load(i)
yield self.p.index[i][6]
def __getitem__(self, key):
try:
return self.p.map[key]
except KeyError:
try:
self.load(key)
return self.p.map[key]
except KeyError:
raise KeyError("node " + hex(key))
def __setitem__(self, key, val):
self.p.map[key] = val
class revlog:
def __init__(self, opener, indexfile, datafile):
self.indexfile = indexfile
self.datafile = datafile
self.opener = opener
self.cache = None
try:
i = self.opener(self.indexfile).read()
except IOError:
i = ""
if len(i) > 10000:
# big index, let's parse it on demand
parser = lazyparser(i, self)
self.index = lazyindex(parser)
self.nodemap = lazymap(parser)
else:
s = struct.calcsize(indexformat)
l = len(i) / s
self.index = [None] * l
m = [None] * l
n = 0
for f in xrange(0, len(i), s):
# offset, size, base, linkrev, p1, p2, nodeid
e = struct.unpack(indexformat, i[f:f + s])
m[n] = (e[6], n)
self.index[n] = e
n += 1
self.nodemap = dict(m)
self.nodemap[nullid] = -1
def tip(self): return self.node(len(self.index) - 1)
def count(self): return len(self.index)
def node(self, rev): return (rev < 0) and nullid or self.index[rev][6]
def rev(self, node): return self.nodemap[node]
def linkrev(self, node): return self.index[self.nodemap[node]][3]
def parents(self, node):
if node == nullid: return (nullid, nullid)
return self.index[self.nodemap[node]][4:6]
def start(self, rev): return self.index[rev][0]
def length(self, rev): return self.index[rev][1]
def end(self, rev): return self.start(rev) + self.length(rev)
def base(self, rev): return self.index[rev][2]
def heads(self):
p = {}
h = []
for r in range(self.count() - 1, -1, -1):
n = self.node(r)
if n not in p:
h.append(n)
for pn in self.parents(n):
p[pn] = 1
return h
def children(self, node):
c = []
p = self.rev(node)
for r in range(p + 1, self.count()):
n = self.node(r)
for pn in self.parents(n):
if pn == node:
c.append(n)
continue
elif pn == nullid:
continue
return c
def lookup(self, id):
try:
rev = int(id)
if str(rev) != id: raise ValueError
if rev < 0: rev = self.count() + rev
if rev < 0 or rev >= self.count(): raise ValueError
return self.node(rev)
except (ValueError, OverflowError):
c = []
for n in self.nodemap:
if hex(n).startswith(id):
c.append(n)
if len(c) > 1: raise KeyError("Ambiguous identifier")
if len(c) < 1: raise KeyError("No match found")
return c[0]
return None
def diff(self, a, b):
return mdiff.textdiff(a, b)
def patches(self, t, pl):
return mdiff.patches(t, pl)
def delta(self, node):
r = self.rev(node)
b = self.base(r)
if r == b:
return self.diff(self.revision(self.node(r - 1)),
self.revision(node))
else:
f = self.opener(self.datafile)
f.seek(self.start(r))
data = f.read(self.length(r))
return decompress(data)
def revision(self, node):
if node == nullid: return ""
if self.cache and self.cache[0] == node: return self.cache[2]
text = None
rev = self.rev(node)
start, length, base, link, p1, p2, node = self.index[rev]
end = start + length
if base != rev: start = self.start(base)
if self.cache and self.cache[1] >= base and self.cache[1] < rev:
base = self.cache[1]
start = self.start(base + 1)
text = self.cache[2]
last = 0
f = self.opener(self.datafile)
f.seek(start)
data = f.read(end - start)
if text is None:
last = self.length(base)
text = decompress(data[:last])
bins = []
for r in xrange(base + 1, rev + 1):
s = self.length(r)
bins.append(decompress(data[last:last + s]))
last = last + s
text = mdiff.patches(text, bins)
if node != hash(text, p1, p2):
raise IOError("integrity check failed on %s:%d"
% (self.datafile, rev))
self.cache = (node, rev, text)
return text
def addrevision(self, text, transaction, link, p1=None, p2=None, d=None):
if text is None: text = ""
if p1 is None: p1 = self.tip()
if p2 is None: p2 = nullid
node = hash(text, p1, p2)
if node in self.nodemap:
return node
n = self.count()
t = n - 1
if n:
base = self.base(t)
start = self.start(base)
end = self.end(t)
if not d:
prev = self.revision(self.tip())
d = self.diff(prev, text)
data = compress(d)
dist = end - start + len(data)
# full versions are inserted when the needed deltas
# become comparable to the uncompressed text
if not n or dist > len(text) * 2:
data = compress(text)
base = n
else:
base = self.base(t)
offset = 0
if t >= 0:
offset = self.end(t)
e = (offset, len(data), base, link, p1, p2, node)
self.index.append(e)
self.nodemap[node] = n
entry = struct.pack(indexformat, *e)
transaction.add(self.datafile, e[0])
self.opener(self.datafile, "a").write(data)
transaction.add(self.indexfile, n * len(entry))
self.opener(self.indexfile, "a").write(entry)
self.cache = (node, n, text)
return node
def ancestor(self, a, b):
# calculate the distance of every node from root
dist = {nullid: 0}
for i in xrange(self.count()):
n = self.node(i)
p1, p2 = self.parents(n)
dist[n] = max(dist[p1], dist[p2]) + 1
# traverse ancestors in order of decreasing distance from root
def ancestors(node):
# we store negative distances because heap returns smallest member
h = [(-dist[node], node)]
seen = {}
earliest = self.count()
while h:
d, n = heapq.heappop(h)
if n not in seen:
seen[n] = 1
r = self.rev(n)
yield (-d, r, n)
for p in self.parents(n):
heapq.heappush(h, (-dist[p], p))
x = ancestors(a)
y = ancestors(b)
lx = x.next()
ly = y.next()
# increment each ancestor list until it is closer to root than
# the other, or they match
while 1:
if lx == ly:
return lx[2]
elif lx < ly:
ly = y.next()
elif lx > ly:
lx = x.next()
def group(self, linkmap):
# given a list of changeset revs, return a set of deltas and
# metadata corresponding to nodes. the first delta is
# parent(nodes[0]) -> nodes[0] the receiver is guaranteed to
# have this parent as it has all history before these
# changesets. parent is parent[0]
revs = []
needed = {}
# find file nodes/revs that match changeset revs
for i in xrange(0, self.count()):
if self.index[i][3] in linkmap:
revs.append(i)
needed[i] = 1
# if we don't have any revisions touched by these changesets, bail
if not revs:
yield struct.pack(">l", 0)
return
# add the parent of the first rev
p = self.parents(self.node(revs[0]))[0]
revs.insert(0, self.rev(p))
# for each delta that isn't contiguous in the log, we need to
# reconstruct the base, reconstruct the result, and then
# calculate the delta. We also need to do this where we've
# stored a full version and not a delta
for i in xrange(0, len(revs) - 1):
a, b = revs[i], revs[i + 1]
if a + 1 != b or self.base(b) == b:
for j in xrange(self.base(a), a + 1):
needed[j] = 1
for j in xrange(self.base(b), b + 1):
needed[j] = 1
# calculate spans to retrieve from datafile
needed = needed.keys()
needed.sort()
spans = []
oo = -1
ol = 0
for n in needed:
if n < 0: continue
o = self.start(n)
l = self.length(n)
if oo + ol == o: # can we merge with the previous?
nl = spans[-1][2]
nl.append((n, l))
ol += l
spans[-1] = (oo, ol, nl)
else:
oo = o
ol = l
spans.append((oo, ol, [(n, l)]))
# read spans in, divide up chunks
chunks = {}
for span in spans:
# we reopen the file for each span to make http happy for now
f = self.opener(self.datafile)
f.seek(span[0])
data = f.read(span[1])
# divide up the span
pos = 0
for r, l in span[2]:
chunks[r] = decompress(data[pos: pos + l])
pos += l
# helper to reconstruct intermediate versions
def construct(text, base, rev):
bins = [chunks[r] for r in xrange(base + 1, rev + 1)]
return mdiff.patches(text, bins)
# build deltas
deltas = []
for d in xrange(0, len(revs) - 1):
a, b = revs[d], revs[d + 1]
n = self.node(b)
# do we need to construct a new delta?
if a + 1 != b or self.base(b) == b:
if a >= 0:
base = self.base(a)
ta = chunks[self.base(a)]
ta = construct(ta, base, a)
else:
ta = ""
base = self.base(b)
if a > base:
base = a
tb = ta
else:
tb = chunks[self.base(b)]
tb = construct(tb, base, b)
d = self.diff(ta, tb)
else:
d = chunks[b]
p = self.parents(n)
meta = n + p[0] + p[1] + linkmap[self.linkrev(n)]
l = struct.pack(">l", len(meta) + len(d) + 4)
yield l
yield meta
yield d
yield struct.pack(">l", 0)
def addgroup(self, revs, linkmapper, transaction, unique = 0):
# given a set of deltas, add them to the revision log. the
# first delta is against its parent, which should be in our
# log, the rest are against the previous delta.
# track the base of the current delta log
r = self.count()
t = r - 1
node = nullid
base = prev = -1
start = end = measure = 0
if r:
start = self.start(self.base(t))
end = self.end(t)
measure = self.length(self.base(t))
base = self.base(t)
prev = self.tip()
transaction.add(self.datafile, end)
transaction.add(self.indexfile, r * struct.calcsize(indexformat))
dfh = self.opener(self.datafile, "a")
ifh = self.opener(self.indexfile, "a")
# loop through our set of deltas
chain = None
for chunk in revs:
node, p1, p2, cs = struct.unpack("20s20s20s20s", chunk[:80])
link = linkmapper(cs)
if node in self.nodemap:
# this can happen if two branches make the same change
if unique:
raise "already have %s" % hex(node[:4])
chain = node
continue
delta = chunk[80:]
if not chain:
# retrieve the parent revision of the delta chain
chain = p1
if not chain in self.nodemap:
raise "unknown base %s" % short(chain[:4])
# full versions are inserted when the needed deltas become
# comparable to the uncompressed text or when the previous
# version is not the one we have a delta against. We use
# the size of the previous full rev as a proxy for the
# current size.
if chain == prev:
cdelta = compress(delta)
if chain != prev or (end - start + len(cdelta)) > measure * 2:
# flush our writes here so we can read it in revision
dfh.flush()
ifh.flush()
text = self.revision(chain)
text = self.patches(text, [delta])
chk = self.addrevision(text, transaction, link, p1, p2)
if chk != node:
raise "consistency error adding group"
measure = len(text)
else:
e = (end, len(cdelta), self.base(t), link, p1, p2, node)
self.index.append(e)
self.nodemap[node] = r
dfh.write(cdelta)
ifh.write(struct.pack(indexformat, *e))
t, r, chain, prev = r, r + 1, node, node
start = self.start(self.base(t))
end = self.end(t)
dfh.close()
ifh.close()
return node