Introduce SHA1_FILE_DIRECTORIES to support multiple object databases.

SHA1_FILE_DIRECTORIES environment variable is a colon separated paths
used when looking for SHA1 files not found in the usual place for
reading.  Creating a new SHA1 file does not use this alternate object
database location mechanism.  This is useful to archive older, rarely
used objects into separate directories.

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/cache.h b/cache.h
index 1dba40570..314ee0dd0 100644
--- a/cache.h
+++ b/cache.h
@@ -101,6 +101,7 @@ unsigned int active_nr, active_alloc, active_cache_changed;
 
 #define DB_ENVIRONMENT "SHA1_FILE_DIRECTORY"
 #define DEFAULT_DB_ENVIRONMENT ".git/objects"
+#define ALTERNATE_DB_ENVIRONMENT "SHA1_FILE_DIRECTORIES"
 
 #define get_object_directory() (getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT)