Fully implement database lazy loading

Commit 34e1413d75 attempted to implement lazy loading of package databases.
Although it took care of my main complaint (creating the database directory
if it didn't exist), it didn't allow sync repos to be registered before
alpm_option_set_dbpath() had been called.

With this patch, we no longer compute the individual repository DB paths
until necessary, allowing full lazy loading to work as intended, and
allowing us to drop the extra setlibpath() calls from the frontend. This
allows the changes introduced in a2cd48960 (but later reverted) to be added
back in again.

Signed-off-by: Dan McGee <dan@archlinux.org>

1 files changed, 36 insertions, 25 deletions

diff --git a/lib/libalpm/db.c b/lib/libalpm/db.c
index 62c2e0a3..e57ff935 100644
--- a/lib/libalpm/db.c
+++ b/lib/libalpm/db.c
@@ -323,18 +323,15 @@ alpm_list_t SYMEXPORT *alpm_db_search(pmdb_t *db, const alpm_list_t* needles)
 
 /** @} */
 
-pmdb_t *_alpm_db_new(const char *dbpath, const char *treename)
+static pmdb_t *_alpm_db_new(const char *treename, unsigned short is_local)
 {
 	pmdb_t *db;
-	const size_t pathsize = strlen(dbpath) + strlen(treename) + 2;
 
 	ALPM_LOG_FUNC;
 
 	CALLOC(db, 1, sizeof(pmdb_t), RET_ERR(PM_ERR_MEMORY, NULL));
-	CALLOC(db->path, 1, pathsize, RET_ERR(PM_ERR_MEMORY, NULL));
-
-	sprintf(db->path, "%s%s/", dbpath, treename);
 	STRDUP(db->treename, treename, RET_ERR(PM_ERR_MEMORY, NULL));
+	db->is_local = is_local;
 
 	return(db);
 }
@@ -347,13 +344,44 @@ void _alpm_db_free(pmdb_t *db)
 	_alpm_db_free_pkgcache(db);
 	/* cleanup server list */
 	FREELIST(db->servers);
-	FREE(db->path);
+	FREE(db->_path);
 	FREE(db->treename);
 	FREE(db);
 
 	return;
 }
 
+const char *_alpm_db_path(pmdb_t *db)
+{
+	if(!db) {
+		return(NULL);
+	}
+	if(!db->_path) {
+		const char *dbpath;
+		size_t pathsize;
+
+		dbpath = alpm_option_get_dbpath();
+		if(!dbpath) {
+			_alpm_log(PM_LOG_ERROR, _("database path is undefined\n"));
+			RET_ERR(PM_ERR_DB_OPEN, NULL);
+		}
+
+		if(db->is_local) {
+			pathsize = strlen(dbpath) + strlen(db->treename) + 2;
+			CALLOC(db->_path, 1, pathsize, RET_ERR(PM_ERR_MEMORY, NULL));
+			sprintf(db->_path, "%s%s/", dbpath, db->treename);
+		} else {
+			pathsize = strlen(dbpath) + 5 + strlen(db->treename) + 2;
+			CALLOC(db->_path, 1, pathsize, RET_ERR(PM_ERR_MEMORY, NULL));
+			/* all sync DBs now reside in the sync/ subdir of the dbpath */
+			sprintf(db->_path, "%ssync/%s/", dbpath, db->treename);
+		}
+		_alpm_log(PM_LOG_DEBUG, "database path for tree %s set to %s\n",
+				db->treename, db->_path);
+	}
+	return(db->_path);
+}
+
 int _alpm_db_cmp(const void *d1, const void *d2)
 {
 	pmdb_t *db1 = (pmdb_t *)d1;
@@ -440,7 +468,6 @@ alpm_list_t *_alpm_db_search(pmdb_t *db, const alpm_list_t *needles)
 pmdb_t *_alpm_db_register_local(void)
 {
 	pmdb_t *db;
-	const char *dbpath;
 
 	ALPM_LOG_FUNC;
 
@@ -451,13 +478,7 @@ pmdb_t *_alpm_db_register_local(void)
 
 	_alpm_log(PM_LOG_DEBUG, "registering local database\n");
 
-	dbpath = alpm_option_get_dbpath();
-	if(!dbpath) {
-		_alpm_log(PM_LOG_ERROR, _("database path is undefined\n"));
-			RET_ERR(PM_ERR_DB_OPEN, NULL);
-	}
-
-	db = _alpm_db_new(dbpath, "local");
+	db = _alpm_db_new("local", 1);
 	if(db == NULL) {
 		RET_ERR(PM_ERR_DB_CREATE, NULL);
 	}
@@ -469,8 +490,6 @@ pmdb_t *_alpm_db_register_local(void)
 pmdb_t *_alpm_db_register_sync(const char *treename)
 {
 	pmdb_t *db;
-	const char *dbpath;
-	char path[PATH_MAX];
 	alpm_list_t *i;
 
 	ALPM_LOG_FUNC;
@@ -485,15 +504,7 @@ pmdb_t *_alpm_db_register_sync(const char *treename)
 
 	_alpm_log(PM_LOG_DEBUG, "registering sync database '%s'\n", treename);
 
-	dbpath = alpm_option_get_dbpath();
-	if(!dbpath) {
-		_alpm_log(PM_LOG_ERROR, _("database path is undefined\n"));
-			RET_ERR(PM_ERR_DB_OPEN, NULL);
-	}
-	/* all sync DBs now reside in the sync/ subdir of the dbpath */
-	snprintf(path, PATH_MAX, "%ssync/", dbpath);
-
-	db = _alpm_db_new(path, treename);
+	db = _alpm_db_new(treename, 0);
 	if(db == NULL) {
 		RET_ERR(PM_ERR_DB_CREATE, NULL);
 	}