Quelle MozZipFile.py Sprache: Python

# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

import os
import time
import zipfile

import six
from filelock import SoftFileLock

class ZipFile(zipfile.ZipFile):
    """Class with methods to open, read, write, close, list zip files.

    Subclassing zipfile.ZipFile to allow for overwriting of existing
    entries, though only for writestr, not for write.
    """

    def __init__(self, file, mode="r", compression=zipfile.ZIP_STORED, lock=False):
        if lock:
            assert isinstance(file, six.text_type)
            self.lockfile = SoftFileLock(file + ".lck")
            self.lockfile.acquire()
        else:
            self.lockfile = None

        if mode == "a" and lock:
            # appending to a file which doesn't exist fails, but we can't check
            # existence util we hold the lock
            if (not os.path.isfile(file)) or os.path.getsize(file) == 0:
                mode = "w"

        zipfile.ZipFile.__init__(self, file, mode, compression)
        self._remove = []
        self.end = self.fp.tell()
        self.debug = 0

    def writestr(self, zinfo_or_arcname, bytes):
        """Write contents into the archive.

        The contents is the argument 'bytes',  'zinfo_or_arcname' is either
        a ZipInfo instance or the name of the file in the archive.
        This method is overloaded to allow overwriting existing entries.
        """
        if not isinstance(zinfo_or_arcname, zipfile.ZipInfo):
            zinfo = zipfile.ZipInfo(
                filename=zinfo_or_arcname, date_time=time.localtime(time.time())
            )
            zinfo.compress_type = self.compression
            # Add some standard UNIX file access permissions (-rw-r--r--).
            zinfo.external_attr = (0x81A4 & 0xFFFF) << 16
        else:
            zinfo = zinfo_or_arcname

        # Now to the point why we overwrote this in the first place,
        # remember the entry numbers if we already had this entry.
        # Optimizations:
        # If the entry to overwrite is the last one, just reuse that.
        # If we store uncompressed and the new content has the same size
        # as the old, reuse the existing entry.

        doSeek = False  # store if we need to seek to the eof after overwriting
        if zinfo.filename in self.NameToInfo:
            # Find the last ZipInfo with our name.
            # Last, because that's catching multiple overwrites
            i = len(self.filelist)
            while i > 0:
                i -= 1
                if self.filelist[i].filename == zinfo.filename:
                    break
            zi = self.filelist[i]
            if (
                zinfo.compress_type == zipfile.ZIP_STORED
                and zi.compress_size == len(bytes)
            ) or (i + 1) == len(self.filelist):
                # make sure we're allowed to write, otherwise done by writestr below
                self._writecheck(zi)
                # overwrite existing entry
                self.fp.seek(zi.header_offset)
                if (i + 1) == len(self.filelist):
                    # this is the last item in the file, just truncate
                    self.fp.truncate()
                else:
                    # we need to move to the end of the file afterwards again
                    doSeek = True
                # unhook the current zipinfo, the writestr of our superclass
                # will add a new one
                self.filelist.pop(i)
                self.NameToInfo.pop(zinfo.filename)
            else:
                # Couldn't optimize, sadly, just remember the old entry for removal
                self._remove.append(self.filelist.pop(i))
        zipfile.ZipFile.writestr(self, zinfo, bytes)
        self.filelist.sort(key=lambda l: l.header_offset)
        if doSeek:
            self.fp.seek(self.end)
        self.end = self.fp.tell()

    def close(self):
        """Close the file, and for mode "w" and "a" write the ending
        records.

        Overwritten to compact overwritten entries.
        """
        if not self._remove:
            # we don't have anything special to do, let's just call base
            r = zipfile.ZipFile.close(self)
            if self.lockfile is not None:
                self.lockfile.release()
                self.lockfile = None
            return r

        if self.fp.mode != "r+b":
            # adjust file mode if we originally just wrote, now we rewrite
            self.fp.close()
            self.fp = open(self.filename, "r+b")
        all = map(lambda zi: (zi, True), self.filelist) + map(
            lambda zi: (zi, False), self._remove
        )
        all.sort(key=lambda l: l[0].header_offset)
        # empty _remove for multiple closes
        self._remove = []

        lengths = [
            all[i + 1][0].header_offset - all[i][0].header_offset
            for i in xrange(len(all) - 1)
        ]
        lengths.append(self.end - all[-1][0].header_offset)
        to_pos = 0
        for (zi, keep), length in zip(all, lengths):
            if not keep:
                continue
            oldoff = zi.header_offset
            # python <= 2.4 has file_offset
            if hasattr(zi, "file_offset"):
                zi.file_offset = zi.file_offset + to_pos - oldoff
            zi.header_offset = to_pos
            self.fp.seek(oldoff)
            content = self.fp.read(length)
            self.fp.seek(to_pos)
            self.fp.write(content)
            to_pos += length
        self.fp.truncate()
        zipfile.ZipFile.close(self)
        if self.lockfile is not None:
            self.lockfile.release()
            self.lockfile = None

quality82%

¤ Dauer der Verarbeitung: 0.1 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.