wallet-core/lib/wallet/query.ts
2016-10-19 18:40:29 +02:00

542 lines
13 KiB
TypeScript

/*
This file is part of TALER
(C) 2016 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, see <http://www.gnu.org/licenses/>
*/
/**
* Database query abstractions.
* @module Query
* @author Florian Dold
*/
"use strict";
export interface JoinResult<L,R> {
left: L;
right: R;
}
export class Store<T> {
name: string;
validator?: (v: T) => T;
storeParams: IDBObjectStoreParameters;
constructor(name: string, storeParams: IDBObjectStoreParameters,
validator?: (v: T) => T) {
this.name = name;
this.validator = validator;
this.storeParams = storeParams;
}
}
export class Index<S extends IDBValidKey,T> {
indexName: string;
storeName: string;
keyPath: string | string[];
constructor(s: Store<T>, indexName: string, keyPath: string | string[]) {
this.storeName = s.name;
this.indexName = indexName;
}
}
/**
* Stream that can be filtered, reduced or joined
* with indices.
*/
export interface QueryStream<T> {
indexJoin<S,I extends IDBValidKey>(index: Index<I,S>,
keyFn: (obj: T) => I): QueryStream<[T, S]>;
keyJoin<S,I extends IDBValidKey>(store: Store<S>,
keyFn: (obj: T) => I): QueryStream<JoinResult<T,S>>;
filter(f: (T: any) => boolean): QueryStream<T>;
reduce<S>(f: (v: T, acc: S) => S, start?: S): Promise<S>;
flatMap(f: (x: T) => T[]): QueryStream<T>;
toArray(): Promise<T[]>;
}
export let AbortTransaction = Symbol("abort_transaction");
/**
* Get an unresolved promise together with its extracted resolve / reject
* function.
*/
function openPromise<T>() {
let resolve: ((value?: T | PromiseLike<T>) => void) | null = null;
let reject: ((reason?: any) => void) | null = null;
const promise = new Promise<T>((res, rej) => {
resolve = res;
reject = rej;
});
if (!(resolve && reject)) {
// Never happens, unless JS implementation is broken
throw Error();
}
return {resolve, reject, promise};
}
abstract class QueryStreamBase<T> implements QueryStream<T> {
abstract subscribe(f: (isDone: boolean,
value: any,
tx: IDBTransaction) => void): void;
root: QueryRoot;
constructor(root: QueryRoot) {
this.root = root;
}
flatMap(f: (x: T) => T[]): QueryStream<T> {
return new QueryStreamFlatMap(this, f);
}
indexJoin<S,I extends IDBValidKey>(index: Index<I,S>,
keyFn: (obj: T) => I): QueryStream<[T, S]> {
this.root.addStoreAccess(index.storeName, false);
return new QueryStreamIndexJoin(this, index.storeName, index.indexName, keyFn);
}
keyJoin<S, I extends IDBValidKey>(store: Store<S>,
keyFn: (obj: T) => I): QueryStream<JoinResult<T, S>> {
this.root.addStoreAccess(store.name, false);
return new QueryStreamKeyJoin(this, store.name, keyFn);
}
filter(f: (x: any) => boolean): QueryStream<T> {
return new QueryStreamFilter(this, f);
}
toArray(): Promise<T[]> {
let {resolve, promise} = openPromise();
let values: T[] = [];
this.subscribe((isDone, value) => {
if (isDone) {
resolve(values);
return;
}
values.push(value);
});
return Promise.resolve()
.then(() => this.root.finish())
.then(() => promise);
}
reduce<A>(f: (x: any, acc?: A) => A, init?: A): Promise<any> {
let {resolve, promise} = openPromise();
let acc = init;
this.subscribe((isDone, value) => {
if (isDone) {
resolve(acc);
return;
}
acc = f(value, acc);
});
return Promise.resolve()
.then(() => this.root.finish())
.then(() => promise);
}
}
type FilterFn = (e: any) => boolean;
type SubscribeFn = (done: boolean, value: any, tx: IDBTransaction) => void;
interface FlatMapFn<T> {
(v: T): T[];
}
class QueryStreamFilter<T> extends QueryStreamBase<T> {
s: QueryStreamBase<T>;
filterFn: FilterFn;
constructor(s: QueryStreamBase<T>, filterFn: FilterFn) {
super(s.root);
this.s = s;
this.filterFn = filterFn;
}
subscribe(f: SubscribeFn) {
this.s.subscribe((isDone, value, tx) => {
if (isDone) {
f(true, undefined, tx);
return;
}
if (this.filterFn(value)) {
f(false, value, tx);
}
});
}
}
class QueryStreamFlatMap<T> extends QueryStreamBase<T> {
s: QueryStreamBase<T>;
flatMapFn: (v: T) => T[];
constructor(s: QueryStreamBase<T>, flatMapFn: (v: T) => T[]) {
super(s.root);
this.s = s;
this.flatMapFn = flatMapFn;
}
subscribe(f: SubscribeFn) {
this.s.subscribe((isDone, value, tx) => {
if (isDone) {
f(true, undefined, tx);
return;
}
let values = this.flatMapFn(value);
for (let v in values) {
f(false, value, tx)
}
});
}
}
class QueryStreamIndexJoin<T, S> extends QueryStreamBase<[T, S]> {
s: QueryStreamBase<T>;
storeName: string;
key: any;
indexName: string;
constructor(s: QueryStreamBase<T>, storeName: string, indexName: string,
key: any) {
super(s.root);
this.s = s;
this.storeName = storeName;
this.key = key;
this.indexName = indexName;
}
subscribe(f: SubscribeFn) {
this.s.subscribe((isDone, value, tx) => {
if (isDone) {
f(true, undefined, tx);
return;
}
console.log("joining on", this.key(value));
let s = tx.objectStore(this.storeName).index(this.indexName);
let req = s.openCursor(IDBKeyRange.only(this.key(value)));
req.onsuccess = () => {
let cursor = req.result;
if (cursor) {
f(false, [value, cursor.value], tx);
cursor.continue();
} else {
f(true, undefined, tx);
}
}
});
}
}
class QueryStreamKeyJoin<T, S> extends QueryStreamBase<JoinResult<T, S>> {
s: QueryStreamBase<T>;
storeName: string;
key: any;
constructor(s: QueryStreamBase<T>, storeName: string,
key: any) {
super(s.root);
this.s = s;
this.storeName = storeName;
this.key = key;
}
subscribe(f: SubscribeFn) {
this.s.subscribe((isDone, value, tx) => {
if (isDone) {
f(true, undefined, tx);
return;
}
console.log("joining on", this.key(value));
let s = tx.objectStore(this.storeName);
let req = s.openCursor(IDBKeyRange.only(this.key(value)));
req.onsuccess = () => {
let cursor = req.result;
if (cursor) {
f(false, {left:value, right: cursor.value}, tx);
cursor.continue();
} else {
f(true, undefined, tx);
}
}
});
}
}
class IterQueryStream<T> extends QueryStreamBase<T> {
private storeName: string;
private options: any;
private subscribers: SubscribeFn[];
constructor(qr: QueryRoot, storeName: string, options: any) {
super(qr);
this.options = options;
this.storeName = storeName;
this.subscribers = [];
let doIt = (tx: IDBTransaction) => {
const {indexName = void 0, only = void 0} = this.options;
let s: any;
if (indexName !== void 0) {
s = tx.objectStore(this.storeName)
.index(this.options.indexName);
} else {
s = tx.objectStore(this.storeName);
}
let kr: IDBKeyRange | undefined = undefined;
if (only !== undefined) {
kr = IDBKeyRange.only(this.options.only);
}
let req = s.openCursor(kr);
req.onsuccess = () => {
let cursor: IDBCursorWithValue = req.result;
if (cursor) {
for (let f of this.subscribers) {
f(false, cursor.value, tx);
}
cursor.continue();
} else {
for (let f of this.subscribers) {
f(true, undefined, tx);
}
}
}
};
this.root.addWork(doIt);
}
subscribe(f: SubscribeFn) {
this.subscribers.push(f);
}
}
export class QueryRoot {
private work: ((t: IDBTransaction) => void)[] = [];
private db: IDBDatabase;
private stores = new Set();
private kickoffPromise: Promise<void>;
/**
* Some operations is a write operation,
* and we need to do a "readwrite" transaction/
*/
private hasWrite: boolean;
constructor(db: IDBDatabase) {
this.db = db;
}
iter<T>(store: Store<T>): QueryStream<T> {
this.stores.add(store.name);
return new IterQueryStream(this, store.name, {});
}
iterIndex<S extends IDBValidKey,T>(index: Index<S,T>,
only?: S): QueryStream<T> {
this.stores.add(index.storeName);
return new IterQueryStream(this, index.storeName, {
only,
indexName: index.indexName
});
}
/**
* Put an object into the given object store.
* Overrides if an existing object with the same key exists
* in the store.
*/
put<T>(store: Store<T>, val: T): QueryRoot {
let doPut = (tx: IDBTransaction) => {
tx.objectStore(store.name).put(val);
};
this.addWork(doPut, store.name, true);
return this;
}
mutate<T>(store: Store<T>, key: any, f: (v: T) => T): QueryRoot {
let doPut = (tx: IDBTransaction) => {
let reqGet = tx.objectStore(store.name).get(key);
reqGet.onsuccess = () => {
let r = reqGet.result;
let m: T;
try {
m = f(r);
} catch (e) {
if (e == AbortTransaction) {
tx.abort();
return;
}
throw e;
}
tx.objectStore(store.name).put(m);
}
};
this.addWork(doPut, store.name, true);
return this;
}
/**
* Add all object from an iterable to the given object store.
* Fails if the object's key is already present
* in the object store.
*/
putAll<T>(store: Store<T>, iterable: T[]): QueryRoot {
const doPutAll = (tx: IDBTransaction) => {
for (let obj of iterable) {
tx.objectStore(store.name).put(obj);
}
};
this.addWork(doPutAll, store.name, true);
return this;
}
/**
* Add an object to the given object store.
* Fails if the object's key is already present
* in the object store.
*/
add<T>(store: Store<T>, val: T): QueryRoot {
const doAdd = (tx: IDBTransaction) => {
tx.objectStore(store.name).add(val);
};
this.addWork(doAdd, store.name, true);
return this;
}
/**
* Get one object from a store by its key.
*/
get<T>(store: Store<T>, key: any): Promise<T|undefined> {
if (key === void 0) {
throw Error("key must not be undefined");
}
const {resolve, promise} = openPromise();
const doGet = (tx: IDBTransaction) => {
const req = tx.objectStore(store.name).get(key);
req.onsuccess = () => {
resolve(req.result);
};
};
this.addWork(doGet, store.name, false);
return Promise.resolve()
.then(() => this.finish())
.then(() => promise);
}
/**
* Get one object from a store by its key.
*/
getIndexed<I extends IDBValidKey,T>(index: Index<I,T>,
key: I): Promise<T|undefined> {
if (key === void 0) {
throw Error("key must not be undefined");
}
const {resolve, promise} = openPromise();
const doGetIndexed = (tx: IDBTransaction) => {
const req = tx.objectStore(index.storeName)
.index(index.indexName)
.get(key);
req.onsuccess = () => {
resolve(req.result);
};
};
this.addWork(doGetIndexed, index.storeName, false);
return Promise.resolve()
.then(() => this.finish())
.then(() => promise);
}
/**
* Finish the query, and start the query in the first place if necessary.
*/
finish(): Promise<void> {
if (this.kickoffPromise) {
return this.kickoffPromise;
}
this.kickoffPromise = new Promise<void>((resolve, reject) => {
if (this.work.length == 0) {
resolve();
return;
}
const mode = this.hasWrite ? "readwrite" : "readonly";
const tx = this.db.transaction(Array.from(this.stores), mode);
tx.oncomplete = () => {
resolve();
};
tx.onabort = () => {
reject(Error("transaction aborted"));
};
for (let w of this.work) {
w(tx);
}
});
return this.kickoffPromise;
}
/**
* Delete an object by from the given object store.
*/
delete(storeName: string, key: any): QueryRoot {
const doDelete = (tx: IDBTransaction) => {
tx.objectStore(storeName).delete(key);
};
this.addWork(doDelete, storeName, true);
return this;
}
/**
* Low-level function to add a task to the internal work queue.
*/
addWork(workFn: (t: IDBTransaction) => void,
storeName?: string,
isWrite?: boolean) {
this.work.push(workFn);
if (storeName) {
this.addStoreAccess(storeName, isWrite);
}
}
addStoreAccess(storeName: string, isWrite?: boolean) {
if (storeName) {
this.stores.add(storeName);
}
if (isWrite) {
this.hasWrite = true;
}
}
}