diff options
Diffstat (limited to 'examples/librados')
| -rw-r--r-- | examples/librados/Makefile | 39 | ||||
| -rw-r--r-- | examples/librados/hello_radosstriper.cc | 102 | ||||
| -rw-r--r-- | examples/librados/hello_world.cc | 292 | ||||
| -rw-r--r-- | examples/librados/hello_world.readme | 14 | ||||
| -rw-r--r-- | examples/librados/hello_world_c.c | 304 |
5 files changed, 751 insertions, 0 deletions
diff --git a/examples/librados/Makefile b/examples/librados/Makefile new file mode 100644 index 000000000..a97d640eb --- /dev/null +++ b/examples/librados/Makefile @@ -0,0 +1,39 @@ + +CXX?=g++ +CXX_FLAGS+=-Wno-unused-parameter -Wall -Wextra -Werror -g +CXX_LIBS?=-lrados -lradosstriper +CXX_INC?=$(LOCAL_LIBRADOS_INC) +CXX_CC=$(CXX) $(CXX_FLAGS) $(CXX_INC) $(LOCAL_LIBRADOS) + +CC?=gcc +CC_FLAGS=-Wno-unused-parameter -Wall -Wextra -Werror -g +CC_INC=$(LOCAL_LIBRADOS_INC) +CC_LIBS?=-lrados +CC_CC=$(CC) $(CC_FLAGS) $(CC_INC) $(LOCAL_LIBRADOS) + +# Relative path to the Ceph source: +CEPH_SRC_HOME?=../../src +CEPH_BLD_HOME?=../../build + +LOCAL_LIBRADOS?=-L$(CEPH_BLD_HOME)/lib/ -Wl,-rpath,$(CEPH_BLD_HOME)/lib +LOCAL_LIBRADOS_INC?=-I$(CEPH_SRC_HOME)/include + +all: hello_world_cpp hello_radosstriper_cpp hello_world_c + +# Build against the system librados instead of the one in the build tree: +all-system: LOCAL_LIBRADOS= +all-system: LOCAL_LIBRADOS_INC= +all-system: all + +hello_world_cpp: hello_world.cc + $(CXX_CC) -o hello_world_cpp hello_world.cc $(CXX_LIBS) + +hello_radosstriper_cpp: hello_radosstriper.cc + $(CXX_CC) -o hello_radosstriper_cpp hello_radosstriper.cc $(CXX_LIBS) + +hello_world_c: hello_world_c.c + $(CC_CC) -o hello_world_c hello_world_c.c $(CC_LIBS) + +clean: + rm -f hello_world_cpp hello_radosstriper_cpp hello_world_c + diff --git a/examples/librados/hello_radosstriper.cc b/examples/librados/hello_radosstriper.cc new file mode 100644 index 000000000..f1b43d8fc --- /dev/null +++ b/examples/librados/hello_radosstriper.cc @@ -0,0 +1,102 @@ +#include "rados/librados.hpp" +#include "radosstriper/libradosstriper.hpp" +#include <iostream> +#include <string> + + +int main(int argc, char* argv[]) +{ + if(argc != 6) + { + std::cout <<"Please put in correct params\n"<< + "Stripe Count:\n"<< + "Object Size:\n" << + "File Name:\n" << + "Object Name:\n" + "Pool Name:"<< std::endl; + return EXIT_FAILURE; + } + uint32_t strip_count = std::stoi(argv[1]); + uint32_t obj_size = std::stoi(argv[2]); + std::string fname = argv[3]; + std::string obj_name = argv[4]; + std::string pool_name = argv[5]; + int ret = 0; + librados::IoCtx io_ctx; + librados::Rados cluster; + libradosstriper::RadosStriper* rs = new libradosstriper::RadosStriper; + + // make sure the keyring file is in /etc/ceph/ and is world readable + ret = cluster.init2("client.admin","ceph",0); + if( ret < 0) + { + std::cerr << "Couldn't init cluster "<< ret << std::endl; + } + + // make sure ceph.conf is in /etc/ceph/ and is world readable + ret = cluster.conf_read_file("ceph.conf"); + if( ret < 0) + { + std::cerr << "Couldn't read conf file "<< ret << std::endl; + } + ret = cluster.connect(); + if(ret < 0) + { + std::cerr << "Couldn't connect to cluster "<< ret << std::endl; + } + else + { + std::cout << "Connected to Cluster"<< std::endl; + } + + ret = cluster.ioctx_create(pool_name.c_str(), io_ctx); + + if(ret < 0) + { + std::cerr << "Couldn't Create IO_CTX"<< ret << std::endl; + } + ret = libradosstriper::RadosStriper::striper_create(io_ctx,rs); + if(ret < 0) + { + std::cerr << "Couldn't Create RadosStriper"<< ret << std::endl; + delete rs; + } + uint64_t alignment = 0; + ret = io_ctx.pool_required_alignment2(&alignment); + if(ret < 0) + { + std::cerr << "IO_CTX didn't give alignment "<< ret + << "\n Is this an erasure coded pool? "<< std::endl; + + delete rs; + io_ctx.close(); + cluster.shutdown(); + return EXIT_FAILURE; + } + std::cout << "Pool alignment: "<< alignment << std::endl; + rs->set_object_layout_stripe_unit(alignment); + // how many objects are we striping across? + rs->set_object_layout_stripe_count(strip_count); + // how big should each object be? + rs->set_object_layout_object_size(obj_size); + + std::string err = "no_err"; + librados::bufferlist bl; + bl.read_file(fname.c_str(),&err); + if(err != "no_err") + { + std::cout << "Error reading file into bufferlist: "<< err << std::endl; + delete rs; + io_ctx.close(); + cluster.shutdown(); + return EXIT_FAILURE; + } + + std::cout << "Writing: " << fname << "\nas: "<< obj_name << std::endl; + rs->write_full(obj_name,bl); + std::cout << "done with: " << fname << std::endl; + + delete rs; + io_ctx.close(); + cluster.shutdown(); +} diff --git a/examples/librados/hello_world.cc b/examples/librados/hello_world.cc new file mode 100644 index 000000000..3607311c1 --- /dev/null +++ b/examples/librados/hello_world.cc @@ -0,0 +1,292 @@ +// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- +// vim: ts=8 sw=2 smarttab +/* + * Ceph - scalable distributed file system + * + * This is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License version 2.1, as published by the Free Software + * Foundation. See file COPYING. + * Copyright 2013 Inktank + */ + +// install the librados-dev package to get this +#include <rados/librados.hpp> +#include <iostream> +#include <string> + +int main(int argc, const char **argv) +{ + int ret = 0; + + // we will use all of these below + const char *pool_name = "hello_world_pool"; + std::string hello("hello world!"); + std::string object_name("hello_object"); + librados::IoCtx io_ctx; + + // first, we create a Rados object and initialize it + librados::Rados rados; + { + ret = rados.init("admin"); // just use the client.admin keyring + if (ret < 0) { // let's handle any error that might have come back + std::cerr << "couldn't initialize rados! error " << ret << std::endl; + ret = EXIT_FAILURE; + goto out; + } + std::cout << "we just set up a rados cluster object" << std::endl; + } + + /* + * Now we need to get the rados object its config info. It can + * parse argv for us to find the id, monitors, etc, so let's just + * use that. + */ + { + ret = rados.conf_parse_argv(argc, argv); + if (ret < 0) { + // This really can't happen, but we need to check to be a good citizen. + std::cerr << "failed to parse config options! error " << ret << std::endl; + ret = EXIT_FAILURE; + goto out; + } + + std::cout << "we just parsed our config options" << std::endl; + // We also want to apply the config file if the user specified + // one, and conf_parse_argv won't do that for us. + for (int i = 0; i < argc; ++i) { + if ((strcmp(argv[i], "-c") == 0) || (strcmp(argv[i], "--conf") == 0)) { + ret = rados.conf_read_file(argv[i+1]); + if (ret < 0) { + // This could fail if the config file is malformed, but it'd be hard. + std::cerr << "failed to parse config file " << argv[i+1] + << "! error" << ret << std::endl; + ret = EXIT_FAILURE; + goto out; + } + break; + } + } + } + + /* + * next, we actually connect to the cluster + */ + { + ret = rados.connect(); + if (ret < 0) { + std::cerr << "couldn't connect to cluster! error " << ret << std::endl; + ret = EXIT_FAILURE; + goto out; + } + std::cout << "we just connected to the rados cluster" << std::endl; + } + + /* + * let's create our own pool instead of scribbling over real data. + * Note that this command creates pools with default PG counts specified + * by the monitors, which may not be appropriate for real use -- it's fine + * for testing, though. + */ + { + ret = rados.pool_create(pool_name); + if (ret < 0) { + std::cerr << "couldn't create pool! error " << ret << std::endl; + return EXIT_FAILURE; + } + std::cout << "we just created a new pool named " << pool_name << std::endl; + } + + /* + * create an "IoCtx" which is used to do IO to a pool + */ + { + ret = rados.ioctx_create(pool_name, io_ctx); + if (ret < 0) { + std::cerr << "couldn't set up ioctx! error " << ret << std::endl; + ret = EXIT_FAILURE; + goto out; + } + std::cout << "we just created an ioctx for our pool" << std::endl; + } + + /* + * now let's do some IO to the pool! We'll write "hello world!" to a + * new object. + */ + { + /* + * "bufferlist"s are Ceph's native transfer type, and are carefully + * designed to be efficient about copying. You can fill them + * up from a lot of different data types, but strings or c strings + * are often convenient. Just make sure not to deallocate the memory + * until the bufferlist goes out of scope and any requests using it + * have been finished! + */ + librados::bufferlist bl; + bl.append(hello); + + /* + * now that we have the data to write, let's send it to an object. + * We'll use the synchronous interface for simplicity. + */ + ret = io_ctx.write_full(object_name, bl); + if (ret < 0) { + std::cerr << "couldn't write object! error " << ret << std::endl; + ret = EXIT_FAILURE; + goto out; + } + std::cout << "we just wrote new object " << object_name + << ", with contents\n" << hello << std::endl; + } + + /* + * now let's read that object back! Just for fun, we'll do it using + * async IO instead of synchronous. (This would be more useful if we + * wanted to send off multiple reads at once; see + * http://docs.ceph.com/docs/master/rados/api/librados/#asychronous-io ) + */ + { + librados::bufferlist read_buf; + int read_len = 4194304; // this is way more than we need + // allocate the completion from librados + librados::AioCompletion *read_completion = librados::Rados::aio_create_completion(); + // send off the request. + ret = io_ctx.aio_read(object_name, read_completion, &read_buf, read_len, 0); + if (ret < 0) { + std::cerr << "couldn't start read object! error " << ret << std::endl; + ret = EXIT_FAILURE; + read_completion->release(); + goto out; + } + // 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; + ret = EXIT_FAILURE; + read_completion->release(); + goto out; + } + std::cout << "we read our object " << object_name + << ", and got back " << ret << " bytes with contents\n"; + std::string read_string; + read_buf.begin().copy(ret, read_string); + std::cout << read_string << std::endl; + read_completion->release(); + } + + /* + * We can also use xattrs that go alongside the object. + */ + { + librados::bufferlist version_bl; + version_bl.append('1'); + ret = io_ctx.setxattr(object_name, "version", version_bl); + if (ret < 0) { + std::cerr << "failed to set xattr version entry! error " + << ret << std::endl; + ret = EXIT_FAILURE; + goto out; + } + std::cout << "we set the xattr 'version' on our object!" << std::endl; + } + + /* + * And if we want to be really cool, we can do multiple things in a single + * atomic operation. For instance, we can update the contents of our object + * and set the version at the same time. + */ + { + librados::bufferlist bl; + bl.append(hello); + bl.append("v2"); + librados::ObjectWriteOperation write_op; + write_op.write_full(bl); + librados::bufferlist version_bl; + version_bl.append('2'); + write_op.setxattr("version", version_bl); + ret = io_ctx.operate(object_name, &write_op); + if (ret < 0) { + std::cerr << "failed to do compound write! error " << ret << std::endl; + ret = EXIT_FAILURE; + goto out; + } + std::cout << "we overwrote our object " << object_name + << " with contents\n" << bl.c_str() << std::endl; + } + + /* + * And to be even cooler, we can make sure that the object looks the + * way we expect before doing the write! Notice how this attempt fails + * because the xattr differs. + */ + { + librados::ObjectWriteOperation failed_write_op; + librados::bufferlist bl; + bl.append(hello); + bl.append("v2"); + librados::ObjectWriteOperation write_op; + write_op.write_full(bl); + librados::bufferlist version_bl; + version_bl.append('2'); + librados::bufferlist old_version_bl; + old_version_bl.append('1'); + failed_write_op.cmpxattr("version", LIBRADOS_CMPXATTR_OP_EQ, old_version_bl); + failed_write_op.write_full(bl); + failed_write_op.setxattr("version", version_bl); + ret = io_ctx.operate(object_name, &failed_write_op); + if (ret < 0) { + std::cout << "we just failed a write because the xattr wasn't as specified" + << std::endl; + } else { + std::cerr << "we succeeded on writing despite an xattr comparison mismatch!" + << std::endl; + ret = EXIT_FAILURE; + goto out; + } + + /* + * Now let's do the update with the correct xattr values so it + * actually goes through + */ + bl.clear(); + bl.append(hello); + bl.append("v3"); + old_version_bl.clear(); + old_version_bl.append('2'); + version_bl.clear(); + version_bl.append('3'); + librados::ObjectWriteOperation update_op; + update_op.cmpxattr("version", LIBRADOS_CMPXATTR_OP_EQ, old_version_bl); + update_op.write_full(bl); + update_op.setxattr("version", version_bl); + ret = io_ctx.operate(object_name, &update_op); + if (ret < 0) { + std::cerr << "failed to do a compound write update! error " << ret + << std::endl; + ret = EXIT_FAILURE; + goto out; + } + std::cout << "we overwrote our object " << object_name + << " following an xattr test with contents\n" << bl.c_str() + << std::endl; + } + + ret = EXIT_SUCCESS; + out: + /* + * And now we're done, so let's remove our pool and then + * shut down the connection gracefully. + */ + int delete_ret = rados.pool_delete(pool_name); + if (delete_ret < 0) { + // be careful not to + std::cerr << "We failed to delete our test pool!" << std::endl; + ret = EXIT_FAILURE; + } + + rados.shutdown(); + + return ret; +} diff --git a/examples/librados/hello_world.readme b/examples/librados/hello_world.readme new file mode 100644 index 000000000..afa1cb32e --- /dev/null +++ b/examples/librados/hello_world.readme @@ -0,0 +1,14 @@ +This simple librados program can be built by running "make" (and cleaned up +with "make clean"), assuming you have librados-dev already installed. + +By default, the makefile will build against the librados headers and library in your +build tree (ie. using relative paths). If you would like to build the examples against +your system librados and headers, use "make all-system". + +And executed using +./hello_world_cpp -c ../../src/ceph.conf +(or whatever path to a ceph.conf is appropriate to you, or +by explicitly specifying monitors, user id, and keys). + +It demonstrates using librados in a non-Ceph project and the code should +be self-explanatory. diff --git a/examples/librados/hello_world_c.c b/examples/librados/hello_world_c.c new file mode 100644 index 000000000..2f91828de --- /dev/null +++ b/examples/librados/hello_world_c.c @@ -0,0 +1,304 @@ +// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- +// vim: ts=8 sw=2 smarttab +/* + * Ceph - scalable distributed file system + * + * This is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License version 2.1, as published by the Free Software + * Foundation. See file COPYING. + * Copyright 2013 Inktank + */ + +// install the librados-dev package to get this +#include <rados/librados.h> +#include <stdio.h> +#include <stdlib.h> + +int main(int argc, const char **argv) +{ + int ret = 0; + + // we will use all of these below + const char *pool_name = "hello_world_pool"; + const char* hello = "hello world!"; + const char* object_name = "hello_object"; + rados_ioctx_t io_ctx = NULL; + int pool_created = 0; + + // first, we create a Rados object and initialize it + rados_t rados = NULL; + { + ret = rados_create(&rados, "admin"); // just use the client.admin keyring + if (ret < 0) { // let's handle any error that might have come back + printf("couldn't initialize rados! error %d\n", ret); + ret = EXIT_FAILURE; + goto out; + } + printf("we just set up a rados cluster object\n"); + } + + /* + * Now we need to get the rados object its config info. It can + * parse argv for us to find the id, monitors, etc, so let's just + * use that. + */ + { + ret = rados_conf_parse_argv(rados, argc, argv); + if (ret < 0) { + // This really can't happen, but we need to check to be a good citizen. + printf("failed to parse config options! error %d\n", ret); + ret = EXIT_FAILURE; + goto out; + } + + printf("we just parsed our config options\n"); + // We also want to apply the config file if the user specified + // one, and conf_parse_argv won't do that for us. + int i; + for (i = 0; i < argc; ++i) { + if ((strcmp(argv[i], "-c") == 0) || (strcmp(argv[i], "--conf") == 0)) { + ret = rados_conf_read_file(rados, argv[i+1]); + if (ret < 0) { + // This could fail if the config file is malformed, but it'd be hard. + printf("failed to parse config file %s! error %d\n", argv[i+1], ret); + ret = EXIT_FAILURE; + goto out; + } + break; + } + } + } + + /* + * next, we actually connect to the cluster + */ + { + ret = rados_connect(rados); + if (ret < 0) { + printf("couldn't connect to cluster! error %d\n", ret); + ret = EXIT_FAILURE; + goto out; + } + printf("we just connected to the rados cluster\n"); + } + + /* + * let's create our own pool instead of scribbling over real data. + * Note that this command creates pools with default PG counts specified + * by the monitors, which may not be appropriate for real use -- it's fine + * for testing, though. + */ + { + ret = rados_pool_create(rados, pool_name); + if (ret < 0) { + printf("couldn't create pool! error %d\n", ret); + return EXIT_FAILURE; + } + printf("we just created a new pool named %s\n", pool_name); + pool_created = 1; + } + + /* + * create an "IoCtx" which is used to do IO to a pool + */ + { + ret = rados_ioctx_create(rados, pool_name, &io_ctx); + if (ret < 0) { + printf("couldn't set up ioctx! error %d\n", ret); + ret = EXIT_FAILURE; + goto out; + } + printf("we just created an ioctx for our pool\n"); + } + + /* + * now let's do some IO to the pool! We'll write "hello world!" to a + * new object. + */ + { + /* + * now that we have the data to write, let's send it to an object. + * We'll use the synchronous interface for simplicity. + */ + ret = rados_write_full(io_ctx, object_name, hello, strlen(hello)); + if (ret < 0) { + printf("couldn't write object! error %d\n", ret); + ret = EXIT_FAILURE; + goto out; + } + printf("we just wrote new object %s, with contents '%s'\n", object_name, hello); + } + + /* + * now let's read that object back! Just for fun, we'll do it using + * async IO instead of synchronous. (This would be more useful if we + * wanted to send off multiple reads at once; see + * http://docs.ceph.com/docs/master/rados/api/librados/#asychronous-io ) + */ + { + int read_len = 4194304; // this is way more than we need + char* read_buf = malloc(read_len + 1); // add one for the terminating 0 we'll add later + if (!read_buf) { + printf("couldn't allocate read buffer\n"); + ret = EXIT_FAILURE; + goto out; + } + // allocate the completion from librados + rados_completion_t read_completion; + ret = rados_aio_create_completion2(NULL, NULL, &read_completion); + if (ret < 0) { + printf("couldn't create completion! error %d\n", ret); + ret = EXIT_FAILURE; + free(read_buf); + goto out; + } + printf("we just created a new completion\n"); + + // send off the request. + ret = rados_aio_read(io_ctx, object_name, read_completion, read_buf, read_len, 0); + if (ret < 0) { + printf("couldn't start read object! error %d\n", ret); + ret = EXIT_FAILURE; + free(read_buf); + rados_aio_release(read_completion); + goto out; + } + // wait for the request to complete, and check that it succeeded. + rados_aio_wait_for_complete(read_completion); + ret = rados_aio_get_return_value(read_completion); + if (ret < 0) { + printf("couldn't read object! error %d\n", ret); + ret = EXIT_FAILURE; + free(read_buf); + rados_aio_release(read_completion); + goto out; + } + read_buf[ret] = 0; // null-terminate the string + printf("we read our object %s, and got back %d bytes with contents\n%s\n", object_name, ret, read_buf); + + free(read_buf); + rados_aio_release(read_completion); + } + + /* + * We can also use xattrs that go alongside the object. + */ + { + const char* version = "1"; + ret = rados_setxattr(io_ctx, object_name, "version", version, strlen(version)); + if (ret < 0) { + printf("failed to set xattr version entry! error %d\n", ret); + ret = EXIT_FAILURE; + goto out; + } + printf("we set the xattr 'version' on our object!\n"); + } + + /* + * And if we want to be really cool, we can do multiple things in a single + * atomic operation. For instance, we can update the contents of our object + * and set the version at the same time. + */ + { + const char* content = "v2"; + rados_write_op_t write_op = rados_create_write_op(); + if (!write_op) { + printf("failed to allocate write op\n"); + ret = EXIT_FAILURE; + goto out; + } + rados_write_op_write_full(write_op, content, strlen(content)); + const char* version = "2"; + rados_write_op_setxattr(write_op, "version", version, strlen(version)); + ret = rados_write_op_operate(write_op, io_ctx, object_name, NULL, 0); + if (ret < 0) { + printf("failed to do compound write! error %d\n", ret); + ret = EXIT_FAILURE; + rados_release_write_op(write_op); + goto out; + } + printf("we overwrote our object %s with contents\n%s\n", object_name, content); + rados_release_write_op(write_op); + } + + /* + * And to be even cooler, we can make sure that the object looks the + * way we expect before doing the write! Notice how this attempt fails + * because the xattr differs. + */ + { + rados_write_op_t failed_write_op = rados_create_write_op(); + if (!failed_write_op) { + printf("failed to allocate write op\n"); + ret = EXIT_FAILURE; + goto out; + } + const char* content = "v2"; + const char* version = "2"; + const char* old_version = "1"; + rados_write_op_cmpxattr(failed_write_op, "version", LIBRADOS_CMPXATTR_OP_EQ, old_version, strlen(old_version)); + rados_write_op_write_full(failed_write_op, content, strlen(content)); + rados_write_op_setxattr(failed_write_op, "version", version, strlen(version)); + ret = rados_write_op_operate(failed_write_op, io_ctx, object_name, NULL, 0); + if (ret < 0) { + printf("we just failed a write because the xattr wasn't as specified\n"); + } else { + printf("we succeeded on writing despite an xattr comparison mismatch!\n"); + ret = EXIT_FAILURE; + rados_release_write_op(failed_write_op); + goto out; + } + rados_release_write_op(failed_write_op); + + /* + * Now let's do the update with the correct xattr values so it + * actually goes through + */ + content = "v3"; + old_version = "2"; + version = "3"; + rados_write_op_t update_op = rados_create_write_op(); + if (!failed_write_op) { + printf("failed to allocate write op\n"); + ret = EXIT_FAILURE; + goto out; + } + rados_write_op_cmpxattr(update_op, "version", LIBRADOS_CMPXATTR_OP_EQ, old_version, strlen(old_version)); + rados_write_op_write_full(update_op, content, strlen(content)); + rados_write_op_setxattr(update_op, "version", version, strlen(version)); + ret = rados_write_op_operate(update_op, io_ctx, object_name, NULL, 0); + if (ret < 0) { + printf("failed to do a compound write update! error %d\n", ret); + ret = EXIT_FAILURE; + rados_release_write_op(update_op); + goto out; + } + printf("we overwrote our object %s following an xattr test with contents\n%s\n", object_name, content); + rados_release_write_op(update_op); + } + + ret = EXIT_SUCCESS; + + out: + if (io_ctx) { + rados_ioctx_destroy(io_ctx); + } + + if (pool_created) { + /* + * And now we're done, so let's remove our pool and then + * shut down the connection gracefully. + */ + int delete_ret = rados_pool_delete(rados, pool_name); + if (delete_ret < 0) { + // be careful not to + printf("We failed to delete our test pool!\n"); + ret = EXIT_FAILURE; + } + } + + rados_shutdown(rados); + + return ret; +} |