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Annotation of parser3/src/main/pa_db_manager.C, revision 1.11

1.1       parser      1: /** @file
                      2:        Parser: sql driver manager implementation.
                      3: 
                      4:        Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com)
                      5:        Author: Alexander Petrosyan <paf@design.ru> (http://design.ru/paf)
                      6: 
1.11    ! paf         7:        $Id: pa_db_manager.C,v 1.10 2001/10/30 15:08:19 paf Exp $
1.1       parser      8: */
                      9: 
1.3       parser     10: #include "pa_config_includes.h"
1.9       paf        11: #ifdef DB2
1.3       parser     12: 
1.1       parser     13: #include "pa_db_manager.h"
1.2       parser     14: #include "pa_db_connection.h"
1.1       parser     15: #include "pa_exception.h"
                     16: #include "pa_threads.h"
                     17: #include "pa_stack.h"
1.11    ! paf        18: #include "pa_vhash.h"
1.1       parser     19: 
                     20: // globals
                     21: 
                     22: DB_Manager *DB_manager;
                     23: 
                     24: // consts
                     25: 
                     26: const int EXPIRE_UNUSED_CONNECTION_SECONDS=60;
                     27: const int CHECK_EXPIRED_CONNECTIONS_SECONDS=EXPIRE_UNUSED_CONNECTION_SECONDS*2;
                     28: 
1.4       parser     29: // callbacks
                     30: 
1.7       paf        31: static void expire_connection(const Hash::Key& key, Hash::Val *& value, void *info) {
1.6       paf        32:        DB_Connection& connection=*static_cast<DB_Connection *>(value);
                     33:        time_t older_dies=reinterpret_cast<time_t>(info);
                     34: 
1.7       paf        35:        if(connection.expired(older_dies)) {
                     36:                connection.~DB_Connection();  value=0;
                     37:        }
1.4       parser     38: }
1.1       parser     39: 
                     40: // DB_Manager
                     41: 
1.11    ! paf        42: DB_Manager::DB_Manager(Pool& apool) : Pooled(apool),
        !            43:        connection_cache(apool),
1.1       parser     44:        prev_expiration_pass_time(0) {
                     45: 
1.11    ! paf        46:        status_providers->put(*NEW String(pool(), "db"), this);
1.1       parser     47: }
                     48: 
                     49: DB_Manager::~DB_Manager() {
1.6       paf        50:        // close connections
1.7       paf        51:        connection_cache.for_each(expire_connection, 
1.6       paf        52:                reinterpret_cast<void *>(0/* =in the past = expire[close] all*/));
1.1       parser     53: }
                     54: 
1.7       paf        55: /// @test subpools mechanizm. one connection, one subpool. ~connection destructs it
                     56: DB_Connection_ptr DB_Manager::get_connection_ptr(const String& request_db_home,
                     57:                                                                                                   const String *source) {
1.6       paf        58:        if(request_db_home.size()==0)
                     59:                throw Exception(0, 0,
1.7       paf        60:                        source,
1.6       paf        61:                        "empty DB_HOME specified");
1.1       parser     62: 
                     63:        // first trying to get cached connection
1.6       paf        64:        DB_Connection *result=get_connection_from_cache(request_db_home);
1.7       paf        65:        if(!result) { // no cached connection
1.6       paf        66:                // make global_db_home C-string on global pool
1.10      paf        67:                const char *request_db_home_cstr=request_db_home.cstr();
1.6       paf        68:                char *global_db_home_cstr=(char *)malloc(strlen(request_db_home_cstr)+1);
                     69:                strcpy(global_db_home_cstr, request_db_home_cstr);
                     70:                // make global_db_home string on global pool
                     71:                String& global_db_home=*new(this->pool()) String(this->pool(), global_db_home_cstr);
1.1       parser     72:                
                     73:                // allocate in global pool 
                     74:                // NOTE: never freed up!
1.6       paf        75:                result=new(this->pool()) DB_Connection(this->pool(), global_db_home);
1.7       paf        76:                // cache it
                     77:                put_connection_to_cache(global_db_home, *result);
1.1       parser     78:        }
                     79: 
1.7       paf        80:        // return auto-it
                     81:        return DB_Connection_ptr(result);
1.2       parser     82: }
                     83: 
1.1       parser     84: // connection cache
                     85: /// @todo get rid of memory spending Stack [zeros deep inside got accumulated]
1.6       paf        86: DB_Connection *DB_Manager::get_connection_from_cache(const String& db_home) { 
1.1       parser     87:        SYNCHRONIZED;
1.8       paf        88: 
                     89:        maybe_expire_connection_cache();
1.1       parser     90: 
1.7       paf        91:        return static_cast<DB_Connection *>(connection_cache.get(db_home));
1.1       parser     92: }
                     93: 
1.6       paf        94: void DB_Manager::put_connection_to_cache(const String& db_home, 
1.1       parser     95:                                                                                                 DB_Connection& connection) { 
                     96:        SYNCHRONIZED;
                     97: 
1.7       paf        98:        connection_cache.put(db_home, &connection);
1.1       parser     99: }
                    100: 
                    101: void DB_Manager::maybe_expire_connection_cache() {
                    102:        time_t now=time(0);
                    103: 
                    104:        if(prev_expiration_pass_time<now-CHECK_EXPIRED_CONNECTIONS_SECONDS) {
1.7       paf       105:                connection_cache.for_each(expire_connection, 
1.1       parser    106:                        reinterpret_cast<void *>(now-EXPIRE_UNUSED_CONNECTION_SECONDS));
                    107: 
                    108:                prev_expiration_pass_time=now;
                    109:        }
1.11    ! paf       110: }
        !           111: 
        !           112: Value& DB_Manager::get_status(Pool& pool, const String *source) {
        !           113:        VHash& result=*new(pool) VHash(pool);
        !           114: /*     
        !           115:        // cache
        !           116:        {
        !           117:                Array& columns=*new(pool) Array(pool, 3);
        !           118:                columns+=new(pool) String(pool, "protocol");
        !           119:                columns+=new(pool) String(pool, "time");
        !           120:                columns+=new(pool) String(pool, "times");
        !           121:                Table& table=*new(pool) Table(pool, 0, &columns, connection_cache.size());
        !           122: 
        !           123:                connection_cache.for_each(add_connections_to_status_cache_table, &table);
        !           124: 
        !           125:                result.hash(source).put(*new(pool) String(pool, "cache"), new(pool) VTable(pool, &table));
        !           126:        }
        !           127: */
        !           128:        return result;
1.1       parser    129: }
1.3       parser    130: 
                    131: #endif