/*
 * jcomapi.c
 *
 * Copyright (C) 1994, 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;

	/* 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 */
	cinfo->global_state = ( cinfo->is_decompressor ? DSTATE_START : 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;
}
