initial setup for a PacketByteArray

libraries/networking/src/PacketByteArray.cpp

@@ -0,0 +1,60 @@
+//
+//  PacketByteArray.cpp
+//  libraries/networking/src
+//
+//  Created by Stephen Birarda on 07/06/15.
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "PacketByteArray.h"
+
+PacketByteArray::PacketByteArray(char* data, int maxBytes) :
+    _data(data)
+    _maxBytes(maxBytes)
+{
+
+}
+
+int PacketByteArray::append(const char* src, int srcBytes) {
+    // this is a call to write at the current index
+    int numWrittenBytes = write(src, srcBytes, _index);
+
+    if (numWrittenBytes > 0) {
+        // we wrote some bytes, push the index
+        _index += numWrittenBytes;
+        return numWrittenBytes;
+    } else {
+        return numWrittenBytes;
+    }
+}
+
+const int PACKET_WRITE_ERROR = -1;
+
+int PacketByteArray::write(const char* src, int srcBytes, int index) {
+    if (index >= _maxBytes) {
+        // we were passed a bad index, return -1
+        return PACKET_WRITE_ERROR;
+    }
+
+    // make sure we have the space required to write this block
+    int bytesAvailable = _maxBytes - index;
+
+    if (bytesAvailable < srcBytes) {
+        // good to go - write the data
+        memcpy(_data + index, src, srcBytes);
+
+        // should this cause us to push our index (is this the farthest we've written in data)?
+        _index = std::max(_data + index + srcBytes, _index);
+
+        // return the number of bytes written
+        return srcBytes;
+    } else {
+        // not enough space left for this write - return an error
+        return PACKET_WRITE_ERROR;
+    }
+}
+
+

libraries/networking/src/PacketByteArray.h

@@ -0,0 +1,29 @@
+//
+//  PacketByteArray.h
+//  libraries/networking/src
+//
+//  Created by Stephen Birarda on 07/06/15.
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#ifndef hifi_PacketByteArray_h
+#define hifi_PacketByteArray_h
+
+#pragma once
+
+class PacketByteArray {
+public:
+    PacketByteArray(char* data, int maxBytes);
+
+    int write(const char* src, int srcBytes, int index = 0);
+    int append(const char* src, int srcBytes)
+private:
+    char* _data;
+    int _index = 0;
+    int _maxBytes = 0;
+};
+
+#endif // hifi_PacketByteArray_h