diff options
Diffstat (limited to 'cpp/src/qpid/legacystore/jrnl/aio.h')
| -rw-r--r-- | cpp/src/qpid/legacystore/jrnl/aio.h | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/cpp/src/qpid/legacystore/jrnl/aio.h b/cpp/src/qpid/legacystore/jrnl/aio.h new file mode 100644 index 0000000000..b1de5f79f7 --- /dev/null +++ b/cpp/src/qpid/legacystore/jrnl/aio.h @@ -0,0 +1,153 @@ +/* + * + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + * + */ + +/** + * \file aio.h + * + * Qpid asynchronous store plugin library + * + * This file contains an encapsulation of the libaio interface used + * by the journal. + * + * \author Kim van der Riet + */ + +#ifndef QPID_LEGACYSTORE_JRNL_AIO_H +#define QPID_LEGACYSTORE_JRNL_AIO_H + +#include <libaio.h> +#include <cstring> +#include <sys/types.h> +#include <string.h> + +namespace mrg +{ +namespace journal +{ + +typedef iocb aio_cb; +typedef io_event aio_event; + +/** + * \brief This class is a C++ wrapper class for the libaio functions used by the journal. Note that only those + * functions used by the journal are included here. This is not a complete implementation of all libaio functions. + */ +class aio +{ +public: + static inline int queue_init(int maxevents, io_context_t* ctxp) + { + return ::io_queue_init(maxevents, ctxp); + } + + static inline int queue_release(io_context_t ctx) + { + return ::io_queue_release(ctx); + } + + static inline int submit(io_context_t ctx, long nr, aio_cb* aios[]) + { + return ::io_submit(ctx, nr, aios); + } + + static inline int getevents(io_context_t ctx, long min_nr, long nr, aio_event* events, timespec* const timeout) + { + return ::io_getevents(ctx, min_nr, nr, events, timeout); + } + + /** + * \brief This function allows iocbs to be initialized with a pointer that can be re-used. This prepares an + * aio_cb struct for read use. (This is a wrapper for libaio's ::io_prep_pread() function.) + * + * \param aiocbp Pointer to the aio_cb struct to be prepared. + * \param fd File descriptor to be used for read. + * \param buf Pointer to buffer in which read data is to be placed. + * \param count Number of bytes to read - buffer must be large enough. + * \param offset Offset within file from which data will be read. + */ + static inline void prep_pread(aio_cb* aiocbp, int fd, void* buf, std::size_t count, int64_t offset) + { + ::io_prep_pread(aiocbp, fd, buf, count, offset); + } + + /** + * \brief Special version of libaio's io_prep_pread() which preserves the value of the data pointer. This allows + * iocbs to be initialized with a pointer that can be re-used. This prepares a aio_cb struct for read use. + * + * \param aiocbp Pointer to the aio_cb struct to be prepared. + * \param fd File descriptor to be used for read. + * \param buf Pointer to buffer in which read data is to be placed. + * \param count Number of bytes to read - buffer must be large enough. + * \param offset Offset within file from which data will be read. + */ + static inline void prep_pread_2(aio_cb* aiocbp, int fd, void* buf, std::size_t count, int64_t offset) + { + std::memset((void*) ((char*) aiocbp + sizeof(void*)), 0, sizeof(aio_cb) - sizeof(void*)); + aiocbp->aio_fildes = fd; + aiocbp->aio_lio_opcode = IO_CMD_PREAD; + aiocbp->aio_reqprio = 0; + aiocbp->u.c.buf = buf; + aiocbp->u.c.nbytes = count; + aiocbp->u.c.offset = offset; + } + + /** + * \brief This function allows iocbs to be initialized with a pointer that can be re-used. This function prepares + * an aio_cb struct for write use. (This is a wrapper for libaio's ::io_prep_pwrite() function.) + * + * \param aiocbp Pointer to the aio_cb struct to be prepared. + * \param fd File descriptor to be used for write. + * \param buf Pointer to buffer in which data to be written is located. + * \param count Number of bytes to write. + * \param offset Offset within file to which data will be written. + */ + static inline void prep_pwrite(aio_cb* aiocbp, int fd, void* buf, std::size_t count, int64_t offset) + { + ::io_prep_pwrite(aiocbp, fd, buf, count, offset); + } + + /** + * \brief Special version of libaio's io_prep_pwrite() which preserves the value of the data pointer. This allows + * iocbs to be initialized with a pointer that can be re-used. This function prepares an aio_cb struct for write + * use. + * + * \param aiocbp Pointer to the aio_cb struct to be prepared. + * \param fd File descriptor to be used for write. + * \param buf Pointer to buffer in which data to be written is located. + * \param count Number of bytes to write. + * \param offset Offset within file to which data will be written. + */ + static inline void prep_pwrite_2(aio_cb* aiocbp, int fd, void* buf, std::size_t count, int64_t offset) + { + std::memset((void*) ((char*) aiocbp + sizeof(void*)), 0, sizeof(aio_cb) - sizeof(void*)); + aiocbp->aio_fildes = fd; + aiocbp->aio_lio_opcode = IO_CMD_PWRITE; + aiocbp->aio_reqprio = 0; + aiocbp->u.c.buf = buf; + aiocbp->u.c.nbytes = count; + aiocbp->u.c.offset = offset; + } +}; + +} // namespace journal +} // namespace mrg + +#endif // ifndef QPID_LEGACYSTORE_JRNL_AIO_H |