libalpm: introduce a usage level for repos

This defines a level of interest a user has in a repository. These are
described by the bitmask flags in the alpm_db_usage_t enum:

  ALPM_DB_USAGE_SEARCH: repo is valid for searching
  ALPM_DB_USAGE_INSTALL: repo is valid for installs (e.g. -S pkg)
  ALPM_DB_USAGE_UPGRADE: repo is valid for sysupgrades
  ALPM_DB_USAGE_ALL: all of the above are valid

Explicitly listing the contents of a repo will always be valid, and the
repo will always be refreshed appropriately on sync operations.

Signed-off-by: Dave Reisner <dreisner@archlinux.org>
Signed-off-by: Allan McRae <allan@archlinux.org>

7 files changed, 76 insertions, 4 deletions

diff --git a/lib/libalpm/alpm.h b/lib/libalpm/alpm.h
index c6d97c59..b049007c 100644
--- a/lib/libalpm/alpm.h
+++ b/lib/libalpm/alpm.h
@@ -709,6 +709,28 @@ alpm_list_t *alpm_db_get_groupcache(alpm_db_t *db);
  */
 alpm_list_t *alpm_db_search(alpm_db_t *db, const alpm_list_t *needles);
 
+typedef enum _alpm_db_usage_ {
+	ALPM_DB_USAGE_SYNC = 1,
+	ALPM_DB_USAGE_SEARCH = (1 << 1),
+	ALPM_DB_USAGE_INSTALL = (1 << 2),
+	ALPM_DB_USAGE_UPGRADE = (1 << 3),
+	ALPM_DB_USAGE_ALL = (1 << 4) - 1,
+} alpm_db_usage_t;
+
+/** Sets the usage of a database.
+ * @param db pointer to the package database to set the status for
+ * @param usage a bitmask of alpm_db_usage_t values
+ * @return 0 on success, or -1 on error
+ */
+int alpm_db_set_usage(alpm_db_t *db, alpm_db_usage_t usage);
+
+/** Gets the usage of a database.
+ * @param db pointer to the package database to get the status of
+ * @param usage pointer to an alpm_db_usage_t to store db's status
+ * @return 0 on success, or -1 on error
+ */
+int alpm_db_get_usage(alpm_db_t *db, alpm_db_usage_t *usage);
+
 /** @} */
 
 /** @addtogroup alpm_api_packages Package Functions
diff --git a/lib/libalpm/be_local.c b/lib/libalpm/be_local.c
index 49b1c742..2c18a453 100644
--- a/lib/libalpm/be_local.c
+++ b/lib/libalpm/be_local.c
@@ -1091,6 +1091,7 @@ alpm_db_t *_alpm_db_register_local(alpm_handle_t *handle)
 	}
 	db->ops = &local_db_ops;
 	db->handle = handle;
+	db->usage = ALPM_DB_USAGE_ALL;
 
 	if(local_db_validate(db)) {
 		/* pm_errno set in local_db_validate() */
diff --git a/lib/libalpm/be_sync.c b/lib/libalpm/be_sync.c
index 0b996843..123d9539 100644
--- a/lib/libalpm/be_sync.c
+++ b/lib/libalpm/be_sync.c
@@ -183,6 +183,10 @@ int SYMEXPORT alpm_db_update(int force, alpm_db_t *db)
 	ASSERT(db != handle->db_local, RET_ERR(handle, ALPM_ERR_WRONG_ARGS, -1));
 	ASSERT(db->servers != NULL, RET_ERR(handle, ALPM_ERR_SERVER_NONE, -1));
 
+	if(!(db->usage & ALPM_DB_USAGE_SYNC)) {
+		return 0;
+	}
+
 	syncpath = get_sync_dir(handle);
 	if(!syncpath) {
 		return -1;
diff --git a/lib/libalpm/db.c b/lib/libalpm/db.c
index 3a04a87b..3245d64f 100644
--- a/lib/libalpm/db.c
+++ b/lib/libalpm/db.c
@@ -292,6 +292,23 @@ alpm_list_t SYMEXPORT *alpm_db_search(alpm_db_t *db, const alpm_list_t *needles)
 	return _alpm_db_search(db, needles);
 }
 
+/** Sets the usage bitmask for a repo */
+int SYMEXPORT alpm_db_set_usage(alpm_db_t *db, alpm_db_usage_t usage)
+{
+	ASSERT(db != NULL, return -1);
+	db->usage = usage;
+	return 0;
+}
+
+/** Gets the usage bitmask for a repo */
+int SYMEXPORT alpm_db_get_usage(alpm_db_t *db, alpm_db_usage_t *usage)
+{
+	ASSERT(db != NULL, return -1);
+	ASSERT(usage != NULL, return -1);
+	*usage = db->usage;
+	return 0;
+}
+
 
 /** @} */
 
@@ -365,6 +382,11 @@ alpm_list_t *_alpm_db_search(alpm_db_t *db, const alpm_list_t *needles)
 {
 	const alpm_list_t *i, *j, *k;
 	alpm_list_t *ret = NULL;
+
+	if(!(db->usage & ALPM_DB_USAGE_SEARCH)) {
+		return NULL;
+	}
+
 	/* copy the pkgcache- we will free the list var after each needle */
 	alpm_list_t *list = alpm_list_copy(_alpm_db_get_pkgcache(db));
 
diff --git a/lib/libalpm/db.h b/lib/libalpm/db.h
index 80292933..4bb6ee91 100644
--- a/lib/libalpm/db.h
+++ b/lib/libalpm/db.h
@@ -73,6 +73,7 @@ struct __alpm_db_t {
 	/* flags determining validity, local, loaded caches, etc. */
 	enum _alpm_dbstatus_t status;
 	alpm_siglevel_t siglevel;
+	alpm_db_usage_t usage;
 };
 
 
diff --git a/lib/libalpm/deps.c b/lib/libalpm/deps.c
index c8aabb2d..745eac17 100644
--- a/lib/libalpm/deps.c
+++ b/lib/libalpm/deps.c
@@ -654,7 +654,14 @@ static alpm_pkg_t *resolvedep(alpm_handle_t *handle, alpm_depend_t *dep,
 
 	/* 1. literals */
 	for(i = dbs; i; i = i->next) {
-		alpm_pkg_t *pkg = _alpm_db_get_pkgfromcache(i->data, dep->name);
+		alpm_pkg_t *pkg;
+		alpm_db_t *db = i->data;
+
+		if(!(db->usage & (ALPM_DB_USAGE_INSTALL|ALPM_DB_USAGE_UPGRADE))) {
+			continue;
+		}
+
+		pkg = _alpm_db_get_pkgfromcache(db, dep->name);
 		if(pkg && _alpm_depcmp_literal(pkg, dep)
 				&& !alpm_pkg_find(excluding, pkg->name)) {
 			if(_alpm_pkg_should_ignore(handle, pkg)) {
@@ -676,7 +683,11 @@ static alpm_pkg_t *resolvedep(alpm_handle_t *handle, alpm_depend_t *dep,
 	}
 	/* 2. satisfiers (skip literals here) */
 	for(i = dbs; i; i = i->next) {
-		for(j = _alpm_db_get_pkgcache(i->data); j; j = j->next) {
+		alpm_db_t *db = i->data;
+		if(!(db->usage & (ALPM_DB_USAGE_INSTALL|ALPM_DB_USAGE_UPGRADE))) {
+			continue;
+		}
+		for(j = _alpm_db_get_pkgcache(db); j; j = j->next) {
 			alpm_pkg_t *pkg = j->data;
 			/* with hash != hash, we can even skip the strcmp() as we know they can't
 			 * possibly be the same string */
diff --git a/lib/libalpm/sync.c b/lib/libalpm/sync.c
index f9217bd4..98c0bc1d 100644
--- a/lib/libalpm/sync.c
+++ b/lib/libalpm/sync.c
@@ -60,7 +60,12 @@ alpm_pkg_t SYMEXPORT *alpm_sync_newversion(alpm_pkg_t *pkg, alpm_list_t *dbs_syn
 	pkg->handle->pm_errno = 0;
 
 	for(i = dbs_sync; !spkg && i; i = i->next) {
-		spkg = _alpm_db_get_pkgfromcache(i->data, pkg->name);
+		alpm_db_t *db = i->data;
+		if(!(db->usage & ALPM_DB_USAGE_SEARCH)) {
+			continue;
+		}
+
+		spkg = _alpm_db_get_pkgfromcache(db, pkg->name);
 	}
 
 	if(spkg == NULL) {
@@ -212,8 +217,14 @@ int SYMEXPORT alpm_sync_sysupgrade(alpm_handle_t *handle, int enable_downgrade)
 		/* Search for replacers then literal (if no replacer) in each sync database. */
 		for(j = handle->dbs_sync; j; j = j->next) {
 			alpm_db_t *sdb = j->data;
-			alpm_list_t *replacers = check_replacers(handle, lpkg, sdb);
+			alpm_list_t *replacers;
+
+			if(!(sdb->usage & ALPM_DB_USAGE_UPGRADE)) {
+				continue;
+			}
+
 			/* Check sdb */
+			replacers = check_replacers(handle, lpkg, sdb);
 			if(replacers) {
 				trans->add = alpm_list_join(trans->add, replacers);
 				/* jump to next local package */