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