| 1 | /* Copyright (C) 2010-2020 The RetroArch team |
| 2 | * |
| 3 | * --------------------------------------------------------------------------------------- |
| 4 | * The following license statement only applies to this file (memory_stream.c). |
| 5 | * --------------------------------------------------------------------------------------- |
| 6 | * |
| 7 | * Permission is hereby granted, free of charge, |
| 8 | * to any person obtaining a copy of this software and associated documentation files (the "Software"), |
| 9 | * to deal in the Software without restriction, including without limitation the rights to |
| 10 | * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, |
| 11 | * and to permit persons to whom the Software is furnished to do so, subject to the following conditions: |
| 12 | * |
| 13 | * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. |
| 14 | * |
| 15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, |
| 16 | * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 18 | * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, |
| 19 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 20 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 21 | */ |
| 22 | |
| 23 | #include <stdio.h> |
| 24 | #include <stdlib.h> |
| 25 | #include <string.h> |
| 26 | |
| 27 | #include <streams/memory_stream.h> |
| 28 | |
| 29 | /* TODO/FIXME - static globals */ |
| 30 | static uint8_t* g_buffer = NULL; |
| 31 | static uint64_t g_size = 0; |
| 32 | static uint64_t last_file_size = 0; |
| 33 | |
| 34 | struct memstream |
| 35 | { |
| 36 | uint64_t size; |
| 37 | uint64_t ptr; |
| 38 | uint64_t max_ptr; |
| 39 | uint8_t *buf; |
| 40 | unsigned writing; |
| 41 | }; |
| 42 | |
| 43 | void memstream_set_buffer(uint8_t *buffer, uint64_t size) |
| 44 | { |
| 45 | g_buffer = buffer; |
| 46 | g_size = size; |
| 47 | } |
| 48 | |
| 49 | uint64_t memstream_get_last_size(void) |
| 50 | { |
| 51 | return last_file_size; |
| 52 | } |
| 53 | |
| 54 | memstream_t *memstream_open(unsigned writing) |
| 55 | { |
| 56 | memstream_t *stream; |
| 57 | if (!g_buffer || !g_size) |
| 58 | return NULL; |
| 59 | |
| 60 | stream = (memstream_t*)malloc(sizeof(*stream)); |
| 61 | |
| 62 | if (!stream) |
| 63 | return NULL; |
| 64 | |
| 65 | stream->buf = g_buffer; |
| 66 | stream->size = g_size; |
| 67 | stream->ptr = 0; |
| 68 | stream->max_ptr = 0; |
| 69 | stream->writing = writing; |
| 70 | |
| 71 | g_buffer = NULL; |
| 72 | g_size = 0; |
| 73 | |
| 74 | return stream; |
| 75 | } |
| 76 | |
| 77 | void memstream_close(memstream_t *stream) |
| 78 | { |
| 79 | if (!stream) |
| 80 | return; |
| 81 | |
| 82 | last_file_size = stream->writing ? stream->max_ptr : stream->size; |
| 83 | free(stream); |
| 84 | } |
| 85 | |
| 86 | uint64_t memstream_get_ptr(memstream_t *stream) |
| 87 | { |
| 88 | return stream->ptr; |
| 89 | } |
| 90 | |
| 91 | uint64_t memstream_read(memstream_t *stream, void *data, uint64_t bytes) |
| 92 | { |
| 93 | uint64_t avail = 0; |
| 94 | |
| 95 | if (!stream) |
| 96 | return 0; |
| 97 | |
| 98 | avail = stream->size - stream->ptr; |
| 99 | if (bytes > avail) |
| 100 | bytes = avail; |
| 101 | |
| 102 | memcpy(data, stream->buf + stream->ptr, (size_t)bytes); |
| 103 | stream->ptr += bytes; |
| 104 | if (stream->ptr > stream->max_ptr) |
| 105 | stream->max_ptr = stream->ptr; |
| 106 | return bytes; |
| 107 | } |
| 108 | |
| 109 | uint64_t memstream_write(memstream_t *stream, |
| 110 | const void *data, uint64_t bytes) |
| 111 | { |
| 112 | uint64_t avail = 0; |
| 113 | |
| 114 | if (!stream) |
| 115 | return 0; |
| 116 | |
| 117 | avail = stream->size - stream->ptr; |
| 118 | if (bytes > avail) |
| 119 | bytes = avail; |
| 120 | |
| 121 | memcpy(stream->buf + stream->ptr, data, (size_t)bytes); |
| 122 | stream->ptr += bytes; |
| 123 | if (stream->ptr > stream->max_ptr) |
| 124 | stream->max_ptr = stream->ptr; |
| 125 | return bytes; |
| 126 | } |
| 127 | |
| 128 | int64_t memstream_seek(memstream_t *stream, int64_t offset, int whence) |
| 129 | { |
| 130 | uint64_t ptr; |
| 131 | |
| 132 | switch (whence) |
| 133 | { |
| 134 | case SEEK_SET: |
| 135 | ptr = offset; |
| 136 | break; |
| 137 | case SEEK_CUR: |
| 138 | ptr = stream->ptr + offset; |
| 139 | break; |
| 140 | case SEEK_END: |
| 141 | ptr = (stream->writing ? stream->max_ptr : stream->size) + offset; |
| 142 | break; |
| 143 | default: |
| 144 | return -1; |
| 145 | } |
| 146 | |
| 147 | if (ptr <= stream->size) |
| 148 | { |
| 149 | stream->ptr = ptr; |
| 150 | return 0; |
| 151 | } |
| 152 | |
| 153 | return -1; |
| 154 | } |
| 155 | |
| 156 | void memstream_rewind(memstream_t *stream) |
| 157 | { |
| 158 | memstream_seek(stream, 0L, SEEK_SET); |
| 159 | } |
| 160 | |
| 161 | uint64_t memstream_pos(memstream_t *stream) |
| 162 | { |
| 163 | return stream->ptr; |
| 164 | } |
| 165 | |
| 166 | char *memstream_gets(memstream_t *stream, char *buffer, size_t len) |
| 167 | { |
| 168 | return NULL; |
| 169 | } |
| 170 | |
| 171 | int memstream_getc(memstream_t *stream) |
| 172 | { |
| 173 | int ret = 0; |
| 174 | if (stream->ptr >= stream->size) |
| 175 | return EOF; |
| 176 | ret = stream->buf[stream->ptr++]; |
| 177 | |
| 178 | if (stream->ptr > stream->max_ptr) |
| 179 | stream->max_ptr = stream->ptr; |
| 180 | |
| 181 | return ret; |
| 182 | } |
| 183 | |
| 184 | void memstream_putc(memstream_t *stream, int c) |
| 185 | { |
| 186 | if (stream->ptr < stream->size) |
| 187 | stream->buf[stream->ptr++] = c; |
| 188 | |
| 189 | if (stream->ptr > stream->max_ptr) |
| 190 | stream->max_ptr = stream->ptr; |
| 191 | } |