1 files changed, 10 insertions, 133 deletions

diff --git a/src/corelib/io/qiodevice_p.h b/src/corelib/io/qiodevice_p.h
index 56a89ab680..45f5219240 100644
--- a/src/corelib/io/qiodevice_p.h
+++ b/src/corelib/io/qiodevice_p.h
@@ -62,138 +62,6 @@ QT_BEGIN_NAMESPACE
 
 Q_CORE_EXPORT int qt_subtract_from_timeout(int timeout, int elapsed);
 
-// This is QIODevice's read buffer, optimized for read(), isEmpty() and getChar()
-class QIODevicePrivateLinearBuffer
-{
-public:
-    QIODevicePrivateLinearBuffer(int) : len(0), first(0), buf(0), capacity(0) {
-    }
-    ~QIODevicePrivateLinearBuffer() {
-        delete [] buf;
-    }
-    void clear() {
-        len = 0;
-        delete [] buf;
-        buf = 0;
-        first = buf;
-        capacity = 0;
-    }
-    qint64 size() const {
-        return len;
-    }
-    bool isEmpty() const {
-        return len == 0;
-    }
-    void skip(qint64 n) {
-        if (n >= len) {
-            clear();
-        } else {
-            len -= n;
-            first += n;
-        }
-    }
-    int getChar() {
-        if (len == 0)
-            return -1;
-        int ch = uchar(*first);
-        len--;
-        first++;
-        return ch;
-    }
-    qint64 read(char* target, qint64 size) {
-        qint64 r = qMin(size, len);
-        memcpy(target, first, r);
-        len -= r;
-        first += r;
-        return r;
-    }
-    qint64 peek(char* target, qint64 size) {
-        qint64 r = qMin(size, len);
-        memcpy(target, first, r);
-        return r;
-    }
-    char* reserve(qint64 size) {
-        makeSpace(size + len, freeSpaceAtEnd);
-        char* writePtr = first + len;
-        len += size;
-        return writePtr;
-    }
-    void chop(qint64 size) {
-        if (size >= len) {
-            clear();
-        } else {
-            len -= size;
-        }
-    }
-    QByteArray readAll() {
-        QByteArray retVal(first, len);
-        clear();
-        return retVal;
-    }
-    qint64 readLine(char* target, qint64 size) {
-        qint64 r = qMin(size, len);
-        char* eol = static_cast<char*>(memchr(first, '\n', r));
-        if (eol)
-            r = 1+(eol-first);
-        memcpy(target, first, r);
-        len -= r;
-        first += r;
-        return r;
-    }
-    bool canReadLine() const {
-        return memchr(first, '\n', len);
-    }
-    void ungetChar(char c) {
-        if (first == buf) {
-            // underflow, the existing valid data needs to move to the end of the (potentially bigger) buffer
-            makeSpace(len+1, freeSpaceAtStart);
-        }
-        first--;
-        len++;
-        *first = c;
-    }
-    void ungetBlock(const char* block, qint64 size) {
-        if ((first - buf) < size) {
-            // underflow, the existing valid data needs to move to the end of the (potentially bigger) buffer
-            makeSpace(len + size, freeSpaceAtStart);
-        }
-        first -= size;
-        len += size;
-        memcpy(first, block, size);
-    }
-
-private:
-    enum FreeSpacePos {freeSpaceAtStart, freeSpaceAtEnd};
-    void makeSpace(size_t required, FreeSpacePos where) {
-        size_t newCapacity = qMax(capacity, size_t(QIODEVICE_BUFFERSIZE));
-        while (newCapacity < required)
-            newCapacity *= 2;
-        const size_t moveOffset = (where == freeSpaceAtEnd) ? 0 : newCapacity - size_t(len);
-        if (newCapacity > capacity) {
-            // allocate more space
-            char* newBuf = new char[newCapacity];
-            memmove(newBuf + moveOffset, first, len);
-            delete [] buf;
-            buf = newBuf;
-            capacity = newCapacity;
-        } else {
-            // shift any existing data to make space
-            memmove(buf + moveOffset, first, len);
-        }
-        first = buf + moveOffset;
-    }
-
-private:
-    // length of the unread data
-    qint64 len;
-    // start of the unread data
-    char* first;
-    // the allocated buffer
-    char* buf;
-    // allocated buffer size
-    size_t capacity;
-};
-
 class Q_CORE_EXPORT QIODevicePrivate
 #ifndef QT_NO_QOBJECT
     : public QObjectPrivate
@@ -208,9 +76,11 @@ public:
     QIODevice::OpenMode openMode;
     QString errorString;
 
-    QIODevicePrivateLinearBuffer buffer;
+    QRingBuffer buffer;
     qint64 pos;
     qint64 devicePos;
+    qint64 transactionPos;
+    bool transactionStarted;
     bool baseReadLineDataCalled;
 
     virtual bool putCharHelper(char c);
@@ -228,6 +98,13 @@ public:
         return accessMode == Sequential;
     }
 
+    inline bool isBufferEmpty() const
+    {
+        return buffer.isEmpty() || (transactionStarted && isSequential()
+                                    && transactionPos == buffer.size());
+    }
+    void seekBuffer(qint64 newPos);
+
     virtual qint64 peek(char *data, qint64 maxSize);
     virtual QByteArray peek(qint64 maxSize);