The sixth batch for 2.26

[thirdparty/git.git] / object-store.h

diff --git a/object-store.h b/object-store.h
index 61b8b13e3b21bbcafc1f88aa5f6cdb24fcb4d1dd..5b047637e3e02e9e8eda665095b3630ae20025e4 100644 (file)
--- a/object-store.h
+++ b/object-store.h
@@ -6,6 +6,7 @@
 #include "list.h"
 #include "sha1-array.h"
 #include "strbuf.h"
+#include "thread-utils.h"
 
 struct object_directory {
        struct object_directory *next;
@@ -125,6 +126,8 @@ struct raw_object_store {
         * (see git-replace(1)).
         */
        struct oidmap *replace_map;
+       unsigned replace_map_initialized : 1;
+       pthread_mutex_t replace_mutex; /* protect object replace functions */
 
        struct commit_graph *commit_graph;
        unsigned commit_graph_attempted : 1; /* if loading has been attempted */
@@ -198,8 +201,9 @@ static inline void *repo_read_object_file(struct repository *r,
 /* Read and unpack an object file into memory, write memory to an object file */
 int oid_object_info(struct repository *r, const struct object_id *, unsigned long *);
 
-int hash_object_file(const void *buf, unsigned long len,
-                    const char *type, struct object_id *oid);
+int hash_object_file(const struct git_hash_algo *algo, const void *buf,
+                    unsigned long len, const char *type,
+                    struct object_id *oid);
 
 int write_object_file(const void *buf, unsigned long len,
                      const char *type, struct object_id *oid);
@@ -208,6 +212,14 @@ int hash_object_file_literally(const void *buf, unsigned long len,
                               const char *type, struct object_id *oid,
                               unsigned flags);
 
+/*
+ * Add an object file to the in-memory object store, without writing it
+ * to disk.
+ *
+ * Callers are responsible for calling write_object_file to record the
+ * object in persistent storage before writing any other new objects
+ * that reference it.
+ */
 int pretend_object_file(void *, unsigned long, enum object_type,
                        struct object_id *oid);
 
@@ -249,6 +261,40 @@ int has_loose_object_nonlocal(const struct object_id *);
 
 void assert_oid_type(const struct object_id *oid, enum object_type expect);
 
+/*
+ * Enabling the object read lock allows multiple threads to safely call the
+ * following functions in parallel: repo_read_object_file(), read_object_file(),
+ * read_object_file_extended(), read_object_with_reference(), read_object(),
+ * oid_object_info() and oid_object_info_extended().
+ *
+ * obj_read_lock() and obj_read_unlock() may also be used to protect other
+ * section which cannot execute in parallel with object reading. Since the used
+ * lock is a recursive mutex, these sections can even contain calls to object
+ * reading functions. However, beware that in these cases zlib inflation won't
+ * be performed in parallel, losing performance.
+ *
+ * TODO: oid_object_info_extended()'s call stack has a recursive behavior. If
+ * any of its callees end up calling it, this recursive call won't benefit from
+ * parallel inflation.
+ */
+void enable_obj_read_lock(void);
+void disable_obj_read_lock(void);
+
+extern int obj_read_use_lock;
+extern pthread_mutex_t obj_read_mutex;
+
+static inline void obj_read_lock(void)
+{
+       if(obj_read_use_lock)
+               pthread_mutex_lock(&obj_read_mutex);
+}
+
+static inline void obj_read_unlock(void)
+{
+       if(obj_read_use_lock)
+               pthread_mutex_unlock(&obj_read_mutex);
+}
+
 struct object_info {
        /* Request */
        enum object_type *typep;