/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
* 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 METHOD_H
#define METHOD_H

#include <stddef.h>

#include "data.h"
#include "config.h"
#include "result.h"

/**
* The base class for state that methods keep.
* All derived method state classes must have a member of this type.
*/
typedef struct {
   data_t const* data;
} method_state_t;

/**
* A method that compresses the data using config.
*/
typedef struct {
   char const* name;  /**< The identifier for this method in the results. */
   /**
    * Creates a state that must contain a member variable of method_state_t,
    * and returns a pointer to that member variable.
    *
    * This method can be used to do expensive work that only depends on the
    * data, like loading the data file into a buffer.
    */
   method_state_t* (*create)(data_t const* data);
   /**
    * Compresses the data in the state using the given config.
    *
    * @param state A pointer to the state returned by create().
    *
    * @returns The total compressed size on success, or an error code.
    */
   result_t (*compress)(method_state_t* state, config_t const* config);
   /**
    * Frees the state.
    */
   void (*destroy)(method_state_t* state);
} method_t;

/**
* Set the zstd cli path. Must be called before any methods are used.
*/
void method_set_zstdcli(char const* zstdcli);

/**
* A NULL-terminated list of methods.
*/
extern method_t const* const* methods;

#endif