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#!/usr/bin/python
"""This tool reads a Debian package from stdin and emits a yaml stream on
stdout. It does not access a database. Therefore it can be run in parallel and
on multiple machines. The generated yaml contains multiple documents. The first
document contains package metadata. Then a document is emitted for each file.
And finally a document consisting of the string "commit" is emitted."""
import hashlib
import optparse
import sys
import tarfile
import zlib
import yaml
from dedup.debpkg import DebExtractor, process_control, get_tar_hashes
from dedup.hashing import DecompressedHash, SuppressingHash, HashedStream, \
HashBlacklistContent
from dedup.compression import GzipDecompressor, decompress
from dedup.image import GIFHash, PNGHash
boring_content = set(("", "\n"))
def sha512_nontrivial():
return HashBlacklistContent(hashlib.sha512(), boring_content)
def gziphash():
hashobj = DecompressedHash(GzipDecompressor(), hashlib.sha512())
hashobj = SuppressingHash(hashobj, (ValueError, zlib.error))
hashobj.name = "gzip_sha512"
return HashBlacklistContent(hashobj, boring_content)
def pnghash():
hashobj = PNGHash(hashlib.sha512())
hashobj = SuppressingHash(hashobj, (ValueError,))
hashobj.name = "png_sha512"
return hashobj
def gifhash():
hashobj = GIFHash(hashlib.sha512())
hashobj = SuppressingHash(hashobj, (ValueError,))
hashobj.name = "gif_sha512"
return hashobj
def decompress_tar(filelike, extension):
filelike = decompress(filelike, extension.decode("ascii"))
return tarfile.open(fileobj=filelike, mode="r|")
class ProcessingFinished(Exception):
pass
class ImportpkgExtractor(DebExtractor):
hash_functions = [sha512_nontrivial, gziphash, pnghash, gifhash]
def __init__(self, callback):
self.state = "start"
self.callback = callback
def handle_ar_member(self, name, filelike):
if name.startswith(b"control.tar"):
if self.state != "start":
raise ValueError("unexpected control.tar")
self.state = "control"
tf = decompress_tar(filelike, name[11:])
for elem in tf:
if elem.name not in ("./control", "control"):
continue
if self.state != "control":
raise ValueError("duplicate control file")
self.state = "control_file"
self.callback(process_control(tf.extractfile(elem).read()))
break
elif name.startswith(b"data.tar"):
if self.state != "control_file":
raise ValueError("missing control file")
self.state = "data"
tf = decompress_tar(filelike, name[8:])
for name, size, hashes in get_tar_hashes(tf, self.hash_functions):
try:
name = name.decode("utf8")
except UnicodeDecodeError:
print("warning: skipping filename with encoding error")
continue # skip files with non-utf8 encoding for now
self.callback(dict(name=name, size=size, hashes=hashes))
raise ProcessingFinished()
def handle_ar_end(self):
if self.state != "data":
raise ValueError("data.tar not found")
def main():
parser = optparse.OptionParser()
parser.add_option("-H", "--hash", action="store",
help="verify that stdin hash given sha256 hash")
options, args = parser.parse_args()
try:
stdin = sys.stdin.buffer
except AttributeError: # python2
stdin = sys.stdin
dumper = yaml.SafeDumper(sys.stdout)
dumper.open()
if options.hash:
stdin = HashedStream(stdin, hashlib.sha256())
try:
ImportpkgExtractor(dumper.represent).process(stdin)
except ProcessingFinished:
pass
else:
raise RuntimeError("unexpected termination of extractor")
if options.hash:
stdin.validate(options.hash)
dumper.represent("commit")
dumper.close()
if __name__ == "__main__":
main()
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