platform_build/tools/releasetools/blockimgdiff.py

879 lines
29 KiB
Python

# Copyright (C) 2014 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import print_function
from collections import deque, OrderedDict
from hashlib import sha1
import heapq
import itertools
import multiprocessing
import os
import re
import subprocess
import threading
import tempfile
from rangelib import RangeSet
__all__ = ["EmptyImage", "DataImage", "BlockImageDiff"]
def compute_patch(src, tgt, imgdiff=False):
srcfd, srcfile = tempfile.mkstemp(prefix="src-")
tgtfd, tgtfile = tempfile.mkstemp(prefix="tgt-")
patchfd, patchfile = tempfile.mkstemp(prefix="patch-")
os.close(patchfd)
try:
with os.fdopen(srcfd, "wb") as f_src:
for p in src:
f_src.write(p)
with os.fdopen(tgtfd, "wb") as f_tgt:
for p in tgt:
f_tgt.write(p)
try:
os.unlink(patchfile)
except OSError:
pass
if imgdiff:
p = subprocess.call(["imgdiff", "-z", srcfile, tgtfile, patchfile],
stdout=open("/dev/null", "a"),
stderr=subprocess.STDOUT)
else:
p = subprocess.call(["bsdiff", srcfile, tgtfile, patchfile])
if p:
raise ValueError("diff failed: " + str(p))
with open(patchfile, "rb") as f:
return f.read()
finally:
try:
os.unlink(srcfile)
os.unlink(tgtfile)
os.unlink(patchfile)
except OSError:
pass
class Image(object):
def ReadRangeSet(self, ranges):
raise NotImplementedError
def TotalSha1(self):
raise NotImplementedError
class EmptyImage(Image):
"""A zero-length image."""
blocksize = 4096
care_map = RangeSet()
total_blocks = 0
file_map = {}
def ReadRangeSet(self, ranges):
return ()
def TotalSha1(self):
return sha1().hexdigest()
class DataImage(Image):
"""An image wrapped around a single string of data."""
def __init__(self, data, trim=False, pad=False):
self.data = data
self.blocksize = 4096
assert not (trim and pad)
partial = len(self.data) % self.blocksize
if partial > 0:
if trim:
self.data = self.data[:-partial]
elif pad:
self.data += '\0' * (self.blocksize - partial)
else:
raise ValueError(("data for DataImage must be multiple of %d bytes "
"unless trim or pad is specified") %
(self.blocksize,))
assert len(self.data) % self.blocksize == 0
self.total_blocks = len(self.data) / self.blocksize
self.care_map = RangeSet(data=(0, self.total_blocks))
zero_blocks = []
nonzero_blocks = []
reference = '\0' * self.blocksize
for i in range(self.total_blocks):
d = self.data[i*self.blocksize : (i+1)*self.blocksize]
if d == reference:
zero_blocks.append(i)
zero_blocks.append(i+1)
else:
nonzero_blocks.append(i)
nonzero_blocks.append(i+1)
self.file_map = {"__ZERO": RangeSet(zero_blocks),
"__NONZERO": RangeSet(nonzero_blocks)}
def ReadRangeSet(self, ranges):
return [self.data[s*self.blocksize:e*self.blocksize] for (s, e) in ranges]
def TotalSha1(self):
return sha1(self.data).hexdigest()
class Transfer(object):
def __init__(self, tgt_name, src_name, tgt_ranges, src_ranges, style, by_id):
self.tgt_name = tgt_name
self.src_name = src_name
self.tgt_ranges = tgt_ranges
self.src_ranges = src_ranges
self.style = style
self.intact = (getattr(tgt_ranges, "monotonic", False) and
getattr(src_ranges, "monotonic", False))
# We use OrderedDict rather than dict so that the output is repeatable;
# otherwise it would depend on the hash values of the Transfer objects.
self.goes_before = OrderedDict()
self.goes_after = OrderedDict()
self.stash_before = []
self.use_stash = []
self.id = len(by_id)
by_id.append(self)
def NetStashChange(self):
return (sum(sr.size() for (_, sr) in self.stash_before) -
sum(sr.size() for (_, sr) in self.use_stash))
def __str__(self):
return (str(self.id) + ": <" + str(self.src_ranges) + " " + self.style +
" to " + str(self.tgt_ranges) + ">")
# BlockImageDiff works on two image objects. An image object is
# anything that provides the following attributes:
#
# blocksize: the size in bytes of a block, currently must be 4096.
#
# total_blocks: the total size of the partition/image, in blocks.
#
# care_map: a RangeSet containing which blocks (in the range [0,
# total_blocks) we actually care about; i.e. which blocks contain
# data.
#
# file_map: a dict that partitions the blocks contained in care_map
# into smaller domains that are useful for doing diffs on.
# (Typically a domain is a file, and the key in file_map is the
# pathname.)
#
# ReadRangeSet(): a function that takes a RangeSet and returns the
# data contained in the image blocks of that RangeSet. The data
# is returned as a list or tuple of strings; concatenating the
# elements together should produce the requested data.
# Implementations are free to break up the data into list/tuple
# elements in any way that is convenient.
#
# TotalSha1(): a function that returns (as a hex string) the SHA-1
# hash of all the data in the image (ie, all the blocks in the
# care_map)
#
# When creating a BlockImageDiff, the src image may be None, in which
# case the list of transfers produced will never read from the
# original image.
class BlockImageDiff(object):
def __init__(self, tgt, src=None, threads=None, version=3):
if threads is None:
threads = multiprocessing.cpu_count() // 2
if threads == 0:
threads = 1
self.threads = threads
self.version = version
self.transfers = []
self.src_basenames = {}
self.src_numpatterns = {}
assert version in (1, 2, 3)
self.tgt = tgt
if src is None:
src = EmptyImage()
self.src = src
# The updater code that installs the patch always uses 4k blocks.
assert tgt.blocksize == 4096
assert src.blocksize == 4096
# The range sets in each filemap should comprise a partition of
# the care map.
self.AssertPartition(src.care_map, src.file_map.values())
self.AssertPartition(tgt.care_map, tgt.file_map.values())
def Compute(self, prefix):
# When looking for a source file to use as the diff input for a
# target file, we try:
# 1) an exact path match if available, otherwise
# 2) a exact basename match if available, otherwise
# 3) a basename match after all runs of digits are replaced by
# "#" if available, otherwise
# 4) we have no source for this target.
self.AbbreviateSourceNames()
self.FindTransfers()
# Find the ordering dependencies among transfers (this is O(n^2)
# in the number of transfers).
self.GenerateDigraph()
# Find a sequence of transfers that satisfies as many ordering
# dependencies as possible (heuristically).
self.FindVertexSequence()
# Fix up the ordering dependencies that the sequence didn't
# satisfy.
if self.version == 1:
self.RemoveBackwardEdges()
else:
self.ReverseBackwardEdges()
self.ImproveVertexSequence()
# Double-check our work.
self.AssertSequenceGood()
self.ComputePatches(prefix)
self.WriteTransfers(prefix)
def HashBlocks(self, source, ranges): # pylint: disable=no-self-use
data = source.ReadRangeSet(ranges)
ctx = sha1()
for p in data:
ctx.update(p)
return ctx.hexdigest()
def WriteTransfers(self, prefix):
out = []
total = 0
performs_read = False
stashes = {}
stashed_blocks = 0
max_stashed_blocks = 0
free_stash_ids = []
next_stash_id = 0
for xf in self.transfers:
if self.version < 2:
assert not xf.stash_before
assert not xf.use_stash
for s, sr in xf.stash_before:
assert s not in stashes
if free_stash_ids:
sid = heapq.heappop(free_stash_ids)
else:
sid = next_stash_id
next_stash_id += 1
stashes[s] = sid
stashed_blocks += sr.size()
if self.version == 2:
out.append("stash %d %s\n" % (sid, sr.to_string_raw()))
else:
sh = self.HashBlocks(self.src, sr)
if sh in stashes:
stashes[sh] += 1
else:
stashes[sh] = 1
out.append("stash %s %s\n" % (sh, sr.to_string_raw()))
if stashed_blocks > max_stashed_blocks:
max_stashed_blocks = stashed_blocks
free_string = []
if self.version == 1:
src_str = xf.src_ranges.to_string_raw()
elif self.version >= 2:
# <# blocks> <src ranges>
# OR
# <# blocks> <src ranges> <src locs> <stash refs...>
# OR
# <# blocks> - <stash refs...>
size = xf.src_ranges.size()
src_str = [str(size)]
unstashed_src_ranges = xf.src_ranges
mapped_stashes = []
for s, sr in xf.use_stash:
sid = stashes.pop(s)
stashed_blocks -= sr.size()
unstashed_src_ranges = unstashed_src_ranges.subtract(sr)
sh = self.HashBlocks(self.src, sr)
sr = xf.src_ranges.map_within(sr)
mapped_stashes.append(sr)
if self.version == 2:
src_str.append("%d:%s" % (sid, sr.to_string_raw()))
else:
assert sh in stashes
src_str.append("%s:%s" % (sh, sr.to_string_raw()))
stashes[sh] -= 1
if stashes[sh] == 0:
free_string.append("free %s\n" % (sh))
stashes.pop(sh)
heapq.heappush(free_stash_ids, sid)
if unstashed_src_ranges:
src_str.insert(1, unstashed_src_ranges.to_string_raw())
if xf.use_stash:
mapped_unstashed = xf.src_ranges.map_within(unstashed_src_ranges)
src_str.insert(2, mapped_unstashed.to_string_raw())
mapped_stashes.append(mapped_unstashed)
self.AssertPartition(RangeSet(data=(0, size)), mapped_stashes)
else:
src_str.insert(1, "-")
self.AssertPartition(RangeSet(data=(0, size)), mapped_stashes)
src_str = " ".join(src_str)
# all versions:
# zero <rangeset>
# new <rangeset>
# erase <rangeset>
#
# version 1:
# bsdiff patchstart patchlen <src rangeset> <tgt rangeset>
# imgdiff patchstart patchlen <src rangeset> <tgt rangeset>
# move <src rangeset> <tgt rangeset>
#
# version 2:
# bsdiff patchstart patchlen <tgt rangeset> <src_str>
# imgdiff patchstart patchlen <tgt rangeset> <src_str>
# move <tgt rangeset> <src_str>
#
# version 3:
# bsdiff patchstart patchlen srchash tgthash <tgt rangeset> <src_str>
# imgdiff patchstart patchlen srchash tgthash <tgt rangeset> <src_str>
# move hash <tgt rangeset> <src_str>
tgt_size = xf.tgt_ranges.size()
if xf.style == "new":
assert xf.tgt_ranges
out.append("%s %s\n" % (xf.style, xf.tgt_ranges.to_string_raw()))
total += tgt_size
elif xf.style == "move":
performs_read = True
assert xf.tgt_ranges
assert xf.src_ranges.size() == tgt_size
if xf.src_ranges != xf.tgt_ranges:
if self.version == 1:
out.append("%s %s %s\n" % (
xf.style,
xf.src_ranges.to_string_raw(), xf.tgt_ranges.to_string_raw()))
elif self.version == 2:
out.append("%s %s %s\n" % (
xf.style,
xf.tgt_ranges.to_string_raw(), src_str))
elif self.version >= 3:
out.append("%s %s %s %s\n" % (
xf.style,
self.HashBlocks(self.tgt, xf.tgt_ranges),
xf.tgt_ranges.to_string_raw(), src_str))
total += tgt_size
elif xf.style in ("bsdiff", "imgdiff"):
performs_read = True
assert xf.tgt_ranges
assert xf.src_ranges
if self.version == 1:
out.append("%s %d %d %s %s\n" % (
xf.style, xf.patch_start, xf.patch_len,
xf.src_ranges.to_string_raw(), xf.tgt_ranges.to_string_raw()))
elif self.version == 2:
out.append("%s %d %d %s %s\n" % (
xf.style, xf.patch_start, xf.patch_len,
xf.tgt_ranges.to_string_raw(), src_str))
elif self.version >= 3:
out.append("%s %d %d %s %s %s %s\n" % (
xf.style,
xf.patch_start, xf.patch_len,
self.HashBlocks(self.src, xf.src_ranges),
self.HashBlocks(self.tgt, xf.tgt_ranges),
xf.tgt_ranges.to_string_raw(), src_str))
total += tgt_size
elif xf.style == "zero":
assert xf.tgt_ranges
to_zero = xf.tgt_ranges.subtract(xf.src_ranges)
if to_zero:
out.append("%s %s\n" % (xf.style, to_zero.to_string_raw()))
total += to_zero.size()
else:
raise ValueError("unknown transfer style '%s'\n" % xf.style)
if free_string:
out.append("".join(free_string))
# sanity check: abort if we're going to need more than 512 MB if
# stash space
assert max_stashed_blocks * self.tgt.blocksize < (512 << 20)
all_tgt = RangeSet(data=(0, self.tgt.total_blocks))
if performs_read:
# if some of the original data is used, then at the end we'll
# erase all the blocks on the partition that don't contain data
# in the new image.
new_dontcare = all_tgt.subtract(self.tgt.care_map)
if new_dontcare:
out.append("erase %s\n" % (new_dontcare.to_string_raw(),))
else:
# if nothing is read (ie, this is a full OTA), then we can start
# by erasing the entire partition.
out.insert(0, "erase %s\n" % (all_tgt.to_string_raw(),))
out.insert(0, "%d\n" % (self.version,)) # format version number
out.insert(1, str(total) + "\n")
if self.version >= 2:
# version 2 only: after the total block count, we give the number
# of stash slots needed, and the maximum size needed (in blocks)
out.insert(2, str(next_stash_id) + "\n")
out.insert(3, str(max_stashed_blocks) + "\n")
with open(prefix + ".transfer.list", "wb") as f:
for i in out:
f.write(i)
if self.version >= 2:
print("max stashed blocks: %d (%d bytes)\n" % (
max_stashed_blocks, max_stashed_blocks * self.tgt.blocksize))
def ComputePatches(self, prefix):
print("Reticulating splines...")
diff_q = []
patch_num = 0
with open(prefix + ".new.dat", "wb") as new_f:
for xf in self.transfers:
if xf.style == "zero":
pass
elif xf.style == "new":
for piece in self.tgt.ReadRangeSet(xf.tgt_ranges):
new_f.write(piece)
elif xf.style == "diff":
src = self.src.ReadRangeSet(xf.src_ranges)
tgt = self.tgt.ReadRangeSet(xf.tgt_ranges)
# We can't compare src and tgt directly because they may have
# the same content but be broken up into blocks differently, eg:
#
# ["he", "llo"] vs ["h", "ello"]
#
# We want those to compare equal, ideally without having to
# actually concatenate the strings (these may be tens of
# megabytes).
src_sha1 = sha1()
for p in src:
src_sha1.update(p)
tgt_sha1 = sha1()
tgt_size = 0
for p in tgt:
tgt_sha1.update(p)
tgt_size += len(p)
if src_sha1.digest() == tgt_sha1.digest():
# These are identical; we don't need to generate a patch,
# just issue copy commands on the device.
xf.style = "move"
else:
# For files in zip format (eg, APKs, JARs, etc.) we would
# like to use imgdiff -z if possible (because it usually
# produces significantly smaller patches than bsdiff).
# This is permissible if:
#
# - the source and target files are monotonic (ie, the
# data is stored with blocks in increasing order), and
# - we haven't removed any blocks from the source set.
#
# If these conditions are satisfied then appending all the
# blocks in the set together in order will produce a valid
# zip file (plus possibly extra zeros in the last block),
# which is what imgdiff needs to operate. (imgdiff is
# fine with extra zeros at the end of the file.)
imgdiff = (xf.intact and
xf.tgt_name.split(".")[-1].lower()
in ("apk", "jar", "zip"))
xf.style = "imgdiff" if imgdiff else "bsdiff"
diff_q.append((tgt_size, src, tgt, xf, patch_num))
patch_num += 1
else:
assert False, "unknown style " + xf.style
if diff_q:
if self.threads > 1:
print("Computing patches (using %d threads)..." % (self.threads,))
else:
print("Computing patches...")
diff_q.sort()
patches = [None] * patch_num
# TODO: Rewrite with multiprocessing.ThreadPool?
lock = threading.Lock()
def diff_worker():
while True:
with lock:
if not diff_q:
return
tgt_size, src, tgt, xf, patchnum = diff_q.pop()
patch = compute_patch(src, tgt, imgdiff=(xf.style == "imgdiff"))
size = len(patch)
with lock:
patches[patchnum] = (patch, xf)
print("%10d %10d (%6.2f%%) %7s %s" % (
size, tgt_size, size * 100.0 / tgt_size, xf.style,
xf.tgt_name if xf.tgt_name == xf.src_name else (
xf.tgt_name + " (from " + xf.src_name + ")")))
threads = [threading.Thread(target=diff_worker)
for _ in range(self.threads)]
for th in threads:
th.start()
while threads:
threads.pop().join()
else:
patches = []
p = 0
with open(prefix + ".patch.dat", "wb") as patch_f:
for patch, xf in patches:
xf.patch_start = p
xf.patch_len = len(patch)
patch_f.write(patch)
p += len(patch)
def AssertSequenceGood(self):
# Simulate the sequences of transfers we will output, and check that:
# - we never read a block after writing it, and
# - we write every block we care about exactly once.
# Start with no blocks having been touched yet.
touched = RangeSet()
# Imagine processing the transfers in order.
for xf in self.transfers:
# Check that the input blocks for this transfer haven't yet been touched.
x = xf.src_ranges
if self.version >= 2:
for _, sr in xf.use_stash:
x = x.subtract(sr)
assert not touched.overlaps(x)
# Check that the output blocks for this transfer haven't yet been touched.
assert not touched.overlaps(xf.tgt_ranges)
# Touch all the blocks written by this transfer.
touched = touched.union(xf.tgt_ranges)
# Check that we've written every target block.
assert touched == self.tgt.care_map
def ImproveVertexSequence(self):
print("Improving vertex order...")
# At this point our digraph is acyclic; we reversed any edges that
# were backwards in the heuristically-generated sequence. The
# previously-generated order is still acceptable, but we hope to
# find a better order that needs less memory for stashed data.
# Now we do a topological sort to generate a new vertex order,
# using a greedy algorithm to choose which vertex goes next
# whenever we have a choice.
# Make a copy of the edge set; this copy will get destroyed by the
# algorithm.
for xf in self.transfers:
xf.incoming = xf.goes_after.copy()
xf.outgoing = xf.goes_before.copy()
L = [] # the new vertex order
# S is the set of sources in the remaining graph; we always choose
# the one that leaves the least amount of stashed data after it's
# executed.
S = [(u.NetStashChange(), u.order, u) for u in self.transfers
if not u.incoming]
heapq.heapify(S)
while S:
_, _, xf = heapq.heappop(S)
L.append(xf)
for u in xf.outgoing:
del u.incoming[xf]
if not u.incoming:
heapq.heappush(S, (u.NetStashChange(), u.order, u))
# if this fails then our graph had a cycle.
assert len(L) == len(self.transfers)
self.transfers = L
for i, xf in enumerate(L):
xf.order = i
def RemoveBackwardEdges(self):
print("Removing backward edges...")
in_order = 0
out_of_order = 0
lost_source = 0
for xf in self.transfers:
lost = 0
size = xf.src_ranges.size()
for u in xf.goes_before:
# xf should go before u
if xf.order < u.order:
# it does, hurray!
in_order += 1
else:
# it doesn't, boo. trim the blocks that u writes from xf's
# source, so that xf can go after u.
out_of_order += 1
assert xf.src_ranges.overlaps(u.tgt_ranges)
xf.src_ranges = xf.src_ranges.subtract(u.tgt_ranges)
xf.intact = False
if xf.style == "diff" and not xf.src_ranges:
# nothing left to diff from; treat as new data
xf.style = "new"
lost = size - xf.src_ranges.size()
lost_source += lost
print((" %d/%d dependencies (%.2f%%) were violated; "
"%d source blocks removed.") %
(out_of_order, in_order + out_of_order,
(out_of_order * 100.0 / (in_order + out_of_order))
if (in_order + out_of_order) else 0.0,
lost_source))
def ReverseBackwardEdges(self):
print("Reversing backward edges...")
in_order = 0
out_of_order = 0
stashes = 0
stash_size = 0
for xf in self.transfers:
for u in xf.goes_before.copy():
# xf should go before u
if xf.order < u.order:
# it does, hurray!
in_order += 1
else:
# it doesn't, boo. modify u to stash the blocks that it
# writes that xf wants to read, and then require u to go
# before xf.
out_of_order += 1
overlap = xf.src_ranges.intersect(u.tgt_ranges)
assert overlap
u.stash_before.append((stashes, overlap))
xf.use_stash.append((stashes, overlap))
stashes += 1
stash_size += overlap.size()
# reverse the edge direction; now xf must go after u
del xf.goes_before[u]
del u.goes_after[xf]
xf.goes_after[u] = None # value doesn't matter
u.goes_before[xf] = None
print((" %d/%d dependencies (%.2f%%) were violated; "
"%d source blocks stashed.") %
(out_of_order, in_order + out_of_order,
(out_of_order * 100.0 / (in_order + out_of_order))
if (in_order + out_of_order) else 0.0,
stash_size))
def FindVertexSequence(self):
print("Finding vertex sequence...")
# This is based on "A Fast & Effective Heuristic for the Feedback
# Arc Set Problem" by P. Eades, X. Lin, and W.F. Smyth. Think of
# it as starting with the digraph G and moving all the vertices to
# be on a horizontal line in some order, trying to minimize the
# number of edges that end up pointing to the left. Left-pointing
# edges will get removed to turn the digraph into a DAG. In this
# case each edge has a weight which is the number of source blocks
# we'll lose if that edge is removed; we try to minimize the total
# weight rather than just the number of edges.
# Make a copy of the edge set; this copy will get destroyed by the
# algorithm.
for xf in self.transfers:
xf.incoming = xf.goes_after.copy()
xf.outgoing = xf.goes_before.copy()
# We use an OrderedDict instead of just a set so that the output
# is repeatable; otherwise it would depend on the hash values of
# the transfer objects.
G = OrderedDict()
for xf in self.transfers:
G[xf] = None
s1 = deque() # the left side of the sequence, built from left to right
s2 = deque() # the right side of the sequence, built from right to left
while G:
# Put all sinks at the end of the sequence.
while True:
sinks = [u for u in G if not u.outgoing]
if not sinks:
break
for u in sinks:
s2.appendleft(u)
del G[u]
for iu in u.incoming:
del iu.outgoing[u]
# Put all the sources at the beginning of the sequence.
while True:
sources = [u for u in G if not u.incoming]
if not sources:
break
for u in sources:
s1.append(u)
del G[u]
for iu in u.outgoing:
del iu.incoming[u]
if not G:
break
# Find the "best" vertex to put next. "Best" is the one that
# maximizes the net difference in source blocks saved we get by
# pretending it's a source rather than a sink.
max_d = None
best_u = None
for u in G:
d = sum(u.outgoing.values()) - sum(u.incoming.values())
if best_u is None or d > max_d:
max_d = d
best_u = u
u = best_u
s1.append(u)
del G[u]
for iu in u.outgoing:
del iu.incoming[u]
for iu in u.incoming:
del iu.outgoing[u]
# Now record the sequence in the 'order' field of each transfer,
# and by rearranging self.transfers to be in the chosen sequence.
new_transfers = []
for x in itertools.chain(s1, s2):
x.order = len(new_transfers)
new_transfers.append(x)
del x.incoming
del x.outgoing
self.transfers = new_transfers
def GenerateDigraph(self):
print("Generating digraph...")
for a in self.transfers:
for b in self.transfers:
if a is b:
continue
# If the blocks written by A are read by B, then B needs to go before A.
i = a.tgt_ranges.intersect(b.src_ranges)
if i:
if b.src_name == "__ZERO":
# the cost of removing source blocks for the __ZERO domain
# is (nearly) zero.
size = 0
else:
size = i.size()
b.goes_before[a] = size
a.goes_after[b] = size
def FindTransfers(self):
empty = RangeSet()
for tgt_fn, tgt_ranges in self.tgt.file_map.items():
if tgt_fn == "__ZERO":
# the special "__ZERO" domain is all the blocks not contained
# in any file and that are filled with zeros. We have a
# special transfer style for zero blocks.
src_ranges = self.src.file_map.get("__ZERO", empty)
Transfer(tgt_fn, "__ZERO", tgt_ranges, src_ranges,
"zero", self.transfers)
continue
elif tgt_fn in self.src.file_map:
# Look for an exact pathname match in the source.
Transfer(tgt_fn, tgt_fn, tgt_ranges, self.src.file_map[tgt_fn],
"diff", self.transfers)
continue
b = os.path.basename(tgt_fn)
if b in self.src_basenames:
# Look for an exact basename match in the source.
src_fn = self.src_basenames[b]
Transfer(tgt_fn, src_fn, tgt_ranges, self.src.file_map[src_fn],
"diff", self.transfers)
continue
b = re.sub("[0-9]+", "#", b)
if b in self.src_numpatterns:
# Look for a 'number pattern' match (a basename match after
# all runs of digits are replaced by "#"). (This is useful
# for .so files that contain version numbers in the filename
# that get bumped.)
src_fn = self.src_numpatterns[b]
Transfer(tgt_fn, src_fn, tgt_ranges, self.src.file_map[src_fn],
"diff", self.transfers)
continue
Transfer(tgt_fn, None, tgt_ranges, empty, "new", self.transfers)
def AbbreviateSourceNames(self):
for k in self.src.file_map.keys():
b = os.path.basename(k)
self.src_basenames[b] = k
b = re.sub("[0-9]+", "#", b)
self.src_numpatterns[b] = k
@staticmethod
def AssertPartition(total, seq):
"""Assert that all the RangeSets in 'seq' form a partition of the
'total' RangeSet (ie, they are nonintersecting and their union
equals 'total')."""
so_far = RangeSet()
for i in seq:
assert not so_far.overlaps(i)
so_far = so_far.union(i)
assert so_far == total