Add circular buffer implementation

cores/esp8266/cbuf.h

@@ -0,0 +1,129 @@
+/* Copyright (c) 2014 Ivan Grokhotkov. All rights reserved.
+ * This file is part of the atproto AT protocol library
+ *
+ * Redistribution and use is permitted according to the conditions of the
+ * 3-clause BSD license to be found in the LICENSE file.
+ */
+#ifndef __cbuf_h
+#define __cbuf_h
+
+#include <stdint.h>
+class cbuf
+{
+public:
+    cbuf(size_t size)
+    : _size(size)
+    , _buf(new char[size])
+    , _bufend(_buf + size)
+    , _begin(_buf)
+    , _end(_begin)
+    {
+    }
+    
+    ~cbuf()
+    {
+        delete[] _buf;
+    }
+    
+    size_t getSize() const
+    {
+        if (_end >= _begin)
+            return _end - _begin;
+        
+        return _size - (_begin - _end);
+    }
+    
+    size_t room() const
+    {
+        if (_end >= _begin)
+            return _size - (_end - _begin) - 1;
+        
+        return _begin - _end - 1;
+    }
+    
+    char peek()
+    {
+        if (_end == _begin)
+            return -1;
+        
+        return *_begin;
+    }
+    
+    char read()
+    {
+        if (getSize() == 0)
+            return -1;
+        
+        char result = *_begin;
+        if (++_begin == _bufend)
+            _begin = _buf;
+        return result;
+    }
+    
+    size_t read(char* dst, size_t size)
+    {
+        size_t bytes_available = getSize();
+        size_t size_to_read = (size < bytes_available) ? size : bytes_available;
+        size_t size_read = size_to_read;
+        if (_end < _begin && size_to_read > _bufend - _begin)
+        {
+            size_t top_size = _bufend - _begin;
+            memcpy(dst, _begin, top_size);
+            _begin = _buf;
+            size_to_read -= top_size;
+            dst += top_size;
+        }
+        memcpy(dst, _begin, size_to_read);
+        _begin += size_to_read;
+        if (_begin == _bufend)
+            _begin = _buf;
+        return size_read;
+    }
+    
+    size_t write(char c)
+    {
+        if (room() == 0)
+            return 0;
+        
+        *_end = c;
+        if (++_end == _bufend)
+            _end = _buf;
+        return 1;
+    }
+    
+    size_t write(const char* src, size_t size)
+    {
+        size_t bytes_available = room();
+        size_t size_to_write = (size < bytes_available) ? size : bytes_available;
+        size_t size_written = size_to_write;
+        if (_end > _begin && size_to_write > _bufend - _end)
+        {
+            size_t top_size = _bufend - _end;
+            memcpy(_end, src, top_size);
+            _end = _buf;
+            size_to_write -= top_size;
+            src += top_size;
+        }
+        memcpy(_end, src, size_to_write);
+        _end += size_to_write;
+        if (_end == _bufend)
+            _end = _buf;
+        return size_written;
+    }
+
+    void flush()
+    {
+        _begin = _buf;
+        _end = _buf;
+    }
+    
+private:
+    size_t _size;
+    char*  _buf;
+    char*  _bufend;
+    char*  _begin;
+    char*  _end;
+};
+
+
+#endif//__cbuf_h

cores/esp8266/debug.h

@@ -0,0 +1,10 @@
+#ifndef ARD_DEBUG_H
+#define ARD_DEBUG_H
+
+#include <stddef.h>
+
+extern "C" size_t ets_printf(const char*, ...);
+#define DEBUGV ets_printf
+
+
+#endif//ARD_DEBUG_H