Commit With Frontend and Backend in MERN

backend/node_modules/mongodb/src/cmap/metrics.ts

@@ -0,0 +1,58 @@
+/** @internal */
+export class ConnectionPoolMetrics {
+  static readonly TXN = 'txn' as const;
+  static readonly CURSOR = 'cursor' as const;
+  static readonly OTHER = 'other' as const;
+
+  txnConnections = 0;
+  cursorConnections = 0;
+  otherConnections = 0;
+
+  /**
+   * Mark a connection as pinned for a specific operation.
+   */
+  markPinned(pinType: string): void {
+    if (pinType === ConnectionPoolMetrics.TXN) {
+      this.txnConnections += 1;
+    } else if (pinType === ConnectionPoolMetrics.CURSOR) {
+      this.cursorConnections += 1;
+    } else {
+      this.otherConnections += 1;
+    }
+  }
+
+  /**
+   * Unmark a connection as pinned for an operation.
+   */
+  markUnpinned(pinType: string): void {
+    if (pinType === ConnectionPoolMetrics.TXN) {
+      this.txnConnections -= 1;
+    } else if (pinType === ConnectionPoolMetrics.CURSOR) {
+      this.cursorConnections -= 1;
+    } else {
+      this.otherConnections -= 1;
+    }
+  }
+
+  /**
+   * Return information about the cmap metrics as a string.
+   */
+  info(maxPoolSize: number): string {
+    return (
+      'Timed out while checking out a connection from connection pool: ' +
+      `maxPoolSize: ${maxPoolSize}, ` +
+      `connections in use by cursors: ${this.cursorConnections}, ` +
+      `connections in use by transactions: ${this.txnConnections}, ` +
+      `connections in use by other operations: ${this.otherConnections}`
+    );
+  }
+
+  /**
+   * Reset the metrics to the initial values.
+   */
+  reset(): void {
+    this.txnConnections = 0;
+    this.cursorConnections = 0;
+    this.otherConnections = 0;
+  }
+}