Add a library function to add an alternate to the alternates file

This is in the core so that, if the alternates file has already been
read, the addition can be parsed and put into effect for the current
process.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/cache.h b/cache.h
index 396eabf6ed02214f2c9f9e83c06c19aa7b7626e4..9da9179afd035cf4cc5ae403344d872950d6d3b3 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -599,6 +599,7 @@ extern struct alternate_object_database {
        char base[FLEX_ARRAY]; /* more */
 } *alt_odb_list;
 extern void prepare_alt_odb(void);
+extern void add_to_alternates_file(const char *reference);
 
 struct pack_window {
        struct pack_window *next;

diff --git a/sha1_file.c b/sha1_file.c
index 3516777bc7614c23da02dd7a9aa28a48294d56cb..d21e23b4647225af0c38bb70f8b3140972367f3e 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -380,6 +380,18 @@ static void read_info_alternates(const char * relative_base, int depth)
        munmap(map, mapsz);
 }
 
+void add_to_alternates_file(const char *reference)
+{
+       struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
+       int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), 1);
+       char *alt = mkpath("%s/objects\n", reference);
+       write_or_die(fd, alt, strlen(alt));
+       if (commit_lock_file(lock))
+               die("could not close alternates file");
+       if (alt_odb_tail)
+               link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
+}
+
 void prepare_alt_odb(void)
 {
        const char *alt;