src/cam/buffer_writer.cpp


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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) 2019, Google Inc.
 *
 * buffer_writer.cpp - Buffer writer
 */

#include <fcntl.h>
#include <iomanip>
#include <iostream>
#include <sstream>
#include <string.h>
#include <sys/mman.h>
#include <unistd.h>

#include "buffer_writer.h"

using namespace libcamera;

BufferWriter::BufferWriter(const std::string &pattern)
	: pattern_(pattern)
{
}

BufferWriter::~BufferWriter()
{
	for (auto &iter : mappedBuffers_) {
		void *memory = iter.second.first;
		unsigned int length = iter.second.second;
		munmap(memory, length);
	}
	mappedBuffers_.clear();
}

void BufferWriter::mapBuffer(FrameBuffer *buffer)
{
	for (const FrameBuffer::Plane &plane : buffer->planes()) {
		void *memory = mmap(NULL, plane.length, PROT_READ, MAP_SHARED,
				    plane.fd.fd(), 0);

		mappedBuffers_[plane.fd.fd()] =
			std::make_pair(memory, plane.length);
	}
}

int BufferWriter::write(FrameBuffer *buffer, const std::string &streamName)
{
	std::string filename;
	size_t pos;
	int fd, ret = 0;

	filename = pattern_;
	pos = filename.find_first_of('#');
	if (pos != std::string::npos) {
		std::stringstream ss;
		ss << streamName << "-" << std::setw(6)
		   << std::setfill('0') << buffer->metadata().sequence;
		filename.replace(pos, 1, ss.str());
	}

	fd = open(filename.c_str(), O_CREAT | O_WRONLY |
		  (pos == std::string::npos ? O_APPEND : O_TRUNC),