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/**
* @file parser.h
* @author Radek Krejci <rkrejci@cesnet.cz>
* @brief Generic libyang parsers structures and functions
*
* Copyright (c) 2020 CESNET, z.s.p.o.
*
* This source code is licensed under BSD 3-Clause License (the "License").
* You may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://opensource.org/licenses/BSD-3-Clause
*/
#ifndef LY_PARSER_H_
#define LY_PARSER_H_
#include <stdio.h>
#include "log.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Parser input structure specifying where the data are read.
*/
struct ly_in;
/**
* @brief Types of the parser's inputs
*/
typedef enum LY_IN_TYPE {
LY_IN_ERROR = -1, /**< error value to indicate failure of the functions returning LY_IN_TYPE */
LY_IN_FD, /**< file descriptor printer */
LY_IN_FILE, /**< FILE stream parser */
LY_IN_FILEPATH, /**< filepath parser */
LY_IN_MEMORY /**< memory parser */
} LY_IN_TYPE;
/**
* @brief Get input type of the input handler.
*
* @param[in] in Input handler.
* @return Type of the parser's input.
*/
LY_IN_TYPE ly_in_type(const struct ly_in *in);
/**
* @brief Reset the input medium to read from its beginning, so the following parser function will read from the object's beginning.
*
* Note that in case the underlying output is not seekable (stream referring a pipe/FIFO/socket or the callback output type),
* nothing actually happens despite the function succeeds. Also note that the medium is not returned to the state it was when
* the handler was created. For example, file is seeked into the offset zero, not to the offset where it was opened when
* ly_in_new_file() was called.
*
* @param[in] in Input handler.
* @return LY_SUCCESS in case of success
* @return LY_ESYS in case of failure
*/
LY_ERR ly_in_reset(struct ly_in *in);
/**
* @brief Create input handler using file descriptor.
*
* @param[in] fd File descriptor to use.
* @param[out] in Created input handler supposed to be passed to different ly*_parse() functions.
* @return LY_SUCCESS in case of success
* @return LY_ERR value in case of failure.
*/
LY_ERR ly_in_new_fd(int fd, struct ly_in **in);
/**
* @brief Get or reset file descriptor input handler.
*
* @param[in] in Input handler.
* @param[in] fd Optional value of a new file descriptor for the handler. If -1, only the current file descriptor value is returned.
* @return Previous value of the file descriptor. Note that caller is responsible for closing the returned file descriptor in case of setting new descriptor @p fd.
* @return -1 in case of error when setting up the new file descriptor.
*/
int ly_in_fd(struct ly_in *in, int fd);
/**
* @brief Create input handler using file stream.
*
* @param[in] f File stream to use.
* @param[out] in Created input handler supposed to be passed to different ly*_parse() functions.
* @return LY_SUCCESS in case of success
* @return LY_ERR value in case of failure.
*/
LY_ERR ly_in_new_file(FILE *f, struct ly_in **in);
/**
* @brief Get or reset file stream input handler.
*
* @param[in] in Input handler.
* @param[in] f Optional new file stream for the handler. If NULL, only the current file stream is returned.
* @return NULL in case of invalid argument or an error when setting up the new input file, original input handler @p in is untouched in this case.
* @return Previous file stream of the handler. Note that caller is responsible for closing the returned stream in case of setting new stream @p f.
*/
FILE *ly_in_file(struct ly_in *in, FILE *f);
/**
* @brief Create input handler using memory to read data.
*
* @param[in] str Pointer where to start reading data. The input data are expected to be NULL-terminated.
* Note that in case the destroy argument of ly_in_free() is used, the input string is passed to free(),
* so if it is really a static string, do not use the destroy argument!
* @param[out] in Created input handler supposed to be passed to different ly*_parse() functions.
* @return LY_SUCCESS in case of success
* @return LY_ERR value in case of failure.
*/
LY_ERR ly_in_new_memory(const char *str, struct ly_in **in);
/**
* @brief Get or change memory where the data are read from.
*
* @param[in] in Input handler.
* @param[in] str String containing the data to read. The input data are expected to be NULL-terminated.
* Note that in case the destroy argument of ly_in_free() is used, the input string is passed to free(),
* so if it is really a static string, do not use the destroy argument!
* @return Previous starting address to read data from. Note that the caller is responsible to free
* the data in case of changing string pointer @p str.
*/
const char *ly_in_memory(struct ly_in *in, const char *str);
/**
* @brief Create input handler file of the given filename.
*
* @param[in] filepath Path of the file where to read data.
* @param[in] len Optional number of bytes to use from @p filepath. If 0, the @p filepath is considered to be NULL-terminated and
* the whole string is taken into account.
* @param[out] in Created input handler supposed to be passed to different ly*_parse() functions.
* @return LY_SUCCESS in case of success
* @return LY_ERR value in case of failure.
*/
LY_ERR ly_in_new_filepath(const char *filepath, size_t len, struct ly_in **in);
/**
* @brief Get or change the filepath of the file where the parser reads the data.
*
* Note that in case of changing the filepath, the current file is closed and a new one is
* created/opened instead of renaming the previous file. Also note that the previous filepath
* string is returned only in case of not changing it's value.
*
* @param[in] in Input handler.
* @param[in] filepath Optional new filepath for the handler. If and only if NULL, the current filepath string is returned.
* @param[in] len Optional number of bytes to use from @p filepath. If 0, the @p filepath is considered to be NULL-terminated and
* the whole string is taken into account.
* @return Previous filepath string in case the @p filepath argument is NULL.
* @return NULL if changing filepath succeedes and ((void *)-1) otherwise.
*/
const char *ly_in_filepath(struct ly_in *in, const char *filepath, size_t len);
/**
* @brief Get the number of parsed bytes by the last function.
*
* @param[in] in In structure used.
* @return Number of parsed bytes.
*/
size_t ly_in_parsed(const struct ly_in *in);
/**
* @brief Free the input handler.
* @param[in] in Input handler to free.
* @param[in] destroy Flag to free the input data buffer (for LY_IN_MEMORY) or to
* close stream/file descriptor (for LY_IN_FD and LY_IN_FILE)
*/
void ly_in_free(struct ly_in *in, ly_bool destroy);
#ifdef __cplusplus
}
#endif
#endif /* LY_PARSER_H_ */