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# Copyright 2001-2014 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# The format for a tbz2/xpak:
#
# tbz2: tar.bz2 + xpak + (xpak_offset) + "STOP"
# xpak: "XPAKPACK" + (index_len) + (data_len) + index + data + "XPAKSTOP"
# index: (pathname_len) + pathname + (data_offset) + (data_len)
# index entries are concatenated end-to-end.
# data: concatenated data chunks, end-to-end.
#
# [tarball]XPAKPACKIIIIDDDD[index][data]XPAKSTOPOOOOSTOP
#
# (integer) == encodeint(integer) ===> 4 characters (big-endian copy)
# '+' means concatenate the fields ===> All chunks are strings
__all__ = [
'addtolist', 'decodeint', 'encodeint', 'getboth',
'getindex', 'getindex_mem', 'getitem', 'listindex',
'searchindex', 'tbz2', 'xpak_mem', 'xpak', 'xpand',
'xsplit', 'xsplit_mem',
]
import array
import errno
import sys
import portage
from portage import os
from portage import shutil
from portage import normalize_path
from portage import _encodings
from portage import _unicode_decode
from portage import _unicode_encode
def addtolist(mylist, curdir):
"""(list, dir) --- Takes an array(list) and appends all files from dir down
the directory tree. Returns nothing. list is modified."""
curdir = normalize_path(_unicode_decode(curdir,
encoding=_encodings['fs'], errors='strict'))
for parent, dirs, files in os.walk(curdir):
parent = _unicode_decode(parent,
encoding=_encodings['fs'], errors='strict')
if parent != curdir:
mylist.append(parent[len(curdir) + 1:] + os.sep)
for x in dirs:
try:
_unicode_decode(x, encoding=_encodings['fs'], errors='strict')
except UnicodeDecodeError:
dirs.remove(x)
for x in files:
try:
x = _unicode_decode(x,
encoding=_encodings['fs'], errors='strict')
except UnicodeDecodeError:
continue
mylist.append(os.path.join(parent, x)[len(curdir) + 1:])
def encodeint(myint):
"""Takes a 4 byte integer and converts it into a string of 4 characters.
Returns the characters in a string."""
a = array.array('B')
a.append((myint >> 24) & 0xff)
a.append((myint >> 16) & 0xff)
a.append((myint >> 8) & 0xff)
a.append(myint & 0xff)
try:
# Python >= 3.2
return a.tobytes()
except AttributeError:
return a.tostring()
def decodeint(mystring):
"""Takes a 4 byte string and converts it into a 4 byte integer.
Returns an integer."""
if sys.hexversion < 0x3000000:
mystring = [ord(x) for x in mystring]
myint = 0
myint += mystring[3]
myint += mystring[2] << 8
myint += mystring[1] << 16
myint += mystring[0] << 24
return myint
def xpak(rootdir, outfile=None):
"""(rootdir, outfile) -- creates an xpak segment of the directory 'rootdir'
and under the name 'outfile' if it is specified. Otherwise it returns the
xpak segment."""
mylist = []
addtolist(mylist, rootdir)
mylist.sort()
mydata = {}
for x in mylist:
if x == 'CONTENTS':
# CONTENTS is generated during the merge process.
continue
x = _unicode_encode(x, encoding=_encodings['fs'], errors='strict')
with open(os.path.join(rootdir, x), 'rb') as f:
mydata[x] = f.read()
xpak_segment = xpak_mem(mydata)
if outfile:
outf = open(_unicode_encode(outfile,
encoding=_encodings['fs'], errors='strict'), 'wb')
outf.write(xpak_segment)
outf.close()
else:
return xpak_segment
def xpak_mem(mydata):
"""Create an xpack segment from a map object."""
mydata_encoded = {}
for k, v in mydata.items():
k = _unicode_encode(k,
encoding=_encodings['repo.content'], errors='backslashreplace')
v = _unicode_encode(v,
encoding=_encodings['repo.content'], errors='backslashreplace')
mydata_encoded[k] = v
mydata = mydata_encoded
del mydata_encoded
indexglob = b''
indexpos = 0
dataglob = b''
datapos = 0
for x, newglob in mydata.items():
mydatasize = len(newglob)
indexglob = indexglob + encodeint(len(x)) + x + encodeint(datapos) + encodeint(mydatasize)
indexpos = indexpos + 4 + len(x) + 4 + 4
dataglob = dataglob + newglob
datapos = datapos + mydatasize
return b'XPAKPACK' \
+ encodeint(len(indexglob)) \
+ encodeint(len(dataglob)) \
+ indexglob \
+ dataglob \
+ b'XPAKSTOP'
def xsplit(infile):
"""(infile) -- Splits the infile into two files.
'infile.index' contains the index segment.
'infile.dat' contails the data segment."""
infile = _unicode_decode(infile,
encoding=_encodings['fs'], errors='strict')
myfile = open(_unicode_encode(infile,
encoding=_encodings['fs'], errors='strict'), 'rb')
mydat = myfile.read()
myfile.close()
splits = xsplit_mem(mydat)
if not splits:
return False
myfile = open(_unicode_encode(infile + '.index',
encoding=_encodings['fs'], errors='strict'), 'wb')
myfile.write(splits[0])
myfile.close()
myfile = open(_unicode_encode(infile + '.dat',
encoding=_encodings['fs'], errors='strict'), 'wb')
myfile.write(splits[1])
myfile.close()
return True
def xsplit_mem(mydat):
if mydat[0:8] != b'XPAKPACK':
return None
if mydat[-8:] != b'XPAKSTOP':
return None
indexsize = decodeint(mydat[8:12])
return (mydat[16:indexsize + 16], mydat[indexsize + 16:-8])
def getindex(infile):
"""(infile) -- grabs the index segment from the infile and returns it."""
myfile = open(_unicode_encode(infile,
encoding=_encodings['fs'], errors='strict'), 'rb')
myheader = myfile.read(16)
if myheader[0:8] != b'XPAKPACK':
myfile.close()
return
indexsize = decodeint(myheader[8:12])
myindex = myfile.read(indexsize)
myfile.close()
return myindex
def getboth(infile):
"""(infile) -- grabs the index and data segments from the infile.
Returns an array [indexSegment, dataSegment]"""
myfile = open(_unicode_encode(infile,
encoding=_encodings['fs'], errors='strict'), 'rb')
myheader = myfile.read(16)
if myheader[0:8] != b'XPAKPACK':
myfile.close()
return
indexsize = decodeint(myheader[8:12])
datasize = decodeint(myheader[12:16])
myindex = myfile.read(indexsize)
mydata = myfile.read(datasize)
myfile.close()
return myindex, mydata
def listindex(myindex):
"""Print to the terminal the filenames listed in the indexglob passed in."""
for x in getindex_mem(myindex):
print(x)
def getindex_mem(myindex):
"""Returns the filenames listed in the indexglob passed in."""
myindexlen = len(myindex)
startpos = 0
myret = []
while ((startpos + 8) < myindexlen):
mytestlen = decodeint(myindex[startpos:startpos + 4])
myret = myret + [myindex[startpos + 4:startpos + 4 + mytestlen]]
startpos = startpos + mytestlen + 12
return myret
def searchindex(myindex, myitem):
"""(index, item) -- Finds the offset and length of the file 'item' in the
datasegment via the index 'index' provided."""
myitem = _unicode_encode(myitem,
encoding=_encodings['repo.content'], errors='backslashreplace')
mylen = len(myitem)
myindexlen = len(myindex)
startpos = 0
while ((startpos + 8) < myindexlen):
mytestlen = decodeint(myindex[startpos:startpos + 4])
if mytestlen == mylen:
if myitem == myindex[startpos + 4:startpos + 4 + mytestlen]:
#found
datapos = decodeint(myindex[startpos + 4 + mytestlen:startpos + 8 + mytestlen])
datalen = decodeint(myindex[startpos + 8 + mytestlen:startpos + 12 + mytestlen])
return datapos, datalen
startpos = startpos + mytestlen + 12
def getitem(myid, myitem):
myindex = myid[0]
mydata = myid[1]
myloc = searchindex(myindex, myitem)
if not myloc:
return None
return mydata[myloc[0]:myloc[0] + myloc[1]]
def xpand(myid, mydest):
mydest = normalize_path(mydest) + os.sep
myindex = myid[0]
mydata = myid[1]
myindexlen = len(myindex)
startpos = 0
while ((startpos + 8) < myindexlen):
namelen = decodeint(myindex[startpos:startpos + 4])
datapos = decodeint(myindex[startpos + 4 + namelen:startpos + 8 + namelen])
datalen = decodeint(myindex[startpos + 8 + namelen:startpos + 12 + namelen])
myname = myindex[startpos + 4:startpos + 4 + namelen]
myname = _unicode_decode(myname,
encoding=_encodings['repo.content'], errors='replace')
filename = os.path.join(mydest, myname.lstrip(os.sep))
filename = normalize_path(filename)
if not filename.startswith(mydest):
# myname contains invalid ../ component(s)
continue
dirname = os.path.dirname(filename)
if dirname:
if not os.path.exists(dirname):
os.makedirs(dirname)
mydat = open(_unicode_encode(filename,
encoding=_encodings['fs'], errors='strict'), 'wb')
mydat.write(mydata[datapos:datapos + datalen])
mydat.close()
startpos = startpos + namelen + 12
class tbz2(object):
def __init__(self, myfile):
self.file = myfile
self.filestat = None
self.index = b''
self.infosize = 0
self.xpaksize = 0
self.indexsize = None
self.datasize = None
self.indexpos = None
self.datapos = None
def decompose(self, datadir, cleanup=1):
"""Alias for unpackinfo() --- Complement to recompose() but optionally
deletes the destination directory. Extracts the xpak from the tbz2 into
the directory provided. Raises IOError if scan() fails.
Returns result of upackinfo()."""
if not self.scan():
raise IOError
if cleanup:
self.cleanup(datadir)
if not os.path.exists(datadir):
os.makedirs(datadir)
return self.unpackinfo(datadir)
def compose(self, datadir, cleanup=0):
"""Alias for recompose()."""
return self.recompose(datadir, cleanup)
def recompose(self, datadir, cleanup=0, break_hardlinks=True):
"""Creates an xpak segment from the datadir provided, truncates the tbz2
to the end of regular data if an xpak segment already exists, and adds
the new segment to the file with terminating info."""
xpdata = xpak(datadir)
self.recompose_mem(xpdata, break_hardlinks=break_hardlinks)
if cleanup:
self.cleanup(datadir)
def recompose_mem(self, xpdata, break_hardlinks=True):
"""
Update the xpak segment.
@param xpdata: A new xpak segment to be written, like that returned
from the xpak_mem() function.
@param break_hardlinks: If hardlinks exist, create a copy in order
to break them. This makes it safe to use hardlinks to create
cheap snapshots of the repository, which is useful for solving
race conditions on binhosts as described here:
http://code.google.com/p/chromium-os/issues/detail?id=3225.
Default is True.
"""
self.scan() # Don't care about condition... We'll rewrite the data anyway.
if break_hardlinks and self.filestat and self.filestat.st_nlink > 1:
tmp_fname = "%s.%d" % (self.file, os.getpid())
shutil.copyfile(self.file, tmp_fname)
try:
portage.util.apply_stat_permissions(self.file, self.filestat)
except portage.exception.OperationNotPermitted:
pass
os.rename(tmp_fname, self.file)
myfile = open(_unicode_encode(self.file,
encoding=_encodings['fs'], errors='strict'), 'ab+')
if not myfile:
raise IOError
myfile.seek(-self.xpaksize, 2) # 0,2 or -0,2 just mean EOF.
myfile.truncate()
myfile.write(xpdata + encodeint(len(xpdata)) + b'STOP')
myfile.flush()
myfile.close()
return 1
def cleanup(self, datadir):
datadir_split = os.path.split(datadir)
if len(datadir_split) >= 2 and len(datadir_split[1]) > 0:
# This is potentially dangerous,
# thus the above sanity check.
try:
shutil.rmtree(datadir)
except OSError as oe:
if oe.errno == errno.ENOENT:
pass
else:
raise oe
def scan(self):
"""Scans the tbz2 to locate the xpak segment and setup internal values.
This function is called by relevant functions already."""
a = None
try:
mystat = os.stat(self.file)
if self.filestat:
changed = 0
if mystat.st_size != self.filestat.st_size \
or mystat.st_mtime != self.filestat.st_mtime \
or mystat.st_ctime != self.filestat.st_ctime:
changed = True
if not changed:
return 1
self.filestat = mystat
a = open(_unicode_encode(self.file,
encoding=_encodings['fs'], errors='strict'), 'rb')
a.seek(-16, 2)
trailer = a.read()
self.infosize = 0
self.xpaksize = 0
if trailer[-4:] != b'STOP':
return 0
if trailer[0:8] != b'XPAKSTOP':
return 0
self.infosize = decodeint(trailer[8:12])
self.xpaksize = self.infosize + 8
a.seek(-(self.xpaksize), 2)
header = a.read(16)
if header[0:8] != b'XPAKPACK':
return 0
self.indexsize = decodeint(header[8:12])
self.datasize = decodeint(header[12:16])
self.indexpos = a.tell()
self.index = a.read(self.indexsize)
self.datapos = a.tell()
return 2
except SystemExit:
raise
except:
return 0
finally:
if a is not None:
a.close()
def filelist(self):
"""Return an array of each file listed in the index."""
if not self.scan():
return None
return getindex_mem(self.index)
def getfile(self, myfile, mydefault=None):
"""Finds 'myfile' in the data segment and returns it."""
if not self.scan():
return None
myresult = searchindex(self.index, myfile)
if not myresult:
return mydefault
a = open(_unicode_encode(self.file,
encoding=_encodings['fs'], errors='strict'), 'rb')
a.seek(self.datapos + myresult[0], 0)
myreturn = a.read(myresult[1])
a.close()
return myreturn
def getelements(self, myfile):
"""A split/array representation of tbz2.getfile()"""
mydat = self.getfile(myfile)
if not mydat:
return []
return mydat.split()
def unpackinfo(self, mydest):
"""Unpacks all the files from the dataSegment into 'mydest'."""
if not self.scan():
return 0
mydest = normalize_path(mydest) + os.sep
a = open(_unicode_encode(self.file,
encoding=_encodings['fs'], errors='strict'), 'rb')
if not os.path.exists(mydest):
os.makedirs(mydest)
startpos = 0
while ((startpos + 8) < self.indexsize):
namelen = decodeint(self.index[startpos:startpos + 4])
datapos = decodeint(self.index[startpos + 4 + namelen:startpos + 8 + namelen])
datalen = decodeint(self.index[startpos + 8 + namelen:startpos + 12 + namelen])
myname = self.index[startpos + 4:startpos + 4 + namelen]
myname = _unicode_decode(myname,
encoding=_encodings['repo.content'], errors='replace')
filename = os.path.join(mydest, myname.lstrip(os.sep))
filename = normalize_path(filename)
if not filename.startswith(mydest):
# myname contains invalid ../ component(s)
continue
dirname = os.path.dirname(filename)
if dirname:
if not os.path.exists(dirname):
os.makedirs(dirname)
mydat = open(_unicode_encode(filename,
encoding=_encodings['fs'], errors='strict'), 'wb')
a.seek(self.datapos + datapos)
mydat.write(a.read(datalen))
mydat.close()
startpos = startpos + namelen + 12
a.close()
return 1
def get_data(self):
"""Returns all the files from the dataSegment as a map object."""
if not self.scan():
return {}
a = open(_unicode_encode(self.file,
encoding=_encodings['fs'], errors='strict'), 'rb')
mydata = {}
startpos = 0
while ((startpos + 8) < self.indexsize):
namelen = decodeint(self.index[startpos:startpos + 4])
datapos = decodeint(self.index[startpos + 4 + namelen:startpos + 8 + namelen])
datalen = decodeint(self.index[startpos + 8 + namelen:startpos + 12 + namelen])
myname = self.index[startpos + 4:startpos + 4 + namelen]
a.seek(self.datapos + datapos)
mydata[myname] = a.read(datalen)
startpos = startpos + namelen + 12
a.close()
return mydata
def getboth(self):
"""Returns an array [indexSegment, dataSegment]"""
if not self.scan():
return None
a = open(_unicode_encode(self.file,
encoding=_encodings['fs'], errors='strict'), 'rb')
a.seek(self.datapos)
mydata = a.read(self.datasize)
a.close()
return self.index, mydata