X-Git-Url: https://git.saurik.com/apple/system_cmds.git/blobdiff_plain/1a7e3f61d38d679bba59130891c2031b5a0092b6..bd6521f0fc816ab056bc71376f9706a69b3b52c1:/CPPUtil/UtilMemoryBuffer.hpp

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+//
+//  UtilMemoryBuffer.h
+//  CPPUtil
+//
+//  Created by James McIlree on 4/20/13.
+//  Copyright (c) 2013 Apple. All rights reserved.
+//
+
+#ifndef __CPPUtil__UtilMemoryBuffer__
+#define __CPPUtil__UtilMemoryBuffer__
+
+template <typename T>
+class MemoryBuffer {
+    protected:
+	T*			_data;
+	size_t			_capacity;
+
+	// No copying?
+	MemoryBuffer(const MemoryBuffer& that) = delete;
+	MemoryBuffer& operator=(const MemoryBuffer& other) = delete;
+
+    public:
+	// Capacity is in units of T!
+	//
+	// MemoryBuffer<char>(1); // 1 byte
+	// MemoryBuffer<uint32_t>(1); // 4 bytes
+	MemoryBuffer()		{ _data = NULL; _capacity = 0; }
+	MemoryBuffer(size_t capacity);
+	MemoryBuffer(MemoryBuffer&& rhs) noexcept :
+		_data(rhs._data),
+		_capacity(rhs._capacity)
+	{
+		rhs._data = NULL;
+		rhs._capacity = 0;
+	}
+
+	~MemoryBuffer()					{ if (_data) { free(_data); } }
+
+	MemoryBuffer& operator=(MemoryBuffer&& rhs)	{ std::swap(_data, rhs._data); std::swap(_capacity, rhs._capacity); return *this; }
+
+	T* data()					{ return _data; }
+	size_t capacity() const				{ return _capacity; }
+	size_t capacity_in_bytes() const		{ return _capacity * sizeof(T); }
+	// This always results in an allocation and copy.
+	// If the new capacity is smaller, data is truncated.
+	void set_capacity(size_t capacity);
+};
+
+template <typename T>
+MemoryBuffer<T>::MemoryBuffer(size_t capacity) :
+	_capacity(capacity)
+{
+	_data = capacity ? (T*)malloc(capacity * sizeof(T)) : (T*)NULL;
+}
+
+template <typename T>
+void MemoryBuffer<T>::set_capacity(size_t capacity) {
+	MemoryBuffer<T> newbuf(capacity);
+	memcpy(newbuf.data(), _data, std::min(_capacity * sizeof(T), newbuf.capacity() * sizeof(T)));
+	*this = std::move(newbuf);
+}
+
+#endif /* defined(__CPPUtil__UtilMemoryBuffer__) */