| 1 | /* Copyright (C) 2010-2020 The RetroArch team |
| 2 | * |
| 3 | * --------------------------------------------------------------------------------------- |
| 4 | * The following license statement only applies to this file (rzip_stream.h). |
| 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 | #ifndef _LIBRETRO_SDK_FILE_RZIP_STREAM_H |
| 24 | #define _LIBRETRO_SDK_FILE_RZIP_STREAM_H |
| 25 | |
| 26 | #include <stdio.h> |
| 27 | #include <stdint.h> |
| 28 | #include <stddef.h> |
| 29 | #include <stdarg.h> |
| 30 | |
| 31 | #include <retro_common_api.h> |
| 32 | |
| 33 | RETRO_BEGIN_DECLS |
| 34 | |
| 35 | /* Rudimentary interface for streaming data to/from a |
| 36 | * zlib-compressed chunk-based RZIP archive file. |
| 37 | * |
| 38 | * This is somewhat less efficient than using regular |
| 39 | * gzip code, but this is by design - the intention here |
| 40 | * is to create an interface that integrates seamlessly |
| 41 | * with normal RetroArch functionality, using only |
| 42 | * standard/existing libretro-common routines. |
| 43 | * (Actual efficiency is pretty good, regardless: |
| 44 | * archived file size is almost identical to a solid |
| 45 | * zip file, and compression/decompression speed is |
| 46 | * not substantially worse than external archiving tools; |
| 47 | * it is certainly acceptable for use in real-time |
| 48 | * frontend applications) |
| 49 | * |
| 50 | * When reading existing files, uncompressed content |
| 51 | * is handled automatically. File type (compressed/ |
| 52 | * uncompressed) is detected via the RZIP header. |
| 53 | * |
| 54 | * ## RZIP file format: |
| 55 | * |
| 56 | * <file id header>: 8 bytes |
| 57 | * - [#][R][Z][I][P][v][file format version][#] |
| 58 | * <uncompressed chunk size>: 4 bytes, little endian order |
| 59 | * - nominal (maximum) size of each uncompressed |
| 60 | * chunk, in bytes |
| 61 | * <total uncompressed data size>: 8 bytes, little endian order |
| 62 | * <size of next compressed chunk>: 4 bytes, little endian order |
| 63 | * - size on-disk of next compressed data |
| 64 | * chunk, in bytes |
| 65 | * <next compressed chunk>: n bytes of zlib compressed data |
| 66 | * ... |
| 67 | * <size of next compressed chunk> : repeated until end of file |
| 68 | * <next compressed chunk> : |
| 69 | * |
| 70 | */ |
| 71 | |
| 72 | /* Prevent direct access to rzipstream_t members */ |
| 73 | typedef struct rzipstream rzipstream_t; |
| 74 | |
| 75 | /* File Open */ |
| 76 | |
| 77 | /* Opens a new or existing RZIP file |
| 78 | * > Supported 'mode' values are: |
| 79 | * - RETRO_VFS_FILE_ACCESS_READ |
| 80 | * - RETRO_VFS_FILE_ACCESS_WRITE |
| 81 | * > When reading, 'path' may reference compressed |
| 82 | * or uncompressed data |
| 83 | * Returns NULL if arguments are invalid, file |
| 84 | * is invalid or an IO error occurs */ |
| 85 | rzipstream_t* rzipstream_open(const char *path, unsigned mode); |
| 86 | |
| 87 | /* File Read */ |
| 88 | |
| 89 | /* Reads (a maximum of) 'len' bytes from an RZIP file. |
| 90 | * Returns actual number of bytes read, or -1 in |
| 91 | * the event of an error */ |
| 92 | int64_t rzipstream_read(rzipstream_t *stream, void *data, int64_t len); |
| 93 | |
| 94 | /* Reads next character from an RZIP file. |
| 95 | * Returns character value, or EOF if no data |
| 96 | * remains. |
| 97 | * Note: Always returns EOF if file is open |
| 98 | * for writing. */ |
| 99 | int rzipstream_getc(rzipstream_t *stream); |
| 100 | |
| 101 | /* Reads one line from an RZIP file and stores it |
| 102 | * in the character array pointed to by 's'. |
| 103 | * It stops reading when either (len-1) characters |
| 104 | * are read, the newline character is read, or the |
| 105 | * end-of-file is reached, whichever comes first. |
| 106 | * On success, returns 's'. In the event of an error, |
| 107 | * or if end-of-file is reached and no characters |
| 108 | * have been read, returns NULL. */ |
| 109 | char* rzipstream_gets(rzipstream_t *stream, char *s, size_t len); |
| 110 | |
| 111 | /* Reads all data from file specified by 'path' and |
| 112 | * copies it to 'buf'. |
| 113 | * - 'buf' will be allocated and must be free()'d manually. |
| 114 | * - Allocated 'buf' size is equal to 'len'. |
| 115 | * Returns false in the event of an error */ |
| 116 | bool rzipstream_read_file(const char *path, void **buf, int64_t *len); |
| 117 | |
| 118 | /* File Write */ |
| 119 | |
| 120 | /* Writes 'len' bytes to an RZIP file. |
| 121 | * Returns actual number of bytes written, or -1 |
| 122 | * in the event of an error */ |
| 123 | int64_t rzipstream_write(rzipstream_t *stream, const void *data, int64_t len); |
| 124 | |
| 125 | /* Writes a single character to an RZIP file. |
| 126 | * Returns character written, or EOF in the event |
| 127 | * of an error */ |
| 128 | int rzipstream_putc(rzipstream_t *stream, int c); |
| 129 | |
| 130 | /* Writes a variable argument list to an RZIP file. |
| 131 | * Ugly 'internal' function, required to enable |
| 132 | * 'printf' support in the higher level 'interface_stream'. |
| 133 | * Returns actual number of bytes written, or -1 |
| 134 | * in the event of an error */ |
| 135 | int rzipstream_vprintf(rzipstream_t *stream, const char* format, va_list args); |
| 136 | |
| 137 | /* Writes formatted output to an RZIP file. |
| 138 | * Returns actual number of bytes written, or -1 |
| 139 | * in the event of an error */ |
| 140 | int rzipstream_printf(rzipstream_t *stream, const char* format, ...); |
| 141 | |
| 142 | /* Writes contents of 'data' buffer to file |
| 143 | * specified by 'path'. |
| 144 | * Returns false in the event of an error */ |
| 145 | bool rzipstream_write_file(const char *path, const void *data, int64_t len); |
| 146 | |
| 147 | /* File Control */ |
| 148 | |
| 149 | /* Sets file position to the beginning of the |
| 150 | * specified RZIP file. |
| 151 | * Note: It is not recommended to rewind a file |
| 152 | * that is open for writing, since the caller |
| 153 | * may end up with a file containing junk data |
| 154 | * at the end (harmless, but a waste of space). */ |
| 155 | void rzipstream_rewind(rzipstream_t *stream); |
| 156 | |
| 157 | /* File Status */ |
| 158 | |
| 159 | /* Returns total size (in bytes) of the *uncompressed* |
| 160 | * data in an RZIP file. |
| 161 | * (If reading an uncompressed file, this corresponds |
| 162 | * to the 'physical' file size in bytes) |
| 163 | * Returns -1 in the event of a error. */ |
| 164 | int64_t rzipstream_get_size(rzipstream_t *stream); |
| 165 | |
| 166 | /* Returns EOF when no further *uncompressed* data |
| 167 | * can be read from an RZIP file. */ |
| 168 | int rzipstream_eof(rzipstream_t *stream); |
| 169 | |
| 170 | /* Returns the offset of the current byte of *uncompressed* |
| 171 | * data relative to the beginning of an RZIP file. |
| 172 | * Returns -1 in the event of a error. */ |
| 173 | int64_t rzipstream_tell(rzipstream_t *stream); |
| 174 | |
| 175 | /* Returns true if specified RZIP file contains |
| 176 | * compressed content */ |
| 177 | bool rzipstream_is_compressed(rzipstream_t *stream); |
| 178 | |
| 179 | /* File Close */ |
| 180 | |
| 181 | /* Closes RZIP file. If file is open for writing, |
| 182 | * flushes any remaining buffered data to disk. |
| 183 | * Returns -1 in the event of a error. */ |
| 184 | int rzipstream_close(rzipstream_t *stream); |
| 185 | |
| 186 | RETRO_END_DECLS |
| 187 | |
| 188 | #endif |