[Init] Initial commit - NetMesh terminal manager

components/terminal/runtime/terminalFlowAckBuffer.ts

@@ -0,0 +1,74 @@
+import { FLOW_CHAR_COUNT_ACK_SIZE } from "./terminalFlowConstants";
+
+export type FlowAckBuffer = {
+  ack: (charCount: number) => void;
+  flush: () => void;
+};
+
+/** Mirrors VS Code `AckDataBufferer` in `terminalProcessManager.ts`. */
+export function createFlowAckBuffer(
+  callback: (charCount: number) => void,
+  ackSize = FLOW_CHAR_COUNT_ACK_SIZE,
+): FlowAckBuffer {
+  let unsentCharCount = 0;
+
+  const emitBatchedAcks = (): void => {
+    while (unsentCharCount > ackSize) {
+      unsentCharCount -= ackSize;
+      callback(ackSize);
+    }
+  };
+
+  return {
+    ack(charCount: number): void {
+      if (charCount <= 0) return;
+      unsentCharCount += charCount;
+      emitBatchedAcks();
+    },
+    flush(): void {
+      if (unsentCharCount <= 0) return;
+      const remainder = unsentCharCount;
+      unsentCharCount = 0;
+      callback(remainder);
+    },
+  };
+}
+
+type FlowAckBackend = {
+  ackSessionFlow?: (sessionId: string, bytes: number) => void;
+};
+
+const sessionAckBuffers = new Map<string, FlowAckBuffer>();
+
+const getOrCreateSessionAckBuffer = (
+  backend: FlowAckBackend,
+  sessionId: string,
+): FlowAckBuffer | undefined => {
+  if (!backend.ackSessionFlow) return undefined;
+  let buffer = sessionAckBuffers.get(sessionId);
+  if (!buffer) {
+    buffer = createFlowAckBuffer((bytes) => backend.ackSessionFlow!(sessionId, bytes));
+    sessionAckBuffers.set(sessionId, buffer);
+  }
+  return buffer;
+};
+
+/** Queue IPC flow ACK bytes; emits in VS Code-sized batches. */
+export const ackTerminalSessionFlow = (
+  backend: FlowAckBackend,
+  sessionId: string | null | undefined,
+  bytes: number,
+): void => {
+  if (!sessionId || bytes <= 0) return;
+  getOrCreateSessionAckBuffer(backend, sessionId)?.ack(bytes);
+};
+
+export const flushTerminalSessionFlowAck = (sessionId: string | null | undefined): void => {
+  if (!sessionId) return;
+  sessionAckBuffers.get(sessionId)?.flush();
+};
+
+export const clearTerminalSessionFlowAck = (sessionId: string | null | undefined): void => {
+  if (!sessionId) return;
+  sessionAckBuffers.delete(sessionId);
+};