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Diffstat (limited to 'cpp/src/qpid/legacystore/jrnl/enq_hdr.h')
| -rw-r--r-- | cpp/src/qpid/legacystore/jrnl/enq_hdr.h | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/cpp/src/qpid/legacystore/jrnl/enq_hdr.h b/cpp/src/qpid/legacystore/jrnl/enq_hdr.h new file mode 100644 index 0000000000..0d1e6116be --- /dev/null +++ b/cpp/src/qpid/legacystore/jrnl/enq_hdr.h @@ -0,0 +1,165 @@ +/* + * + * 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 enq_hdr.h + * + * Qpid asynchronous store plugin library + * + * File containing code for class mrg::journal::enq_hdr (enueue header), + * used to start an enqueue record in the journal. + * + * \author Kim van der Riet + */ + +#ifndef QPID_LEGACYSTORE_JRNL_ENQ_HDR_H +#define QPID_LEGACYSTORE_JRNL_ENQ_HDR_H + +#include <cstddef> +#include "qpid/legacystore/jrnl/rec_hdr.h" + +namespace mrg +{ +namespace journal +{ + +#pragma pack(1) + + /** + * \brief Struct for enqueue record. + * + * Struct for enqueue record. In addition to the common data, this header includes both the + * xid and data blob sizes. + * + * This header precedes all enqueue data in journal files. + * + * Record header info in binary format (32 bytes): + * <pre> + * 0 7 + * +---+---+---+---+---+---+---+---+ -+ + * | magic | v | e | flags | | + * +---+---+---+---+---+---+---+---+ | struct hdr + * | rid | | + * +---+---+---+---+---+---+---+---+ -+ + * | xidsize | + * +---+---+---+---+---+---+---+---+ + * | dsize | + * +---+---+---+---+---+---+---+---+ + * v = file version (If the format or encoding of this file changes, then this + * number should be incremented) + * e = endian flag, false (0x00) for little endian, true (0x01) for big endian + * </pre> + * + * Note that journal files should be transferable between 32- and 64-bit + * hardware of the same endianness, but not between hardware of opposite + * entianness without some sort of binary conversion utility. Thus buffering + * will be needed for types that change size between 32- and 64-bit compiles. + */ + struct enq_hdr : rec_hdr + { +#if defined(JRNL_BIG_ENDIAN) && defined(JRNL_32_BIT) + u_int32_t _filler0; ///< Big-endian filler for 32-bit size_t +#endif + std::size_t _xidsize; ///< XID size +#if defined(JRNL_LITTLE_ENDIAN) && defined(JRNL_32_BIT) + u_int32_t _filler0; ///< Little-endian filler for 32-bit size_t +#endif +#if defined(JRNL_BIG_ENDIAN) && defined(JRNL_32_BIT) + u_int32_t _filler1; ///< Big-endian filler for 32-bit size_t +#endif + std::size_t _dsize; ///< Record data size +#if defined(JRNL_LITTLE_ENDIAN) && defined(JRNL_32_BIT) + u_int32_t _filler1; ///< Little-endian filler for 32-bit size_t +#endif + static const u_int16_t ENQ_HDR_TRANSIENT_MASK = 0x10; + static const u_int16_t ENQ_HDR_EXTERNAL_MASK = 0x20; + + /** + * \brief Default constructor, which sets all values to 0. + */ + inline enq_hdr(): rec_hdr(), +#if defined(JRNL_BIG_ENDIAN) && defined(JRNL_32_BIT) + _filler0(0), +#endif + _xidsize(0), +#if defined(JRNL_LITTLE_ENDIAN) && defined(JRNL_32_BIT) + _filler0(0), +#endif +#if defined(JRNL_BIG_ENDIAN) && defined(JRNL_32_BIT) + _filler1(0), +#endif + _dsize(0) +#if defined(JRNL_LITTLE_ENDIAN) && defined(JRNL_32_BIT) + , _filler1(0) +#endif + {} + + /** + * \brief Convenience constructor which initializes values during construction. + */ + inline enq_hdr(const u_int32_t magic, const u_int8_t version, const u_int64_t rid, + const std::size_t xidsize, const std::size_t dsize, const bool owi, + const bool transient = false): rec_hdr(magic, version, rid, owi), +#if defined(JRNL_BIG_ENDIAN) && defined(JRNL_32_BIT) + _filler0(0), +#endif + _xidsize(xidsize), +#if defined(JRNL_LITTLE_ENDIAN) && defined(JRNL_32_BIT) + _filler0(0), +#endif +#if defined(JRNL_BIG_ENDIAN) && defined(JRNL_32_BIT) + _filler1(0), +#endif + _dsize(dsize) +#if defined(JRNL_LITTLE_ENDIAN) && defined(JRNL_32_BIT) + , _filler1(0) +#endif + { set_transient(transient); } + + + inline bool is_transient() const { return _uflag & ENQ_HDR_TRANSIENT_MASK; } + + inline void set_transient(const bool transient) + { + _uflag = transient ? _uflag | ENQ_HDR_TRANSIENT_MASK : + _uflag & (~ENQ_HDR_TRANSIENT_MASK); + } + + inline bool is_external() const { return _uflag & ENQ_HDR_EXTERNAL_MASK; } + + inline void set_external(const bool external) + { + _uflag = external ? _uflag | ENQ_HDR_EXTERNAL_MASK : + _uflag & (~ENQ_HDR_EXTERNAL_MASK); + } + + /** + * \brief Returns the size of the header in bytes. + */ + inline static std::size_t size() { return sizeof(enq_hdr); } + }; + +#pragma pack() + +} // namespace journal +} // namespace mrg + +#endif // ifndef QPID_LEGACYSTORE_JRNL_ENQ_HDR_H |