/**
 * Copyright (C) ARM Limited 2013-2014. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#ifndef BUFFER_H
#define BUFFER_H

#include <stdint.h>
#include <semaphore.h>

#include "k/perf_event.h"

class Sender;

enum {
	FRAME_SUMMARY       =  1,
	FRAME_BLOCK_COUNTER =  5,
	FRAME_EXTERNAL      = 10,
	FRAME_PERF_ATTRS    = 11,
	FRAME_PERF          = 12,
};

class Buffer {
public:
	static const size_t MAXSIZE_PACK32 = 5;
	static const size_t MAXSIZE_PACK64 = 10;

	Buffer(int32_t core, int32_t buftype, const int size, sem_t *const readerSem);
	~Buffer();

	void write(Sender *sender);

	int bytesAvailable() const;
	int contiguousSpaceAvailable() const;
	void commit(const uint64_t time);
	void check(const uint64_t time);

	void frame();

	// Summary messages
	void summary(const int64_t timestamp, const int64_t uptime, const int64_t monotonicDelta, const char *const uname);
	void coreName(const int core, const int cpuid, const char *const name);

	// Block Counter messages
	bool eventHeader(uint64_t curr_time);
	bool eventTid(int tid);
	void event(int32_t key, int32_t value);
	void event64(int64_t key, int64_t value);

	// Perf Attrs messages
	void pea(const struct perf_event_attr *const pea, int key);
	void keys(const int count, const __u64 *const ids, const int *const keys);
	void format(const int length, const char *const format);
	void maps(const int pid, const int tid, const char *const maps);
	void comm(const int pid, const int tid, const char *const image, const char *const comm);

	void setDone();
	bool isDone() const;

	// Prefer a new member to using these functions if possible
	char *getWritePos() { return mBuf + mWritePos; }
	void advanceWrite(int bytes) { mWritePos = (mWritePos + bytes) & /*mask*/(mSize - 1); }

	static void writeLEInt(unsigned char *buf, int v) {
		buf[0] = (v >> 0) & 0xFF;
		buf[1] = (v >> 8) & 0xFF;
		buf[2] = (v >> 16) & 0xFF;
		buf[3] = (v >> 24) & 0xFF;
	}

private:
	bool commitReady() const;
	bool checkSpace(int bytes);

	void packInt(int32_t x);
	void packInt64(int64_t x);
	void writeBytes(const void *const data, size_t count);
	void writeString(const char *const str);

	const int32_t mCore;
	const int32_t mBufType;
	const int mSize;
	int mReadPos;
	int mWritePos;
	int mCommitPos;
	bool mAvailable;
	bool mIsDone;
	char *const mBuf;
	uint64_t mCommitTime;
	sem_t *const mReaderSem;

	// Intentionally unimplemented
	Buffer(const Buffer &);
	Buffer &operator=(const Buffer &);
};

#endif // BUFFER_H