gvsig-raster / libjni-potrace / trunk / libjni-potrace / src / main / native / jpotrace / flate.c @ 1780
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/* Copyright (C) 2001-2007 Peter Selinger.
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This file is part of Potrace. It is free software and it is covered
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by the GNU General Public License. See the file COPYING for details. */
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/* $Id: flate.c 147 2007-04-09 00:44:09Z selinger $ */
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/* the PostScript compression module of Potrace. The basic interface
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is through the *_xship function, which processes a byte array and
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outputs it in compressed or verbatim form, depending on whether
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filter is 1 or 0. To flush the output, simply call with the empty
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string and filter=0. filter=2 is used to output encoded text but
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without the PostScript header to turn on the encoding. Each
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function has variants for shipping a single character, a
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null-terminated string, or a byte array. */
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/* different compression algorithms are available. There is
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dummy_xship, which is just the identity, and flate_xship, which
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uses zlib compression. Also, lzw_xship provides LZW compression
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from the file lzw.c/h. a85_xship provides a85-encoding without
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compression. Each function returns the actual number of characters
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written. */
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/* note: the functions provided here have global state and are not
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reentrant */
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#ifdef HAVE_CONFIG_H
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#include "config.h" |
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#endif
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#include <stdio.h> |
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#include <string.h> |
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#include <stdlib.h> |
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#include <errno.h> |
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#ifdef HAVE_ZLIB
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#include <zlib.h> |
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#endif
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#include "flate.h" |
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#include "lzw.h" |
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#define OUTSIZE 1000 |
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static int a85init(FILE *f); |
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static int a85finish(FILE *f); |
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static int a85write(FILE *f, char *buf, int n); |
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static int a85out(FILE *f, int n); |
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static int a85spool(FILE *f, char c); |
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/* ---------------------------------------------------------------------- */
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/* dummy interface: no encoding */
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int dummy_xship(FILE *f, int filter, char *s, int len) { |
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fwrite(s, 1, len, f);
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return len;
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} |
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/* ---------------------------------------------------------------------- */
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/* flate interface: zlib (=postscript level 3) compression and a85 */
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#ifdef HAVE_ZLIB
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int pdf_xship(FILE *f, int filter, char *s, int len) { |
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static int fstate = 0; |
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static z_stream c_stream;
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char outbuf[OUTSIZE];
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int err;
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int n=0; |
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if (filter && !fstate) {
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/* switch on filtering */
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c_stream.zalloc = Z_NULL; |
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c_stream.zfree = Z_NULL; |
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c_stream.opaque = Z_NULL; |
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err = deflateInit(&c_stream, 9);
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if (err != Z_OK) {
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fprintf(stderr, "deflateInit: %s (%d)\n", c_stream.msg, err);
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exit(1);
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} |
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c_stream.avail_in = 0;
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fstate = 1;
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} else if (!filter && fstate) { |
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/* switch off filtering */
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/* flush stream */
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do {
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c_stream.next_out = (Bytef*)outbuf; |
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c_stream.avail_out = OUTSIZE; |
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err = deflate(&c_stream, Z_FINISH); |
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if (err != Z_OK && err != Z_STREAM_END) {
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fprintf(stderr, "deflate: %s (%d)\n", c_stream.msg, err);
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exit(1);
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} |
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n += fwrite(outbuf, 1, OUTSIZE-c_stream.avail_out, f);
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} while (err != Z_STREAM_END);
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fstate = 0;
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} |
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if (!fstate) {
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fwrite(s, 1, len, f);
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return n+len;
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} |
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/* do the actual compression */
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c_stream.next_in = (Bytef*) s; |
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c_stream.avail_in = len; |
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do {
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c_stream.next_out = (Bytef*) outbuf; |
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c_stream.avail_out = OUTSIZE; |
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err = deflate(&c_stream, Z_NO_FLUSH); |
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if (err != Z_OK) {
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fprintf(stderr, "deflate: %s (%d)\n", c_stream.msg, err);
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exit(1);
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} |
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n += fwrite(outbuf, 1, OUTSIZE-c_stream.avail_out, f);
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} while (!c_stream.avail_out);
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return n;
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} |
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/* ship len bytes from s using zlib compression. */
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int flate_xship(FILE *f, int filter, char *s, int len) { |
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static int fstate = 0; |
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static z_stream c_stream;
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char outbuf[OUTSIZE];
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int err;
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int n=0; |
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if (filter && !fstate) {
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/* switch on filtering */
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if (filter == 1) { |
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n += fprintf(f, "currentfile /ASCII85Decode filter /FlateDecode filter cvx exec\n");
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} |
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c_stream.zalloc = Z_NULL; |
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c_stream.zfree = Z_NULL; |
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c_stream.opaque = Z_NULL; |
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err = deflateInit(&c_stream, 9);
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if (err != Z_OK) {
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fprintf(stderr, "deflateInit: %s (%d)\n", c_stream.msg, err);
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exit(1);
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} |
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c_stream.avail_in = 0;
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n += a85init(f); |
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fstate = 1;
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} else if (!filter && fstate) { |
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/* switch off filtering */
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/* flush stream */
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do {
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c_stream.next_out = (Bytef*)outbuf; |
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c_stream.avail_out = OUTSIZE; |
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err = deflate(&c_stream, Z_FINISH); |
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if (err != Z_OK && err != Z_STREAM_END) {
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fprintf(stderr, "deflate: %s (%d)\n", c_stream.msg, err);
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exit(1);
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} |
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n += a85write(f, outbuf, OUTSIZE-c_stream.avail_out); |
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} while (err != Z_STREAM_END);
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n += a85finish(f); |
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fstate = 0;
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} |
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if (!fstate) {
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fwrite(s, 1, len, f);
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return n+len;
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} |
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/* do the actual compression */
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c_stream.next_in = (Bytef*) s; |
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c_stream.avail_in = len; |
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do {
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c_stream.next_out = (Bytef*) outbuf; |
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c_stream.avail_out = OUTSIZE; |
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err = deflate(&c_stream, Z_NO_FLUSH); |
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if (err != Z_OK) {
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fprintf(stderr, "deflate: %s (%d)\n", c_stream.msg, err);
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exit(1);
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} |
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n += a85write(f, outbuf, OUTSIZE-c_stream.avail_out); |
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} while (!c_stream.avail_out);
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return n;
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} |
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#else /* HAVE_ZLIB */ |
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int pdf_xship(FILE *f, int filter, char *s, int len) { |
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return dummy_xship(f, filter, s, len);
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} |
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int flate_xship(FILE *f, int filter, char *s, int len) { |
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return dummy_xship(f, filter, s, len);
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} |
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#endif /* HAVE_ZLIB */ |
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/* ---------------------------------------------------------------------- */
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/* lzw interface: LZW (=postscript level 2) compression with a85.
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This relies on lzw.c/h to do the actual compression. */
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/* use Postscript level 2 compression. Ship len bytes from str. */
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int lzw_xship(FILE *f, int filter, char *str, int len) { |
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static int fstate = 0; |
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static lzw_stream_t *s = NULL; |
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char outbuf[OUTSIZE];
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int err;
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int n=0; |
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if (filter && !fstate) {
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/* switch on filtering */
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if (filter == 1) { |
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n += fprintf(f, "currentfile /ASCII85Decode filter /LZWDecode filter cvx exec\n");
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} |
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s = lzw_init(); |
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if (s == NULL) { |
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fprintf(stderr, "lzw_init: %s\n", strerror(errno));
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exit(1);
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} |
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n += a85init(f); |
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fstate = 1;
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} else if (!filter && fstate) { |
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/* switch off filtering */
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/* flush stream */
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s->next_in = 0;
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s->avail_in = 0;
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do {
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s->next_out = outbuf; |
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s->avail_out = OUTSIZE; |
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err = lzw_compress(s, LZW_EOD); |
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if (err) {
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fprintf(stderr, "lzw_compress: %s\n", strerror(errno));
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exit(1);
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} |
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n += a85write(f, outbuf, OUTSIZE - s->avail_out); |
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} while (s->avail_out == 0); |
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n += a85finish(f); |
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lzw_free(s); |
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s = NULL;
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fstate = 0;
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} |
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if (!fstate) {
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fwrite(str, 1, len, f);
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return n+len;
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} |
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/* do the actual compression */
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s->next_in = str; |
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s->avail_in = len; |
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do {
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s->next_out = outbuf; |
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s->avail_out = OUTSIZE; |
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err = lzw_compress(s, LZW_NORMAL); |
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if (err) {
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fprintf(stderr, "lzw_compress: %s\n", strerror(errno));
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exit(1);
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} |
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n += a85write(f, outbuf, OUTSIZE - s->avail_out); |
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} while (s->avail_out == 0); |
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return n;
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} |
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/* ---------------------------------------------------------------------- */
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/* a85 interface: a85 encoding without compression */
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/* ship len bytes from s using a85 encoding only. */
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int a85_xship(FILE *f, int filter, char *s, int len) { |
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static int fstate = 0; |
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int n=0; |
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if (filter && !fstate) {
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/* switch on filtering */
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if (filter == 1) { |
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n += fprintf(f, "currentfile /ASCII85Decode filter cvx exec\n");
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} |
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n += a85init(f); |
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fstate = 1;
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} else if (!filter && fstate) { |
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/* switch off filtering */
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/* flush stream */
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n += a85finish(f); |
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fstate = 0;
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} |
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if (!fstate) {
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fwrite(s, 1, len, f);
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return n+len;
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} |
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n += a85write(f, s, len); |
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return n;
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} |
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/* ---------------------------------------------------------------------- */
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/* low-level a85 backend */
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static unsigned long a85buf[4]; |
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static int a85n; |
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static int a85col; |
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static int a85init(FILE *f) { |
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a85n = 0;
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a85col = 0;
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return 0; |
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} |
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static int a85finish(FILE *f) { |
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int r=0; |
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if (a85n) {
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r+=a85out(f, a85n); |
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} |
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fputs("~>\n", f);
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return r+2; |
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} |
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static int a85write(FILE *f, char *buf, int n) { |
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int i;
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int r=0; |
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for (i=0; i<n; i++) { |
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a85buf[a85n] = (unsigned char)buf[i]; |
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a85n++; |
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if (a85n == 4) { |
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r+=a85out(f, 4);
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a85n = 0;
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} |
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} |
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return r;
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} |
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static int a85out(FILE *f, int n) { |
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char out[5]; |
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unsigned long s; |
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int r=0; |
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int i;
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for (i=n; i<4; i++) { |
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a85buf[i] = 0;
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} |
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s = (a85buf[0]<<24) + (a85buf[1]<<16) + (a85buf[2]<<8) + (a85buf[3]<<0); |
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if (!s) {
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r+=a85spool(f, 'z');
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} else {
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for (i=4; i>=0; i--) { |
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out[i] = s % 85;
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s /= 85;
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} |
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for (i=0; i<n+1; i++) { |
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r+=a85spool(f, out[i]+33);
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} |
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} |
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return r;
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} |
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static int a85spool(FILE *f, char c) { |
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fputc(c, f); |
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a85col++; |
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if (a85col>70) { |
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fputc('\n', f);
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a85col=0;
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return 2; |
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} |
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return 1; |
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} |