Patch #1121142: Implement ZipFile.open.
diff --git a/Lib/zipfile.py b/Lib/zipfile.py
index 6e59242..8ac9cac 100644
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -355,6 +355,200 @@
self._UpdateKeys(c)
return c
+class ZipExtFile:
+ """File-like object for reading an archive member.
+ Is returned by ZipFile.open().
+ """
+
+ def __init__(self, fileobj, zipinfo, decrypt=None):
+ self.fileobj = fileobj
+ self.decrypter = decrypt
+ self.bytes_read = 0L
+ self.rawbuffer = ''
+ self.readbuffer = ''
+ self.linebuffer = ''
+ self.eof = False
+ self.univ_newlines = False
+ self.nlSeps = ("\n", )
+ self.lastdiscard = ''
+
+ self.compress_type = zipinfo.compress_type
+ self.compress_size = zipinfo.compress_size
+
+ self.closed = False
+ self.mode = "r"
+ self.name = zipinfo.filename
+
+ # read from compressed files in 64k blocks
+ self.compreadsize = 64*1024
+ if self.compress_type == ZIP_DEFLATED:
+ self.dc = zlib.decompressobj(-15)
+
+ def set_univ_newlines(self, univ_newlines):
+ self.univ_newlines = univ_newlines
+
+ # pick line separator char(s) based on universal newlines flag
+ self.nlSeps = ("\n", )
+ if self.univ_newlines:
+ self.nlSeps = ("\r\n", "\r", "\n")
+
+ def __iter__(self):
+ return self
+
+ def next(self):
+ nextline = self.readline()
+ if not nextline:
+ raise StopIteration()
+
+ return nextline
+
+ def close(self):
+ self.closed = True
+
+ def _checkfornewline(self):
+ nl, nllen = -1, -1
+ if self.linebuffer:
+ # ugly check for cases where half of an \r\n pair was
+ # read on the last pass, and the \r was discarded. In this
+ # case we just throw away the \n at the start of the buffer.
+ if (self.lastdiscard, self.linebuffer[0]) == ('\r','\n'):
+ self.linebuffer = self.linebuffer[1:]
+
+ for sep in self.nlSeps:
+ nl = self.linebuffer.find(sep)
+ if nl >= 0:
+ nllen = len(sep)
+ return nl, nllen
+
+ return nl, nllen
+
+ def readline(self, size = -1):
+ """Read a line with approx. size. If size is negative,
+ read a whole line.
+ """
+ if size < 0:
+ size = sys.maxint
+ elif size == 0:
+ return ''
+
+ # check for a newline already in buffer
+ nl, nllen = self._checkfornewline()
+
+ if nl >= 0:
+ # the next line was already in the buffer
+ nl = min(nl, size)
+ else:
+ # no line break in buffer - try to read more
+ size -= len(self.linebuffer)
+ while nl < 0 and size > 0:
+ buf = self.read(min(size, 100))
+ if not buf:
+ break
+ self.linebuffer += buf
+ size -= len(buf)
+
+ # check for a newline in buffer
+ nl, nllen = self._checkfornewline()
+
+ # we either ran out of bytes in the file, or
+ # met the specified size limit without finding a newline,
+ # so return current buffer
+ if nl < 0:
+ s = self.linebuffer
+ self.linebuffer = ''
+ return s
+
+ buf = self.linebuffer[:nl]
+ self.lastdiscard = self.linebuffer[nl:nl + nllen]
+ self.linebuffer = self.linebuffer[nl + nllen:]
+
+ # line is always returned with \n as newline char (except possibly
+ # for a final incomplete line in the file, which is handled above).
+ return buf + "\n"
+
+ def readlines(self, sizehint = -1):
+ """Return a list with all (following) lines. The sizehint parameter
+ is ignored in this implementation.
+ """
+ result = []
+ while True:
+ line = self.readline()
+ if not line: break
+ result.append(line)
+ return result
+
+ def read(self, size = None):
+ # act like file() obj and return empty string if size is 0
+ if size == 0:
+ return ''
+
+ # determine read size
+ bytesToRead = self.compress_size - self.bytes_read
+
+ # adjust read size for encrypted files since the first 12 bytes
+ # are for the encryption/password information
+ if self.decrypter is not None:
+ bytesToRead -= 12
+
+ if size is not None and size >= 0:
+ if self.compress_type == ZIP_STORED:
+ lr = len(self.readbuffer)
+ bytesToRead = min(bytesToRead, size - lr)
+ elif self.compress_type == ZIP_DEFLATED:
+ if len(self.readbuffer) > size:
+ # the user has requested fewer bytes than we've already
+ # pulled through the decompressor; don't read any more
+ bytesToRead = 0
+ else:
+ # user will use up the buffer, so read some more
+ lr = len(self.rawbuffer)
+ bytesToRead = min(bytesToRead, self.compreadsize - lr)
+
+ # avoid reading past end of file contents
+ if bytesToRead + self.bytes_read > self.compress_size:
+ bytesToRead = self.compress_size - self.bytes_read
+
+ # try to read from file (if necessary)
+ if bytesToRead > 0:
+ bytes = self.fileobj.read(bytesToRead)
+ self.bytes_read += len(bytes)
+ self.rawbuffer += bytes
+
+ # handle contents of raw buffer
+ if self.rawbuffer:
+ newdata = self.rawbuffer
+ self.rawbuffer = ''
+
+ # decrypt new data if we were given an object to handle that
+ if newdata and self.decrypter is not None:
+ newdata = ''.join(map(self.decrypter, newdata))
+
+ # decompress newly read data if necessary
+ if newdata and self.compress_type == ZIP_DEFLATED:
+ newdata = self.dc.decompress(newdata)
+ self.rawbuffer = self.dc.unconsumed_tail
+ if self.eof and len(self.rawbuffer) == 0:
+ # we're out of raw bytes (both from the file and
+ # the local buffer); flush just to make sure the
+ # decompressor is done
+ newdata += self.dc.flush()
+ # prevent decompressor from being used again
+ self.dc = None
+
+ self.readbuffer += newdata
+
+
+ # return what the user asked for
+ if size is None or len(self.readbuffer) <= size:
+ bytes = self.readbuffer
+ self.readbuffer = ''
+ else:
+ bytes = self.readbuffer[:size]
+ self.readbuffer = self.readbuffer[size:]
+
+ return bytes
+
+
class ZipFile:
""" Class with methods to open, read, write, close, list zip files.
@@ -534,73 +728,75 @@
def read(self, name, pwd=None):
"""Return file bytes (as a string) for name."""
- if self.mode not in ("r", "a"):
- raise RuntimeError, 'read() requires mode "r" or "a"'
+ return self.open(name, "r", pwd).read()
+
+ def open(self, name, mode="r", pwd=None):
+ """Return file-like object for 'name'."""
+ if mode not in ("r", "U", "rU"):
+ raise RuntimeError, 'open() requires mode "r", "U", or "rU"'
if not self.fp:
raise RuntimeError, \
"Attempt to read ZIP archive that was already closed"
- zinfo = self.getinfo(name)
- is_encrypted = zinfo.flag_bits & 0x1
- if is_encrypted:
- if not pwd:
- pwd = self.pwd
- if not pwd:
- raise RuntimeError, "File %s is encrypted, " \
- "password required for extraction" % name
- filepos = self.fp.tell()
- self.fp.seek(zinfo.header_offset, 0)
+ # Only open a new file for instances where we were not
+ # given a file object in the constructor
+ if self._filePassed:
+ zef_file = self.fp
+ else:
+ zef_file = open(self.filename, 'rb')
+
+ # Get info object for name
+ zinfo = self.getinfo(name)
+
+ filepos = zef_file.tell()
+
+ zef_file.seek(zinfo.header_offset, 0)
# Skip the file header:
- fheader = self.fp.read(30)
+ fheader = zef_file.read(30)
if fheader[0:4] != stringFileHeader:
raise BadZipfile, "Bad magic number for file header"
fheader = struct.unpack(structFileHeader, fheader)
- fname = self.fp.read(fheader[_FH_FILENAME_LENGTH])
+ fname = zef_file.read(fheader[_FH_FILENAME_LENGTH])
if fheader[_FH_EXTRA_FIELD_LENGTH]:
- self.fp.read(fheader[_FH_EXTRA_FIELD_LENGTH])
+ zef_file.read(fheader[_FH_EXTRA_FIELD_LENGTH])
if fname != zinfo.orig_filename:
raise BadZipfile, \
'File name in directory "%s" and header "%s" differ.' % (
zinfo.orig_filename, fname)
- bytes = self.fp.read(zinfo.compress_size)
- # Go with decryption
+ # check for encrypted flag & handle password
+ is_encrypted = zinfo.flag_bits & 0x1
+ zd = None
if is_encrypted:
+ if not pwd:
+ pwd = self.pwd
+ if not pwd:
+ raise RuntimeError, "File %s is encrypted, " \
+ "password required for extraction" % name
+
zd = _ZipDecrypter(pwd)
# The first 12 bytes in the cypher stream is an encryption header
# used to strengthen the algorithm. The first 11 bytes are
# completely random, while the 12th contains the MSB of the CRC,
# and is used to check the correctness of the password.
+ bytes = zef_file.read(12)
h = map(zd, bytes[0:12])
if ord(h[11]) != ((zinfo.CRC>>24)&255):
raise RuntimeError, "Bad password for file %s" % name
- bytes = "".join(map(zd, bytes[12:]))
- # Go with decompression
- self.fp.seek(filepos, 0)
- if zinfo.compress_type == ZIP_STORED:
- pass
- elif zinfo.compress_type == ZIP_DEFLATED:
- if not zlib:
- raise RuntimeError, \
- "De-compression requires the (missing) zlib module"
- # zlib compress/decompress code by Jeremy Hylton of CNRI
- dc = zlib.decompressobj(-15)
- bytes = dc.decompress(bytes)
- # need to feed in unused pad byte so that zlib won't choke
- ex = dc.decompress('Z') + dc.flush()
- if ex:
- bytes = bytes + ex
+
+ # build and return a ZipExtFile
+ if zd is None:
+ zef = ZipExtFile(zef_file, zinfo)
else:
- raise BadZipfile, \
- "Unsupported compression method %d for file %s" % \
- (zinfo.compress_type, name)
- crc = binascii.crc32(bytes)
- if crc != zinfo.CRC:
- raise BadZipfile, "Bad CRC-32 for file %s" % name
- return bytes
+ zef = ZipExtFile(zef_file, zinfo, zd)
+
+ # set universal newlines on ZipExtFile if necessary
+ if "U" in mode:
+ zef.set_univ_newlines(True)
+ return zef
def _writecheck(self, zinfo):
"""Check for errors before writing a file to the archive."""