/*

* Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  Handler File IO Operations

 *

*/

#include <errno.h>

#include <fcntl.h>

#include <locale.h>

#include <unistd.h>

#include <string>

#include "javacommonutils.h"

#include "jniarrayutils.h"

#include "logger.h"

#include "nativefileiohandler.h"

using namespace std;

using namespace java::util;

using namespace java::fileutils;

NativeFileIOHandler::NativeFileIOHandler(const std::wstring aName)

{

    // Set the current locale to suit unicode for entire process

    setlocale(LC_ALL, "");

    mFileName = aName;

    mFileDescriptor = 0;

    mClosedTemporarily = false;

    // Setting to -1 implies reading is not being done.

    // On call to openForReading, set this to 0 and increment on subsequent reads

    mReadPosition = -1;

    // Setting to -1 implies writing is not being done.

    // On call to openForWriting, set this to 0 and increment on subsequent writes

    mWritePosition = -1;

}

NativeFileIOHandler::~NativeFileIOHandler()

{

    // Set the current locale to suit unicode for entire process

    if (mFileDescriptor)

    {

        close(mFileDescriptor);

    }

}

long NativeFileIOHandler::skip(const long aOffset)

{

    JELOG2(EJavaFile);

    handleReopenCase();

    // lseek can set the offset beyond end of file.

    // but there will be no scenario where read position goes beyond end of file.

    // First set file offset to read position.

    int newOffset = lseek(mFileDescriptor, mReadPosition, SEEK_SET);

    if (newOffset < 0)

    {

        WLOG1(EJavaFile, "NativeFileIOHandler::skip: Seek failure. %d", errno);

        return 0;

    }

    else

    {

        // Now set the file offset in relation to the current read position.

        newOffset = lseek(mFileDescriptor, aOffset, SEEK_CUR);

        if (newOffset < 0)

        {

            WLOG1(EJavaFile, "NativeFileIOHandler::skip: Seek failure. %d",

                  errno);

            return 0;

        }

    }

    long retVal = newOffset - mReadPosition;

    mReadPosition = newOffset;

    return retVal;

}

int NativeFileIOHandler::readBytes(char* aBuffer, int aLength)

{

    JELOG2(EJavaFile);

    // Throws exception in case of errors.

    handleReopenCase();

    // lseek can set the offset beyond end of file.

    // but there will be no scenario where read position goes beyond end of file.

    int error = lseek(mFileDescriptor, mReadPosition, SEEK_SET);

    if (error < 0)

    {

        WLOG2(

            EJavaFile,

            "NativeFileIOHandler::readBytes:Seek failure. Read aborted:%d : Seek to: %d",

            errno, mReadPosition);

        // Errno cannot be thrown in S60. Causes random crashes.

        // So copy and throw.

        int err = errno;

        throw err;

    }

    int bytesRead = read(mFileDescriptor, aBuffer, aLength);

    if (bytesRead < 0)

    {

        LOG1(EJavaFile, EInfo,

             "NativeFileIOHandler::readBytes: Read failure: %d", errno);

        int err = errno;

        throw err;

    }

    // Adding 0 does no harm ;-)

    mReadPosition += bytesRead;

    return bytesRead;

}

int NativeFileIOHandler::writeBytes(char* aBuffer, int aLength)

{

    JELOG2(EJavaFile);

    // Throws exception in case of error

    handleReopenCase();

    // lseek can set the offset beyond end of file.

    // but there will be no scenario where read position goes beyond end of file.

    int error = lseek(mFileDescriptor, mWritePosition, SEEK_SET);

    if (error < 0)

    {

        WLOG1(

            EJavaFile,

            "NativeFileIOHandler::writeBytes: Seek failure. Write aborted: %d",

            errno);

        // Errno cannot be thrown in S60. Causes random crashes.

        // So copy and throw.

        int err = errno;

        throw err;

    }

    int bytesWritten = write(mFileDescriptor, aBuffer, aLength);

    if (bytesWritten <= 0)

    {

        LOG1(EJavaFile, EInfo,

             "NativeFileIOHandler::writeBytes: Write failure: %d", errno);

        int err = errno;

        throw err;

    }

    mWritePosition += bytesWritten;

    return bytesWritten;

}

void NativeFileIOHandler::stopReading()

{

    JELOG2(EJavaFile);

    mReadPosition = -1;

    closeStream();

}

void NativeFileIOHandler::stopWriting()

{

    JELOG2(EJavaFile);

    mWritePosition = -1;

    closeStream();

}

void NativeFileIOHandler::closeStream()

{

    JELOG2(EJavaFile);

    if ((-1 == mReadPosition) && (-1 == mWritePosition))

    {

        close(mFileDescriptor);

        mFileDescriptor = 0;

    }

}

void NativeFileIOHandler::openForReading()

{

    JELOG2(EJavaFile);

    if (!mFileDescriptor)

    {

        // it will never come here if it is not a file.

        // so, if there is a trailing slash, remove it.

        char ch = mFileName.at(mFileName.length() - 1);

        if (ch == '\\' || ch == '/')

        {

            mFileName = mFileName.substr(0, mFileName.length() - 1);

        }

        char* utf8Name = JavaCommonUtils::wstringToUtf8(mFileName);

        if (access(utf8Name, R_OK) < 0)

        {

            // We do not have write access

            delete[] utf8Name;

            ELOG(EJavaFile,

                 "NativeFileUtils::OpenForReading: Exiting in between. no read permission");

            int error = errno;

            throw error;

        }

        mFileDescriptor = open(utf8Name, O_RDWR);

        // If open fails with Read Write mode, try read mode atleast.

        if (mFileDescriptor < 0)

        {

            mFileDescriptor = open(utf8Name, O_RDONLY);

        }

        delete[] utf8Name;

        if (mFileDescriptor < 0)

        {

            // There is some problem opening the file. Throw the cause for error.

            mFileDescriptor = 0;

            ELOG(

                EJavaFile,

                "NativeFileUtils::OpenForReading: Exiting in between unable to open in read only");

            int error = errno;

            throw error;

        }

    }

    mReadPosition = 0;

}

void NativeFileIOHandler::openForWriting(const long aOffset)

{

    JELOG2(EJavaFile);

    char* utf8Name = JavaCommonUtils::wstringToUtf8(mFileName);

    if (access(utf8Name, W_OK) < 0)

    {

        WLOG(EJavaFile,

             "NativeFileIOHandler::openForWriting: Access not allowed");

        // We do not have write access

        delete[] utf8Name;

        int error = errno;

        throw error;

    }

    if (!mFileDescriptor)

    {

        // it will never come here if it is not a file.

        // so, if there is a trailing slash, remove it.

        char ch = mFileName.at(mFileName.length() - 1);

        if (ch == '\\' || ch == '/')

        {

            mFileName = mFileName.substr(0, mFileName.length() - 1);

        }

        mFileDescriptor = open(utf8Name, O_RDWR);

        if (mFileDescriptor < 0)

        {

            delete[] utf8Name;

            mFileDescriptor = 0;

            int error = errno;

            throw error;

        }

    }

    mWritePosition = 0;

    if (aOffset > 0)

    {

        // We will need to stat the file and find out its size just to make sure

        // lseek does not set the offset to beyond end of file.

        struct stat fileStat;

        int error = lstat(utf8Name, &fileStat);

        if (error < 0)

        {

            int error = errno;

            throw error;

        }

        long fileSize = fileStat.st_size;

        if (aOffset >= fileSize)

        {

            // Move to end of file

            if (lseek(mFileDescriptor, 0, SEEK_END) < 0)

            {

                delete[] utf8Name;

                int error = errno;

                throw error;

            }

            mWritePosition = fileSize;

        }

        else

        {

            // Move to given offset

            if (lseek(mFileDescriptor, aOffset, SEEK_SET) < 0)

            {

                delete[] utf8Name;

                int error = errno;

                throw error;

            }

            mWritePosition = aOffset;

        }

    }

    delete[] utf8Name;

}

void NativeFileIOHandler::closeFileToReopen()

{

    JELOG2(EJavaFile);

    // We dont try to synchronize here. It must be done from java.

    // In case of multithreaded apps, set hidden should not be done while read

    // is in progress.

    if (mFileDescriptor)

    {

        LOG(EJavaFile, EInfo,

            "NativeFileUtils::closeFileToReopen: Closing already open Files");

        LOG1(EJavaFile, EInfo, "        Current Read Offset: %ld",

             mReadPosition);

        LOG1(EJavaFile, EInfo, "        Current Write Offset: %ld",

             mWritePosition);

        mClosedTemporarily = true;

        close(mFileDescriptor);

        mFileDescriptor = 0;

    }

}

void NativeFileIOHandler::handleReopenCase()

{

    JELOG2(EJavaFile);

    if (!mClosedTemporarily)

    {

        return;

    }

    if ((-1 == mWritePosition) && (-1 == mReadPosition))

    {

        return;

    }

    if (mWritePosition > -1)

    {

        LOG(EJavaFile, EInfo,

            "NativeFileUtils::handleReopenCase: Reopening for write");

        long curWritePos = mWritePosition;

        openForWriting(curWritePos);

    }

    else if (mReadPosition > -1)

    {

        LOG(EJavaFile, EInfo,

            "NativeFileUtils::handleReopenCase: Reopening for read");

        long curReadPos = mReadPosition;

        openForReading();

        mReadPosition = curReadPos;

    }

    LOG(EJavaFile, EInfo, "NativeFileUtils::handleReopenCase: File Open");

    LOG1(EJavaFile, EInfo, "        Setting Read Offset: %ld", mReadPosition);

    LOG1(EJavaFile, EInfo, "        Setting Write Offset: %ld", mWritePosition);

    mClosedTemporarily = false;

}

long NativeFileIOHandler::available()

{

    JELOG2(EJavaFile);

    char* utf8Name = JavaCommonUtils::wstringToUtf8(mFileName);

    struct stat fileStat;

    int error = lstat(utf8Name, &fileStat);

    if (error < 0)

    {

        int error = errno;

        throw error;

    }

    long fileSize = fileStat.st_size;

    if (mReadPosition > 0)

    {

        return (fileSize - mReadPosition);

    }

    else

    {

        return fileSize;

    }

}