diff options
Diffstat (limited to 'odb/source.h')
| -rw-r--r-- | odb/source.h | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/odb/source.h b/odb/source.h index 4397cada27..be56995389 100644 --- a/odb/source.h +++ b/odb/source.h @@ -53,6 +53,18 @@ struct object_info; struct odb_read_stream; /* + * A callback function that can be used to iterate through objects. If given, + * the optional `oi` parameter will be populated the same as if you would call + * `odb_read_object_info()`. + * + * Returning a non-zero error code will cause iteration to abort. The error + * code will be propagated. + */ +typedef int (*odb_for_each_object_cb)(const struct object_id *oid, + struct object_info *oi, + void *cb_data); + +/* * The source is the part of the object database that stores the actual * objects. It thus encapsulates the logic to read and write the specific * on-disk format. An object database can have multiple sources: @@ -150,6 +162,30 @@ struct odb_source { int (*read_object_stream)(struct odb_read_stream **out, struct odb_source *source, const struct object_id *oid); + + /* + * This callback is expected to iterate over all objects stored in this + * source and invoke the callback function for each of them. It is + * valid to yield the same object multiple time. A non-zero exit code + * from the object callback shall abort iteration. + * + * The optional `request` structure should serve as a template for + * looking up object info for every individual iterated object. It + * should not be modified directly and should instead be copied into a + * separate `struct object_info` that gets passed to the callback. If + * the caller passes a `NULL` pointer then the object itself shall not + * be read. + * + * The callback is expected to return a negative error code in case the + * iteration has failed to read all objects, 0 otherwise. When the + * callback function returns a non-zero error code then that error code + * should be returned. + */ + int (*for_each_object)(struct odb_source *source, + const struct object_info *request, + odb_for_each_object_cb cb, + void *cb_data, + unsigned flags); }; /* @@ -232,4 +268,33 @@ static inline int odb_source_read_object_stream(struct odb_read_stream **out, return source->read_object_stream(out, source, oid); } +/* + * Iterate through all objects contained in the given source and invoke the + * callback function for each of them. Returning a non-zero code from the + * callback function aborts iteration. There is no guarantee that objects + * are only iterated over once. + * + * The optional `request` structure serves as a template for retrieving the + * object info for each indvidual iterated object and will be populated as if + * `odb_source_read_object_info()` was called on the object. It will not be + * modified, the callback will instead be invoked with a separate `struct + * object_info` for every object. Object info will not be read when passing a + * `NULL` pointer. + * + * The flags is a bitfield of `ODB_FOR_EACH_OBJECT_*` flags. Not all flags may + * apply to a specific backend, so whether or not they are honored is defined + * by the implementation. + * + * Returns 0 when all objects have been iterated over, a negative error code in + * case iteration has failed, or a non-zero value returned from the callback. + */ +static inline int odb_source_for_each_object(struct odb_source *source, + const struct object_info *request, + odb_for_each_object_cb cb, + void *cb_data, + unsigned flags) +{ + return source->for_each_object(source, request, cb, cb_data, flags); +} + #endif |