| 1 | /* |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This source code is licensed under both the BSD-style license (found in the |
| 6 | * LICENSE file in the root directory of this source tree) and the GPLv2 (found |
| 7 | * in the COPYING file in the root directory of this source tree). |
| 8 | * You may select, at your option, one of the above-listed licenses. |
| 9 | */ |
| 10 | |
| 11 | #ifndef DATA_H |
| 12 | #define DATA_H |
| 13 | |
| 14 | #include <stddef.h> |
| 15 | #include <stdint.h> |
| 16 | |
| 17 | typedef enum { |
| 18 | data_type_file = 1, /**< This data is a file. *.zst */ |
| 19 | data_type_dir = 2, /**< This data is a directory. *.tar.zst */ |
| 20 | } data_type_t; |
| 21 | |
| 22 | typedef struct { |
| 23 | char const* url; /**< Where to get this resource. */ |
| 24 | uint64_t xxhash64; /**< Hash of the url contents. */ |
| 25 | char const* path; /**< The path of the unpacked resource (derived). */ |
| 26 | } data_resource_t; |
| 27 | |
| 28 | typedef struct { |
| 29 | data_resource_t data; |
| 30 | data_resource_t dict; |
| 31 | data_type_t type; /**< The type of the data. */ |
| 32 | char const* name; /**< The logical name of the data (no extension). */ |
| 33 | } data_t; |
| 34 | |
| 35 | /** |
| 36 | * The NULL-terminated list of data objects. |
| 37 | */ |
| 38 | extern data_t const* const* data; |
| 39 | |
| 40 | |
| 41 | int data_has_dict(data_t const* data); |
| 42 | |
| 43 | /** |
| 44 | * Initializes the data module and downloads the data necessary. |
| 45 | * Caches the downloads in dir. We add a stamp file in the directory after |
| 46 | * a successful download. If a stamp file already exists, and matches our |
| 47 | * current data stamp, we will use the cached data without downloading. |
| 48 | * |
| 49 | * @param dir The directory to cache the downloaded data into. |
| 50 | * |
| 51 | * @returns 0 on success. |
| 52 | */ |
| 53 | int data_init(char const* dir); |
| 54 | |
| 55 | /** |
| 56 | * Must be called at exit to free resources allocated by data_init(). |
| 57 | */ |
| 58 | void data_finish(void); |
| 59 | |
| 60 | typedef struct { |
| 61 | uint8_t* data; |
| 62 | size_t size; |
| 63 | size_t capacity; |
| 64 | } data_buffer_t; |
| 65 | |
| 66 | /** |
| 67 | * Read the file that data points to into a buffer. |
| 68 | * NOTE: data must be a file, not a directory. |
| 69 | * |
| 70 | * @returns The buffer, which is NULL on failure. |
| 71 | */ |
| 72 | data_buffer_t data_buffer_get_data(data_t const* data); |
| 73 | |
| 74 | /** |
| 75 | * Read the dictionary that the data points to into a buffer. |
| 76 | * |
| 77 | * @returns The buffer, which is NULL on failure. |
| 78 | */ |
| 79 | data_buffer_t data_buffer_get_dict(data_t const* data); |
| 80 | |
| 81 | /** |
| 82 | * Read the contents of filename into a buffer. |
| 83 | * |
| 84 | * @returns The buffer, which is NULL on failure. |
| 85 | */ |
| 86 | data_buffer_t data_buffer_read(char const* filename); |
| 87 | |
| 88 | /** |
| 89 | * Create a buffer with the specified capacity. |
| 90 | * |
| 91 | * @returns The buffer, which is NULL on failure. |
| 92 | */ |
| 93 | data_buffer_t data_buffer_create(size_t capacity); |
| 94 | |
| 95 | /** |
| 96 | * Calls memcmp() on the contents [0, size) of both buffers. |
| 97 | */ |
| 98 | int data_buffer_compare(data_buffer_t buffer1, data_buffer_t buffer2); |
| 99 | |
| 100 | /** |
| 101 | * Frees an allocated buffer. |
| 102 | */ |
| 103 | void data_buffer_free(data_buffer_t buffer); |
| 104 | |
| 105 | |
| 106 | typedef struct { |
| 107 | data_buffer_t const* buffers; |
| 108 | size_t size; |
| 109 | } data_buffers_t; |
| 110 | |
| 111 | /** |
| 112 | * @returns a list of buffers for every file in data. It is zero sized on error. |
| 113 | */ |
| 114 | data_buffers_t data_buffers_get(data_t const* data); |
| 115 | |
| 116 | /** |
| 117 | * Frees the data buffers. |
| 118 | */ |
| 119 | void data_buffers_free(data_buffers_t buffers); |
| 120 | |
| 121 | #endif |