Add private sharing to sqlite database

This patch introduces changes to database schema required to store
information about private path sharing.

Change-Id: I5c31decb1af2e062e5fb23108ffc9236c82763b6

diff --git a/db/db.sql b/db/db.sql
index 2d354ea..931cb0f 100644 (file)
--- a/db/db.sql
+++ b/db/db.sql
@@ -44,6 +44,24 @@ FOREIGN KEY (app_id) REFERENCES app (app_id)
 FOREIGN KEY (privilege_id) REFERENCES privilege (privilege_id)
 );
 
+CREATE TABLE IF NOT EXISTS shared_path (
+path_id INTEGER PRIMARY KEY,
+path VARCHAR NOT NULL,
+path_label VARCHAR NOT NULL,
+UNIQUE (path)
+);
+
+CREATE TABLE IF NOT EXISTS app_private_sharing (
+owner_app_id INTEGER NOT NULL,
+target_app_id INTEGER NOT NULL,
+path_id INTEGER NOT NULL,
+counter INTEGER NOT NULL,
+PRIMARY KEY (owner_app_id, target_app_id, path_id)
+FOREIGN KEY (owner_app_id) REFERENCES app (app_id)
+FOREIGN KEY (target_app_id) REFERENCES app (app_id)
+FOREIGN KEY (path_id) REFERENCES shared_path (path_id)
+);
+
 CREATE TABLE IF NOT EXISTS privilege_group (
 privilege_id INTEGER NOT NULL,
 group_name VARCHAR NOT NULL,
@@ -152,6 +170,56 @@ BEGIN
     DELETE FROM pkg WHERE pkg_id NOT IN (SELECT DISTINCT pkg_id from app);
 END;
 
+DROP VIEW IF EXISTS app_private_sharing_view;
+CREATE VIEW app_private_sharing_view AS
+SELECT
+    app1.name AS owner_app_name,
+    app2.name AS target_app_name,
+    path,
+    path_label,
+    counter
+FROM app_private_sharing
+LEFT JOIN app AS app1 ON app1.app_id = owner_app_id
+LEFT JOIN app AS app2 ON app2.app_id = target_app_id
+LEFT JOIN shared_path USING (path_id);
+
+DROP TRIGGER IF EXISTS app_private_sharing_view_insert_trigger;
+CREATE TRIGGER app_private_sharing_view_insert_trigger
+INSTEAD OF INSERT ON app_private_sharing_view
+BEGIN
+    INSERT OR IGNORE INTO shared_path(path, path_label) VALUES (NEW.path, NEW.path_label);
+    INSERT OR REPLACE INTO app_private_sharing VALUES (
+            (SELECT app_id FROM app WHERE NEW.owner_app_name = name),
+            (SELECT app_id FROM app WHERE NEW.target_app_name = name),
+            (SELECT path_id FROM shared_path WHERE NEW.path = path),
+            COALESCE((SELECT counter FROM app_private_sharing
+                      WHERE target_app_id = (SELECT app_id FROM app
+                                             WHERE NEW.target_app_name = name)
+                      AND path_id = (SELECT path_id FROM shared_path WHERE NEW.path = path)),
+                     0) + 1);
+END;
+
+DROP TRIGGER IF EXISTS app_private_sharing_view_remove_delete_trigger;
+CREATE TRIGGER app_private_sharing_view_remove_delete_trigger
+INSTEAD OF DELETE ON app_private_sharing_view
+WHEN OLD.counter = 1
+BEGIN
+    DELETE FROM app_private_sharing
+    WHERE path_id = (SELECT path_id FROM shared_path WHERE path = OLD.path)
+    AND target_app_id = (SELECT app_id FROM app WHERE name = OLD.target_app_name);
+    DELETE FROM shared_path WHERE path_id NOT IN (SELECT path_id FROM app_private_sharing) AND path = OLD.path;
+END;
+
+DROP TRIGGER IF EXISTS app_private_sharing_view_decrement_delete_trigger;
+CREATE TRIGGER app_private_sharing_view_decrement_delete_trigger
+INSTEAD OF DELETE ON app_private_sharing_view
+WHEN OLD.counter > 1
+BEGIN
+    UPDATE app_private_sharing SET counter = OLD.counter - 1
+    WHERE target_app_id = (SELECT app_id FROM app WHERE name = OLD.target_app_name)
+    AND path_id = (SELECT path_id FROM shared_path WHERE path = OLD.path);
+END;
+
 DROP VIEW IF EXISTS privilege_group_view;
 CREATE VIEW privilege_group_view AS
 SELECT