1 files changed, 68 insertions, 0 deletions
diff --git a/cpp/src/qpid/framing/FrameDecoder.cpp b/cpp/src/qpid/framing/FrameDecoder.cpp
new file mode 100644
index 0000000000..07e2f7513d
--- /dev/null
+++ b/cpp/src/qpid/framing/FrameDecoder.cpp
@@ -0,0 +1,68 @@
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+#include "FrameDecoder.h"
+#include "Buffer.h"
+#include "qpid/log/Statement.h"
+#include <algorithm>
+
+namespace qpid {
+namespace framing {
+
+namespace {
+/** Move up to n bytes from start of buf to end of bytes. */
+void move(std::vector<char>& bytes, Buffer& buffer, size_t n) {
+    size_t oldSize = bytes.size();
+    n = std::min(n, size_t(buffer.available()));
+    bytes.resize(oldSize+n);
+    char* p = &bytes[oldSize];
+    buffer.getRawData(reinterpret_cast<uint8_t*>(p), n);
+}
+}
+
+bool FrameDecoder::decode(Buffer& buffer) {
+    if (buffer.available() == 0) return false;
+    if (fragment.empty()) {     
+        if (frame.decode(buffer)) // Decode from buffer
+            return true;
+        else                    // Store fragment
+            move(fragment, buffer, buffer.available());
+    }
+    else {                      // Already have a fragment
+        // Get enough data to decode the frame size.
+        if (fragment.size() < AMQFrame::DECODE_SIZE_MIN) {
+            move(fragment, buffer, AMQFrame::DECODE_SIZE_MIN - fragment.size());
+        }
+        if (fragment.size() >= AMQFrame::DECODE_SIZE_MIN) {
+            uint16_t size = AMQFrame::decodeSize(&fragment[0]);
+            assert(size > fragment.size());
+            move(fragment, buffer, size-fragment.size());
+            Buffer b(&fragment[0], fragment.size());
+            if (frame.decode(b)) {
+                assert(b.available() == 0);
+                fragment.clear();
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+}} // namespace qpid::framing