diff options
Diffstat (limited to 'Lib/zipfile/__init__.py')
| -rw-r--r-- | Lib/zipfile/__init__.py | 80 |
1 files changed, 62 insertions, 18 deletions
diff --git a/Lib/zipfile/__init__.py b/Lib/zipfile/__init__.py index b7840d0f945..18caeb3e04a 100644 --- a/Lib/zipfile/__init__.py +++ b/Lib/zipfile/__init__.py @@ -31,10 +31,15 @@ try: except ImportError: lzma = None +try: + from compression import zstd # We may need its compression method +except ImportError: + zstd = None + __all__ = ["BadZipFile", "BadZipfile", "error", "ZIP_STORED", "ZIP_DEFLATED", "ZIP_BZIP2", "ZIP_LZMA", - "is_zipfile", "ZipInfo", "ZipFile", "PyZipFile", "LargeZipFile", - "Path"] + "ZIP_ZSTANDARD", "is_zipfile", "ZipInfo", "ZipFile", "PyZipFile", + "LargeZipFile", "Path"] class BadZipFile(Exception): pass @@ -58,12 +63,14 @@ ZIP_STORED = 0 ZIP_DEFLATED = 8 ZIP_BZIP2 = 12 ZIP_LZMA = 14 +ZIP_ZSTANDARD = 93 # Other ZIP compression methods not supported DEFAULT_VERSION = 20 ZIP64_VERSION = 45 BZIP2_VERSION = 46 LZMA_VERSION = 63 +ZSTANDARD_VERSION = 63 # we recognize (but not necessarily support) all features up to that version MAX_EXTRACT_VERSION = 63 @@ -227,8 +234,19 @@ class _Extra(bytes): def _check_zipfile(fp): try: - if _EndRecData(fp): - return True # file has correct magic number + endrec = _EndRecData(fp) + if endrec: + if endrec[_ECD_ENTRIES_TOTAL] == 0 and endrec[_ECD_SIZE] == 0 and endrec[_ECD_OFFSET] == 0: + return True # Empty zipfiles are still zipfiles + elif endrec[_ECD_DISK_NUMBER] == endrec[_ECD_DISK_START]: + # Central directory is on the same disk + fp.seek(sum(_handle_prepended_data(endrec))) + if endrec[_ECD_SIZE] >= sizeCentralDir: + data = fp.read(sizeCentralDir) # CD is where we expect it to be + if len(data) == sizeCentralDir: + centdir = struct.unpack(structCentralDir, data) # CD is the right size + if centdir[_CD_SIGNATURE] == stringCentralDir: + return True # First central directory entry has correct magic number except OSError: pass return False @@ -251,6 +269,22 @@ def is_zipfile(filename): pass return result +def _handle_prepended_data(endrec, debug=0): + size_cd = endrec[_ECD_SIZE] # bytes in central directory + offset_cd = endrec[_ECD_OFFSET] # offset of central directory + + # "concat" is zero, unless zip was concatenated to another file + concat = endrec[_ECD_LOCATION] - size_cd - offset_cd + if endrec[_ECD_SIGNATURE] == stringEndArchive64: + # If Zip64 extension structures are present, account for them + concat -= (sizeEndCentDir64 + sizeEndCentDir64Locator) + + if debug > 2: + inferred = concat + offset_cd + print("given, inferred, offset", offset_cd, inferred, concat) + + return offset_cd, concat + def _EndRecData64(fpin, offset, endrec): """ Read the ZIP64 end-of-archive records and use that to update endrec @@ -505,6 +539,8 @@ class ZipInfo: min_version = max(BZIP2_VERSION, min_version) elif self.compress_type == ZIP_LZMA: min_version = max(LZMA_VERSION, min_version) + elif self.compress_type == ZIP_ZSTANDARD: + min_version = max(ZSTANDARD_VERSION, min_version) self.extract_version = max(min_version, self.extract_version) self.create_version = max(min_version, self.create_version) @@ -766,6 +802,7 @@ compressor_names = { 14: 'lzma', 18: 'terse', 19: 'lz77', + 93: 'zstd', 97: 'wavpack', 98: 'ppmd', } @@ -785,6 +822,10 @@ def _check_compression(compression): if not lzma: raise RuntimeError( "Compression requires the (missing) lzma module") + elif compression == ZIP_ZSTANDARD: + if not zstd: + raise RuntimeError( + "Compression requires the (missing) compression.zstd module") else: raise NotImplementedError("That compression method is not supported") @@ -801,6 +842,8 @@ def _get_compressor(compress_type, compresslevel=None): # compresslevel is ignored for ZIP_LZMA elif compress_type == ZIP_LZMA: return LZMACompressor() + elif compress_type == ZIP_ZSTANDARD: + return zstd.ZstdCompressor(level=compresslevel) else: return None @@ -815,6 +858,8 @@ def _get_decompressor(compress_type): return bz2.BZ2Decompressor() elif compress_type == ZIP_LZMA: return LZMADecompressor() + elif compress_type == ZIP_ZSTANDARD: + return zstd.ZstdDecompressor() else: descr = compressor_names.get(compress_type) if descr: @@ -1334,7 +1379,8 @@ class ZipFile: mode: The mode can be either read 'r', write 'w', exclusive create 'x', or append 'a'. compression: ZIP_STORED (no compression), ZIP_DEFLATED (requires zlib), - ZIP_BZIP2 (requires bz2) or ZIP_LZMA (requires lzma). + ZIP_BZIP2 (requires bz2), ZIP_LZMA (requires lzma), or + ZIP_ZSTANDARD (requires compression.zstd). allowZip64: if True ZipFile will create files with ZIP64 extensions when needed, otherwise it will raise an exception when this would be necessary. @@ -1343,6 +1389,9 @@ class ZipFile: When using ZIP_STORED or ZIP_LZMA this keyword has no effect. When using ZIP_DEFLATED integers 0 through 9 are accepted. When using ZIP_BZIP2 integers 1 through 9 are accepted. + When using ZIP_ZSTANDARD integers -7 though 22 are common, + see the CompressionParameter enum in compression.zstd for + details. """ @@ -1479,28 +1528,21 @@ class ZipFile: raise BadZipFile("File is not a zip file") if self.debug > 1: print(endrec) - size_cd = endrec[_ECD_SIZE] # bytes in central directory - offset_cd = endrec[_ECD_OFFSET] # offset of central directory self._comment = endrec[_ECD_COMMENT] # archive comment - # "concat" is zero, unless zip was concatenated to another file - concat = endrec[_ECD_LOCATION] - size_cd - offset_cd - if endrec[_ECD_SIGNATURE] == stringEndArchive64: - # If Zip64 extension structures are present, account for them - concat -= (sizeEndCentDir64 + sizeEndCentDir64Locator) + offset_cd, concat = _handle_prepended_data(endrec, self.debug) + + # self.start_dir: Position of start of central directory + self.start_dir = offset_cd + concat # store the offset to the beginning of data for the # .data_offset property self._data_offset = concat - if self.debug > 2: - inferred = concat + offset_cd - print("given, inferred, offset", offset_cd, inferred, concat) - # self.start_dir: Position of start of central directory - self.start_dir = offset_cd + concat if self.start_dir < 0: raise BadZipFile("Bad offset for central directory") fp.seek(self.start_dir, 0) + size_cd = endrec[_ECD_SIZE] data = fp.read(size_cd) fp = io.BytesIO(data) total = 0 @@ -2075,6 +2117,8 @@ class ZipFile: min_version = max(BZIP2_VERSION, min_version) elif zinfo.compress_type == ZIP_LZMA: min_version = max(LZMA_VERSION, min_version) + elif zinfo.compress_type == ZIP_ZSTANDARD: + min_version = max(ZSTANDARD_VERSION, min_version) extract_version = max(min_version, zinfo.extract_version) create_version = max(min_version, zinfo.create_version) @@ -2317,7 +2361,7 @@ def main(args=None): import argparse description = 'A simple command-line interface for zipfile module.' - parser = argparse.ArgumentParser(description=description) + parser = argparse.ArgumentParser(description=description, color=True) group = parser.add_mutually_exclusive_group(required=True) group.add_argument('-l', '--list', metavar='<zipfile>', help='Show listing of a zipfile') |