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Diffstat (limited to 'cpp/src/qpid/legacystore/jrnl/txn_map.h')
| -rw-r--r-- | cpp/src/qpid/legacystore/jrnl/txn_map.h | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/cpp/src/qpid/legacystore/jrnl/txn_map.h b/cpp/src/qpid/legacystore/jrnl/txn_map.h new file mode 100644 index 0000000000..6b38564e53 --- /dev/null +++ b/cpp/src/qpid/legacystore/jrnl/txn_map.h @@ -0,0 +1,159 @@ +/* + * + * 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 txn_map.h + * + * Qpid asynchronous store plugin library + * + * File containing code for class mrg::journal::txn_map (transaction map). + * See class documentation for details. + * + * \author Kim van der Riet + */ + +#ifndef QPID_LEGACYSTORE_JRNL_TXN_MAP_H +#define QPID_LEGACYSTORE_JRNL_TXN_MAP_H + +namespace mrg +{ +namespace journal +{ + class txn_map; +} +} + +#include "qpid/legacystore/jrnl/smutex.h" +#include <map> +#include <pthread.h> +#include <string> +#include <sys/types.h> +#include <vector> + +namespace mrg +{ +namespace journal +{ + + /** + * \struct txn_data_struct + * \brief Struct encapsulating transaction data necessary for processing a transaction + * in the journal once it is closed with either a commit or abort. + */ + struct txn_data_struct + { + u_int64_t _rid; ///< Record id for this operation + u_int64_t _drid; ///< Dequeue record id for this operation + u_int16_t _pfid; ///< Physical file id, to be used when transferring to emap on commit + bool _enq_flag; ///< If true, enq op, otherwise deq op + bool _commit_flag; ///< (2PC transactions) Records 2PC complete c/a mode + bool _aio_compl; ///< Initially false, set to true when record AIO returns + txn_data_struct(const u_int64_t rid, const u_int64_t drid, const u_int16_t pfid, + const bool enq_flag, const bool commit_flag = false); + }; + typedef txn_data_struct txn_data; + typedef std::vector<txn_data> txn_data_list; + typedef txn_data_list::iterator tdl_itr; + + /** + * \class txn_map + * \brief Class for storing transaction data for each open (ie not committed or aborted) + * xid in the store. If aborted, records are discarded; if committed, they are + * transferred to the enqueue map. + * + * The data is encapsulated by struct txn_data_struct. A vector containing the information + * for each operation included as part of the same transaction is mapped against the + * xid. + * + * The aio_compl flag is set true as each AIO write operation for the enqueue or dequeue + * returns. Checking that all of these flags are true for a given xid is the mechanism + * used to determine if the transaction is syncronized (through method is_txn_synced()). + * + * On transaction commit, then each operation is handled as follows: + * + * If an enqueue (_enq_flag is true), then the rid and pfid are transferred to the enq_map. + * If a dequeue (_enq_flag is false), then the rid stored in the drid field is used to + * remove the corresponding record from the enq_map. + * + * On transaction abort, then each operation is handled as follows: + * + * If an enqueue (_enq_flag is true), then the data is simply discarded. + * If a dequeue (_enq_flag is false), then the lock for the corresponding enqueue in enq_map + * (if not a part of the same transaction) is removed, and the data discarded. + * + * <pre> + * key data + * + * xid1 --- vector< [ rid, drid, pfid, enq_flag, commit_flag, aio_compl ] > + * xid2 --- vector< [ rid, drid, pfid, enq_flag, commit_flag, aio_compl ] > + * xid3 --- vector< [ rid, drid, pfid, enq_flag, commit_flag, aio_compl ] > + * ... + * </pre> + */ + class txn_map + { + public: + // return/error codes + static int16_t TMAP_RID_NOT_FOUND; + static int16_t TMAP_XID_NOT_FOUND; + static int16_t TMAP_OK; + static int16_t TMAP_NOT_SYNCED; + static int16_t TMAP_SYNCED; + + private: + typedef std::pair<std::string, txn_data_list> xmap_param; + typedef std::map<std::string, txn_data_list> xmap; + typedef xmap::iterator xmap_itr; + + xmap _map; + smutex _mutex; + std::vector<u_int32_t> _pfid_txn_cnt; + const txn_data_list _empty_data_list; + + public: + txn_map(); + virtual ~txn_map(); + + void set_num_jfiles(const u_int16_t num_jfiles); + u_int32_t get_txn_pfid_cnt(const u_int16_t pfid) const; + bool insert_txn_data(const std::string& xid, const txn_data& td); + const txn_data_list get_tdata_list(const std::string& xid); + const txn_data_list get_remove_tdata_list(const std::string& xid); + bool in_map(const std::string& xid); + u_int32_t enq_cnt(); + u_int32_t deq_cnt(); + int16_t is_txn_synced(const std::string& xid); // -1=xid not found; 0=not synced; 1=synced + int16_t set_aio_compl(const std::string& xid, const u_int64_t rid); // -2=rid not found; -1=xid not found; 0=done + bool data_exists(const std::string& xid, const u_int64_t rid); + bool is_enq(const u_int64_t rid); + inline void clear() { _map.clear(); } + inline bool empty() const { return _map.empty(); } + inline size_t size() const { return _map.size(); } + void xid_list(std::vector<std::string>& xv); + private: + u_int32_t cnt(const bool enq_flag); + const txn_data_list get_tdata_list_nolock(const std::string& xid); + }; + +} // namespace journal +} // namespace mrg + +#endif // ifndef QPID_LEGACYSTORE_JRNL_TXN_MAP_H |