nsStructuredCloneContainer.cpp
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sw=2 et 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 "nsStructuredCloneContainer.h"
#include "nsCOMPtr.h"
#include "nsIScriptContext.h"
#include "nsIVariant.h"
#include "nsIXPConnect.h"
#include "nsServiceManagerUtils.h"
#include "nsContentUtils.h"
#include "jsapi.h"
#include "js/StructuredClone.h"
#include "mozilla/Base64.h"
using namespace mozilla;
NS_IMPL_ADDREF(nsStructuredCloneContainer)
NS_IMPL_RELEASE(nsStructuredCloneContainer)
NS_INTERFACE_MAP_BEGIN(nsStructuredCloneContainer)
NS_INTERFACE_MAP_ENTRY(nsIStructuredCloneContainer)
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
nsStructuredCloneContainer::nsStructuredCloneContainer()
: mData(nullptr), mSize(0), mVersion(0)
{
}
nsStructuredCloneContainer::~nsStructuredCloneContainer()
{
free(mData);
}
nsresult
nsStructuredCloneContainer::InitFromJSVal(const JS::Value & aData,
JSContext* aCx)
{
NS_ENSURE_STATE(!mData);
NS_ENSURE_ARG_POINTER(aCx);
// Make sure that we serialize in the right context.
MOZ_ASSERT(aCx == nsContentUtils::GetCurrentJSContext());
JS::Rooted<JS::Value> jsData(aCx, aData);
bool success = JS_WrapValue(aCx, &jsData);
NS_ENSURE_STATE(success);
uint64_t* jsBytes = nullptr;
success = JS_WriteStructuredClone(aCx, jsData, &jsBytes, &mSize,
nullptr, nullptr,
JS::UndefinedHandleValue);
NS_ENSURE_STATE(success);
NS_ENSURE_STATE(jsBytes);
// Copy jsBytes into our own buffer.
mData = (uint64_t*) malloc(mSize);
if (!mData) {
mSize = 0;
mVersion = 0;
JS_ClearStructuredClone(jsBytes, mSize);
return NS_ERROR_FAILURE;
}
else {
mVersion = JS_STRUCTURED_CLONE_VERSION;
}
memcpy(mData, jsBytes, mSize);
JS_ClearStructuredClone(jsBytes, mSize);
return NS_OK;
}
nsresult
nsStructuredCloneContainer::InitFromBase64(const nsAString &aData,
uint32_t aFormatVersion,
JSContext *aCx)
{
NS_ENSURE_STATE(!mData);
NS_ConvertUTF16toUTF8 data(aData);
nsAutoCString binaryData;
nsresult rv = Base64Decode(data, binaryData);
NS_ENSURE_SUCCESS(rv, rv);
// Copy the string's data into our own buffer.
mData = (uint64_t*) malloc(binaryData.Length());
NS_ENSURE_STATE(mData);
memcpy(mData, binaryData.get(), binaryData.Length());
mSize = binaryData.Length();
mVersion = aFormatVersion;
return NS_OK;
}
nsresult
nsStructuredCloneContainer::DeserializeToVariant(JSContext *aCx,
nsIVariant **aData)
{
NS_ENSURE_STATE(mData);
NS_ENSURE_ARG_POINTER(aData);
*aData = nullptr;
// Deserialize to a JS::Value.
JS::Rooted<JS::Value> jsStateObj(aCx);
bool hasTransferable = false;
bool success = JS_ReadStructuredClone(aCx, mData, mSize, mVersion,
&jsStateObj, nullptr, nullptr) &&
JS_StructuredCloneHasTransferables(mData, mSize,
&hasTransferable);
// We want to be sure that mData doesn't contain transferable objects
MOZ_ASSERT(!hasTransferable);
NS_ENSURE_STATE(success && !hasTransferable);
// Now wrap the JS::Value as an nsIVariant.
nsCOMPtr<nsIVariant> varStateObj;
nsCOMPtr<nsIXPConnect> xpconnect = do_GetService(nsIXPConnect::GetCID());
NS_ENSURE_STATE(xpconnect);
xpconnect->JSValToVariant(aCx, jsStateObj.address(),
getter_AddRefs(varStateObj));
NS_ENSURE_STATE(varStateObj);
NS_ADDREF(*aData = varStateObj);
return NS_OK;
}
nsresult
nsStructuredCloneContainer::GetDataAsBase64(nsAString &aOut)
{
NS_ENSURE_STATE(mData);
aOut.Truncate();
nsAutoCString binaryData(reinterpret_cast<char*>(mData), mSize);
nsAutoCString base64Data;
nsresult rv = Base64Encode(binaryData, base64Data);
NS_ENSURE_SUCCESS(rv, rv);
aOut.Assign(NS_ConvertASCIItoUTF16(base64Data));
return NS_OK;
}
nsresult
nsStructuredCloneContainer::GetSerializedNBytes(uint64_t *aSize)
{
NS_ENSURE_STATE(mData);
NS_ENSURE_ARG_POINTER(aSize);
// mSize is a size_t, while aSize is a uint64_t. We rely on an implicit cast
// here so that we'll get a compile error if a size_t-to-uint64_t cast is
// narrowing.
*aSize = mSize;
return NS_OK;
}
nsresult
nsStructuredCloneContainer::GetFormatVersion(uint32_t *aFormatVersion)
{
NS_ENSURE_STATE(mData);
NS_ENSURE_ARG_POINTER(aFormatVersion);
*aFormatVersion = mVersion;
return NS_OK;
}