/*
* jcomapi.c
*
* Copyright (C) 1994-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains application interface routines that are used for both
* compression and decompression.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/*
* Abort processing of a JPEG compression or decompression operation,
* but don't destroy the object itself.
*
* For this, we merely clean up all the nonpermanent memory pools.
* Note that temp files (virtual arrays) are not allowed to belong to
* the permanent pool, so we will be able to close all temp files here.
* Closing a data source or destination, if necessary, is the application's
* responsibility.
*/
GLOBAL(void)
jpeg_abort (j_common_ptr cinfo)
{
int pool;
/* Do nothing if called on a not-initialized or destroyed JPEG object. */
if (cinfo->mem == NULL)
return;
/* Releasing pools in reverse order might help avoid fragmentation
* with some (brain-damaged) malloc libraries.
*/
for (pool = JPOOL_NUMPOOLS-1; pool > JPOOL_PERMANENT; pool--) {
(*cinfo->mem->free_pool) (cinfo, pool);
}
/* Reset overall state for possible reuse of object */
if (cinfo->is_decompressor) {
cinfo->global_state = DSTATE_START;
/* Try to keep application from accessing now-deleted marker list.
* A bit kludgy to do it here, but this is the most central place.
*/
((j_decompress_ptr) cinfo)->marker_list = NULL;
} else {
cinfo->global_state = CSTATE_START;
}
}
/*
* Destruction of a JPEG object.
*
* Everything gets deallocated except the master jpeg_compress_struct itself
* and the error manager struct. Both of these are supplied by the application
* and must be freed, if necessary, by the application. (Often they are on
* the stack and so don't need to be freed anyway.)
* Closing a data source or destination, if necessary, is the application's
* responsibility.
*/
GLOBAL(void)
jpeg_destroy (j_common_ptr cinfo)
{
/* We need only tell the memory manager to release everything. */
/* NB: mem pointer is NULL if memory mgr failed to initialize. */
if (cinfo->mem != NULL)
(*cinfo->mem->self_destruct) (cinfo);
cinfo->mem = NULL; /* be safe if jpeg_destroy is called twice */
cinfo->global_state = 0; /* mark it destroyed */
}
/*
* Convenience routines for allocating quantization and Huffman tables.
* (Would jutils.c be a more reasonable place to put these?)
*/
GLOBAL(JQUANT_TBL *)
jpeg_alloc_quant_table (j_common_ptr cinfo)
{
JQUANT_TBL *tbl;
tbl = (JQUANT_TBL *)
(*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JQUANT_TBL));
tbl->sent_table = FALSE; /* make sure this is false in any new table */
return tbl;
}
GLOBAL(JHUFF_TBL *)
jpeg_alloc_huff_table (j_common_ptr cinfo)
{
JHUFF_TBL *tbl;
tbl = (JHUFF_TBL *)
(*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JHUFF_TBL));
tbl->sent_table = FALSE; /* make sure this is false in any new table */
return tbl;
}