1 files changed, 72 insertions, 0 deletions
diff --git a/devtools/server/actors/heap-snapshot-file.js b/devtools/server/actors/heap-snapshot-file.js
new file mode 100644
index 0000000000..f3fd9242b2
--- /dev/null
+++ b/devtools/server/actors/heap-snapshot-file.js
@@ -0,0 +1,72 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const { Actor } = require("resource://devtools/shared/protocol.js");
+const {
+  heapSnapshotFileSpec,
+} = require("resource://devtools/shared/specs/heap-snapshot-file.js");
+
+loader.lazyRequireGetter(
+  this,
+  "DevToolsUtils",
+  "resource://devtools/shared/DevToolsUtils.js"
+);
+loader.lazyRequireGetter(
+  this,
+  "HeapSnapshotFileUtils",
+  "resource://devtools/shared/heapsnapshot/HeapSnapshotFileUtils.js"
+);
+
+/**
+ * The HeapSnapshotFileActor handles transferring heap snapshot files from the
+ * server to the client. This has to be a global actor in the parent process
+ * because child processes are sandboxed and do not have access to the file
+ * system.
+ */
+exports.HeapSnapshotFileActor = class HeapSnapshotFileActor extends Actor {
+  constructor(conn, parent) {
+    super(conn, heapSnapshotFileSpec);
+
+    if (
+      Services.appinfo.processType !== Services.appinfo.PROCESS_TYPE_DEFAULT
+    ) {
+      const err = new Error(
+        "Attempt to create a HeapSnapshotFileActor in a " +
+          "child process! The HeapSnapshotFileActor *MUST* " +
+          "be in the parent process!"
+      );
+      DevToolsUtils.reportException("HeapSnapshotFileActor's constructor", err);
+    }
+  }
+
+  /**
+   * @see MemoryFront.prototype.transferHeapSnapshot
+   */
+  async transferHeapSnapshot(snapshotId) {
+    const snapshotFilePath =
+      HeapSnapshotFileUtils.getHeapSnapshotTempFilePath(snapshotId);
+    if (!snapshotFilePath) {
+      throw new Error(`No heap snapshot with id: ${snapshotId}`);
+    }
+
+    const streamPromise = DevToolsUtils.openFileStream(snapshotFilePath);
+
+    const { size } = await IOUtils.stat(snapshotFilePath);
+    const bulkPromise = this.conn.startBulkSend({
+      actor: this.actorID,
+      type: "heap-snapshot",
+      length: size,
+    });
+
+    const [bulk, stream] = await Promise.all([bulkPromise, streamPromise]);
+
+    try {
+      await bulk.copyFrom(stream);
+    } finally {
+      stream.close();
+    }
+  }
+};