rados_tmap_to_omap
使用示例
#include <rados/librados.hpp>
#include <string> #include <list> int main(int argc, const char **argv) { int ret = 0 ; /* * Errors are not checked to avoid pollution. * After each Ceph operation: * if (ret < 0) error_condition * else success */ // Get cluster handle and connect to cluster std::string cluster_name("ceph"); std::string user_name("client.admin"); librados::Rados cluster ; cluster.init2(user_name.c_str(), cluster_name.c_str(), 0); cluster.conf_read_file("/etc/ceph/ceph.conf"); cluster.connect(); // IO context librados::IoCtx io_ctx ; std::string pool_name("data"); cluster.ioctx_create(pool_name.c_str(), io_ctx); // Write an object synchronously librados::bufferlist bl; std::string objectId("hw"); std::string objectContent("Hello World!"); bl.append(objectContent); io_ctx.write(objectId, bl, objectContent.size(), 0); // Add an xattr to the object. librados::bufferlist lang_bl; lang_bl.append("en_US"); io_ctx.setxattr(objectId, "lang", lang_bl); // 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. io_ctx.aio_read(objectId, read_completion, &read_buf, read_len, 0 ); // Wait for the request to complete, and print content read_completion->wait_for_complete(); read_completion->get_return_value(); std::cout<< "Object name: " << objectId << "\n" << "Content: " << read_buf.c_str() << std::endl ; // Read the xattr. librados::bufferlist lang_res; io_ctx.getxattr(objectId, "lang", lang_res); std::cout<< "Object xattr: " << lang_res.c_str() << std::endl ; // Print the list of pools std::list<std::string> pools ; cluster.pool_list(pools ); std::cout << "List of pools from this cluster handle" << std::endl ; for (std::list<std::string>::iterator i = pools.begin(); i != pools.end(); ++i) std::cout << *i << std::endl; // Print the list of objects librados::ObjectIterator oit=io_ctx.objects_begin(); librados::ObjectIterator oet=io_ctx.objects_end(); std::cout<< "List of objects from this pool" << std::endl ; for(; oit!= oet; oit++ ) { std::cout << "\t" << oit->first << std::endl ; } // Remove the xattr io_ctx.rmxattr(objectId, "lang"); // Remove the object. io_ctx.remove(objectId); // Cleanup io_ctx.close(); cluster.shutdown(); return 0 ; }保存为cephrados.cpp，编译命令行如下
g++ cephrados.cpp -lrados -o cephrados
rados getxattr rbd.py lang -p data显示data池中对象rbd.py的扩展属性lang的值
rados listxattr -p data rbd.py显示data池中对象rbd.py的扩展属性,如果没有设置显示为空
rados stat rbd.py -p data 显示data池中对象rbd.py的大小、时间