feat: concurrency

mx-interpreter/utils/concurrency.ts

@@ -0,0 +1,59 @@
+
+export default class Concurrency {
+  
+    maxConcurrency : number = 1;
+  
+    
+    activeWorkers : number = 0;
+  
+    
+    private jobQueue : Function[] = [];
+  
+   
+    private waiting : Function[] = [];
+  
+  
+    constructor(maxConcurrency: number) {
+      this.maxConcurrency = maxConcurrency;
+    }
+  
+   
+    private runNextJob() : void {
+      const job = this.jobQueue.pop();
+  
+      if (job) {
+        // console.debug("Running a job...");
+        job().then(() => {
+          // console.debug("Job finished, running the next waiting job...");
+          this.runNextJob();
+        });
+      } else {
+        // console.debug("No waiting job found!");
+        this.activeWorkers -= 1;
+        if (this.activeWorkers === 0) {
+          // console.debug("This concurrency manager is idle!");
+          this.waiting.forEach((x) => x());
+        }
+      }
+    }
+  
+   
+    addJob(job: () => Promise<any>) : void {
+      // console.debug("Adding a worker!");
+      this.jobQueue.push(job);
+  
+      if (!this.maxConcurrency || this.activeWorkers < this.maxConcurrency) {
+        this.runNextJob();
+        this.activeWorkers += 1;
+      } else {
+        // console.debug("No capacity to run a worker now, waiting!");
+      }
+    }
+  
+   
+    waitForCompletion() : Promise<void> {
+      return new Promise((res) => {
+        this.waiting.push(res);
+      });
+    }
+  }