add priorities to crypto work

lib/wallet/cryptoApi.ts

@@ -27,17 +27,55 @@ import {Denomination} from "./types";
 import {Offer} from "./wallet";
 import {CoinWithDenom} from "./wallet";
 import {PayCoinInfo} from "./types";
-type RegistryEntry = {resolve: any; reject: any};
+
+interface RegistryEntry {
+  resolve: any;
+  reject: any;
+  workerIndex: number;
+}
+
+interface WorkerState {
+  /**
+   * The actual worker thread.
+   */
+  w: Worker;
+  /**
+   * Are we currently running a task on this worker?
+   */
+  busy: boolean;
+}
+
+interface WorkItem {
+  operation: string;
+  args: any[];
+  resolve: any;
+  reject: any;
+}
+
+
+/**
+ * Number of different priorities. Each priority p
+ * must be 0 <= p < NUM_PRIO.
+ */
+const NUM_PRIO = 5;
+
 export class CryptoApi {
   private nextRpcId: number = 1;
   private rpcRegistry: {[n: number]: RegistryEntry} = {};
-  private cryptoWorker: Worker;
+  private workers: WorkerState[];
+  private workQueues: WorkItem[][];
+  /**
+   * Number of busy workers.
+   */
+  private numBusy: number = 0;
+  /**
+   * Number if pending work items.
+   */
+  private numWaiting: number = 0;
 
 
   constructor() {
-    this.cryptoWorker = new Worker("/lib/wallet/cryptoWorker.js");
-
-    this.cryptoWorker.onmessage = (msg: MessageEvent) => {
+    let handler = (msg: MessageEvent) => {
       let id = msg.data.id;
       if (typeof id !== "number") {
         console.error("rpc id must be number");
@@ -47,54 +85,111 @@ export class CryptoApi {
         console.error(`RPC with id ${id} has no registry entry`);
         return;
       }
-      let {resolve, reject} = this.rpcRegistry[id];
+      let {resolve, workerIndex} = this.rpcRegistry[id];
+      delete this.rpcRegistry[id];
+      let ws = this.workers[workerIndex];
+      ws.busy = false;
+      this.numBusy--;
       resolve(msg.data.result);
+
+      // try to find more work for this worker
+      for (let i = 0; i < NUM_PRIO; i++) {
+        let q = this.workQueues[NUM_PRIO - i - 1];
+        if (q.length != 0) {
+          let work: WorkItem = q.shift()!;
+          let msg: any = {
+            operation: work.operation,
+            args: work.args,
+            id: this.registerRpcId(work.resolve, work.reject, workerIndex),
+          };
+          ws.w.postMessage(msg);
+          ws.busy = true;
+          this.numBusy++;
+        }
+      }
+    };
+
+    this.workers = new Array<WorkerState>((navigator as any)["hardwareConcurrency"] || 2);
+
+    for (let i = 0; i < this.workers.length; i++) {
+      let w = new Worker("/lib/wallet/cryptoWorker.js");
+      w.onmessage = handler;
+      this.workers[i] = {
+        w,
+        busy: false,
+      };
+    }
+    this.workQueues = [];
+    for (let i = 0; i < NUM_PRIO; i++) {
+      this.workQueues.push([]);
     }
   }
 
 
-  private registerRpcId(resolve: any, reject: any): number {
+  private registerRpcId(resolve: any, reject: any,
+                        workerIndex: number): number {
     let id = this.nextRpcId++;
-    this.rpcRegistry[id] = {resolve, reject};
+    this.rpcRegistry[id] = {resolve, reject, workerIndex};
     return id;
   }
 
 
-  private doRpc<T>(methodName: string, ...args: any[]): Promise<T> {
-    return new Promise<T>((resolve, reject) => {
-      let msg = {
-        operation: methodName,
-        id: this.registerRpcId(resolve, reject),
-        args: args,
-      };
-      this.cryptoWorker.postMessage(msg);
-    });
+  private doRpc<T>(operation: string, priority: number,
+                   ...args: any[]): Promise<T> {
+    if (this.numBusy == this.workers.length) {
+      let q = this.workQueues[priority];
+      if (!q) {
+        throw Error("assertion failed");
+      }
+      return new Promise<T>((resolve, reject) => {
+        this.workQueues[priority].push({operation, args, resolve, reject});
+      });
+    }
+
+    for (let i = 0; i < this.workers.length; i++) {
+      let ws = this.workers[i];
+      if (ws.busy) {
+        continue;
+      }
+
+      return new Promise<T>((resolve, reject) => {
+        let msg: any = {
+          operation, args,
+          id: this.registerRpcId(resolve, reject, i),
+        };
+        ws.w.postMessage(msg);
+        ws.busy = true;
+        this.numBusy++;
+      });
+    }
+
+    throw Error("assertion failed");
   }
 
 
   createPreCoin(denom: Denomination, reserve: Reserve): Promise<PreCoin> {
-    return this.doRpc("createPreCoin", denom, reserve);
+    return this.doRpc("createPreCoin", 1, denom, reserve);
   }
 
   hashRsaPub(rsaPub: string): Promise<string> {
-    return this.doRpc("hashRsaPub", rsaPub);
+    return this.doRpc("hashRsaPub", 2, rsaPub);
   }
 
   isValidDenom(denom: Denomination,
                masterPub: string): Promise<boolean> {
-    return this.doRpc("isValidDenom", denom, masterPub);
+    return this.doRpc("isValidDenom", 2, denom, masterPub);
   }
 
   signDeposit(offer: Offer,
               cds: CoinWithDenom[]): Promise<PayCoinInfo> {
-    return this.doRpc("signDeposit", offer, cds);
+    return this.doRpc("signDeposit", 3, offer, cds);
   }
 
   createEddsaKeypair(): Promise<{priv: string, pub: string}> {
-    return this.doRpc("createEddsaKeypair");
+    return this.doRpc("createEddsaKeypair", 1);
   }
 
   rsaUnblind(sig: string, bk: string, pk: string): Promise<string> {
-    return this.doRpc("rsaUnblind", sig, bk, pk);
+    return this.doRpc("rsaUnblind", 4, sig, bk, pk);
   }
 }