Make QRingBuffer a 64-bit safe

According to I/O API, QIODevice and its inherited classes should be
able to process a full 64-bit offsets and lengths. This requires
64-bit parameters in operations with internal buffers. Rework
QRingBuffer to avoid implicit truncation of numbers and fix some
64-bit issues in code.

Change-Id: Iadd6fd5fefd2d64e6c084e2feebb4dc2d6df66de
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

4 files changed, 10 insertions, 10 deletions

diff --git a/src/corelib/io/qfiledevice.cpp b/src/corelib/io/qfiledevice.cpp
index 3ee0e33573..4c5ed0aef6 100644
--- a/src/corelib/io/qfiledevice.cpp
+++ b/src/corelib/io/qfiledevice.cpp
@@ -481,7 +481,7 @@ bool QFileDevicePrivate::putCharHelper(char c)
 #else
 
     // Cutoff for code that doesn't only touch the buffer.
-    int writeBufferSize = writeBuffer.size();
+    qint64 writeBufferSize = writeBuffer.size();
     if ((openMode & QIODevice::Unbuffered) || writeBufferSize + 1 >= QFILE_WRITEBUFFER_SIZE
 #ifdef Q_OS_WIN
         || ((openMode & QIODevice::Text) && c == '\n' && writeBufferSize + 2 >= QFILE_WRITEBUFFER_SIZE)
diff --git a/src/corelib/io/qprocess.cpp b/src/corelib/io/qprocess.cpp
index 6451bae0ba..d5c861f9ad 100644
--- a/src/corelib/io/qprocess.cpp
+++ b/src/corelib/io/qprocess.cpp
@@ -1912,12 +1912,12 @@ qint64 QProcess::readData(char *data, qint64 maxlen)
         return 1;
     }
 
-    qint64 bytesToRead = qint64(qMin(readBuffer->size(), (int)maxlen));
+    qint64 bytesToRead = qMin(readBuffer->size(), maxlen);
     qint64 readSoFar = 0;
     while (readSoFar < bytesToRead) {
         const char *ptr = readBuffer->readPointer();
-        int bytesToReadFromThisBlock = qMin<qint64>(bytesToRead - readSoFar,
-                                            readBuffer->nextDataBlockSize());
+        qint64 bytesToReadFromThisBlock = qMin(bytesToRead - readSoFar,
+                                               readBuffer->nextDataBlockSize());
         memcpy(data + readSoFar, ptr, bytesToReadFromThisBlock);
         readSoFar += bytesToReadFromThisBlock;
         readBuffer->free(bytesToReadFromThisBlock);
diff --git a/src/corelib/io/qwindowspipereader.cpp b/src/corelib/io/qwindowspipereader.cpp
index ab2025ee5c..1502e5dada 100644
--- a/src/corelib/io/qwindowspipereader.cpp
+++ b/src/corelib/io/qwindowspipereader.cpp
@@ -45,8 +45,8 @@ QWindowsPipeReader::QWindowsPipeReader(QObject *parent)
       handle(INVALID_HANDLE_VALUE),
       readBufferMaxSize(0),
       actualReadBufferSize(0),
-      readSequenceStarted(false),
       emitReadyReadTimer(new QTimer(this)),
+      readSequenceStarted(false),
       pipeBroken(false),
       readyReadEmitted(false)
 {
@@ -133,12 +133,12 @@ qint64 QWindowsPipeReader::read(char *data, qint64 maxlen)
         actualReadBufferSize--;
         readSoFar = 1;
     } else {
-        qint64 bytesToRead = qMin(qint64(actualReadBufferSize), maxlen);
+        qint64 bytesToRead = qMin(actualReadBufferSize, maxlen);
         readSoFar = 0;
         while (readSoFar < bytesToRead) {
             const char *ptr = readBuffer.readPointer();
-            int bytesToReadFromThisBlock = qMin(bytesToRead - readSoFar,
-                                                qint64(readBuffer.nextDataBlockSize()));
+            qint64 bytesToReadFromThisBlock = qMin(bytesToRead - readSoFar,
+                                                   readBuffer.nextDataBlockSize());
             memcpy(data + readSoFar, ptr, bytesToReadFromThisBlock);
             readSoFar += bytesToReadFromThisBlock;
             readBuffer.free(bytesToReadFromThisBlock);
diff --git a/src/corelib/io/qwindowspipereader_p.h b/src/corelib/io/qwindowspipereader_p.h
index 7904f116cb..53872e2552 100644
--- a/src/corelib/io/qwindowspipereader_p.h
+++ b/src/corelib/io/qwindowspipereader_p.h
@@ -98,9 +98,9 @@ private:
     QWinOverlappedIoNotifier *dataReadNotifier;
     qint64 readBufferMaxSize;
     QRingBuffer readBuffer;
-    int actualReadBufferSize;
-    bool readSequenceStarted;
+    qint64 actualReadBufferSize;
     QTimer *emitReadyReadTimer;
+    bool readSequenceStarted;
     bool pipeBroken;
     bool readyReadEmitted;
 };