1 files changed, 157 insertions, 0 deletions
diff --git a/extension/background/query.ts b/extension/background/query.ts
new file mode 100644
index 000000000..bfe3102f3
--- /dev/null
+++ b/extension/background/query.ts
@@ -0,0 +1,157 @@
+/*
+ This file is part of TALER
+ (C) 2015 GNUnet e.V.
+
+ TALER is free software; you can redistribute it and/or modify it under the
+ terms of the GNU General Public License as published by the Free Software
+ Foundation; either version 3, or (at your option) any later version.
+
+ TALER is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ TALER; see the file COPYING.  If not, If not, see <http://www.gnu.org/licenses/>
+ */
+
+/// <reference path="../decl/chrome/chrome.d.ts" />
+
+"use strict";
+
+
+function Query(db) {
+  return new QueryRoot(db);
+}
+
+class QueryStream  {
+  qr: QueryRoot;
+  storeName;
+  constructor(qr, storeName) {
+    this.qr = qr;
+    this.storeName = storeName;
+  }
+  join(indexName: string, key: any) {
+    // join on the source relation's key, which may be
+    // a path or a transformer function
+    throw Error("Not implemented");
+  }
+  reduce(f, acc): Promise<any> {
+    let leakedResolve;
+    let p = new Promise((resolve, reject) => {
+      leakedResolve = resolve;
+    });
+    let qr = this.qr;
+    let storeName = this.storeName;
+
+    function doReduce() {
+      let req = qr.tx.objectStore(storeName).openCursor();
+      req.onsuccess = (e) => {
+        let cursor: IDBCursorWithValue = req.result;
+        if (cursor) {
+          acc = f(acc, cursor.value);
+          cursor.continue();
+        } else {
+          leakedResolve(acc);
+        }
+      }
+    }
+
+    this.qr.work.push(doReduce);
+    // We need this one level of indirection so that the kickoff
+    // is run asynchronously.
+    return Promise.resolve().then(() => this.qr.finish().then(() => p));
+  }
+}
+
+
+class QueryRoot {
+  work = [];
+  db: IDBDatabase;
+  tx: IDBTransaction;
+  stores = new Set();
+  kickoffPromise;
+
+  constructor(db) {
+    this.db = db;
+  }
+
+  iter(storeName): QueryStream {
+    this.stores.add(storeName);
+    return new QueryStream(this, storeName);
+  }
+
+  put(storeName, val): QueryRoot {
+    this.stores.add(storeName);
+    function doPut() {
+      this.tx.objectStore(storeName).put(val);
+    }
+    this.work.push(doPut);
+    return this;
+  }
+
+  putAll(storeName, iterable): QueryRoot {
+    this.stores.add(storeName);
+    function doPutAll() {
+      for (let obj of iterable) {
+        this.tx.objectStore(storeName).put(obj);
+      }
+    }
+    this.work.push(doPutAll);
+    return this;
+  }
+
+  add(storeName, val): QueryRoot {
+    this.stores.add(storeName);
+    function doAdd() {
+      this.tx.objectStore(storeName).add(val);
+    }
+    this.work.push(doAdd);
+    return this;
+  }
+
+  get(storeName, key): Promise<any> {
+    this.stores.add(storeName);
+    let leakedResolve;
+    let p = new Promise((resolve, reject) => {
+      leakedResolve = resolve;
+    });
+    if (!leakedResolve) {
+      // According to ES6 spec (paragraph 25.4.3.1), this can't happen.
+      throw Error("assertion failed");
+    }
+    function doGet() {
+      let req = this.tx.objectStore(storeName).get(key);
+      req.onsuccess = (r) => {
+        leakedResolve(r);
+      };
+    }
+    this.work.push(doGet);
+    return p;
+  }
+
+  finish(): Promise<void> {
+    if (this.kickoffPromise) {
+      return this.kickoffPromise;
+    }
+    this.kickoffPromise = new Promise((resolve, reject) => {
+
+      this.tx = this.db.transaction(Array.from(this.stores), "readwrite");
+      this.tx.oncomplete = () => {
+        resolve();
+      };
+      for (let w of this.work) {
+        w();
+      }
+    });
+    return this.kickoffPromise;
+  }
+
+  delete(storeName: string, key): QueryRoot {
+    this.stores.add(storeName);
+    function doDelete() {
+      this.tx.objectStore(storeName).delete(key);
+    }
+    this.work.push(doDelete);
+    return this;
+  }
+}
+\ No newline at end of file