Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1 | /* |
| 2 | * jcomapi.c |
| 3 | * |
| 4 | * Copyright (C) 1994, 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 | /* Releasing pools in reverse order might help avoid fragmentation |
| 34 | * with some (brain-damaged) malloc libraries. |
| 35 | */ |
| 36 | for (pool = JPOOL_NUMPOOLS-1; pool > JPOOL_PERMANENT; pool--) { |
| 37 | (*cinfo->mem->free_pool) (cinfo, pool); |
| 38 | } |
| 39 | |
| 40 | /* Reset overall state for possible reuse of object */ |
| 41 | cinfo->global_state = (cinfo->is_decompressor ? DSTATE_START : CSTATE_START); |
| 42 | } |
| 43 | |
| 44 | |
| 45 | /* |
| 46 | * Destruction of a JPEG object. |
| 47 | * |
| 48 | * Everything gets deallocated except the master jpeg_compress_struct itself |
| 49 | * and the error manager struct. Both of these are supplied by the application |
| 50 | * and must be freed, if necessary, by the application. (Often they are on |
| 51 | * the stack and so don't need to be freed anyway.) |
| 52 | * Closing a data source or destination, if necessary, is the application's |
| 53 | * responsibility. |
| 54 | */ |
| 55 | |
| 56 | GLOBAL void |
| 57 | jpeg_destroy (j_common_ptr cinfo) |
| 58 | { |
| 59 | /* We need only tell the memory manager to release everything. */ |
| 60 | /* NB: mem pointer is NULL if memory mgr failed to initialize. */ |
| 61 | if (cinfo->mem != NULL) |
| 62 | (*cinfo->mem->self_destruct) (cinfo); |
| 63 | cinfo->mem = NULL; /* be safe if jpeg_destroy is called twice */ |
| 64 | cinfo->global_state = 0; /* mark it destroyed */ |
| 65 | } |
| 66 | |
| 67 | |
| 68 | /* |
| 69 | * Convenience routines for allocating quantization and Huffman tables. |
| 70 | * (Would jutils.c be a more reasonable place to put these?) |
| 71 | */ |
| 72 | |
| 73 | GLOBAL JQUANT_TBL * |
| 74 | jpeg_alloc_quant_table (j_common_ptr cinfo) |
| 75 | { |
| 76 | JQUANT_TBL *tbl; |
| 77 | |
| 78 | tbl = (JQUANT_TBL *) |
| 79 | (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JQUANT_TBL)); |
| 80 | tbl->sent_table = FALSE; /* make sure this is false in any new table */ |
| 81 | return tbl; |
| 82 | } |
| 83 | |
| 84 | |
| 85 | GLOBAL JHUFF_TBL * |
| 86 | jpeg_alloc_huff_table (j_common_ptr cinfo) |
| 87 | { |
| 88 | JHUFF_TBL *tbl; |
| 89 | |
| 90 | tbl = (JHUFF_TBL *) |
| 91 | (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JHUFF_TBL)); |
| 92 | tbl->sent_table = FALSE; /* make sure this is false in any new table */ |
| 93 | return tbl; |
| 94 | } |