FileSystem_Store_Engine/block_write_test.cpp at main · Brendon3Tang/FileSystem_Store_Engine · GitHub

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#include "file_op.h"
#include "index_handle.h"
#include <sstream>

using namespace std;
using namespace qiniu;

const static largefile::MMapOption mmap_option = { 1024000, 4096, 4096 };
const static uint32_t main_block_size = 1024 * 1024 * 64;//主块文件的大小，64MB
const static uint32_t bucket_size = 1000;//哈希桶的大小

int main(int argc, char** argv) {
	uint32_t block_id;
	string main_block_path;
	string index_path;
	int32_t ret = largefile::TFS_SUCCESS;

	cout << "Type your block id: " << endl;
	cin >> block_id;

	if (block_id < 1) {
		cerr << "无效的block id" << endl;
		exit(-1);
	}

	//1.加载索引文件
	largefile::IndexHandler* index_handler = new largefile::IndexHandler(".", block_id);
	if (debug)	printf("Load index ..\n");

	ret = index_handler->load(block_id, bucket_size, mmap_option);
	if (ret != largefile::TFS_SUCCESS) {
		fprintf(stderr, "Load index: %d failed\n", block_id);
		delete index_handler;
		exit(-2);
	}

	//2.分配一块内存作为主块文件，并写入内容到主块文件。
	stringstream tmp_stream;
	tmp_stream << "." << largefile::MAINBLOCK_DIR_PREFIX << block_id;
	tmp_stream >> main_block_path;
	largefile::FileOperation* main_block = new largefile::FileOperation(main_block_path, O_RDWR | O_LARGEFILE | O_CREAT);
	//main_block->open_file();
	char buffer[4096];
	memset(buffer, '6', 4096);

	int32_t data_file_offset = index_handler->get_data_file_offset();
	uint32_t file_no = index_handler->block_info()->seq_no_;

	//把内容写入到内存中的主块文件
	ret = main_block->pWrite_file(buffer, sizeof(buffer), data_file_offset);
	if (ret != largefile::TFS_SUCCESS) {
		fprintf(stderr, "Write to main block %s failed. Reason: %s\n", main_block_path.c_str(), strerror(errno));
		main_block->close_file();

		delete index_handler;
		delete main_block;
		exit(-3);
	}

	//3.成功写入主块文件后更新索引文件的头部信息与块信息，并在索引文件中写入MetaInfo
	//先写好要加入索引文件的meta_info
	largefile::MetaInfo meta_info;
	meta_info.set_file_id(file_no);
	meta_info.set_offset(data_file_offset);
	meta_info.set_size(sizeof(buffer));

	//将meta_info写入索引文件中
	ret = index_handler->write_segment_meta(meta_info.get_key(), meta_info);
	//如果写入成功了，那么要更新索引头部信息与块信息
	if (ret == largefile::TFS_SUCCESS) {
		//更新索引文件头部信息中的block_data_offset，表示块文件的最新偏移量
		index_handler->commit_block_data_offset(sizeof(buffer));
		//更新索引文件头部信息中的块文件信息
		index_handler->update_block_info(largefile::C_OPER_INSERT, sizeof(buffer));

		//将索引文件和块文件保存到磁盘中
		ret = index_handler->flush();
		if (ret != largefile::TFS_SUCCESS) {
			fprintf(stderr, "flush mainblock %d failed, file no: %u\n", block_id, file_no);
		}
	}
	else {
		fprintf(stderr, "write_segment_meta - mainblock %d failed, file no: %u\n", block_id, file_no);
	}

	if (ret != largefile::TFS_SUCCESS) {
		fprintf(stderr, "write to mainblock %d failed, file no: %u\n", block_id, file_no);
	}
	else {
		if (debug)
			printf("write to mainblock %d successfully, file no: %u\n", block_id, file_no);
	}

	main_block->close_file();
	delete main_block;
	delete index_handler;
	return 0;
}