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Annotation of parser3/src/include/pa_db_connection.h, revision 1.16

1.1       parser      1: /** @file
1.9       paf         2:        Parser: sql driver connection decl.
                      3:        global sql driver connection, must be thread-safe
1.1       parser      4: 
                      5:        Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com)
                      6:        Author: Alexander Petrosyan <paf@design.ru> (http://design.ru/paf)
                      7: 
1.16    ! paf         8:        $Id: pa_db_connection.h,v 1.15 2001/10/29 08:23:49 paf Exp $
1.1       parser      9: */
                     10: 
                     11: #ifndef PA_DB_CONNECTION_H
                     12: #define PA_DB_CONNECTION_H
                     13: 
                     14: #include "pa_config_includes.h"
                     15: #include "pa_pool.h"
1.9       paf        16: #include "pa_hash.h"
1.10      paf        17: #include "pa_db_table.h"
1.1       parser     18: 
                     19: // defines
                     20: 
1.2       parser     21: // forwards
                     22: 
1.9       paf        23: class DB_Table;
1.10      paf        24: class DB_Connection_ptr;
1.1       parser     25: 
1.9       paf        26: /// sql driver connection
1.1       parser     27: class DB_Connection : public Pooled {
1.15      paf        28:        friend class DB_Table;
                     29:        friend class DB_Connection_ptr;
1.1       parser     30: public:
                     31: 
1.10      paf        32:        DB_Connection(Pool& apool, const String& db_home);
                     33:        ~DB_Connection();
1.1       parser     34: 
                     35:        bool expired(time_t older_dies) {
1.10      paf        36:                return !used && time_used<older_dies;
1.1       parser     37:        }
1.16    ! paf        38:        time_t get_time_used() { return time_used; }
        !            39:        int get_users_count() { return used; }
1.1       parser     40: 
1.9       paf        41:        /**
1.16    ! paf        42:                connect to specified file_name
1.9       paf        43:        */
1.11      paf        44:        DB_Table_ptr get_table_ptr(const String& file_name, const String *source);
1.9       paf        45: 
1.10      paf        46: private: // connection usage methods
                     47: 
                     48:        void use() {
                     49:                time_used=time(0); // they started to use at this time
                     50:                used++;
                     51:        }
                     52:        void unuse() {
                     53:                used--;
                     54:        }
                     55: 
                     56: private: // connection usage data
                     57: 
                     58:        int used;
                     59: 
1.9       paf        60: private: // table cache
                     61: 
                     62:        DB_Table *get_table_from_cache(const String& file_name);
                     63:        void put_table_to_cache(const String& file_name, DB_Table& table);
                     64:        void maybe_expire_table_cache();
1.1       parser     65: private:
1.9       paf        66:        time_t prev_expiration_pass_time;
1.1       parser     67: 
1.9       paf        68: private: // for DB_Table
1.1       parser     69: 
1.9       paf        70:        /// caches table
                     71:        void close_table(const String& file_name, DB_Table& table);
1.2       parser     72: 
1.9       paf        73: private:
1.2       parser     74: 
1.9       paf        75:        time_t time_used;
1.2       parser     76: 
1.9       paf        77:        const String& fdb_home;
                     78:        DB_ENV dbenv;
                     79:        Hash table_cache;
1.2       parser     80: 
1.1       parser     81: private:
                     82: 
                     83:        void check(const char *operation, const String *source, int error);
1.10      paf        84: };
                     85: 
                     86: /// Auto-object used to track DB_Connection usage
                     87: class DB_Connection_ptr {
                     88:        DB_Connection *fconnection;
                     89: public:
                     90:        DB_Connection_ptr(DB_Connection *aconnection) : fconnection(aconnection) {
                     91:                fconnection->use();
                     92:        }
                     93:        ~DB_Connection_ptr() {
                     94:                fconnection->unuse();
                     95:        }
                     96:        DB_Connection* operator->() {
                     97:                return fconnection;
                     98:        }
                     99: 
                    100:        // copying
                    101:        DB_Connection_ptr(const DB_Connection_ptr& src) : fconnection(src.fconnection) {
                    102:                fconnection->use();
                    103:        }
                    104:        DB_Connection_ptr& operator =(const DB_Connection_ptr& src) {
                    105:                // may do without this=src check
                    106:                fconnection->unuse();
                    107:                fconnection=src.fconnection;
                    108:                fconnection->use();
                    109: 
                    110:                return *this;
                    111:        }
1.1       parser    112: };
                    113: 
                    114: #endif