QRingBuffer: allow to change the chunk size of the buffer dynamically

Change-Id: I0ac55713c7bb8c48d2c9c774376543caef781980
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

3 files changed, 16 insertions, 0 deletions

diff --git a/src/corelib/io/qiodevice_p.h b/src/corelib/io/qiodevice_p.h
index d264bfd31d..eed98a8fe3 100644
--- a/src/corelib/io/qiodevice_p.h
+++ b/src/corelib/io/qiodevice_p.h
@@ -92,6 +92,8 @@ public:
         friend class QIODevicePrivate;
     public:
         // wrap functions from QRingBuffer
+        inline void setChunkSize(int size) { Q_ASSERT(m_buf); m_buf->setChunkSize(size); }
+        inline int chunkSize() const { Q_ASSERT(m_buf); return m_buf->chunkSize(); }
         inline qint64 nextDataBlockSize() const { return (m_buf ? m_buf->nextDataBlockSize() : Q_INT64_C(0)); }
         inline const char *readPointer() const { return (m_buf ? m_buf->readPointer() : Q_NULLPTR); }
         inline const char *readPointerAtPosition(qint64 pos, qint64 &length) const { Q_ASSERT(m_buf); return m_buf->readPointerAtPosition(pos, length); }
diff --git a/src/corelib/tools/qringbuffer_p.h b/src/corelib/tools/qringbuffer_p.h
index 44716cf4d3..325b71f267 100644
--- a/src/corelib/tools/qringbuffer_p.h
+++ b/src/corelib/tools/qringbuffer_p.h
@@ -67,6 +67,14 @@ public:
     explicit inline QRingBuffer(int growth = QRINGBUFFER_CHUNKSIZE) :
         head(0), tail(0), tailBuffer(0), basicBlockSize(growth), bufferSize(0) { }
 
+    inline void setChunkSize(int size) {
+        basicBlockSize = size;
+    }
+
+    inline int chunkSize() const {
+        return basicBlockSize;
+    }
+
     inline qint64 nextDataBlockSize() const {
         return (tailBuffer == 0 ? tail : buffers.first().size()) - head;
     }
diff --git a/tests/auto/corelib/tools/qringbuffer/tst_qringbuffer.cpp b/tests/auto/corelib/tools/qringbuffer/tst_qringbuffer.cpp
index c212589f59..4e14fd7a9b 100644
--- a/tests/auto/corelib/tools/qringbuffer/tst_qringbuffer.cpp
+++ b/tests/auto/corelib/tools/qringbuffer/tst_qringbuffer.cpp
@@ -58,6 +58,12 @@ void tst_QRingBuffer::constructing()
 {
     QRingBuffer ringBuffer;
 
+    const int chunkSize = ringBuffer.chunkSize();
+    ringBuffer.setChunkSize(0);
+    QCOMPARE(ringBuffer.chunkSize(), Q_INT64_C(0));
+    ringBuffer.setChunkSize(chunkSize);
+    QCOMPARE(ringBuffer.chunkSize(), chunkSize);
+
     QCOMPARE(ringBuffer.size(), Q_INT64_C(0));
     QVERIFY(ringBuffer.isEmpty());
     QCOMPARE(ringBuffer.nextDataBlockSize(), Q_INT64_C(0));