1 files changed, 69 insertions, 0 deletions
diff --git a/devtools/server/actors/array-buffer.js b/devtools/server/actors/array-buffer.js
new file mode 100644
index 0000000000..940d17e166
--- /dev/null
+++ b/devtools/server/actors/array-buffer.js
@@ -0,0 +1,69 @@
+/* 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 {
+  arrayBufferSpec,
+} = require("resource://devtools/shared/specs/array-buffer.js");
+
+/**
+ * Creates an actor for the specified ArrayBuffer.
+ *
+ * @param {DevToolsServerConnection} conn
+ *    The server connection.
+ * @param buffer ArrayBuffer
+ *        The buffer.
+ */
+class ArrayBufferActor extends Actor {
+  constructor(conn, buffer) {
+    super(conn, arrayBufferSpec);
+    this.buffer = buffer;
+    this.bufferLength = buffer.byteLength;
+  }
+
+  rawValue() {
+    return this.buffer;
+  }
+
+  form() {
+    return {
+      actor: this.actorID,
+      length: this.bufferLength,
+      // The `typeName` is read in the source spec when reading "sourcedata"
+      // which can either be an ArrayBuffer actor or a LongString actor.
+      typeName: this.typeName,
+    };
+  }
+
+  slice(start, count) {
+    const slice = new Uint8Array(this.buffer, start, count);
+    const parts = [];
+    let offset = 0;
+    const PortionSize = 0x6000; // keep it divisible by 3 for btoa() and join()
+    while (offset + PortionSize < count) {
+      parts.push(
+        btoa(
+          String.fromCharCode.apply(
+            null,
+            slice.subarray(offset, offset + PortionSize)
+          )
+        )
+      );
+      offset += PortionSize;
+    }
+    parts.push(
+      btoa(String.fromCharCode.apply(null, slice.subarray(offset, count)))
+    );
+    return {
+      from: this.actorID,
+      encoded: parts.join(""),
+    };
+  }
+}
+
+module.exports = {
+  ArrayBufferActor,
+};