On 22 Sep 2022, at 13:33, Andreas Rheinhardt wrote:
> Marvin Scholz: >> This is a more explicit iteration API rather than using the "magic" >> av_dict_get(d, "", t, AV_DICT_IGNORE_SUFFIX) which is not really >> trivial to grasp what it does when casually reading through code. >> --- >> libavutil/dict.c | 19 +++++++++++++++++++ >> libavutil/dict.h | 27 +++++++++++++++++++++++++++ >> libavutil/version.h | 2 +- >> 3 files changed, 47 insertions(+), 1 deletion(-) >> >> diff --git a/libavutil/dict.c b/libavutil/dict.c >> index 14ad780a79..2f690a5b8e 100644 >> --- a/libavutil/dict.c >> +++ b/libavutil/dict.c >> @@ -20,6 +20,7 @@ >> >> #include <string.h> >> >> +#include "avassert.h" >> #include "avstring.h" >> #include "dict.h" >> #include "dict_internal.h" >> @@ -38,6 +39,24 @@ int av_dict_count(const AVDictionary *m) >> return m ? m->count : 0; >> } >> >> +AVDictionaryEntry *av_dict_iterate(const AVDictionary *m, >> + const AVDictionaryEntry *prev) >> +{ >> + int i = 0; >> + >> + if (!m) >> + return NULL; >> + >> + if (prev) >> + i = prev - m->elems + 1; >> + >> + av_assert2(i >= 0); >> + if (i >= m->count) >> + return NULL; >> + >> + return &m->elems[i]; >> +} >> + >> AVDictionaryEntry *av_dict_get(const AVDictionary *m, const char *key, >> const AVDictionaryEntry *prev, int flags) >> { >> diff --git a/libavutil/dict.h b/libavutil/dict.h >> index 0d1afc6c64..b42b3f07fd 100644 >> --- a/libavutil/dict.h >> +++ b/libavutil/dict.h >> @@ -32,6 +32,8 @@ >> >> #include <stdint.h> >> >> +#include "attributes.h" >> + >> /** >> * @addtogroup lavu_dict AVDictionary >> * @ingroup lavu_data >> @@ -101,6 +103,31 @@ typedef struct AVDictionary AVDictionary; >> AVDictionaryEntry *av_dict_get(const AVDictionary *m, const char *key, >> const AVDictionaryEntry *prev, int flags); >> >> +/** >> + * Iterate over a dictionary >> + * >> + * Iterates through all entries in the dictionary. >> + * >> + * @warning The returned AVDictionaryEntry key/value must not be changed. >> + * >> + * @param m The dictionary to iterate over >> + * @param prev Pointer to the previous AVDictionaryEntry, NULL initially >> + * >> + * @retval AVDictionaryEntry* The next element in the dictionary >> + * @retval NULL No more elements in the dictionary >> + * >> + * Typical usage: >> + * @code >> + * AVDictionaryEntry *e = NULL; >> + * while (e = av_dict_iterate(m, e)) { >> + * // ... >> + * } >> + * @endcode >> + */ >> +av_warn_unused_result >> +AVDictionaryEntry *av_dict_iterate(const AVDictionary *m, >> + const AVDictionaryEntry *prev); > > The user is not allowed to modify the returned AVDictionaryEntries, so > you should return a const AVDictionaryEntry here. Ok. Shouldn't _get return const as well then? If so, can that be changed or would it break ABI? > And there is no reason > to use av_warn_unused_result at all; nothing bad happens if you ignore > the result (except that you called av_dict_iterate unnecessarily). Yeah nothing bad happens but it is probably still wrong use of the API that seemed beneficial to highlight or is there any valid use-case to call it without using the return? I could not think of any… > > Furthermore, av_dict_set's documentation contains "Adding a new entry to > a dictionary invalidates all existing entries previously returned with > av_dict_get." This needs to be updated, too. Sure, I will update the docs more, I just wanted to have some general feedback if this is acceptable addition before I invest more time to polish it. > >> + >> /** >> * Get number of entries in dictionary. >> * >> diff --git a/libavutil/version.h b/libavutil/version.h >> index 0585fa7b80..6fd07ed2a4 100644 >> --- a/libavutil/version.h >> +++ b/libavutil/version.h >> @@ -80,7 +80,7 @@ >> >> #define LIBAVUTIL_VERSION_MAJOR 57 >> #define LIBAVUTIL_VERSION_MINOR 36 >> -#define LIBAVUTIL_VERSION_MICRO 102 >> +#define LIBAVUTIL_VERSION_MICRO 103 > > New API additions need a minor bump (and need to reset micro). Oh indeed, sorry, will fix that in the next version. > >> >> #define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \ >> LIBAVUTIL_VERSION_MINOR, \ > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".