Annotation of parser3/src/main/pa_sql_driver_manager.C, revision 1.1
1.1 ! paf 1: /** @file
! 2: Parser: sql driver manager implementation.
! 3:
! 4: Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com)
! 5:
! 6: Author: Alexander Petrosyan <paf@design.ru> (http://design.ru/paf)
! 7:
! 8: $Id: pa_exception.C,v 1.9 2001/03/19 17:42:16 paf Exp $
! 9: */
! 10:
! 11: #include "pa_config_includes.h"
! 12: #include "ltdl.h"
! 13: #include "pa_sql_driver_manager.h"
! 14: #include "pa_exception.h"
! 15: #include "pa_common.h"
! 16:
! 17: // globals
! 18:
! 19: SQL_Driver_manager *SQL_driver_manager;
! 20:
! 21: // consts
! 22:
! 23: const int MAX_PROTOCOL=20;
! 24: const char *LIBRARY_CREATE_FUNC_NAME="create";
! 25:
! 26: // url:
! 27: // protocol://user:pass@host:port/database
! 28: // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this is driver-dependent
! 29: SQL_Connection& SQL_Driver_manager::get_connection(const String& url,
! 30: Table *protocol2library) {
! 31: SYNCHRONIZED(true);
! 32:
! 33: Pool& pool=url.pool(); // request pool
! 34:
! 35: // we have table for locating protocol's library
! 36: if(!protocol2library)
! 37: PTHROW(0, 0,
! 38: &url,
! 39: "SQL:drivers table must be defined");
! 40:
! 41: // first trying to get cached connection
! 42: if(SQL_Connection *result=get_connection_from_cache(url))
! 43: return *result;
! 44: // no cached connection
! 45:
! 46: int pos=url.pos("://", 3);
! 47: if(pos<0)
! 48: PTHROW(0, 0,
! 49: &url,
! 50: "no protocol specified"); // NOTE: not THROW, but PTHROW
! 51:
! 52: // make url string on global pool
! 53: char *url_cstr=(char *)malloc(MAX_STRING);
! 54: strncpy(url_cstr, url.cstr(String::UL_AS_IS), MAX_STRING);
! 55:
! 56: char *protocol_cstr=lsplit(&url_cstr, ':');
! 57: String& protocol=*new(this->pool()) String(this->pool(), protocol_cstr);
! 58:
! 59: // skip // after :
! 60: while(*url_cstr=='/')
! 61: url_cstr++;
! 62:
! 63: SQL_Driver *driver;
! 64: // first trying to get cached driver
! 65: if(!(driver=get_driver_from_cache(protocol))) {
! 66: // no cached
! 67: const String *library=0;
! 68: if(protocol2library->locate(0, protocol)) {
! 69: if(!(library=protocol2library->item(1)))
! 70: PTHROW(0, 0,
! 71: protocol2library->origin_string(),
! 72: "library column for protocol '%s' is empty", protocol_cstr);
! 73: } else
! 74: PTHROW(0, 0,
! 75: protocol2library->origin_string(),
! 76: "protocol '%s' not found", protocol_cstr);
! 77:
! 78: const char *filename=library->cstr(String::UL_FILE_NAME);
! 79: lt_dlhandle handle = lt_dlopen(filename);
! 80: if (!handle)
! 81: PTHROW(0, 0,
! 82: library,
! 83: "can not open the module, %s", lt_dlerror());
! 84:
! 85: SQL_Driver_create_func create=(SQL_Driver_create_func)lt_dlsym(handle,
! 86: LIBRARY_CREATE_FUNC_NAME);
! 87: if(!create)
! 88: PTHROW(0, 0,
! 89: library,
! 90: "function '%s' was not found", LIBRARY_CREATE_FUNC_NAME);
! 91:
! 92: // create library-driver
! 93: driver=(*create)();
! 94:
! 95: // validate driver api version
! 96: int driver_api_version=driver->api_version();
! 97: if(driver_api_version < SQL_API_VERSION)
! 98: PTHROW(0, 0,
! 99: library,
! 100: "driver API version is 0x%04X while current minimum is 0x%04X",
! 101: driver_api_version, SQL_API_VERSION);
! 102:
! 103: // cache it
! 104: put_driver_to_cache(protocol, *driver);
! 105: }
! 106:
! 107: void *info;
! 108: char *error;
! 109: if(!driver->connect(url_cstr, &info, &error))
! 110: PTHROW(0, 0,
! 111: &url,
! 112: "can not connect - %s", error);
! 113:
! 114: return *new(this->pool()) SQL_Connection(url.pool(), //< associate with request
! 115: *driver, info, url);
! 116: }
! 117:
! 118: void SQL_Driver_manager::close_connection(const String& url,
! 119: SQL_Connection& connection) {
! 120: SYNCHRONIZED(true);
! 121:
! 122: connection.set_pool(0); // deassociate from request
! 123: put_connection_to_cache(url, connection);
! 124: }
! 125:
! 126:
! 127: // driver cache
! 128:
! 129: SQL_Driver *SQL_Driver_manager::get_driver_from_cache(const String& protocol) {
! 130: if(SQL_Driver *result=static_cast<SQL_Driver *>(driver_cache.get(protocol)))
! 131: return result;
! 132:
! 133: return 0;
! 134: }
! 135:
! 136: void SQL_Driver_manager::put_driver_to_cache(const String& protocol,
! 137: SQL_Driver& driver) {
! 138: driver_cache.put(protocol, &driver);
! 139: }
! 140:
! 141: // connection cache
! 142:
! 143: SQL_Connection *SQL_Driver_manager::get_connection_from_cache(const String& url) {
! 144: if(Stack *connections=static_cast<Stack *>(connection_cache.get(url)))
! 145: if(connections->size()) // there are cached connections to that 'url'
! 146: return static_cast<SQL_Connection *>(connections->pop());
! 147:
! 148: return 0;
! 149: }
! 150:
! 151: void SQL_Driver_manager::put_connection_to_cache(const String& url,
! 152: SQL_Connection& connection) {
! 153: Stack *connections;
! 154: if(!(connections=static_cast<Stack *>(connection_cache.get(url)))) {
! 155: // there are no cached connections to that 'url' yet
! 156: connections=NEW Stack(pool()); // NOTE: never freed up!
! 157: connection_cache.put(url, connections);
! 158: }
! 159: connections->push(&connection);
! 160: }
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