EmbeddedPkg: Extend NvVarStoreFormattedLib LIBRARY_CLASS

[mirror_edk2.git] / AppPkg / Applications / Python / Python-2.7.2 / Demo / zlib / minigzip.py

#!/usr/bin/env python\r
# Demo program for zlib; it compresses or decompresses files, but *doesn't*\r
# delete the original.  This doesn't support all of gzip's options.\r
#\r
# The 'gzip' module in the standard library provides a more complete\r
# implementation of gzip-format files.\r
\r
import zlib, sys, os\r
\r
FTEXT, FHCRC, FEXTRA, FNAME, FCOMMENT = 1, 2, 4, 8, 16\r
\r
def write32(output, value):\r
    output.write(chr(value & 255)) ; value=value // 256\r
    output.write(chr(value & 255)) ; value=value // 256\r
    output.write(chr(value & 255)) ; value=value // 256\r
    output.write(chr(value & 255))\r
\r
def read32(input):\r
    v = ord(input.read(1))\r
    v += (ord(input.read(1)) << 8 )\r
    v += (ord(input.read(1)) << 16)\r
    v += (ord(input.read(1)) << 24)\r
    return v\r
\r
def compress (filename, input, output):\r
    output.write('\037\213\010')        # Write the header, ...\r
    output.write(chr(FNAME))            # ... flag byte ...\r
\r
    statval = os.stat(filename)           # ... modification time ...\r
    mtime = statval[8]\r
    write32(output, mtime)\r
    output.write('\002')                # ... slowest compression alg. ...\r
    output.write('\377')                # ... OS (=unknown) ...\r
    output.write(filename+'\000')       # ... original filename ...\r
\r
    crcval = zlib.crc32("")\r
    compobj = zlib.compressobj(9, zlib.DEFLATED, -zlib.MAX_WBITS,\r
                             zlib.DEF_MEM_LEVEL, 0)\r
    while True:\r
        data = input.read(1024)\r
        if data == "":\r
            break\r
        crcval = zlib.crc32(data, crcval)\r
        output.write(compobj.compress(data))\r
    output.write(compobj.flush())\r
    write32(output, crcval)             # ... the CRC ...\r
    write32(output, statval[6])         # and the file size.\r
\r
def decompress (input, output):\r
    magic = input.read(2)\r
    if magic != '\037\213':\r
        print 'Not a gzipped file'\r
        sys.exit(0)\r
    if ord(input.read(1)) != 8:\r
        print 'Unknown compression method'\r
        sys.exit(0)\r
    flag = ord(input.read(1))\r
    input.read(4+1+1)                   # Discard modification time,\r
                                        # extra flags, and OS byte.\r
    if flag & FEXTRA:\r
        # Read & discard the extra field, if present\r
        xlen = ord(input.read(1))\r
        xlen += 256*ord(input.read(1))\r
        input.read(xlen)\r
    if flag & FNAME:\r
        # Read and discard a null-terminated string containing the filename\r
        while True:\r
            s = input.read(1)\r
            if s == '\0': break\r
    if flag & FCOMMENT:\r
        # Read and discard a null-terminated string containing a comment\r
        while True:\r
            s=input.read(1)\r
            if s=='\0': break\r
    if flag & FHCRC:\r
        input.read(2)                   # Read & discard the 16-bit header CRC\r
\r
    decompobj = zlib.decompressobj(-zlib.MAX_WBITS)\r
    crcval = zlib.crc32("")\r
    length = 0\r
    while True:\r
        data=input.read(1024)\r
        if data == "":\r
            break\r
        decompdata = decompobj.decompress(data)\r
        output.write(decompdata)\r
        length += len(decompdata)\r
        crcval = zlib.crc32(decompdata, crcval)\r
\r
    decompdata = decompobj.flush()\r
    output.write(decompdata)\r
    length += len(decompdata)\r
    crcval = zlib.crc32(decompdata, crcval)\r
\r
    # We've read to the end of the file, so we have to rewind in order\r
    # to reread the 8 bytes containing the CRC and the file size.  The\r
    # decompressor is smart and knows when to stop, so feeding it\r
    # extra data is harmless.\r
    input.seek(-8, 2)\r
    crc32 = read32(input)\r
    isize = read32(input)\r
    if crc32 != crcval:\r
        print 'CRC check failed.'\r
    if isize != length:\r
        print 'Incorrect length of data produced'\r
\r
def main():\r
    if len(sys.argv)!=2:\r
        print 'Usage: minigzip.py <filename>'\r
        print '  The file will be compressed or decompressed.'\r
        sys.exit(0)\r
\r
    filename = sys.argv[1]\r
    if filename.endswith('.gz'):\r
        compressing = False\r
        outputname = filename[:-3]\r
    else:\r
        compressing = True\r
        outputname = filename + '.gz'\r
\r
    input = open(filename, 'rb')\r
    output = open(outputname, 'wb')\r
\r
    if compressing:\r
        compress(filename, input, output)\r
    else:\r
        decompress(input, output)\r
\r
    input.close()\r
    output.close()\r
\r
if __name__ == '__main__':\r
    main()\r