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Diffstat (limited to 'cpp/src/qpid/legacystore/jrnl/wrfc.h')
| -rw-r--r-- | cpp/src/qpid/legacystore/jrnl/wrfc.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/cpp/src/qpid/legacystore/jrnl/wrfc.h b/cpp/src/qpid/legacystore/jrnl/wrfc.h new file mode 100644 index 0000000000..f0e4e73151 --- /dev/null +++ b/cpp/src/qpid/legacystore/jrnl/wrfc.h @@ -0,0 +1,154 @@ +/* + * + * 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 wrfc.h + * + * Qpid asynchronous store plugin library + * + * File containing code for class mrg::journal::wrfc (write rotating + * file controller). See class documentation for details. + * + * \author Kim van der Riet + */ + +#ifndef QPID_LEGACYSTORE_JRNL_WRFC_H +#define QPID_LEGACYSTORE_JRNL_WRFC_H + +namespace mrg +{ +namespace journal +{ +class wrfc; +} +} + +#include <cstddef> +#include "qpid/legacystore/jrnl/enums.h" +#include "qpid/legacystore/jrnl/rrfc.h" + +namespace mrg +{ +namespace journal +{ + + /** + * \class wrfc + * \brief Class to handle write management of a journal rotating file controller. + */ + class wrfc : public rfc + { + private: + u_int32_t _fsize_sblks; ///< Size of journal files in sblks + u_int32_t _fsize_dblks; ///< Size of journal files in dblks + u_int32_t _enq_cap_offs_dblks; ///< Enqueue capacity offset + u_int64_t _rid; ///< Master counter for record ID (rid) + bool _reset_ok; ///< Flag set when reset succeeds + bool _owi; ///< Overwrite indicator + bool _frot; ///< Flag is true for first rotation, false otherwise + + public: + wrfc(const lpmgr* lpmp); + virtual ~wrfc(); + + /** + * \brief Initialize the controller. + * \param fsize_sblks Size of each journal file in sblks. + * \param rdp Struct carrying restore information. Optional for non-restore use, defaults to 0 (NULL). + */ + using rfc::initialize; + void initialize(const u_int32_t fsize_sblks, rcvdat* rdp = 0); + + /** + * \brief Rotate active file controller to next file in rotating file group. + * \exception jerrno::JERR__NINIT if called before calling initialize(). + */ + iores rotate(); + + /** + * \brief Returns the index of the earliest complete file within the rotating + * file group. Unwritten files are excluded. The currently active file is + * excluded unless it is the only written file. + */ + u_int16_t earliest_index() const; + + /** + * \brief Determines if a proposed write would cause the enqueue threshold to be exceeded. + * + * The following routine finds whether the next write will take the write pointer to beyond the + * enqueue limit threshold. The following illustrates how this is achieved. + * <pre> + * Current file index: 4 +---+----------+ + * X's mark still-enqueued records |msg| 1-thresh | + * msg = current msg size + unwritten cache +---+----------+ + * thresh = JRNL_ENQ_THRESHOLD as a fraction ^ V + * +-------+-------+-------+-------+--+----+-------+-+-----+-------+ + * file num ->| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | + * enq recs ->| X XX |XX XXX |XX XXXX|XXXXXXX|XX | | | X | + * +-------+-------+-------+-------+--+----+-------+-+-----+-------+ + * ^ ^ ^ + * subm_dblks --+ | | + * These files must be free of enqueues + * If not, return true. + * </pre> + * \param enq_dsize_dblks Proposed size of write in dblocks + */ + bool enq_threshold(const u_int32_t enq_dsize_dblks) const; + + inline u_int64_t rid() const { return _rid; } + inline u_int64_t get_incr_rid() { return _rid++; } + bool wr_reset(); + inline bool is_wr_reset() const { return _reset_ok; } + inline bool owi() const { return _owi; } + inline bool frot() const { return _frot; } + + // Convenience access methods to current file controller + + inline int fh() const { return _curr_fc->wr_fh(); } + + inline u_int32_t subm_cnt_dblks() const { return _curr_fc->wr_subm_cnt_dblks(); } + inline std::size_t subm_offs() const { return _curr_fc->wr_subm_offs(); } + inline u_int32_t add_subm_cnt_dblks(u_int32_t a) { return _curr_fc->add_wr_subm_cnt_dblks(a); } + + inline u_int32_t cmpl_cnt_dblks() const { return _curr_fc->wr_cmpl_cnt_dblks(); } + inline std::size_t cmpl_offs() const { return _curr_fc->wr_cmpl_offs(); } + inline u_int32_t add_cmpl_cnt_dblks(u_int32_t a) { return _curr_fc->add_wr_cmpl_cnt_dblks(a); } + + inline u_int16_t aio_cnt() const { return _curr_fc->aio_cnt(); } + inline u_int16_t incr_aio_cnt() { return _curr_fc->incr_aio_cnt(); } + inline u_int16_t decr_aio_cnt() { return _curr_fc->decr_aio_cnt(); } + + inline bool is_void() const { return _curr_fc->wr_void(); } + inline bool is_empty() const { return _curr_fc->wr_empty(); } + inline u_int32_t remaining_dblks() const { return _curr_fc->wr_remaining_dblks(); } + inline bool is_full() const { return _curr_fc->is_wr_full(); }; + inline bool is_compl() const { return _curr_fc->is_wr_compl(); }; + inline u_int32_t aio_outstanding_dblks() const { return _curr_fc->wr_aio_outstanding_dblks(); } + inline bool file_rotate() const { return _curr_fc->wr_file_rotate(); } + + // Debug aid + std::string status_str() const; + }; + +} // namespace journal +} // namespace mrg + +#endif // ifndef QPID_LEGACYSTORE_JRNL_WRFC_H |