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Diffstat (limited to 'Build/source/utils/gzip/bits.c')
-rw-r--r-- | Build/source/utils/gzip/bits.c | 205 |
1 files changed, 0 insertions, 205 deletions
diff --git a/Build/source/utils/gzip/bits.c b/Build/source/utils/gzip/bits.c deleted file mode 100644 index 544d6da9d39..00000000000 --- a/Build/source/utils/gzip/bits.c +++ /dev/null @@ -1,205 +0,0 @@ -/* bits.c -- output variable-length bit strings - * Copyright (C) 1992-1993 Jean-loup Gailly - * This is free software; you can redistribute it and/or modify it under the - * terms of the GNU General Public License, see the file COPYING. - */ - - -/* - * PURPOSE - * - * Output variable-length bit strings. Compression can be done - * to a file or to memory. (The latter is not supported in this version.) - * - * DISCUSSION - * - * The PKZIP "deflate" file format interprets compressed file data - * as a sequence of bits. Multi-bit strings in the file may cross - * byte boundaries without restriction. - * - * The first bit of each byte is the low-order bit. - * - * The routines in this file allow a variable-length bit value to - * be output right-to-left (useful for literal values). For - * left-to-right output (useful for code strings from the tree routines), - * the bits must have been reversed first with bi_reverse(). - * - * For in-memory compression, the compressed bit stream goes directly - * into the requested output buffer. The input data is read in blocks - * by the mem_read() function. The buffer is limited to 64K on 16 bit - * machines. - * - * INTERFACE - * - * void bi_init (FILE *zipfile) - * Initialize the bit string routines. - * - * void send_bits (int value, int length) - * Write out a bit string, taking the source bits right to - * left. - * - * int bi_reverse (int value, int length) - * Reverse the bits of a bit string, taking the source bits left to - * right and emitting them right to left. - * - * void bi_windup (void) - * Write out any remaining bits in an incomplete byte. - * - * void copy_block(char *buf, unsigned len, int header) - * Copy a stored block to the zip file, storing first the length and - * its one's complement if requested. - * - */ - -#include "tailor.h" -#include "gzip.h" -#include "crypt.h" - -#ifdef DEBUG -# include <stdio.h> -#endif - -#ifdef RCSID -static char rcsid[] = "$Id: bits.c,v 0.9 1993/06/11 10:16:58 jloup Exp $"; -#endif - -/* =========================================================================== - * Local data used by the "bit string" routines. - */ - -local file_t zfile; /* output gzip file */ - -local unsigned short bi_buf; -/* Output buffer. bits are inserted starting at the bottom (least significant - * bits). - */ - -#define Buf_size (8 * 2*sizeof(char)) -/* Number of bits used within bi_buf. (bi_buf might be implemented on - * more than 16 bits on some systems.) - */ - -local int bi_valid; -/* Number of valid bits in bi_buf. All bits above the last valid bit - * are always zero. - */ - -int (*read_buf) OF((char *buf, unsigned size)); -/* Current input function. Set to mem_read for in-memory compression */ - -#ifdef DEBUG - ulg bits_sent; /* bit length of the compressed data */ -#endif - -/* =========================================================================== - * Initialize the bit string routines. - */ -void bi_init (zipfile) - file_t zipfile; /* output zip file, NO_FILE for in-memory compression */ -{ - zfile = zipfile; - bi_buf = 0; - bi_valid = 0; -#ifdef DEBUG - bits_sent = 0L; -#endif - - /* Set the defaults for file compression. They are set by memcompress - * for in-memory compression. - */ - if (zfile != NO_FILE) { - read_buf = file_read; - } -} - -/* =========================================================================== - * Send a value on a given number of bits. - * IN assertion: length <= 16 and value fits in length bits. - */ -void send_bits(value, length) - int value; /* value to send */ - int length; /* number of bits */ -{ -#ifdef DEBUG - Tracev((stderr," l %2d v %4x ", length, value)); - Assert(length > 0 && length <= 15, "invalid length"); - bits_sent += (ulg)length; -#endif - /* If not enough room in bi_buf, use (valid) bits from bi_buf and - * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) - * unused bits in value. - */ - if (bi_valid > (int)Buf_size - length) { - bi_buf |= (value << bi_valid); - put_short(bi_buf); - bi_buf = (ush)value >> (Buf_size - bi_valid); - bi_valid += length - Buf_size; - } else { - bi_buf |= value << bi_valid; - bi_valid += length; - } -} - -/* =========================================================================== - * Reverse the first len bits of a code, using straightforward code (a faster - * method would use a table) - * IN assertion: 1 <= len <= 15 - */ -unsigned bi_reverse(code, len) - unsigned code; /* the value to invert */ - int len; /* its bit length */ -{ - register unsigned res = 0; - do { - res |= code & 1; - code >>= 1, res <<= 1; - } while (--len > 0); - return res >> 1; -} - -/* =========================================================================== - * Write out any remaining bits in an incomplete byte. - */ -void bi_windup() -{ - if (bi_valid > 8) { - put_short(bi_buf); - } else if (bi_valid > 0) { - put_byte(bi_buf); - } - bi_buf = 0; - bi_valid = 0; -#ifdef DEBUG - bits_sent = (bits_sent+7) & ~7; -#endif -} - -/* =========================================================================== - * Copy a stored block to the zip file, storing first the length and its - * one's complement if requested. - */ -void copy_block(buf, len, header) - char *buf; /* the input data */ - unsigned len; /* its length */ - int header; /* true if block header must be written */ -{ - bi_windup(); /* align on byte boundary */ - - if (header) { - put_short((ush)len); - put_short((ush)~len); -#ifdef DEBUG - bits_sent += 2*16; -#endif - } -#ifdef DEBUG - bits_sent += (ulg)len<<3; -#endif - while (len--) { -#ifdef CRYPT - int t; - if (key) zencode(*buf, t); -#endif - put_byte(*buf++); - } -} |