1 files changed, 78 insertions, 0 deletions
diff --git a/js/xpconnect/loader/mozJSLoaderUtils.cpp b/js/xpconnect/loader/mozJSLoaderUtils.cpp
new file mode 100644
index 0000000000..522d85c304
--- /dev/null
+++ b/js/xpconnect/loader/mozJSLoaderUtils.cpp
@@ -0,0 +1,78 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#include "mozilla/scache/StartupCache.h"
+
+#include "jsapi.h"
+#include "jsfriendapi.h"
+
+#include "mozilla/BasePrincipal.h"
+
+using namespace JS;
+using namespace mozilla::scache;
+using mozilla::UniquePtr;
+
+// We only serialize scripts with system principals. So we don't serialize the
+// principals when writing a script. Instead, when reading it back, we set the
+// principals to the system principals.
+nsresult ReadCachedScript(StartupCache* cache, nsACString& uri, JSContext* cx,
+                          const JS::ReadOnlyCompileOptions& options,
+                          MutableHandleScript scriptp) {
+  const char* buf;
+  uint32_t len;
+  nsresult rv = cache->GetBuffer(PromiseFlatCString(uri).get(), &buf, &len);
+  if (NS_FAILED(rv)) {
+    return rv;  // don't warn since NOT_AVAILABLE is an ok error
+  }
+  void* copy = malloc(len);
+  if (!copy) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  memcpy(copy, buf, len);
+  JS::TranscodeBuffer buffer;
+  buffer.replaceRawBuffer(reinterpret_cast<uint8_t*>(copy), len);
+  JS::TranscodeResult code = JS::DecodeScript(cx, options, buffer, scriptp);
+  if (code == JS::TranscodeResult_Ok) {
+    return NS_OK;
+  }
+
+  if ((code & JS::TranscodeResult_Failure) != 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  MOZ_ASSERT((code & JS::TranscodeResult_Throw) != 0);
+  JS_ClearPendingException(cx);
+  return NS_ERROR_OUT_OF_MEMORY;
+}
+
+nsresult WriteCachedScript(StartupCache* cache, nsACString& uri, JSContext* cx,
+                           HandleScript script) {
+  MOZ_ASSERT(
+      nsJSPrincipals::get(JS_GetScriptPrincipals(script))->IsSystemPrincipal());
+
+  JS::TranscodeBuffer buffer;
+  JS::TranscodeResult code = JS::EncodeScript(cx, buffer, script);
+  if (code != JS::TranscodeResult_Ok) {
+    if ((code & JS::TranscodeResult_Failure) != 0) {
+      return NS_ERROR_FAILURE;
+    }
+    MOZ_ASSERT((code & JS::TranscodeResult_Throw) != 0);
+    JS_ClearPendingException(cx);
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  size_t size = buffer.length();
+  if (size > UINT32_MAX) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Move the vector buffer into a unique pointer buffer.
+  UniquePtr<char[]> buf(
+      reinterpret_cast<char*>(buffer.extractOrCopyRawBuffer()));
+  nsresult rv =
+      cache->PutBuffer(PromiseFlatCString(uri).get(), std::move(buf), size);
+  return rv;
+}