Lots of file splits

buffer.h

@@ -0,0 +1,48 @@
+#pragma once
+
+#include <glog/logging.h>
+#include <memory>
+
+class ConstBuffer {
+  public:
+	ConstBuffer(const char *buf, size_t len);
+
+	size_t ReadMaxLen() const;
+	const char *Read(size_t len);
+	template<class T> const T *ReadObj();
+
+	bool Discard(size_t len); // like Read() but don't use the result
+	void ResetRead(); // next read from last commit
+	void Commit(); // commit read position
+
+  protected:
+	const char *const_buf_;
+	size_t len_;
+	size_t start_ = 0;
+	size_t commit_ = 0;
+};
+
+class Buffer : public ConstBuffer {
+  public:
+  	Buffer(const char *buf, size_t len) = delete;
+	Buffer(char *buf, size_t size, size_t len);
+  	Buffer(size_t size);
+
+	char *WritePtr();
+	size_t WriteMaxLen() const;
+	void Wrote(size_t len);
+
+	void Consume(); // discard up to last commit
+
+  private:
+  	std::unique_ptr<char> own_buf_;
+	char *buf_;
+	const size_t size_;
+};
+
+template<class T> const T *ConstBuffer::ReadObj() {
+	if (ReadMaxLen() < sizeof(T)) {
+		return nullptr;
+	}
+	return reinterpret_cast<const T*>(Read(sizeof(T)));
+}