From 2508e846a82bcab19fc7feaa573f4b0863b1a8b7 Mon Sep 17 00:00:00 2001 From: Marvin Scholz Date: Sat, 24 Sep 2022 16:36:59 +0200 Subject: [PATCH] avutil/dict: Improve documentation Mostly consistent formatting and consistently ordering of warnings/notes to be next to the description. Additionally group the AV_DICT_* macros. Signed-off-by: Anton Khirnov --- libavutil/dict.h | 91 +++++++++++++++++++++++++++++------------------- 1 file changed, 55 insertions(+), 36 deletions(-) diff --git a/libavutil/dict.h b/libavutil/dict.h index 9414cf61c0..713c9e361a 100644 --- a/libavutil/dict.h +++ b/libavutil/dict.h @@ -39,13 +39,15 @@ * @brief Simple key:value store * * @{ - * Dictionaries are used for storing key:value pairs. To create - * an AVDictionary, simply pass an address of a NULL pointer to - * av_dict_set(). NULL can be used as an empty dictionary wherever - * a pointer to an AVDictionary is required. - * Use av_dict_get() to retrieve an entry and av_dict_iterate() to - * iterate over all entries and finally av_dict_free() to free the - * dictionary and all its contents. + * Dictionaries are used for storing key-value pairs. + * + * - To **create an AVDictionary**, simply pass an address of a NULL + * pointer to av_dict_set(). NULL can be used as an empty dictionary + * wherever a pointer to an AVDictionary is required. + * - To **insert an entry**, use av_dict_set(). + * - Use av_dict_get() to **retrieve an entry**. + * - To **iterate over all entries**, use av_dict_iterate(). + * - In order to **free the dictionary and all its contents**, use av_dict_free(). * @code AVDictionary *d = NULL; // "create" an empty dictionary @@ -57,13 +59,18 @@ char *v = av_strdup("value"); // you can avoid copying them like this av_dict_set(&d, k, v, AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL); - while (t = av_dict_iterate(d, t)) { + while ((t = av_dict_iterate(d, t))) { <....> // iterate over all entries in d } av_dict_free(&d); @endcode */ +/** + * @name AVDictionary Flags + * Flags that influence behavior of the matching of keys or insertion to the dictionary. + * @{ + */ #define AV_DICT_MATCH_CASE 1 /**< Only get an entry with exact-case key match. Only relevant in av_dict_get(). */ #define AV_DICT_IGNORE_SUFFIX 2 /**< Return first entry in a dictionary whose first part corresponds to the search key, ignoring the suffix of the found key string. Only relevant in av_dict_get(). */ @@ -71,10 +78,13 @@ allocated with av_malloc() or another memory allocation function. */ #define AV_DICT_DONT_STRDUP_VAL 8 /**< Take ownership of a value that's been allocated with av_malloc() or another memory allocation function. */ -#define AV_DICT_DONT_OVERWRITE 16 ///< Don't overwrite existing entries. +#define AV_DICT_DONT_OVERWRITE 16 /**< Don't overwrite existing entries. */ #define AV_DICT_APPEND 32 /**< If the entry already exists, append to it. Note that no - delimiter is added, the strings are simply concatenated. */ + delimiter is added, the strings are simply concatenated. */ #define AV_DICT_MULTIKEY 64 /**< Allow to store several equal keys in the dictionary */ +/** + * @} + */ typedef struct AVDictionaryEntry { char *key; @@ -89,11 +99,13 @@ typedef struct AVDictionary AVDictionary; * The returned entry key or value must not be changed, or it will * cause undefined behavior. * - * @param prev Set to the previous matching element to find the next. - * If set to NULL the first matching element is returned. - * @param key matching key - * @param flags a collection of AV_DICT_* flags controlling how the entry is retrieved - * @return found entry or NULL in case no matching entry was found in the dictionary + * @param prev Set to the previous matching element to find the next. + * If set to NULL the first matching element is returned. + * @param key Matching key + * @param flags A collection of AV_DICT_* flags controlling how the + * entry is retrieved + * + * @return Found entry or NULL in case no matching entry was found in the dictionary */ AVDictionaryEntry *av_dict_get(const AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags); @@ -142,20 +154,21 @@ int av_dict_count(const AVDictionary *m); * @warning Adding a new entry to a dictionary invalidates all existing entries * previously returned with av_dict_get() or av_dict_iterate(). * - * @param pm pointer to a pointer to a dictionary struct. If *pm is NULL - * a dictionary struct is allocated and put in *pm. - * @param key entry key to add to *pm (will either be av_strduped or added as a new key depending on flags) - * @param value entry value to add to *pm (will be av_strduped or added as a new key depending on flags). - * Passing a NULL value will cause an existing entry to be deleted. - * @return >= 0 on success otherwise an error code <0 + * @param pm Pointer to a pointer to a dictionary struct. If *pm is NULL + * a dictionary struct is allocated and put in *pm. + * @param key Entry key to add to *pm (will either be av_strduped or added as a new key depending on flags) + * @param value Entry value to add to *pm (will be av_strduped or added as a new key depending on flags). + * Passing a NULL value will cause an existing entry to be deleted. + * + * @return >= 0 on success otherwise an error code <0 */ int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags); /** - * Convenience wrapper for av_dict_set that converts the value to a string + * Convenience wrapper for av_dict_set() that converts the value to a string * and stores it. * - * Note: If AV_DICT_DONT_STRDUP_KEY is set, key will be freed on error. + * Note: If ::AV_DICT_DONT_STRDUP_KEY is set, key will be freed on error. */ int av_dict_set_int(AVDictionary **pm, const char *key, int64_t value, int flags); @@ -165,14 +178,15 @@ int av_dict_set_int(AVDictionary **pm, const char *key, int64_t value, int flags * In case of failure, all the successfully set entries are stored in * *pm. You may need to manually free the created dictionary. * - * @param key_val_sep a 0-terminated list of characters used to separate + * @param key_val_sep A 0-terminated list of characters used to separate * key from value - * @param pairs_sep a 0-terminated list of characters used to separate + * @param pairs_sep A 0-terminated list of characters used to separate * two pairs from each other - * @param flags flags to use when adding to dictionary. - * AV_DICT_DONT_STRDUP_KEY and AV_DICT_DONT_STRDUP_VAL + * @param flags Flags to use when adding to the dictionary. + * ::AV_DICT_DONT_STRDUP_KEY and ::AV_DICT_DONT_STRDUP_VAL * are ignored since the key/value tokens will always * be duplicated. + * * @return 0 on success, negative AVERROR code on failure */ int av_dict_parse_string(AVDictionary **pm, const char *str, @@ -181,11 +195,14 @@ int av_dict_parse_string(AVDictionary **pm, const char *str, /** * Copy entries from one AVDictionary struct into another. - * @param dst pointer to a pointer to a AVDictionary struct. If *dst is NULL, - * this function will allocate a struct for you and put it in *dst - * @param src pointer to source AVDictionary struct - * @param flags flags to use when setting entries in *dst - * @note metadata is read using the AV_DICT_IGNORE_SUFFIX flag + * + * @note Metadata is read using the ::AV_DICT_IGNORE_SUFFIX flag + * + * @param dst Pointer to a pointer to a AVDictionary struct to copy into. If *dst is NULL, + * this function will allocate a struct for you and put it in *dst + * @param src Pointer to the source AVDictionary struct to copy items from. + * @param flags Flags to use when setting entries in *dst + * * @return 0 on success, negative AVERROR code on failure. If dst was allocated * by this function, callers should free the associated memory. */ @@ -204,13 +221,15 @@ void av_dict_free(AVDictionary **m); * Such string may be passed back to av_dict_parse_string(). * @note String is escaped with backslashes ('\'). * - * @param[in] m dictionary + * @warning Separators cannot be neither '\\' nor '\0'. They also cannot be the same. + * + * @param[in] m The dictionary * @param[out] buffer Pointer to buffer that will be allocated with string containg entries. * Buffer must be freed by the caller when is no longer needed. - * @param[in] key_val_sep character used to separate key from value - * @param[in] pairs_sep character used to separate two pairs from each other + * @param[in] key_val_sep Character used to separate key from value + * @param[in] pairs_sep Character used to separate two pairs from each other + * * @return >= 0 on success, negative on error - * @warning Separators cannot be neither '\\' nor '\0'. They also cannot be the same. */ int av_dict_get_string(const AVDictionary *m, char **buffer, const char key_val_sep, const char pairs_sep);