qiodevice.cpp

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//#define QIODEVICE_DEBUG

#include "qbytearray.h"
#include "qdebug.h"
#include "qiodevice_p.h"
#include "qfile.h"
#include "qstringlist.h"
#include <limits.h>

#ifdef QIODEVICE_DEBUG
#  include <ctype.h>
#endif

QT_BEGIN_NAMESPACE

#ifdef QIODEVICE_DEBUG
void debugBinaryString(const QByteArray &input)
{
    QByteArray tmp;
    int startOffset = 0;
    for (int i = 0; i < input.size(); ++i) {
        tmp += input[i];

        if ((i % 16) == 15 || i == (input.size() - 1)) {
            printf("\n%15d:", startOffset);
            startOffset += tmp.size();

            for (int j = 0; j < tmp.size(); ++j)
                printf(" %02x", int(uchar(tmp[j])));
            for (int j = tmp.size(); j < 16 + 1; ++j)
                printf("   ");
            for (int j = 0; j < tmp.size(); ++j)
                printf("%c", isprint(int(uchar(tmp[j]))) ? tmp[j] : '.');
            tmp.clear();
        }
    }
    printf("\n\n");
}

void debugBinaryString(const char *data, qint64 maxlen)
{
    debugBinaryString(QByteArray(data, maxlen));
}
#endif

#define Q_VOID

#define CHECK_MAXLEN(function, returnType) \
    do { \
        if (maxSize < 0) { \
            qWarning("QIODevice::"#function": Called with maxSize < 0"); \
            return returnType; \
        } \
    } while (0)

#define CHECK_WRITABLE(function, returnType) \
   do { \
       if ((d->openMode & WriteOnly) == 0) { \
           if (d->openMode == NotOpen) \
               return returnType; \
           qWarning("QIODevice::"#function": ReadOnly device"); \
           return returnType; \
       } \
   } while (0)

#define CHECK_READABLE(function, returnType) \
   do { \
       if ((d->openMode & ReadOnly) == 0) { \
           if (d->openMode == NotOpen) \
               return returnType; \
           qWarning("QIODevice::"#function": WriteOnly device"); \
           return returnType; \
       } \
   } while (0)

QIODevicePrivate::QIODevicePrivate()
    : openMode(QIODevice::NotOpen), buffer(QIODEVICE_BUFFERSIZE),
      pos(0), devicePos(0), seqDumpPos(0)
       , pPos(&pos), pDevicePos(&devicePos)
       , baseReadLineDataCalled(false)
       , firstRead(true)
       , accessMode(Unset)
#ifdef QT_NO_QOBJECT
       , q_ptr(0)
#endif
{
}

QIODevicePrivate::~QIODevicePrivate()
{
}

#ifdef QT_NO_QOBJECT
QIODevice::QIODevice()
    : d_ptr(new QIODevicePrivate)
{
    d_ptr->q_ptr = this;
}

QIODevice::QIODevice(QIODevicePrivate &dd)
    : d_ptr(&dd)
{
    d_ptr->q_ptr = this;
}
#else

QIODevice::QIODevice()
    : QObject(*new QIODevicePrivate, 0)
{
#if defined QIODEVICE_DEBUG
    QFile *file = qobject_cast<QFile *>(this);
    printf("%p QIODevice::QIODevice(\"%s\") %s\n", this, metaObject()->className(),
           qPrintable(file ? file->fileName() : QString()));
#endif
}

QIODevice::QIODevice(QObject *parent)
    : QObject(*new QIODevicePrivate, parent)
{
#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::QIODevice(%p \"%s\")\n", this, parent, metaObject()->className());
#endif
}

QIODevice::QIODevice(QIODevicePrivate &dd, QObject *parent)
    : QObject(dd, parent)
{
}
#endif


QIODevice::~QIODevice()
{
#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::~QIODevice()\n", this);
#endif
}

bool QIODevice::isSequential() const
{
    return false;
}

QIODevice::OpenMode QIODevice::openMode() const
{
    return d_func()->openMode;
}

void QIODevice::setOpenMode(OpenMode openMode)
{
    Q_D(QIODevice);
#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::setOpenMode(0x%x)\n", this, int(openMode));
#endif
    d->openMode = openMode;
    d->accessMode = QIODevicePrivate::Unset;
    d->firstRead = true;
    if (!isReadable())
        d->buffer.clear();
}

void QIODevice::setTextModeEnabled(bool enabled)
{
    Q_D(QIODevice);
    if (!isOpen()) {
        qWarning("QIODevice::setTextModeEnabled: The device is not open");
        return;
    }
    if (enabled)
        d->openMode |= Text;
    else
        d->openMode &= ~Text;
}

bool QIODevice::isTextModeEnabled() const
{
    return d_func()->openMode & Text;
}

bool QIODevice::isOpen() const
{
    return d_func()->openMode != NotOpen;
}

bool QIODevice::isReadable() const
{
    return (openMode() & ReadOnly) != 0;
}

bool QIODevice::isWritable() const
{
    return (openMode() & WriteOnly) != 0;
}

bool QIODevice::open(OpenMode mode)
{
    Q_D(QIODevice);
    d->openMode = mode;
    d->pos = (mode & Append) ? size() : qint64(0);
    d->buffer.clear();
    d->accessMode = QIODevicePrivate::Unset;
    d->firstRead = true;
#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::open(0x%x)\n", this, quint32(mode));
#endif
    return true;
}

void QIODevice::close()
{
    Q_D(QIODevice);
    if (d->openMode == NotOpen)
        return;

#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::close()\n", this);
#endif

#ifndef QT_NO_QOBJECT
    emit aboutToClose();
#endif
    d->openMode = NotOpen;
    d->errorString.clear();
    d->pos = 0;
    d->seqDumpPos = 0;
    d->buffer.clear();
    d->firstRead = true;
}

qint64 QIODevice::pos() const
{
    Q_D(const QIODevice);
#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::pos() == %d\n", this, int(d->pos));
#endif
    return d->pos;
}

qint64 QIODevice::size() const
{
    return d_func()->isSequential() ?  bytesAvailable() : qint64(0);
}

bool QIODevice::seek(qint64 pos)
{
    Q_D(QIODevice);
    if (d->openMode == NotOpen) {
        qWarning("QIODevice::seek: The device is not open");
        return false;
    }
    if (pos < 0) {
        qWarning("QIODevice::seek: Invalid pos: %d", int(pos));
        return false;
    }

#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::seek(%d), before: d->pos = %d, d->buffer.size() = %d\n",
           this, int(pos), int(d->pos), d->buffer.size());
#endif

    qint64 offset = pos - d->pos;
    if (!d->isSequential()) {
        d->pos = pos;
        d->devicePos = pos;
    }

    if (offset < 0
            || offset >= qint64(d->buffer.size()))
        // When seeking backwards, an operation that is only allowed for
        // random-access devices, the buffer is cleared. The next read
        // operation will then refill the buffer. We can optimize this, if we
        // find that seeking backwards becomes a significant performance hit.
        d->buffer.clear();
    else if (!d->buffer.isEmpty())
        d->buffer.skip(int(offset));

#if defined QIODEVICE_DEBUG
    printf("%p \tafter: d->pos == %d, d->buffer.size() == %d\n", this, int(d->pos),
           d->buffer.size());
#endif
    return true;
}

bool QIODevice::atEnd() const
{
    Q_D(const QIODevice);
#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::atEnd() returns %s, d->openMode == %d, d->pos == %d\n", this, (d->openMode == NotOpen || d->pos == size()) ? "true" : "false",
           int(d->openMode), int(d->pos));
#endif
    return d->openMode == NotOpen || (d->buffer.isEmpty() && bytesAvailable() == 0);
}

bool QIODevice::reset()
{
#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::reset()\n", this);
#endif
    return seek(0);
}

qint64 QIODevice::bytesAvailable() const
{
    Q_D(const QIODevice);
    if (!d->isSequential())
        return qMax(size() - d->pos, qint64(0));
    return d->buffer.size();
}

qint64 QIODevice::bytesToWrite() const
{
    return qint64(0);
}

#ifdef Q_CC_RVCT
// arm mode makes the 64-bit integer operations much faster in RVCT 2.2
#pragma push
#pragma arm
#endif

qint64 QIODevice::read(char *data, qint64 maxSize)
{
    Q_D(QIODevice);

#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::read(%p, %d), d->pos = %d, d->buffer.size() = %d\n",
           this, data, int(maxSize), int(d->pos), int(d->buffer.size()));
#endif

    // Short circuit for getChar()
    if (maxSize == 1) {
        int chint;
        while ((chint = d->buffer.getChar()) != -1) {
            ++(*d->pPos);

            char c = char(uchar(chint));
            if (c == '\r' && (d->openMode & Text))
                continue;
            *data = c;
#if defined QIODEVICE_DEBUG
            printf("%p \tread 0x%hhx (%c) returning 1 (shortcut)\n", this,
                   int(c), isprint(c) ? c : '?');
#endif
            return qint64(1);
        }
    }

    CHECK_MAXLEN(read, qint64(-1));
    qint64 readSoFar = 0;
    bool moreToRead = true;
    do {
        // Try reading from the buffer.
        int lastReadChunkSize = d->buffer.read(data, maxSize);
        if (lastReadChunkSize > 0) {
            *d->pPos += lastReadChunkSize;
            readSoFar += lastReadChunkSize;
            // fast exit when satisfied by buffer
            if (lastReadChunkSize == maxSize && !(d->openMode & Text))
                return readSoFar;

            data += lastReadChunkSize;
            maxSize -= lastReadChunkSize;
#if defined QIODEVICE_DEBUG
            printf("%p \treading %d bytes from buffer into position %d\n", this, lastReadChunkSize,
                   int(readSoFar) - lastReadChunkSize);
#endif
        } else {
            if (d->firstRead) {
                // this is the first time the file has been read, check it's valid and set up pos pointers
                // for fast pos updates.
                CHECK_READABLE(read, qint64(-1));
                d->firstRead = false;
                if (d->isSequential()) {
                    d->pPos = &d->seqDumpPos;
                    d->pDevicePos = &d->seqDumpPos;
                }
            }

            if (!maxSize)
                return readSoFar;

            if ((d->openMode & Unbuffered) == 0 && maxSize < QIODEVICE_BUFFERSIZE) {
                // In buffered mode, we try to fill up the QIODevice buffer before
                // we do anything else.
                // buffer is empty at this point, try to fill it
                int bytesToBuffer = QIODEVICE_BUFFERSIZE;
                char *writePointer = d->buffer.reserve(bytesToBuffer);

                // Make sure the device is positioned correctly.
                if (d->pos != d->devicePos && !d->isSequential() && !seek(d->pos))
                    return readSoFar ? readSoFar : qint64(-1);
                qint64 readFromDevice = readData(writePointer, bytesToBuffer);
                d->buffer.chop(bytesToBuffer - (readFromDevice < 0 ? 0 : int(readFromDevice)));

                if (readFromDevice > 0) {
                    *d->pDevicePos += readFromDevice;
#if defined QIODEVICE_DEBUG
                    printf("%p \treading %d from device into buffer\n", this, int(readFromDevice));
#endif

                    if (!d->buffer.isEmpty()) {
                        lastReadChunkSize = d->buffer.read(data, maxSize);
                        readSoFar += lastReadChunkSize;
                        data += lastReadChunkSize;
                        maxSize -= lastReadChunkSize;
                        *d->pPos += lastReadChunkSize;
#if defined QIODEVICE_DEBUG
                        printf("%p \treading %d bytes from buffer at position %d\n", this,
                               lastReadChunkSize, int(readSoFar));
#endif
                    }
                }
            }
        }

        // If we need more, try reading from the device.
        if (maxSize > 0) {
            // Make sure the device is positioned correctly.
            if (d->pos != d->devicePos && !d->isSequential() && !seek(d->pos))
                return readSoFar ? readSoFar : qint64(-1);
            qint64 readFromDevice = readData(data, maxSize);
#if defined QIODEVICE_DEBUG
            printf("%p \treading %d bytes from device (total %d)\n", this, int(readFromDevice), int(readSoFar));
#endif
            if (readFromDevice == -1 && readSoFar == 0) {
                // error and we haven't read anything: return immediately
                return -1;
            }
            if (readFromDevice > 0) {
                lastReadChunkSize += int(readFromDevice);
                readSoFar += readFromDevice;
                data += readFromDevice;
                maxSize -= readFromDevice;
                *d->pPos += readFromDevice;
                *d->pDevicePos += readFromDevice;
            }
        }
        // Best attempt has been made to read data, don't try again except for text mode adjustment below
        moreToRead = false;

        if (readSoFar && d->openMode & Text) {
            char *readPtr = data - lastReadChunkSize;
            const char *endPtr = data;

            if (readPtr < endPtr) {
                // optimization to avoid initial self-assignment
                while (*readPtr != '\r') {
                    if (++readPtr == endPtr)
                        return readSoFar;
                }

                char *writePtr = readPtr;

                while (readPtr < endPtr) {
                    char ch = *readPtr++;
                    if (ch != '\r')
                        *writePtr++ = ch;
                    else {
                        --readSoFar;
                        --data;
                        ++maxSize;
                    }
                }

                // Make sure we get more data if there is room for more. This
                // is very important for when someone seeks to the start of a
                // '\r\n' and reads one character - they should get the '\n'.
                moreToRead = (readPtr != writePtr);
            }
        }
    } while (moreToRead);

#if defined QIODEVICE_DEBUG
    printf("%p \treturning %d, d->pos == %d, d->buffer.size() == %d\n", this,
           int(readSoFar), int(d->pos), d->buffer.size());
    debugBinaryString(data - readSoFar, readSoFar);
#endif
    return readSoFar;
}

#ifdef Q_CC_RVCT
#pragma pop
#endif

QByteArray QIODevice::read(qint64 maxSize)
{
    Q_D(QIODevice);
    QByteArray result;

    CHECK_MAXLEN(read, result);

#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::read(%d), d->pos = %d, d->buffer.size() = %d\n",
           this, int(maxSize), int(d->pos), int(d->buffer.size()));
#else
    Q_UNUSED(d);
#endif

    if (maxSize != qint64(int(maxSize))) {
        qWarning("QIODevice::read: maxSize argument exceeds QByteArray size limit");
        maxSize = INT_MAX;
    }

    qint64 readBytes = 0;
    if (maxSize) {
        result.resize(int(maxSize));
        if (!result.size()) {
            // If resize fails, read incrementally.
            qint64 readResult;
            do {
                result.resize(int(qMin(maxSize, result.size() + QIODEVICE_BUFFERSIZE)));
                readResult = read(result.data() + readBytes, result.size() - readBytes);
                if (readResult > 0 || readBytes == 0)
                    readBytes += readResult;
            } while (readResult == QIODEVICE_BUFFERSIZE);
        } else {
            readBytes = read(result.data(), result.size());
        }
    }

    if (readBytes <= 0)
        result.clear();
    else
        result.resize(int(readBytes));

    return result;
}

QByteArray QIODevice::readAll()
{
    Q_D(QIODevice);
#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::readAll(), d->pos = %d, d->buffer.size() = %d\n",
           this, int(d->pos), int(d->buffer.size()));
#endif

    QByteArray result;
    qint64 readBytes = 0;

    // flush internal read buffer
    if (!(d->openMode & Text) && !d->buffer.isEmpty()) {
        result = d->buffer.readAll();
        readBytes = result.size();
        d->pos += readBytes;
    }

    qint64 theSize;
    if (d->isSequential() || (theSize = size()) == 0) {
        // Size is unknown, read incrementally.
        qint64 readResult;
        do {
            result.resize(result.size() + QIODEVICE_BUFFERSIZE);
            readResult = read(result.data() + readBytes, result.size() - readBytes);
            if (readResult > 0 || readBytes == 0)
                readBytes += readResult;
        } while (readResult > 0);
    } else {
        // Read it all in one go.
        // If resize fails, don't read anything.
        result.resize(int(readBytes + theSize - d->pos));
        readBytes += read(result.data() + readBytes, result.size() - readBytes);
    }

    if (readBytes <= 0)
        result.clear();
    else
        result.resize(int(readBytes));

    return result;
}

#ifdef Q_CC_RVCT
// arm mode makes the 64-bit integer operations much faster in RVCT 2.2
#pragma push
#pragma arm
#endif

qint64 QIODevice::readLine(char *data, qint64 maxSize)
{
    Q_D(QIODevice);
    if (maxSize < 2) {
        qWarning("QIODevice::readLine: Called with maxSize < 2");
        return qint64(-1);
    }

#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::readLine(%p, %d), d->pos = %d, d->buffer.size() = %d\n",
           this, data, int(maxSize), int(d->pos), int(d->buffer.size()));
#endif

    // Leave room for a '\0'
    --maxSize;

    const bool sequential = d->isSequential();

    qint64 readSoFar = 0;
    if (!d->buffer.isEmpty()) {
        readSoFar = d->buffer.readLine(data, maxSize);
        if (!sequential)
            d->pos += readSoFar;
#if defined QIODEVICE_DEBUG
        printf("%p \tread from buffer: %d bytes, last character read: %hhx\n", this,
               int(readSoFar), data[int(readSoFar) - 1]);
        if (readSoFar)
            debugBinaryString(data, int(readSoFar));
#endif
#if defined(Q_OS_SYMBIAN)
        // Open C fgets strips '\r' but readSoFar gets returned as if it was still there
        if ((d->openMode & Text) &&
            readSoFar > 1 &&
            data[readSoFar - 1] == '\0' &&
            data[readSoFar - 2] == '\n') {
            --readSoFar;
        }
#endif
        if (readSoFar && data[readSoFar - 1] == '\n') {
            if (d->openMode & Text) {
                // QRingBuffer::readLine() isn't Text aware.
                if (readSoFar > 1 && data[readSoFar - 2] == '\r') {
                    --readSoFar;
                    data[readSoFar - 1] = '\n';
                }
            }
            data[readSoFar] = '\0';
            return readSoFar;
        }
    }

    if (d->pos != d->devicePos && !sequential && !seek(d->pos))
        return qint64(-1);
    d->baseReadLineDataCalled = false;
    qint64 readBytes = readLineData(data + readSoFar, maxSize - readSoFar);
#if defined QIODEVICE_DEBUG
    printf("%p \tread from readLineData: %d bytes, readSoFar = %d bytes\n", this,
           int(readBytes), int(readSoFar));
    if (readBytes > 0) {
        debugBinaryString(data, int(readSoFar + readBytes));
    }
#endif
    if (readBytes < 0) {
        data[readSoFar] = '\0';
        return readSoFar ? readSoFar : -1;
    }
    readSoFar += readBytes;
    if (!d->baseReadLineDataCalled && !sequential) {
        d->pos += readBytes;
        // If the base implementation was not called, then we must
        // assume the device position is invalid and force a seek.
        d->devicePos = qint64(-1);
    }
    data[readSoFar] = '\0';

    if (d->openMode & Text) {
#if defined(Q_OS_SYMBIAN)
        // Open C fgets strips '\r' but readSoFar gets returned as if it was still there
        if (readSoFar > 1 && data[readSoFar - 1] == '\0' && data[readSoFar - 2] == '\n') {
            --readSoFar;
        }
#endif
        if (readSoFar > 1 && data[readSoFar - 1] == '\n' && data[readSoFar - 2] == '\r') {
            data[readSoFar - 2] = '\n';
            data[readSoFar - 1] = '\0';
            --readSoFar;
        }
    }

#if defined QIODEVICE_DEBUG
    printf("%p \treturning %d, d->pos = %d, d->buffer.size() = %d, size() = %d\n",
           this, int(readSoFar), int(d->pos), d->buffer.size(), int(size()));
    debugBinaryString(data, int(readSoFar));
#endif
    return readSoFar;
}

QByteArray QIODevice::readLine(qint64 maxSize)
{
    Q_D(QIODevice);
    QByteArray result;

    CHECK_MAXLEN(readLine, result);

#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::readLine(%d), d->pos = %d, d->buffer.size() = %d\n",
           this, int(maxSize), int(d->pos), int(d->buffer.size()));
#else
    Q_UNUSED(d);
#endif

    if (maxSize > INT_MAX) {
        qWarning("QIODevice::read: maxSize argument exceeds QByteArray size limit");
        maxSize = INT_MAX;
    }

    result.resize(int(maxSize));
    qint64 readBytes = 0;
    if (!result.size()) {
        // If resize fails or maxSize == 0, read incrementally
        if (maxSize == 0)
            maxSize = INT_MAX;

        // The first iteration needs to leave an extra byte for the terminating null
        result.resize(1);

        qint64 readResult;
        do {
            result.resize(int(qMin(maxSize, result.size() + QIODEVICE_BUFFERSIZE)));
            readResult = readLine(result.data() + readBytes, result.size() - readBytes);
            if (readResult > 0 || readBytes == 0)
                readBytes += readResult;
        } while (readResult == QIODEVICE_BUFFERSIZE
                && result[int(readBytes - 1)] != '\n');
    } else
        readBytes = readLine(result.data(), result.size());

    if (readBytes <= 0)
        result.clear();
    else
        result.resize(readBytes);

    return result;
}

qint64 QIODevice::readLineData(char *data, qint64 maxSize)
{
    Q_D(QIODevice);
    qint64 readSoFar = 0;
    char c;
    int lastReadReturn = 0;
    d->baseReadLineDataCalled = true;

    while (readSoFar < maxSize && (lastReadReturn = read(&c, 1)) == 1) {
        *data++ = c;
        ++readSoFar;
        if (c == '\n')
            break;
    }

#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::readLineData(%p, %d), d->pos = %d, d->buffer.size() = %d, returns %d\n",
           this, data, int(maxSize), int(d->pos), int(d->buffer.size()), int(readSoFar));
#endif
    if (lastReadReturn != 1 && readSoFar == 0)
        return isSequential() ? lastReadReturn : -1;
    return readSoFar;
}

#ifdef Q_CC_RVCT
#pragma pop
#endif

bool QIODevice::canReadLine() const
{
    return d_func()->buffer.canReadLine();
}

qint64 QIODevice::write(const char *data, qint64 maxSize)
{
    Q_D(QIODevice);
    CHECK_WRITABLE(write, qint64(-1));
    CHECK_MAXLEN(write, qint64(-1));

    const bool sequential = d->isSequential();
    // Make sure the device is positioned correctly.
    if (d->pos != d->devicePos && !sequential && !seek(d->pos))
        return qint64(-1);

#ifdef Q_OS_WIN
    if (d->openMode & Text) {
        const char *endOfData = data + maxSize;
        const char *startOfBlock = data;

        qint64 writtenSoFar = 0;

        forever {
            const char *endOfBlock = startOfBlock;
            while (endOfBlock < endOfData && *endOfBlock != '\n')
                ++endOfBlock;

            qint64 blockSize = endOfBlock - startOfBlock;
            if (blockSize > 0) {
                qint64 ret = writeData(startOfBlock, blockSize);
                if (ret <= 0) {
                    if (writtenSoFar && !sequential)
                        d->buffer.skip(writtenSoFar);
                    return writtenSoFar ? writtenSoFar : ret;
                }
                if (!sequential) {
                    d->pos += ret;
                    d->devicePos += ret;
                }
                writtenSoFar += ret;
            }

            if (endOfBlock == endOfData)
                break;

            qint64 ret = writeData("\r\n", 2);
            if (ret <= 0) {
                if (writtenSoFar && !sequential)
                    d->buffer.skip(writtenSoFar);
                return writtenSoFar ? writtenSoFar : ret;
            }
            if (!sequential) {
                d->pos += ret;
                d->devicePos += ret;
            }
            ++writtenSoFar;

            startOfBlock = endOfBlock + 1;
        }

        if (writtenSoFar && !sequential)
            d->buffer.skip(writtenSoFar);
        return writtenSoFar;
    }
#endif

    qint64 written = writeData(data, maxSize);
    if (written > 0) {
        if (!sequential) {
            d->pos += written;
            d->devicePos += written;
        }
        if (!d->buffer.isEmpty() && !sequential)
            d->buffer.skip(written);
    }
    return written;
}

qint64 QIODevice::write(const char *data)
{
    return write(data, qstrlen(data));
}

void QIODevice::ungetChar(char c)
{
    Q_D(QIODevice);
    CHECK_READABLE(read, Q_VOID);

#if defined QIODEVICE_DEBUG
    printf("%p QIODevice::ungetChar(0x%hhx '%c')\n", this, c, isprint(c) ? c : '?');
#endif

    d->buffer.ungetChar(c);
    if (!d->isSequential())
        --d->pos;
}

bool QIODevice::putChar(char c)
{
    return d_func()->putCharHelper(c);
}

bool QIODevicePrivate::putCharHelper(char c)
{
    return q_func()->write(&c, 1) == 1;
}

qint64 QIODevicePrivate::peek(char *data, qint64 maxSize)
{
    qint64 readBytes = q_func()->read(data, maxSize);
    if (readBytes <= 0)
        return readBytes;

    buffer.ungetBlock(data, readBytes);
    *pPos -= readBytes;
    return readBytes;
}

QByteArray QIODevicePrivate::peek(qint64 maxSize)
{
    QByteArray result = q_func()->read(maxSize);

    if (result.isEmpty())
        return result;

    buffer.ungetBlock(result.constData(), result.size());
    *pPos -= result.size();
    return result;
}

bool QIODevice::getChar(char *c)
{
    // readability checked in read()
    char ch;
    return (1 == read(c ? c : &ch, 1));
}

qint64 QIODevice::peek(char *data, qint64 maxSize)
{
    return d_func()->peek(data, maxSize);
}

QByteArray QIODevice::peek(qint64 maxSize)
{
    return d_func()->peek(maxSize);
}

bool QIODevice::waitForReadyRead(int msecs)
{
    Q_UNUSED(msecs);
    return false;
}

bool QIODevice::waitForBytesWritten(int msecs)
{
    Q_UNUSED(msecs);
    return false;
}

void QIODevice::setErrorString(const QString &str)
{
    d_func()->errorString = str;
}

QString QIODevice::errorString() const
{
    Q_D(const QIODevice);
    if (d->errorString.isEmpty()) {
#ifdef QT_NO_QOBJECT
        return QLatin1String(QT_TRANSLATE_NOOP(QIODevice, "Unknown error"));
#else
        return tr("Unknown error");
#endif
    }
    return d->errorString;
}

#if defined QT3_SUPPORT
QIODevice::Status QIODevice::status() const
{
#if !defined(QT_NO_QOBJECT)
    const QFile *f = qobject_cast<const QFile *>(this);
    if (f) return (int) f->error();
#endif
    return isOpen() ? 0 /* IO_Ok */ : 8 /* IO_UnspecifiedError */;
}

void QIODevice::resetStatus()
{
#if !defined(QT_NO_QOBJECT)
    QFile *f = qobject_cast<QFile *>(this);
    if (f) f->unsetError();
#endif
}
#endif

#if !defined(QT_NO_DEBUG_STREAM)
QDebug operator<<(QDebug debug, QIODevice::OpenMode modes)
{
    debug << "OpenMode(";
    QStringList modeList;
    if (modes == QIODevice::NotOpen) {
        modeList << QLatin1String("NotOpen");
    } else {
        if (modes & QIODevice::ReadOnly)
            modeList << QLatin1String("ReadOnly");
        if (modes & QIODevice::WriteOnly)
            modeList << QLatin1String("WriteOnly");
        if (modes & QIODevice::Append)
            modeList << QLatin1String("Append");
        if (modes & QIODevice::Truncate)
            modeList << QLatin1String("Truncate");
        if (modes & QIODevice::Text)
            modeList << QLatin1String("Text");
        if (modes & QIODevice::Unbuffered)
            modeList << QLatin1String("Unbuffered");
    }
    qSort(modeList);
    debug << modeList.join(QLatin1String("|"));
    debug << ')';
    return debug;
}
#endif

QT_END_NAMESPACE