gecko-dev/xpcom/io/nsUnicharInputStream.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
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* decision by deleting the provisions above and replace them with the notice
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* the provisions above, a recipient may use your version of this file under
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*
* ***** END LICENSE BLOCK ***** */
#include "nsIUnicharInputStream.h"
#include "nsIInputStream.h"
#include "nsIByteBuffer.h"
#include "nsIUnicharBuffer.h"
#include "nsIServiceManager.h"
#include "nsString.h"
#include "nsCRT.h"
#include "nsUTF8Utils.h"
#include <fcntl.h>
#if defined(NS_WIN32)
#include <io.h>
#else
#include <unistd.h>
#endif
class StringUnicharInputStream : public nsIUnicharInputStream {
public:
StringUnicharInputStream(const nsAString* aString,
PRBool aTakeOwnership);
NS_DECL_ISUPPORTS
NS_DECL_NSIUNICHARINPUTSTREAM
const nsAString* mString;
PRUint32 mPos;
PRUint32 mLen;
PRBool mOwnsString;
private:
~StringUnicharInputStream();
};
StringUnicharInputStream::StringUnicharInputStream(const nsAString* aString,
PRBool aTakeOwnership)
: mString(aString),
mPos(0),
mLen(aString->Length()),
mOwnsString(aTakeOwnership)
{
}
StringUnicharInputStream::~StringUnicharInputStream()
{
if (mString && mOwnsString) {
// Some compilers dislike deleting const pointers
nsAString* mutable_string = NS_CONST_CAST(nsAString*, mString);
delete mutable_string;
}
}
NS_IMETHODIMP
StringUnicharInputStream::Read(PRUnichar* aBuf,
PRUint32 aCount,
PRUint32 *aReadCount)
{
if (mPos >= mLen) {
*aReadCount = 0;
return NS_OK;
}
nsAString::const_iterator iter;
mString->BeginReading(iter);
const PRUnichar* us = iter.get();
PRUint32 amount = mLen - mPos;
if (amount > aCount) {
amount = aCount;
}
memcpy(aBuf, us + mPos, sizeof(PRUnichar) * amount);
mPos += amount;
*aReadCount = amount;
return NS_OK;
}
NS_IMETHODIMP
StringUnicharInputStream::ReadSegments(nsWriteUnicharSegmentFun aWriter,
void* aClosure,
PRUint32 aCount, PRUint32 *aReadCount)
{
PRUint32 bytesWritten;
PRUint32 totalBytesWritten = 0;
nsresult rv;
aCount = PR_MIN(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(PRUint32 aCount, nsAString& aString,
PRUint32* aReadCount)
{
if (mPos >= mLen) {
*aReadCount = 0;
return NS_OK;
}
PRUint32 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;
if (mString && mOwnsString) {
// Some compilers dislike deleting const pointers
nsAString* mutable_string = NS_CONST_CAST(nsAString*, mString);
delete mutable_string;
}
mString = nsnull;
return NS_OK;
}
NS_IMPL_ISUPPORTS1(StringUnicharInputStream, nsIUnicharInputStream)
NS_COM nsresult
NS_NewStringUnicharInputStream(nsIUnicharInputStream** aInstancePtrResult,
const nsAString* aString,
PRBool aTakeOwnership)
{
NS_ENSURE_ARG_POINTER(aString);
NS_PRECONDITION(aInstancePtrResult, "null ptr");
StringUnicharInputStream* it = new StringUnicharInputStream(aString,
aTakeOwnership);
if (!it) {
return NS_ERROR_OUT_OF_MEMORY;
}
NS_ADDREF(*aInstancePtrResult = it);
return NS_OK;
}
//----------------------------------------------------------------------
class UTF8InputStream : public nsIUnicharInputStream {
public:
UTF8InputStream();
nsresult Init(nsIInputStream* aStream, PRUint32 aBufSize);
NS_DECL_ISUPPORTS
NS_DECL_NSIUNICHARINPUTSTREAM
private:
~UTF8InputStream();
protected:
PRInt32 Fill(nsresult * aErrorCode);
static void CountValidUTF8Bytes(const char *aBuf, PRUint32 aMaxBytes, PRUint32& aValidUTF8bytes, PRUint32& aValidUTF16CodeUnits);
nsCOMPtr<nsIInputStream> mInput;
nsCOMPtr<nsIByteBuffer> mByteData;
nsCOMPtr<nsIUnicharBuffer> mUnicharData;
PRUint32 mByteDataOffset;
PRUint32 mUnicharDataOffset;
PRUint32 mUnicharDataLength;
};
UTF8InputStream::UTF8InputStream() :
mByteDataOffset(0),
mUnicharDataOffset(0),
mUnicharDataLength(0)
{
}
nsresult
UTF8InputStream::Init(nsIInputStream* aStream, PRUint32 aBufferSize)
{
if (aBufferSize == 0) {
aBufferSize = 8192;
}
nsresult rv = NS_NewByteBuffer(getter_AddRefs(mByteData), nsnull, aBufferSize);
if (NS_FAILED(rv)) return rv;
rv = NS_NewUnicharBuffer(getter_AddRefs(mUnicharData), nsnull, aBufferSize);
if (NS_FAILED(rv)) return rv;
mInput = aStream;
return NS_OK;
}
NS_IMPL_ISUPPORTS1(UTF8InputStream,nsIUnicharInputStream)
UTF8InputStream::~UTF8InputStream()
{
Close();
}
nsresult UTF8InputStream::Close()
{
mInput = nsnull;
mByteData = nsnull;
mUnicharData = nsnull;
return NS_OK;
}
nsresult UTF8InputStream::Read(PRUnichar* aBuf,
PRUint32 aCount,
PRUint32 *aReadCount)
{
NS_ASSERTION(mUnicharDataLength >= mUnicharDataOffset, "unsigned madness");
PRUint32 readCount = mUnicharDataLength - mUnicharDataOffset;
nsresult errorCode;
if (0 == readCount) {
// Fill the unichar buffer
readCount = Fill(&errorCode);
if (readCount <= 0) {
*aReadCount = 0;
return errorCode;
}
}
if (readCount > aCount) {
readCount = aCount;
}
memcpy(aBuf, mUnicharData->GetBuffer() + mUnicharDataOffset,
readCount * sizeof(PRUnichar));
mUnicharDataOffset += readCount;
*aReadCount = readCount;
return NS_OK;
}
NS_IMETHODIMP
UTF8InputStream::ReadSegments(nsWriteUnicharSegmentFun aWriter,
void* aClosure,
PRUint32 aCount, PRUint32 *aReadCount)
{
NS_ASSERTION(mUnicharDataLength >= mUnicharDataOffset, "unsigned madness");
PRUint32 bytesToWrite = mUnicharDataLength - mUnicharDataOffset;
nsresult rv = NS_OK;
if (0 == bytesToWrite) {
// Fill the unichar buffer
bytesToWrite = Fill(&rv);
if (bytesToWrite <= 0) {
*aReadCount = 0;
return rv;
}
}
if (bytesToWrite > aCount)
bytesToWrite = aCount;
PRUint32 bytesWritten;
PRUint32 totalBytesWritten = 0;
while (bytesToWrite) {
rv = aWriter(this, aClosure,
mUnicharData->GetBuffer() + 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
UTF8InputStream::ReadString(PRUint32 aCount, nsAString& aString,
PRUint32* aReadCount)
{
NS_ASSERTION(mUnicharDataLength >= mUnicharDataOffset, "unsigned madness");
PRUint32 readCount = mUnicharDataLength - mUnicharDataOffset;
nsresult errorCode;
if (0 == readCount) {
// Fill the unichar buffer
readCount = Fill(&errorCode);
if (readCount <= 0) {
*aReadCount = 0;
return errorCode;
}
}
if (readCount > aCount) {
readCount = aCount;
}
const PRUnichar* buf = NS_REINTERPRET_CAST(const PRUnichar*,
mUnicharData->GetBuffer() +
mUnicharDataOffset);
aString.Assign(buf, readCount);
mUnicharDataOffset += readCount;
*aReadCount = readCount;
return NS_OK;
}
PRInt32 UTF8InputStream::Fill(nsresult * aErrorCode)
{
if (nsnull == mInput) {
// We already closed the stream!
*aErrorCode = NS_BASE_STREAM_CLOSED;
return -1;
}
NS_ASSERTION(mByteData->GetLength() >= mByteDataOffset, "unsigned madness");
PRUint32 remainder = mByteData->GetLength() - mByteDataOffset;
mByteDataOffset = remainder;
PRInt32 nb = mByteData->Fill(aErrorCode, mInput, remainder);
if (nb <= 0) {
// Because we assume a many to one conversion, the lingering data
// in the byte buffer must be a partial conversion
// fragment. Because we know that we have received no more new
// data to add to it, we can't convert it. Therefore, we discard
// it.
return nb;
}
NS_ASSERTION(remainder + nb == mByteData->GetLength(), "bad nb");
// Now convert as much of the byte buffer to unicode as possible
PRUint32 srcLen, dstLen;
CountValidUTF8Bytes(mByteData->GetBuffer(),remainder + nb, srcLen, dstLen);
// the number of UCS2 characters should always be <= the number of
// UTF8 chars
NS_ASSERTION( (remainder+nb >= srcLen), "cannot be longer than out buffer");
NS_ASSERTION(PRInt32(dstLen) <= mUnicharData->GetBufferSize(),
"Ouch. I would overflow my buffer if I wasn't so careful.");
if (PRInt32(dstLen) > mUnicharData->GetBufferSize()) return 0;
ConvertUTF8toUTF16 converter(mUnicharData->GetBuffer());
nsASingleFragmentCString::const_char_iterator start = mByteData->GetBuffer();
nsASingleFragmentCString::const_char_iterator end = mByteData->GetBuffer() + srcLen;
copy_string(start, end, converter);
NS_ASSERTION(converter.Length() == dstLen, "length mismatch");
mUnicharDataOffset = 0;
mUnicharDataLength = dstLen;
mByteDataOffset = srcLen;
return dstLen;
}
void
UTF8InputStream::CountValidUTF8Bytes(const char* aBuffer, PRUint32 aMaxBytes, PRUint32& aValidUTF8bytes, PRUint32& aValidUTF16CodeUnits)
{
const char *c = aBuffer;
const char *end = aBuffer + aMaxBytes;
const char *lastchar = c; // pre-initialize in case of 0-length buffer
PRUint32 utf16length = 0;
while (c < end && *c) {
lastchar = c;
utf16length++;
if (UTF8traits::isASCII(*c))
c++;
else if (UTF8traits::is2byte(*c))
c += 2;
else if (UTF8traits::is3byte(*c))
c += 3;
else if (UTF8traits::is4byte(*c)) {
c += 4;
utf16length++; // add 1 more because this will be converted to a
// surrogate pair.
}
else if (UTF8traits::is5byte(*c))
c += 5;
else if (UTF8traits::is6byte(*c))
c += 6;
else {
NS_WARNING("Unrecognized UTF8 string in UTF8InputStream::CountValidUTF8Bytes()");
break; // Otherwise we go into an infinite loop. But what happens now?
}
}
if (c > end) {
c = lastchar;
utf16length--;
}
aValidUTF8bytes = c - aBuffer;
aValidUTF16CodeUnits = utf16length;
}
NS_COM nsresult
NS_NewUTF8ConverterStream(nsIUnicharInputStream** aInstancePtrResult,
nsIInputStream* aStreamToWrap,
PRInt32 aBufferSize)
{
// Create converter input stream
UTF8InputStream* it = new UTF8InputStream();
if (nsnull == it) {
return NS_ERROR_OUT_OF_MEMORY;
}
nsresult rv = it->Init(aStreamToWrap, aBufferSize);
if (NS_FAILED(rv))
return rv;
return it->QueryInterface(NS_GET_IID(nsIUnicharInputStream),
(void **) aInstancePtrResult);
}