/* Copyright (C) 1995, 1997, 1998 Aladdin Enterprises.  All rights reserved.

   This file is part of Aladdin Ghostscript.

   Aladdin Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author
   or distributor accepts any responsibility for the consequences of using it,
   or for whether it serves any particular purpose or works at all, unless he
   or she says so in writing.  Refer to the Aladdin Ghostscript Free Public
   License (the "License") for full details.

   Every copy of Aladdin Ghostscript must include a copy of the License,
   normally in a plain ASCII text file named PUBLIC.  The License grants you
   the right to copy, modify and redistribute Aladdin Ghostscript, but only
   under certain conditions described in the License.  Among other things, the
   License requires that the copyright notice and this notice be preserved on
   all copies.
 */

/*$Id: szlibc.c $ */
/* Code common to zlib encoding and decoding streams */
#include "std.h"
#include "gserror.h"
#include "gserrors.h"
#include "gstypes.h"
#include "gsmemory.h"
#include "gsmalloc.h"
#include "gsstruct.h"
#include "strimpl.h"
#include "szlibxx.h"
#include "zconf.h"

private_st_zlib_block();
private_st_zlib_dynamic_state();
public_st_zlib_state();

/* Set defaults for stream parameters. */
void
s_zlib_set_defaults(stream_state * st)
{
    stream_zlib_state *const ss = (stream_zlib_state *)st;

    ss->windowBits = MAX_WBITS;
    ss->no_wrapper = false;
    ss->level = Z_DEFAULT_COMPRESSION;
    ss->method = Z_DEFLATED;
    /* DEF_MEM_LEVEL should be in zlib.h or zconf.h, but it isn't. */
    ss->memLevel = min(MAX_MEM_LEVEL, 8);
    ss->strategy = Z_DEFAULT_STRATEGY;
}

/* Allocate the dynamic state. */
int
s_zlib_alloc_dynamic_state(stream_zlib_state *ss)
{
    gs_memory_t *mem = (ss->memory ? ss->memory : &gs_memory_default);
    zlib_dynamic_state_t *zds =
	gs_alloc_struct_immovable(mem, zlib_dynamic_state_t,
				  &st_zlib_dynamic_state,
				  "s_zlib_alloc_dynamic_state");

    ss->dynamic = zds;
    if (zds == 0)
	return_error(gs_error_VMerror);
    zds->blocks = 0;
    zds->memory = mem;
    zds->zstate.zalloc = (alloc_func)s_zlib_alloc;
    zds->zstate.zfree = (free_func)s_zlib_free;
    zds->zstate.opaque = (voidpf)zds;
    return 0;
}

/* Free the dynamic state. */
void
s_zlib_free_dynamic_state(stream_zlib_state *ss)
{
    if (ss->dynamic)
	gs_free_object(ss->dynamic->memory, ss->dynamic,
		       "s_zlib_free_dynamic_state");
}

/* Provide zlib-compatible allocation and freeing functions. */
void *
s_zlib_alloc(void *zmem, uint items, uint size)
{
    zlib_dynamic_state_t *const zds = zmem;
    gs_memory_t *mem = zds->memory;
    zlib_block_t *block =
	gs_alloc_struct(mem, zlib_block_t, &st_zlib_block,
			"s_zlib_alloc(block)");
    void *data =
	gs_alloc_byte_array_immovable(mem, items, size, "s_zlib_alloc(data)");

    if (block == 0 || data == 0) {
	gs_free_object(mem, data, "s_zlib_alloc(data)");
	gs_free_object(mem, block, "s_zlib_alloc(block)");
	return Z_NULL;
    }
    block->data = data;
    block->next = zds->blocks;
    block->prev = 0;
    if (zds->blocks)
	zds->blocks->prev = block;
    zds->blocks = block;
    return data;
}
void
s_zlib_free(void *zmem, void *data)
{
    zlib_dynamic_state_t *const zds = zmem;
    gs_memory_t *mem = zds->memory;
    zlib_block_t *block = zds->blocks;

    gs_free_object(mem, data, "s_zlib_free(data)");
    for (; ; block = block->next) {
	if (block == 0) {
	    lprintf1("Freeing unrecorded data 0x%lx!\n", (ulong)data);
	    return;
	}
	if (block->data == data)
	    break;
    }
    if (block->next)
	block->next->prev = block->prev;
    if (block->prev)
	block->prev->next = block->next;
    else
	zds->blocks = block->next;
    gs_free_object(mem, block, "s_zlib_free(block)");
}
