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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/DebugOnly.h"
#include "nsUnicharStreamLoader.h"
#include "nsIInputStream.h"
#include <algorithm>
#include "mozilla/dom/EncodingUtils.h"
// 1024 bytes is specified in
// http://www.whatwg.org/specs/web-apps/current-work/#charset for HTML; for
// other resource types (e.g. CSS) typically fewer bytes are fine too, since
// they only look at things right at the beginning of the data.
#define SNIFFING_BUFFER_SIZE 1024
using namespace mozilla;
using mozilla::dom::EncodingUtils;
NS_IMETHODIMP
nsUnicharStreamLoader::Init(nsIUnicharStreamLoaderObserver *aObserver)
{
NS_ENSURE_ARG_POINTER(aObserver);
mObserver = aObserver;
if (!mRawData.SetCapacity(SNIFFING_BUFFER_SIZE, fallible))
return NS_ERROR_OUT_OF_MEMORY;
return NS_OK;
}
nsresult
nsUnicharStreamLoader::Create(nsISupports *aOuter,
REFNSIID aIID,
void **aResult)
{
if (aOuter) return NS_ERROR_NO_AGGREGATION;
nsUnicharStreamLoader* it = new nsUnicharStreamLoader();
NS_ADDREF(it);
nsresult rv = it->QueryInterface(aIID, aResult);
NS_RELEASE(it);
return rv;
}
NS_IMPL_ISUPPORTS(nsUnicharStreamLoader, nsIUnicharStreamLoader,
nsIRequestObserver, nsIStreamListener)
NS_IMETHODIMP
nsUnicharStreamLoader::GetChannel(nsIChannel **aChannel)
{
NS_IF_ADDREF(*aChannel = mChannel);
return NS_OK;
}
NS_IMETHODIMP
nsUnicharStreamLoader::GetCharset(nsACString& aCharset)
{
aCharset = mCharset;
return NS_OK;
}
/* nsIRequestObserver implementation */
NS_IMETHODIMP
nsUnicharStreamLoader::OnStartRequest(nsIRequest*, nsISupports*)
{
return NS_OK;
}
NS_IMETHODIMP
nsUnicharStreamLoader::OnStopRequest(nsIRequest *aRequest,
nsISupports *aContext,
nsresult aStatus)
{
if (!mObserver) {
NS_ERROR("nsUnicharStreamLoader::OnStopRequest called before ::Init");
return NS_ERROR_UNEXPECTED;
}
mContext = aContext;
mChannel = do_QueryInterface(aRequest);
nsresult rv = NS_OK;
if (mRawData.Length() > 0 && NS_SUCCEEDED(aStatus)) {
MOZ_ASSERT(mBuffer.Length() == 0,
"should not have both decoded and raw data");
rv = DetermineCharset();
}
if (NS_FAILED(rv)) {
// Call the observer but pass it no data.
mObserver->OnStreamComplete(this, mContext, rv, EmptyString());
} else {
mObserver->OnStreamComplete(this, mContext, aStatus, mBuffer);
}
mObserver = nullptr;
mDecoder = nullptr;
mContext = nullptr;
mChannel = nullptr;
mCharset.Truncate();
mRawData.Truncate();
mRawBuffer.Truncate();
mBuffer.Truncate();
return rv;
}
NS_IMETHODIMP
nsUnicharStreamLoader::GetRawBuffer(nsACString& aRawBuffer)
{
aRawBuffer = mRawBuffer;
return NS_OK;
}
/* nsIStreamListener implementation */
NS_IMETHODIMP
nsUnicharStreamLoader::OnDataAvailable(nsIRequest *aRequest,
nsISupports *aContext,
nsIInputStream *aInputStream,
uint64_t aSourceOffset,
uint32_t aCount)
{
if (!mObserver) {
NS_ERROR("nsUnicharStreamLoader::OnDataAvailable called before ::Init");
return NS_ERROR_UNEXPECTED;
}
mContext = aContext;
mChannel = do_QueryInterface(aRequest);
nsresult rv = NS_OK;
if (mDecoder) {
// process everything we've got
uint32_t dummy;
aInputStream->ReadSegments(WriteSegmentFun, this, aCount, &dummy);
} else {
// no decoder yet. Read up to SNIFFING_BUFFER_SIZE octets into
// mRawData (this is the cutoff specified in
// draft-abarth-mime-sniff-06). If we can get that much, then go
// ahead and fire charset detection and read the rest. Otherwise
// wait for more data.
uint32_t haveRead = mRawData.Length();
uint32_t toRead = std::min(SNIFFING_BUFFER_SIZE - haveRead, aCount);
uint32_t n;
char *here = mRawData.BeginWriting() + haveRead;
rv = aInputStream->Read(here, toRead, &n);
if (NS_SUCCEEDED(rv)) {
mRawData.SetLength(haveRead + n);
if (mRawData.Length() == SNIFFING_BUFFER_SIZE) {
rv = DetermineCharset();
if (NS_SUCCEEDED(rv)) {
// process what's left
uint32_t dummy;
aInputStream->ReadSegments(WriteSegmentFun, this, aCount - n, &dummy);
}
} else {
MOZ_ASSERT(n == aCount, "didn't read as much as was available");
}
}
}
mContext = nullptr;
mChannel = nullptr;
return rv;
}
nsresult
nsUnicharStreamLoader::DetermineCharset()
{
nsresult rv = mObserver->OnDetermineCharset(this, mContext,
mRawData, mCharset);
if (NS_FAILED(rv) || mCharset.IsEmpty()) {
// The observer told us nothing useful
mCharset.AssignLiteral("UTF-8");
}
// Sadly, nsIUnicharStreamLoader is exposed to extensions, so we can't
// assume mozilla::css::Loader to be the only caller. Special-casing
// replacement, since it's not invariant under a second label resolution
// operation.
if (mCharset.EqualsLiteral("replacement")) {
mDecoder = EncodingUtils::DecoderForEncoding(mCharset);
} else {
nsAutoCString charset;
if (!EncodingUtils::FindEncodingForLabelNoReplacement(mCharset, charset)) {
// If we got replacement here, the caller was not mozilla::css::Loader
// but an extension.
return NS_ERROR_UCONV_NOCONV;
}
mDecoder = EncodingUtils::DecoderForEncoding(charset);
}
// Process the data into mBuffer
uint32_t dummy;
rv = WriteSegmentFun(nullptr, this,
mRawData.BeginReading(),
0, mRawData.Length(),
&dummy);
mRawData.Truncate();
return rv;
}
nsresult
nsUnicharStreamLoader::WriteSegmentFun(nsIInputStream *,
void *aClosure,
const char *aSegment,
uint32_t,
uint32_t aCount,
uint32_t *aWriteCount)
{
nsUnicharStreamLoader* self = static_cast<nsUnicharStreamLoader*>(aClosure);
uint32_t haveRead = self->mBuffer.Length();
int32_t srcLen = aCount;
int32_t dstLen;
nsresult rv = self->mDecoder->GetMaxLength(aSegment, srcLen, &dstLen);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
uint32_t capacity = haveRead + dstLen;
if (!self->mBuffer.SetCapacity(capacity, fallible)) {
return NS_ERROR_OUT_OF_MEMORY;
}
if (!self->mRawBuffer.Append(aSegment, aCount, fallible)) {
return NS_ERROR_OUT_OF_MEMORY;
}
rv = self->mDecoder->Convert(aSegment,
&srcLen,
self->mBuffer.BeginWriting() + haveRead,
&dstLen);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
MOZ_ASSERT(srcLen == static_cast<int32_t>(aCount));
haveRead += dstLen;
self->mBuffer.SetLength(haveRead);
*aWriteCount = aCount;
return NS_OK;
}
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