gecko-dev/xpcom/io/nsUnicharInputStream.cpp

133 строки
3.4 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 "nsUnicharInputStream.h"
#include "nsIInputStream.h"
#include "nsString.h"
#include "nsTArray.h"
#include "nsCRT.h"
#include "nsStreamUtils.h"
#include "nsConverterInputStream.h"
#include "mozilla/Attributes.h"
#include <fcntl.h>
#if defined(XP_WIN)
# include <io.h>
#else
# include <unistd.h>
#endif
#define STRING_BUFFER_SIZE 8192
class StringUnicharInputStream final : public nsIUnicharInputStream {
public:
explicit StringUnicharInputStream(const nsAString& aString)
: mString(aString), mPos(0), mLen(aString.Length()) {}
NS_DECL_ISUPPORTS
NS_DECL_NSIUNICHARINPUTSTREAM
nsString mString;
uint32_t mPos;
uint32_t mLen;
private:
~StringUnicharInputStream() = default;
};
NS_IMETHODIMP
StringUnicharInputStream::Read(char16_t* aBuf, uint32_t aCount,
uint32_t* aReadCount) {
if (mPos >= mLen) {
*aReadCount = 0;
return NS_OK;
}
nsAString::const_iterator iter;
mString.BeginReading(iter);
const char16_t* us = iter.get();
uint32_t amount = mLen - mPos;
if (amount > aCount) {
amount = aCount;
}
memcpy(aBuf, us + mPos, sizeof(char16_t) * amount);
mPos += amount;
*aReadCount = amount;
return NS_OK;
}
NS_IMETHODIMP
StringUnicharInputStream::ReadSegments(nsWriteUnicharSegmentFun aWriter,
void* aClosure, uint32_t aCount,
uint32_t* aReadCount) {
uint32_t bytesWritten;
uint32_t totalBytesWritten = 0;
nsresult rv;
aCount = XPCOM_MIN<uint32_t>(mString.Length() - mPos, aCount);
nsAString::const_iterator iter;
mString.BeginReading(iter);
while (aCount) {
rv = aWriter(this, aClosure, iter.get() + mPos, totalBytesWritten, aCount,
&bytesWritten);
if (NS_FAILED(rv)) {
// don't propagate errors to the caller
break;
}
aCount -= bytesWritten;
totalBytesWritten += bytesWritten;
mPos += bytesWritten;
}
*aReadCount = totalBytesWritten;
return NS_OK;
}
NS_IMETHODIMP
StringUnicharInputStream::ReadString(uint32_t aCount, nsAString& aString,
uint32_t* aReadCount) {
if (mPos >= mLen) {
*aReadCount = 0;
return NS_OK;
}
uint32_t amount = mLen - mPos;
if (amount > aCount) {
amount = aCount;
}
aString = Substring(mString, mPos, amount);
mPos += amount;
*aReadCount = amount;
return NS_OK;
}
nsresult StringUnicharInputStream::Close() {
mPos = mLen;
return NS_OK;
}
NS_IMPL_ISUPPORTS(StringUnicharInputStream, nsIUnicharInputStream)
//----------------------------------------------------------------------
nsresult NS_NewUnicharInputStream(nsIInputStream* aStreamToWrap,
nsIUnicharInputStream** aResult) {
*aResult = nullptr;
// Create converter input stream
RefPtr<nsConverterInputStream> it = new nsConverterInputStream();
nsresult rv = it->Init(aStreamToWrap, "UTF-8", STRING_BUFFER_SIZE,
nsIConverterInputStream::ERRORS_ARE_FATAL);
if (NS_FAILED(rv)) {
return rv;
}
it.forget(aResult);
return NS_OK;
}