1 /* 2 * jmemnobs.c 3 * 4 * This file was part of the Independent JPEG Group's software: 5 * Copyright (C) 1992-1996, Thomas G. Lane. 6 * libjpeg-turbo Modifications: 7 * Copyright (C) 2017-2018, D. R. Commander. 8 * For conditions of distribution and use, see the accompanying README.ijg 9 * file. 10 * 11 * This file provides a really simple implementation of the system- 12 * dependent portion of the JPEG memory manager. This implementation 13 * assumes that no backing-store files are needed: all required space 14 * can be obtained from malloc(). 15 * This is very portable in the sense that it'll compile on almost anything, 16 * but you'd better have lots of main memory (or virtual memory) if you want 17 * to process big images. 18 */ 19 20 #define JPEG_INTERNALS 21 #include "jinclude.h" 22 #include "jpeglib.h" 23 #include "jmemsys.h" /* import the system-dependent declarations */ 24 25 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc(),free() */ 26 extern void *malloc(size_t size); 27 extern void free(void *ptr); 28 #endif 29 30 31 /* 32 * Memory allocation and freeing are controlled by the regular library 33 * routines malloc() and free(). 34 */ 35 36 GLOBAL(void *) 37 jpeg_get_small(j_common_ptr cinfo, size_t sizeofobject) 38 { 39 return (void *)malloc(sizeofobject); 40 } 41 42 GLOBAL(void) 43 jpeg_free_small(j_common_ptr cinfo, void *object, size_t sizeofobject) 44 { 45 free(object); 46 } 47 48 49 /* 50 * "Large" objects are treated the same as "small" ones. 51 */ 52 53 GLOBAL(void *) 54 jpeg_get_large(j_common_ptr cinfo, size_t sizeofobject) 55 { 56 return (void *)malloc(sizeofobject); 57 } 58 59 GLOBAL(void) 60 jpeg_free_large(j_common_ptr cinfo, void *object, size_t sizeofobject) 61 { 62 free(object); 63 } 64 65 66 /* 67 * This routine computes the total memory space available for allocation. 68 */ 69 70 GLOBAL(size_t) 71 jpeg_mem_available(j_common_ptr cinfo, size_t min_bytes_needed, 72 size_t max_bytes_needed, size_t already_allocated) 73 { 74 if (cinfo->mem->max_memory_to_use) { 75 if ((size_t)cinfo->mem->max_memory_to_use > already_allocated) 76 return cinfo->mem->max_memory_to_use - already_allocated; 77 else 78 return 0; 79 } else { 80 /* Here we always say, "we got all you want bud!" */ 81 return max_bytes_needed; 82 } 83 } 84 85 86 /* 87 * Backing store (temporary file) management. 88 * Since jpeg_mem_available always promised the moon, 89 * this should never be called and we can just error out. 90 */ 91 92 GLOBAL(void) 93 jpeg_open_backing_store(j_common_ptr cinfo, backing_store_ptr info, 94 long total_bytes_needed) 95 { 96 ERREXIT(cinfo, JERR_NO_BACKING_STORE); 97 } 98 99 100 /* 101 * These routines take care of any system-dependent initialization and 102 * cleanup required. Here, there isn't any. 103 */ 104 105 GLOBAL(long) 106 jpeg_mem_init(j_common_ptr cinfo) 107 { 108 return 0; /* just set max_memory_to_use to 0 */ 109 } 110 111 GLOBAL(void) 112 jpeg_mem_term(j_common_ptr cinfo) 113 { 114 /* no work */ 115 } 116