gecko-dev/js/xpconnect/loader/mozJSLoaderUtils.cpp
2019-01-03 20:55:38 +00:00

73 lines
2.4 KiB
C++

/* -*- 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,
MutableHandleScript scriptp) {
UniquePtr<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
}
JS::TranscodeBuffer buffer;
buffer.replaceRawBuffer(reinterpret_cast<uint8_t*>(buf.release()), len);
JS::TranscodeResult code = JS::DecodeScript(cx, 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;
}