gecko-dev/intl/uconv/nsConverterInputStream.cpp

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7.5 KiB
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/* -*- Mode: C; tab-width: 4; 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 "nsConverterInputStream.h"
#include "nsIInputStream.h"
#include "nsReadLine.h"
#include "nsStreamUtils.h"
#include <algorithm>
#include "mozilla/dom/EncodingUtils.h"
using mozilla::dom::EncodingUtils;
#define CONVERTER_BUFFER_SIZE 8192
NS_IMPL_ISUPPORTS(nsConverterInputStream, nsIConverterInputStream,
nsIUnicharInputStream, nsIUnicharLineInputStream)
NS_IMETHODIMP
nsConverterInputStream::Init(nsIInputStream* aStream,
const char *aCharset,
int32_t aBufferSize,
char16_t aReplacementChar)
{
nsAutoCString label;
if (!aCharset) {
label.AssignLiteral("UTF-8");
} else {
label = aCharset;
}
if (aBufferSize <=0) aBufferSize=CONVERTER_BUFFER_SIZE;
// get the decoder
nsAutoCString encoding;
if (label.EqualsLiteral("UTF-16")) {
// Compat with old test cases. Unclear if any extensions really care.
encoding.Assign(label);
} else if (!EncodingUtils::FindEncodingForLabelNoReplacement(label,
encoding)) {
return NS_ERROR_UCONV_NOCONV;
}
mConverter = EncodingUtils::DecoderForEncoding(encoding);
// set up our buffers
if (!mByteData.SetCapacity(aBufferSize) ||
!mUnicharData.SetCapacity(aBufferSize)) {
return NS_ERROR_OUT_OF_MEMORY;
}
mInput = aStream;
mReplacementChar = aReplacementChar;
if (!aReplacementChar ||
aReplacementChar != mConverter->GetCharacterForUnMapped()) {
mConverter->SetInputErrorBehavior(nsIUnicodeDecoder::kOnError_Signal);
}
return NS_OK;
}
NS_IMETHODIMP
nsConverterInputStream::Close()
{
nsresult rv = mInput ? mInput->Close() : NS_OK;
mLineBuffer = nullptr;
mInput = nullptr;
mConverter = nullptr;
mByteData.Clear();
mUnicharData.Clear();
return rv;
}
NS_IMETHODIMP
nsConverterInputStream::Read(char16_t* aBuf,
uint32_t aCount,
uint32_t *aReadCount)
{
NS_ASSERTION(mUnicharDataLength >= mUnicharDataOffset, "unsigned madness");
uint32_t readCount = mUnicharDataLength - mUnicharDataOffset;
if (0 == readCount) {
// Fill the unichar buffer
readCount = Fill(&mLastErrorCode);
if (readCount == 0) {
*aReadCount = 0;
return mLastErrorCode;
}
}
if (readCount > aCount) {
readCount = aCount;
}
memcpy(aBuf, mUnicharData.Elements() + mUnicharDataOffset,
readCount * sizeof(char16_t));
mUnicharDataOffset += readCount;
*aReadCount = readCount;
return NS_OK;
}
NS_IMETHODIMP
nsConverterInputStream::ReadSegments(nsWriteUnicharSegmentFun aWriter,
void* aClosure,
uint32_t aCount, uint32_t *aReadCount)
{
NS_ASSERTION(mUnicharDataLength >= mUnicharDataOffset, "unsigned madness");
uint32_t bytesToWrite = mUnicharDataLength - mUnicharDataOffset;
nsresult rv;
if (0 == bytesToWrite) {
// Fill the unichar buffer
bytesToWrite = Fill(&rv);
if (bytesToWrite <= 0) {
*aReadCount = 0;
return rv;
}
}
if (bytesToWrite > aCount)
bytesToWrite = aCount;
uint32_t bytesWritten;
uint32_t totalBytesWritten = 0;
while (bytesToWrite) {
rv = aWriter(this, aClosure,
mUnicharData.Elements() + mUnicharDataOffset,
totalBytesWritten, bytesToWrite, &bytesWritten);
if (NS_FAILED(rv)) {
// don't propagate errors to the caller
break;
}
bytesToWrite -= bytesWritten;
totalBytesWritten += bytesWritten;
mUnicharDataOffset += bytesWritten;
}
*aReadCount = totalBytesWritten;
return NS_OK;
}
NS_IMETHODIMP
nsConverterInputStream::ReadString(uint32_t aCount, nsAString& aString,
uint32_t* aReadCount)
{
NS_ASSERTION(mUnicharDataLength >= mUnicharDataOffset, "unsigned madness");
uint32_t readCount = mUnicharDataLength - mUnicharDataOffset;
if (0 == readCount) {
// Fill the unichar buffer
readCount = Fill(&mLastErrorCode);
if (readCount == 0) {
*aReadCount = 0;
return mLastErrorCode;
}
}
if (readCount > aCount) {
readCount = aCount;
}
const char16_t* buf = mUnicharData.Elements() + mUnicharDataOffset;
aString.Assign(buf, readCount);
mUnicharDataOffset += readCount;
*aReadCount = readCount;
return NS_OK;
}
uint32_t
nsConverterInputStream::Fill(nsresult * aErrorCode)
{
if (nullptr == mInput) {
// We already closed the stream!
*aErrorCode = NS_BASE_STREAM_CLOSED;
return 0;
}
if (NS_FAILED(mLastErrorCode)) {
// We failed to completely convert last time, and error-recovery
// is disabled. We will fare no better this time, so...
*aErrorCode = mLastErrorCode;
return 0;
}
// We assume a many to one conversion and are using equal sizes for
// the two buffers. However if an error happens at the very start
// of a byte buffer we may end up in a situation where n bytes lead
// to n+1 unicode chars. Thus we need to keep track of the leftover
// bytes as we convert.
uint32_t nb;
*aErrorCode = NS_FillArray(mByteData, mInput, mLeftOverBytes, &nb);
if (nb == 0 && mLeftOverBytes == 0) {
// No more data
*aErrorCode = NS_OK;
return 0;
}
NS_ASSERTION(uint32_t(nb) + mLeftOverBytes == mByteData.Length(),
"mByteData is lying to us somewhere");
// Now convert as much of the byte buffer to unicode as possible
mUnicharDataOffset = 0;
mUnicharDataLength = 0;
uint32_t srcConsumed = 0;
do {
int32_t srcLen = mByteData.Length() - srcConsumed;
int32_t dstLen = mUnicharData.Capacity() - mUnicharDataLength;
*aErrorCode = mConverter->Convert(mByteData.Elements()+srcConsumed,
&srcLen,
mUnicharData.Elements()+mUnicharDataLength,
&dstLen);
mUnicharDataLength += dstLen;
// XXX if srcLen is negative, we want to drop the _first_ byte in
// the erroneous byte sequence and try again. This is not quite
// possible right now -- see bug 160784
srcConsumed += srcLen;
if (NS_FAILED(*aErrorCode) && mReplacementChar) {
NS_ASSERTION(0 < mUnicharData.Capacity() - mUnicharDataLength,
"Decoder returned an error but filled the output buffer! "
"Should not happen.");
mUnicharData.Elements()[mUnicharDataLength++] = mReplacementChar;
++srcConsumed;
// XXX this is needed to make sure we don't underrun our buffer;
// bug 160784 again
srcConsumed = std::max<uint32_t>(srcConsumed, 0);
mConverter->Reset();
}
NS_ASSERTION(srcConsumed <= mByteData.Length(),
"Whoa. The converter should have returned NS_OK_UDEC_MOREINPUT before this point!");
} while (mReplacementChar &&
NS_FAILED(*aErrorCode) &&
mUnicharData.Capacity() > mUnicharDataLength);
mLeftOverBytes = mByteData.Length() - srcConsumed;
return mUnicharDataLength;
}
NS_IMETHODIMP
nsConverterInputStream::ReadLine(nsAString& aLine, bool* aResult)
{
if (!mLineBuffer) {
mLineBuffer = new nsLineBuffer<char16_t>;
}
return NS_ReadLine(this, mLineBuffer.get(), aLine, aResult);
}