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Diffstat (limited to 'cpp/src/qpid/legacystore/jrnl/rfc.h')
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diff --git a/cpp/src/qpid/legacystore/jrnl/rfc.h b/cpp/src/qpid/legacystore/jrnl/rfc.h new file mode 100644 index 0000000000..faa5d566ba --- /dev/null +++ b/cpp/src/qpid/legacystore/jrnl/rfc.h @@ -0,0 +1,193 @@ +/* + * + * 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 rfc.h + * + * Qpid asynchronous store plugin library + * + * File containing code for class mrg::journal::rfc (rotating + * file controller). See class documentation for details. + * + * \author Kim van der Riet + */ + +#ifndef QPID_LEGACYSTORE_JRNL_RFC_H +#define QPID_LEGACYSTORE_JRNL_RFC_H + +namespace mrg +{ +namespace journal +{ +class rfc; +} +} + +#include "qpid/legacystore/jrnl/lpmgr.h" +#include "qpid/legacystore/jrnl/enums.h" + +namespace mrg +{ +namespace journal +{ + + /** + * \class rfc + * \brief Rotating File Controller (rfc) - Class to handle the manangement of an array of file controllers (fcntl) + * objects for use in a circular disk buffer (journal). Each fcntl object corresponds to a file in the journal. + * + * The following states exist in this class: + * + * <pre> + * is_init() is_active() + * +===+ _lpmp.is_init() == false + * +---------->| | Uninitialized: _curr_fc == 0 F F + * | +-->+===+ --+ + * | | | + * | | | + * | finalize() initialize() + * | | | + * | | | + * | +-- +===+<--+ _lpmp.is_init() == true + * finalize() | | Inactive: _curr_fc == 0 T F + * | +-->+===+ --+ + * | | | + * | | | + * | unset_findex() set_findex() + * | | | + * | | | + * | +-- +===+<--+ _lpmp.is_init() == true + * +---------- | | Active: _curr_fc != 0 T T + * +===+ + * </pre> + * + * The Uninitialized state is where the class starts after construction. Once the number of files is known and + * the array of file controllers allocated, then initialize() is called to set these, causing the state to move + * to Inactive. + * + * The Inactive state has the file controllers allocated and pointing to their respective journal files, but no + * current file controller has been selected. The pointer to the current file controller _curr_fc is null. Once the + * index of the active file is known, then calling set_findex() will set the index and internal pointer + * to the currently active file controller. This moves the state to Active. + * + * Note TODO: Comment on sync issues between change in num files in _lpmp and _fc_index/_curr_fc. + */ + class rfc + { + protected: + const lpmgr* _lpmp; ///< Pointer to jcntl's lpmgr instance containing lfid/pfid map and fcntl objects + u_int16_t _fc_index; ///< Index of current file controller + fcntl* _curr_fc; ///< Pointer to current file controller + + public: + rfc(const lpmgr* lpmp); + virtual ~rfc(); + + /** + * \brief Initialize the controller, moving from state Uninitialized to Inactive. The main function of + * initialize() is to set the number of files and the pointer to the fcntl array. + */ + virtual inline void initialize() {} + + /** + * \brief Reset the controller to Uninitialized state, usually called when the journal is stopped. Once called, + * initialize() must be called to reuse an instance. + */ + virtual void finalize(); + + /** + * \brief Check initialization state: true = Not Uninitialized, ie Initialized or Active; false = Uninitialized. + */ + virtual inline bool is_init() const { return _lpmp->is_init(); } + + /** + * \brief Check active state: true = Initialized and _curr_fc not null; false otherwise. + */ + virtual inline bool is_active() const { return _lpmp->is_init() && _curr_fc != 0; } + + /** + * \brief Sets the current file index and active fcntl object. Moves to state Active. + */ + virtual void set_findex(const u_int16_t fc_index); + + /** + * \brief Nulls the current file index and active fcntl pointer, moves to state Inactive. + */ + virtual void unset_findex(); + + /** + * \brief Rotate active file controller to next file in rotating file group. + * \exception jerrno::JERR__NINIT if called before calling initialize(). + */ + virtual iores rotate() = 0; + + /** + * \brief Returns the index of the currently active file within the rotating file group. + */ + inline u_int16_t index() const { return _fc_index; } + + /** + * \brief Returns the currently active journal file controller within the rotating file group. + */ + inline fcntl* file_controller() const { return _curr_fc; } + + /** + * \brief Returns the currently active physical file id (pfid) + */ + inline u_int16_t pfid() const { return _curr_fc->pfid(); } + + // Convenience access methods to current file controller + // Note: Do not call when not in active state + + inline u_int32_t enqcnt() const { return _curr_fc->enqcnt(); } + inline u_int32_t incr_enqcnt() { return _curr_fc->incr_enqcnt(); } + inline u_int32_t incr_enqcnt(const u_int16_t fid) { return _lpmp->get_fcntlp(fid)->incr_enqcnt(); } + inline u_int32_t add_enqcnt(const u_int32_t a) { return _curr_fc->add_enqcnt(a); } + inline u_int32_t add_enqcnt(const u_int16_t fid, const u_int32_t a) + { return _lpmp->get_fcntlp(fid)->add_enqcnt(a); } + inline u_int32_t decr_enqcnt(const u_int16_t fid) { return _lpmp->get_fcntlp(fid)->decr_enqcnt(); } + inline u_int32_t subtr_enqcnt(const u_int16_t fid, const u_int32_t s) + { return _lpmp->get_fcntlp(fid)->subtr_enqcnt(s); } + + virtual inline u_int32_t subm_cnt_dblks() const = 0; + virtual inline std::size_t subm_offs() const = 0; + virtual inline u_int32_t add_subm_cnt_dblks(u_int32_t a) = 0; + + virtual inline u_int32_t cmpl_cnt_dblks() const = 0; + virtual inline std::size_t cmpl_offs() const = 0; + virtual inline u_int32_t add_cmpl_cnt_dblks(u_int32_t a) = 0; + + virtual inline bool is_void() const = 0; + virtual inline bool is_empty() const = 0; + virtual inline u_int32_t remaining_dblks() const = 0; + virtual inline bool is_full() const = 0; + virtual inline bool is_compl() const = 0; + virtual inline u_int32_t aio_outstanding_dblks() const = 0; + virtual inline bool file_rotate() const = 0; + + // Debug aid + virtual std::string status_str() const; + }; // class rfc + +} // namespace journal +} // namespace mrg + +#endif // ifndef QPID_LEGACYSTORE_JRNL_RFC_H |