| Message ID | 20220924143659.74756-1-epirat07@gmail.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [FFmpeg-devel,v2,1/5] avutil/dict: Add av_dict_iterate | expand |
| Context | Check | Description |
|---|---|---|
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
On 24 Sep 2022, at 16:36, Marvin Scholz wrote: > 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 | 46 +++++++++++++++++++++++++++++++++++---------- > libavutil/version.h | 4 ++-- > 3 files changed, 57 insertions(+), 12 deletions(-) > > diff --git a/libavutil/dict.c b/libavutil/dict.c > index 14ad780a79..ee059d712c 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; > } > > +const 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..344afb452b 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 > @@ -43,9 +45,9 @@ > * 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 or iterate over all > - * entries and finally av_dict_free() to free the dictionary > - * and all its contents. > + * 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. > * > @code > AVDictionary *d = NULL; // "create" an empty dictionary > @@ -57,8 +59,8 @@ > 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_get(d, "", t, AV_DICT_IGNORE_SUFFIX)) { > - <....> // iterate over all entries in d > + while (t = av_dict_iterate(d, t)) { > + <....> // iterate over all entries in d > } > av_dict_free(&d); > @endcode > @@ -89,9 +91,6 @@ typedef struct AVDictionary AVDictionary; > * The returned entry key or value must not be changed, or it will > * cause undefined behavior. > * > - * To iterate through all the dictionary entries, you can set the matching key > - * to the null string "" and set the AV_DICT_IGNORE_SUFFIX flag. > - * > * @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 > @@ -101,6 +100,33 @@ 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. > + * > + * @warning As av_dict_set() invalidates all previous entries returned > + * by this function, it must not be called while iterating over the dict. > + * > + * Typical usage: > + * @code > + * const AVDictionaryEntry *e = NULL; > + * while ((e = av_dict_iterate(m, e))) { > + * // ... > + * } > + * @endcode > + * > + * @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 > + */ > +const AVDictionaryEntry *av_dict_iterate(const AVDictionary *m, > + const AVDictionaryEntry *prev); > + > /** > * Get number of entries in dictionary. > * > @@ -115,8 +141,8 @@ int av_dict_count(const AVDictionary *m); > * Note: If AV_DICT_DONT_STRDUP_KEY or AV_DICT_DONT_STRDUP_VAL is set, > * these arguments will be freed on error. > * > - * Warning: Adding a new entry to a dictionary invalidates all existing entries > - * previously returned with av_dict_get. > + * @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. > diff --git a/libavutil/version.h b/libavutil/version.h > index 0585fa7b80..9c44cef6aa 100644 > --- a/libavutil/version.h > +++ b/libavutil/version.h > @@ -79,8 +79,8 @@ > */ > > #define LIBAVUTIL_VERSION_MAJOR 57 > -#define LIBAVUTIL_VERSION_MINOR 36 > -#define LIBAVUTIL_VERSION_MICRO 102 > +#define LIBAVUTIL_VERSION_MINOR 37 > +#define LIBAVUTIL_VERSION_MICRO 100 > > #define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \ > LIBAVUTIL_VERSION_MINOR, \ > -- > 2.37.0 (Apple Git-136) Ping for review/merge, please.
Quoting Marvin Scholz (2022-09-24 16:36:55) > diff --git a/libavutil/dict.h b/libavutil/dict.h > index 0d1afc6c64..344afb452b 100644 > --- a/libavutil/dict.h > +++ b/libavutil/dict.h > @@ -32,6 +32,8 @@ > > #include <stdint.h> > > +#include "attributes.h" This seems unnecessary now. Will push with this include removed, if noone objects.
diff --git a/libavutil/dict.c b/libavutil/dict.c index 14ad780a79..ee059d712c 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; } +const 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..344afb452b 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 @@ -43,9 +45,9 @@ * 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 or iterate over all - * entries and finally av_dict_free() to free the dictionary - * and all its contents. + * 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. * @code AVDictionary *d = NULL; // "create" an empty dictionary @@ -57,8 +59,8 @@ 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_get(d, "", t, AV_DICT_IGNORE_SUFFIX)) { - <....> // iterate over all entries in d + while (t = av_dict_iterate(d, t)) { + <....> // iterate over all entries in d } av_dict_free(&d); @endcode @@ -89,9 +91,6 @@ typedef struct AVDictionary AVDictionary; * The returned entry key or value must not be changed, or it will * cause undefined behavior. * - * To iterate through all the dictionary entries, you can set the matching key - * to the null string "" and set the AV_DICT_IGNORE_SUFFIX flag. - * * @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 @@ -101,6 +100,33 @@ 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. + * + * @warning As av_dict_set() invalidates all previous entries returned + * by this function, it must not be called while iterating over the dict. + * + * Typical usage: + * @code + * const AVDictionaryEntry *e = NULL; + * while ((e = av_dict_iterate(m, e))) { + * // ... + * } + * @endcode + * + * @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 + */ +const AVDictionaryEntry *av_dict_iterate(const AVDictionary *m, + const AVDictionaryEntry *prev); + /** * Get number of entries in dictionary. * @@ -115,8 +141,8 @@ int av_dict_count(const AVDictionary *m); * Note: If AV_DICT_DONT_STRDUP_KEY or AV_DICT_DONT_STRDUP_VAL is set, * these arguments will be freed on error. * - * Warning: Adding a new entry to a dictionary invalidates all existing entries - * previously returned with av_dict_get. + * @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. diff --git a/libavutil/version.h b/libavutil/version.h index 0585fa7b80..9c44cef6aa 100644 --- a/libavutil/version.h +++ b/libavutil/version.h @@ -79,8 +79,8 @@ */ #define LIBAVUTIL_VERSION_MAJOR 57 -#define LIBAVUTIL_VERSION_MINOR 36 -#define LIBAVUTIL_VERSION_MICRO 102 +#define LIBAVUTIL_VERSION_MINOR 37 +#define LIBAVUTIL_VERSION_MICRO 100 #define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \ LIBAVUTIL_VERSION_MINOR, \