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