text: /*
  * 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;
  }
  