odb/source: introduce generic object counting

Introduce generic object counting on the object database source level
with a new backend-specific callback function.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/odb/source-files.c b/odb/source-files.c
index 14cb9adecadd99fcbbed7ad5601a5196e6787ff7..c08d8993e378a0c9459d4616bd3e459c0f7bca57 100644 (file)
--- a/odb/source-files.c
+++ b/odb/source-files.c
@@ -93,6 +93,35 @@ static int odb_source_files_for_each_object(struct odb_source *source,
        return 0;
 }
 
+static int odb_source_files_count_objects(struct odb_source *source,
+                                         enum odb_count_objects_flags flags,
+                                         unsigned long *out)
+{
+       struct odb_source_files *files = odb_source_files_downcast(source);
+       unsigned long count;
+       int ret;
+
+       ret = packfile_store_count_objects(files->packed, flags, &count);
+       if (ret < 0)
+               goto out;
+
+       if (!(flags & ODB_COUNT_OBJECTS_APPROXIMATE)) {
+               unsigned long loose_count;
+
+               ret = odb_source_loose_count_objects(source, flags, &loose_count);
+               if (ret < 0)
+                       goto out;
+
+               count += loose_count;
+       }
+
+       *out = count;
+       ret = 0;
+
+out:
+       return ret;
+}
+
 static int odb_source_files_freshen_object(struct odb_source *source,
                                           const struct object_id *oid)
 {
@@ -220,6 +249,7 @@ struct odb_source_files *odb_source_files_new(struct object_database *odb,
        files->base.read_object_info = odb_source_files_read_object_info;
        files->base.read_object_stream = odb_source_files_read_object_stream;
        files->base.for_each_object = odb_source_files_for_each_object;
+       files->base.count_objects = odb_source_files_count_objects;
        files->base.freshen_object = odb_source_files_freshen_object;
        files->base.write_object = odb_source_files_write_object;
        files->base.write_object_stream = odb_source_files_write_object_stream;

diff --git a/odb/source.h b/odb/source.h
index a1fd9dd92091378fee5a856d462073dcdb51851a..96c906e7a1b350ee0e8688edeaf6ce66892812f5 100644 (file)
--- a/odb/source.h
+++ b/odb/source.h
@@ -142,6 +142,21 @@ struct odb_source {
                               void *cb_data,
                               unsigned flags);
 
+       /*
+        * This callback is expected to count objects in the given object
+        * database source. The callback function does not have to guarantee
+        * that only unique objects are counted. The result shall be assigned
+        * to the `out` pointer.
+        *
+        * Accepts `enum odb_count_objects_flag` flags to alter the behaviour.
+        *
+        * The callback is expected to return 0 on success, or a negative error
+        * code otherwise.
+        */
+       int (*count_objects)(struct odb_source *source,
+                            enum odb_count_objects_flags flags,
+                            unsigned long *out);
+
        /*
         * This callback is expected to freshen the given object so that its
         * last access time is set to the current time. This is used to ensure
@@ -333,6 +348,18 @@ static inline int odb_source_for_each_object(struct odb_source *source,
        return source->for_each_object(source, request, cb, cb_data, flags);
 }
 
+/*
+ * Count the number of objects in the given object database source.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+static inline int odb_source_count_objects(struct odb_source *source,
+                                          enum odb_count_objects_flags flags,
+                                          unsigned long *out)
+{
+       return source->count_objects(source, flags, out);
+}
+
 /*
  * Freshen an object in the object database by updating its timestamp.
  * Returns 1 in case the object has been freshened, 0 in case the object does

diff --git a/packfile.c b/packfile.c
index 1ee5dd3da35c071017e7efbfc03edf51fa8c8e4a..8ee462303afa79b382e80aa63f1eff5db87c90a6 100644 (file)
--- a/packfile.c
+++ b/packfile.c
@@ -1102,6 +1102,7 @@ struct packfile_list_entry *packfile_store_get_packs(struct packfile_store *stor
 }
 
 int packfile_store_count_objects(struct packfile_store *store,
+                                enum odb_count_objects_flags flags UNUSED,
                                 unsigned long *out)
 {
        struct packfile_list_entry *e;
@@ -1146,10 +1147,9 @@ unsigned long repo_approximate_object_count(struct repository *r)
 
                odb_prepare_alternates(r->objects);
                for (source = r->objects->sources; source; source = source->next) {
-                       struct odb_source_files *files = odb_source_files_downcast(source);
                        unsigned long c;
 
-                       if (!packfile_store_count_objects(files->packed, &c))
+                       if (!odb_source_count_objects(source, ODB_COUNT_OBJECTS_APPROXIMATE, &c))
                                count += c;
                }
 

diff --git a/packfile.h b/packfile.h
index 1da8c729cba131ae7e130081e8910a70e9a6ae6a..74b6bc58c5a6b7f0b741ae7b4f88c370c0d93227 100644 (file)
--- a/packfile.h
+++ b/packfile.h
@@ -275,6 +275,7 @@ enum kept_pack_type {
  * Return 0 on success, a negative error code otherwise.
  */
 int packfile_store_count_objects(struct packfile_store *store,
+                                enum odb_count_objects_flags flags,
                                 unsigned long *out);
 
 /*