1/*
2 * jcomapi.c
3 *
4 * This file was part of the Independent JPEG Group's software:
5 * Copyright (C) 1994-1997, Thomas G. Lane.0
6 * It was modified by The libjpeg-turbo Project to include only code relevant
7 * to libjpeg-turbo.
8 * For conditions of distribution and use, see the accompanying README file.
9 *
10 * This file contains application interface routines that are used for both
11 * compression and decompression.
12 */
13
14#define JPEG_INTERNALS
15#include "jinclude.h"
16#include "jpeglib.h"
17
18
19/*
20 * Abort processing of a JPEG compression or decompression operation,
21 * but don't destroy the object itself.
22 *
23 * For this, we merely clean up all the nonpermanent memory pools.
24 * Note that temp files (virtual arrays) are not allowed to belong to
25 * the permanent pool, so we will be able to close all temp files here.
26 * Closing a data source or destination, if necessary, is the application's
27 * responsibility.
28 */
29
30GLOBAL(void)
31jpeg_abort (j_common_ptr cinfo)
32{
33  int pool;
34
35  /* Do nothing if called on a not-initialized or destroyed JPEG object. */
36  if (cinfo->mem == NULL)
37    return;
38
39  /* Releasing pools in reverse order might help avoid fragmentation
40   * with some (brain-damaged) malloc libraries.
41   */
42  for (pool = JPOOL_NUMPOOLS-1; pool > JPOOL_PERMANENT; pool--) {
43    (*cinfo->mem->free_pool) (cinfo, pool);
44  }
45
46  /* Reset overall state for possible reuse of object */
47  if (cinfo->is_decompressor) {
48    cinfo->global_state = DSTATE_START;
49    /* Try to keep application from accessing now-deleted marker list.
50     * A bit kludgy to do it here, but this is the most central place.
51     */
52    ((j_decompress_ptr) cinfo)->marker_list = NULL;
53  } else {
54    cinfo->global_state = CSTATE_START;
55  }
56}
57
58
59/*
60 * Destruction of a JPEG object.
61 *
62 * Everything gets deallocated except the master jpeg_compress_struct itself
63 * and the error manager struct.  Both of these are supplied by the application
64 * and must be freed, if necessary, by the application.  (Often they are on
65 * the stack and so don't need to be freed anyway.)
66 * Closing a data source or destination, if necessary, is the application's
67 * responsibility.
68 */
69
70GLOBAL(void)
71jpeg_destroy (j_common_ptr cinfo)
72{
73  /* We need only tell the memory manager to release everything. */
74  /* NB: mem pointer is NULL if memory mgr failed to initialize. */
75  if (cinfo->mem != NULL)
76    (*cinfo->mem->self_destruct) (cinfo);
77  cinfo->mem = NULL;            /* be safe if jpeg_destroy is called twice */
78  cinfo->global_state = 0;      /* mark it destroyed */
79}
80
81
82/*
83 * Convenience routines for allocating quantization and Huffman tables.
84 * (Would jutils.c be a more reasonable place to put these?)
85 */
86
87GLOBAL(JQUANT_TBL *)
88jpeg_alloc_quant_table (j_common_ptr cinfo)
89{
90  JQUANT_TBL *tbl;
91
92  tbl = (JQUANT_TBL *)
93    (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, sizeof(JQUANT_TBL));
94  tbl->sent_table = FALSE;      /* make sure this is false in any new table */
95  return tbl;
96}
97
98
99GLOBAL(JHUFF_TBL *)
100jpeg_alloc_huff_table (j_common_ptr cinfo)
101{
102  JHUFF_TBL *tbl;
103
104  tbl = (JHUFF_TBL *)
105    (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, sizeof(JHUFF_TBL));
106  tbl->sent_table = FALSE;      /* make sure this is false in any new table */
107  return tbl;
108}
109