| /* |
| * |
| * 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 file_hdr.h |
| * |
| * Qpid asynchronous store plugin library |
| * |
| * File containing code for class mrg::journal::file_hdr (file |
| * record header), used to start a journal file. It contains some |
| * file metadata and information to aid journal recovery. |
| * |
| * \author Kim van der Riet |
| */ |
| |
| #ifndef QPID_LEGACYSTORE_JRNL_FILE_HDR_H |
| #define QPID_LEGACYSTORE_JRNL_FILE_HDR_H |
| |
| #include <cerrno> |
| #include <ctime> |
| #include "qpid/legacystore/jrnl/rec_hdr.h" |
| #include "qpid/legacystore/jrnl/jerrno.h" |
| #include "qpid/legacystore/jrnl/jexception.h" |
| #include <sstream> |
| |
| namespace mrg |
| { |
| namespace journal |
| { |
| |
| #pragma pack(1) |
| |
| /** |
| * \brief Struct for data common to the head of all journal files. In addition to |
| * the common data, this includes the record ID and offset of the first record in |
| * the file. |
| * |
| * This header precedes all data in journal files and occupies the first complete |
| * block in the file. The record ID and offset are updated on each overwrite of the |
| * file. |
| * |
| * File header info in binary format (48 bytes): |
| * <pre> |
| * 0 7 |
| * +---+---+---+---+---+---+---+---+ -+ |
| * | magic | v | e | flags | | |
| * +---+---+---+---+---+---+---+---+ | struct hdr |
| * | first rid in file | | |
| * +---+---+---+---+---+---+---+---+ -+ |
| * | pfid | lfid | reserved (0) | |
| * +---+---+---+---+---+---+---+---+ |
| * | fro | |
| * +---+---+---+---+---+---+---+---+ |
| * | timestamp (sec) | |
| * +---+---+---+---+---+---+---+---+ |
| * | timestamp (ns) | |
| * +---+---+---+---+---+---+---+---+ |
| * 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 |
| * pfid = File ID (number used in naming file) |
| * lfid = Logical ID (order used in circular buffer) |
| * fro = First record offset, offset from start of file to first record header |
| * </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 file_hdr : rec_hdr |
| { |
| u_int16_t _pfid; ///< Physical file ID (pfid) |
| u_int16_t _lfid; ///< Logical file ID (lfid) |
| u_int32_t _res; ///< Reserved (for alignment/flags) |
| #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 _fro; ///< First record offset |
| #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 time_t |
| #endif |
| std::time_t _ts_sec; ///< Timestamp of journal initilailization |
| #if defined(JRNL_LITTLE_ENDIAN) && defined(JRNL_32_BIT) |
| u_int32_t _filler1; ///< Little-endian filler for 32-bit time_t |
| #endif |
| #if defined(JRNL_BIG_ENDIAN) |
| u_int32_t _filler2; ///< Big endian filler for u_int32_t |
| #endif |
| u_int32_t _ts_nsec; ///< Timestamp of journal initilailization |
| #if defined(JRNL_LITTLE_ENDIAN) |
| u_int32_t _filler2; ///< Little-endian filler for u_int32_t |
| #endif |
| |
| /** |
| * \brief Default constructor, which sets all values to 0. |
| */ |
| inline file_hdr(): rec_hdr(), _pfid(0), _lfid(0), _res(0), |
| #if defined(JRNL_BIG_ENDIAN) && defined(JRNL_32_BIT) |
| _filler0(0), |
| #endif |
| _fro(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 |
| _ts_sec(0), |
| #if defined(JRNL_LITTLE_ENDIAN) && defined(JRNL_32_BIT) |
| _filler1(0), |
| #endif |
| #if defined(JRNL_BIG_ENDIAN) |
| _filler2(0), |
| #endif |
| _ts_nsec(0) |
| #if defined(JRNL_LITTLE_ENDIAN) |
| , _filler2(0) |
| #endif |
| {} |
| |
| /** |
| * \brief Convenience constructor which initializes values during construction. |
| */ |
| inline file_hdr(const u_int32_t magic, const u_int8_t version, const u_int64_t rid, |
| const u_int16_t pfid, const u_int16_t lfid, const std::size_t fro, |
| const bool owi, const bool settime = false): |
| rec_hdr(magic, version, rid, owi), _pfid(pfid), _lfid(lfid), _res(0), |
| #if defined(JRNL_BIG_ENDIAN) && defined(JRNL_32_BIT) |
| _filler0(0), |
| #endif |
| _fro(fro), |
| #if defined(JRNL_LITTLE_ENDIAN) && defined(JRNL_32_BIT) |
| _filler0(0), |
| #endif |
| #if defined(JRNL_BIG_ENDIAN) && defined(JRNL_32_BIT) |
| _filler1(0), |
| #endif |
| _ts_sec(0), |
| #if defined(JRNL_LITTLE_ENDIAN) && defined(JRNL_32_BIT) |
| _filler1(0), |
| #endif |
| #if defined(JRNL_BIG_ENDIAN) |
| _filler2(0), |
| #endif |
| _ts_nsec(0) |
| #if defined(JRNL_LITTLE_ENDIAN) |
| , _filler2(0) |
| #endif |
| { if (settime) set_time(); } |
| |
| /** |
| * \brief Gets the current time from the system clock and sets the timestamp in the struct. |
| */ |
| inline void set_time() |
| { |
| // TODO: Standardize on method for getting time that does not requrie a context switch. |
| timespec ts; |
| if (::clock_gettime(CLOCK_REALTIME, &ts)) |
| { |
| std::ostringstream oss; |
| oss << FORMAT_SYSERR(errno); |
| throw jexception(jerrno::JERR__RTCLOCK, oss.str(), "file_hdr", "set_time"); |
| } |
| _ts_sec = ts.tv_sec; |
| _ts_nsec = ts.tv_nsec; |
| } |
| |
| /** |
| * \brief Sets the timestamp in the struct to the provided value (in seconds and |
| * nanoseconds). |
| */ |
| inline void set_time(timespec& ts) |
| { |
| _ts_sec = ts.tv_sec; |
| _ts_nsec = ts.tv_nsec; |
| } |
| |
| /** |
| * \brief Returns the size of the header in bytes. |
| */ |
| inline static std::size_t size() { return sizeof(file_hdr); } |
| }; // struct file_hdr |
| |
| #pragma pack() |
| |
| } // namespace journal |
| } // namespace mrg |
| |
| #endif // ifndef QPID_LEGACYSTORE_JRNL_FILE_HDR_H |
