依赖
# centos
yum install librados2-devel
源程序
#include <iostream>
#include <string>
#include <rados/librados.hpp>
int main(int argc, const char **argv)
{
int ret = 0;
/* Declare the cluster handle and required variables. */
librados::Rados cluster;
char cluster_name[] = "ceph";
char user_name[] = "client.admin";
uint64_t flags = 0;
/* Initialize the cluster handle with the "ceph" cluster name and "client.admin" user */
{
ret = cluster.init2(user_name, cluster_name, flags);
if (ret < 0) {
std::cerr << "Couldn't initialize the cluster handle! error " << ret << std::endl;
return EXIT_FAILURE;
} else {
std::cout << "Created a cluster handle." << std::endl;
}
}
/* Read a Ceph configuration file to configure the cluster handle. */
{
ret = cluster.conf_read_file("/etc/ceph/ceph.conf");
if (ret < 0) {
std::cerr << "Couldn't read the Ceph configuration file! error " << ret << std::endl;
return EXIT_FAILURE;
} else {
std::cout << "Read the Ceph configuration file." << std::endl;
}
}
/* Read command line arguments */
{
ret = cluster.conf_parse_argv(argc, argv);
if (ret < 0) {
std::cerr << "Couldn't parse command line options! error " << ret << std::endl;
return EXIT_FAILURE;
} else {
std::cout << "Parsed command line options." << std::endl;
}
}
/* Connect to the cluster */
{
ret = cluster.connect();
if (ret < 0) {
std::cerr << "Couldn't connect to cluster! error " << ret << std::endl;
return EXIT_FAILURE;
} else {
std::cout << "Connected to the cluster." << std::endl;
}
}
librados::IoCtx io_ctx;
const char *pool_name = "testpool";
{
ret = cluster.ioctx_create(pool_name, io_ctx);
if (ret < 0) {
std::cerr << "Couldn't set up ioctx! error " << ret << std::endl;
exit(EXIT_FAILURE);
} else {
std::cout << "Created an ioctx for the pool." << std::endl;
}
}
/* Write an object synchronously. */
{
librados::bufferlist bl;
bl.append("Hello World!");
ret = io_ctx.write_full("hw", bl);
if (ret < 0) {
std::cerr << "Couldn't write object! error " << ret << std::endl;
exit(EXIT_FAILURE);
} else {
std::cout << "Wrote new object 'hw' " << std::endl;
}
}
/*
* Add an xattr to the object.
*/
{
librados::bufferlist lang_bl;
lang_bl.append("en_US");
ret = io_ctx.setxattr("hw", "lang", lang_bl);
if (ret < 0) {
std::cerr << "failed to set xattr version entry! error "
<< ret << std::endl;
exit(EXIT_FAILURE);
} else {
std::cout << "Set the xattr 'lang' on our object!" << std::endl;
}
}
/*
* Read the object back asynchronously.
*/
{
librados::bufferlist read_buf;
int read_len = 4194304;
//Create I/O Completion.
librados::AioCompletion *read_completion = librados::Rados::aio_create_completion();
//Send read request.
ret = io_ctx.aio_read("hw", read_completion, &read_buf, read_len, 0);
if (ret < 0) {
std::cerr << "Couldn't start read object! error " << ret << std::endl;
exit(EXIT_FAILURE);
}
// Wait for the request to complete, and check that it succeeded.
read_completion->wait_for_complete();
ret = read_completion->get_return_value();
if (ret < 0) {
std::cerr << "Couldn't read object! error " << ret << std::endl;
exit(EXIT_FAILURE);
} else {
std::cout << "Read object hw asynchronously with contents.\n"
<< read_buf.c_str() << std::endl;
}
}
/*
* Read the xattr.
*/
{
librados::bufferlist lang_res;
ret = io_ctx.getxattr("hw", "lang", lang_res);
if (ret < 0) {
std::cerr << "failed to get xattr version entry! error "
<< ret << std::endl;
exit(EXIT_FAILURE);
} else {
std::cout << "Got the xattr 'lang' from object hw!"
<< lang_res.c_str() << std::endl;
}
}
/*
* Remove the xattr.
*/
{
ret = io_ctx.rmxattr("hw", "lang");
if (ret < 0) {
std::cerr << "Failed to remove xattr! error "
<< ret << std::endl;
exit(EXIT_FAILURE);
} else {
std::cout << "Removed the xattr 'lang' from our object!" << std::endl;
}
}
/*
* Remove the object.
*/
{
ret = io_ctx.remove("hw");
if (ret < 0) {
std::cerr << "Couldn't remove object! error " << ret << std::endl;
exit(EXIT_FAILURE);
} else {
std::cout << "Removed object 'hw'." << std::endl;
}
}
io_ctx.close();
cluster.shutdown();
return 0;
}
编译
g++ -g -c cephclient.cc -o cephclient.o -std=c++11
g++ -g cephclient.o -lrados -o cephclient
运行
注意运行前要先创建“testpool”存储池
