/*
 * 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;
}
