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/* Copyright (C) 1995, 1996, 1997, 1998 Aladdin Enterprises. All rights reserved.
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This software is provided AS-IS with no warranty, either express or
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implied.
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This software is distributed under license and may not be copied,
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modified or distributed except as expressly authorized under the terms
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of the license contained in the file LICENSE in this distribution.
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For more information about licensing, please refer to
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http://www.ghostscript.com/licensing/. For information on
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commercial licensing, go to http://www.artifex.com/licensing/ or
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contact Artifex Software, Inc., 101 Lucas Valley Road #110,
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San Rafael, CA 94903, U.S.A., +1(415)492-9861.
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*/
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/* $Id: szlibd.c,v 1.7 2004/03/11 14:50:50 igor Exp $ */
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/* zlib decoding (decompression) filter stream */
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#include "memory_.h"
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#include "std.h"
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#include "gsmemory.h"
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#include "gsmalloc.h" /* for gs_memory_default */
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#include "strimpl.h"
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#include "szlibxx.h"
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/* Initialize the filter. */
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private int
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s_zlibD_init(stream_state * st)
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{
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stream_zlib_state *const ss = (stream_zlib_state *)st;
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int code = s_zlib_alloc_dynamic_state(ss);
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if (code < 0)
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return ERRC; /****** WRONG ******/
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if (inflateInit2(&ss->dynamic->zstate,
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(ss->no_wrapper ? -ss->windowBits : ss->windowBits))
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!= Z_OK
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) {
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s_zlib_free_dynamic_state(ss);
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return ERRC; /****** WRONG ******/
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}
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st->min_left=1;
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return 0;
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}
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/* Reinitialize the filter. */
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private int
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s_zlibD_reset(stream_state * st)
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{
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stream_zlib_state *const ss = (stream_zlib_state *)st;
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if (inflateReset(&ss->dynamic->zstate) != Z_OK)
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return ERRC; /****** WRONG ******/
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return 0;
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}
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/* Process a buffer */
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private int
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s_zlibD_process(stream_state * st, stream_cursor_read * pr,
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stream_cursor_write * pw, bool ignore_last)
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{
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stream_zlib_state *const ss = (stream_zlib_state *)st;
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z_stream *zs = &ss->dynamic->zstate;
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const byte *p = pr->ptr;
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int status;
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static const unsigned char jaws_empty[] = {0x58, 0x85, 1, 0, 0, 0, 0, 0, 1, 0x0A};
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/* Detect no input or full output so that we don't get */
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/* a Z_BUF_ERROR return. */
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if (pw->ptr == pw->limit)
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return 1;
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if (pr->ptr == pr->limit)
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return 0;
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zs->next_in = (Bytef *)p + 1;
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zs->avail_in = pr->limit - p;
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zs->next_out = pw->ptr + 1;
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zs->avail_out = pw->limit - pw->ptr;
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if (zs->total_in == 0 && zs->avail_in >= 10 && !memcmp(zs->next_in, jaws_empty, 10)) {
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/* JAWS PDF generator encodes empty stream as jaws_empty[].
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* The stream declares that the data block length is zero
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* but zlib routines regard a zero length data block to be an error.
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*/
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pr->ptr += 10;
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return EOFC;
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}
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status = inflate(zs, Z_PARTIAL_FLUSH);
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pr->ptr = zs->next_in - 1;
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pw->ptr = zs->next_out - 1;
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switch (status) {
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case Z_OK:
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return (pw->ptr == pw->limit ? 1 : pr->ptr > p ? 0 : 1);
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case Z_STREAM_END:
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return EOFC;
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default:
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return ERRC;
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}
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}
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/* Release the stream */
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private void
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s_zlibD_release(stream_state * st)
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{
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stream_zlib_state *const ss = (stream_zlib_state *)st;
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inflateEnd(&ss->dynamic->zstate);
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s_zlib_free_dynamic_state(ss);
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}
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/* Stream template */
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const stream_template s_zlibD_template = {
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&st_zlib_state, s_zlibD_init, s_zlibD_process, 1, 1, s_zlibD_release,
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s_zlib_set_defaults, s_zlibD_reset
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};
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