odb: read alternates via sources

Adapt how we read alternates so that the interface is structured around
the object database source we're reading from. This will eventually
allow us to abstract away this behaviour with pluggable object databases
so that every format can have its own mechanism for listing alternates.

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

diff --git a/odb.c b/odb.c
index dcf4a62..c5ba26b 100644 (file)
--- a/odb.c
+++ b/odb.c
@@ -199,19 +199,19 @@ static void parse_alternates(const char *string,
        strbuf_release(&buf);
 }
 
-static void read_info_alternates(const char *relative_base,
-                                struct strvec *out)
+static void odb_source_read_alternates(struct odb_source *source,
+                                      struct strvec *out)
 {
        struct strbuf buf = STRBUF_INIT;
        char *path;
 
-       path = xstrfmt("%s/info/alternates", relative_base);
+       path = xstrfmt("%s/info/alternates", source->path);
        if (strbuf_read_file(&buf, path, 1024) < 0) {
                warn_on_fopen_errors(path);
                free(path);
                return;
        }
-       parse_alternates(buf.buf, '\n', relative_base, out);
+       parse_alternates(buf.buf, '\n', source->path, out);
 
        strbuf_release(&buf);
        free(path);
@@ -257,7 +257,7 @@ static struct odb_source *odb_add_alternate_recursively(struct object_database *
        kh_value(odb->source_by_path, pos) = alternate;
 
        /* recursively add alternates */
-       read_info_alternates(alternate->path, &sources);
+       odb_source_read_alternates(alternate, &sources);
        if (sources.nr && depth + 1 > 5) {
                error(_("%s: ignoring alternate object stores, nesting too deep"),
                      source);
@@ -599,7 +599,7 @@ void odb_prepare_alternates(struct object_database *odb)
                return;
 
        parse_alternates(odb->alternate_db, PATH_SEP, NULL, &sources);
-       read_info_alternates(odb->sources->path, &sources);
+       odb_source_read_alternates(odb->sources, &sources);
        for (size_t i = 0; i < sources.nr; i++)
                odb_add_alternate_recursively(odb, sources.v[i], 0);