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/*
* Copyright (c) 2016-2020, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/
#ifndef DATA_H
#define DATA_H
#include <stddef.h>
#include <stdint.h>
typedef enum {
data_type_file = 1, /**< This data is a file. *.zst */
data_type_dir = 2, /**< This data is a directory. *.tar.zst */
} data_type_t;
typedef struct {
char const* url; /**< Where to get this resource. */
uint64_t xxhash64; /**< Hash of the url contents. */
char const* path; /**< The path of the unpacked resource (derived). */
} data_resource_t;
typedef struct {
data_resource_t data;
data_resource_t dict;
data_type_t type; /**< The type of the data. */
char const* name; /**< The logical name of the data (no extension). */
} data_t;
/**
* The NULL-terminated list of data objects.
*/
extern data_t const* const* data;
int data_has_dict(data_t const* data);
/**
* Initializes the data module and downloads the data necessary.
* Caches the downloads in dir. We add a stamp file in the directory after
* a successful download. If a stamp file already exists, and matches our
* current data stamp, we will use the cached data without downloading.
*
* @param dir The directory to cache the downloaded data into.
*
* @returns 0 on success.
*/
int data_init(char const* dir);
/**
* Must be called at exit to free resources allocated by data_init().
*/
void data_finish(void);
typedef struct {
uint8_t* data;
size_t size;
size_t capacity;
} data_buffer_t;
/**
* Read the file that data points to into a buffer.
* NOTE: data must be a file, not a directory.
*
* @returns The buffer, which is NULL on failure.
*/
data_buffer_t data_buffer_get_data(data_t const* data);
/**
* Read the dictionary that the data points to into a buffer.
*
* @returns The buffer, which is NULL on failure.
*/
data_buffer_t data_buffer_get_dict(data_t const* data);
/**
* Read the contents of filename into a buffer.
*
* @returns The buffer, which is NULL on failure.
*/
data_buffer_t data_buffer_read(char const* filename);
/**
* Create a buffer with the specified capacity.
*
* @returns The buffer, which is NULL on failure.
*/
data_buffer_t data_buffer_create(size_t capacity);
/**
* Calls memcmp() on the contents [0, size) of both buffers.
*/
int data_buffer_compare(data_buffer_t buffer1, data_buffer_t buffer2);
/**
* Frees an allocated buffer.
*/
void data_buffer_free(data_buffer_t buffer);
typedef struct {
data_buffer_t const* buffers;
size_t size;
} data_buffers_t;
/**
* @returns a list of buffers for every file in data. It is zero sized on error.
*/
data_buffers_t data_buffers_get(data_t const* data);
/**
* Frees the data buffers.
*/
void data_buffers_free(data_buffers_t buffers);
#endif