Annotation of parser3/src/main/pa_sql_driver_manager.C, revision 1.12
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:
1.12 ! parser 8: $Id: pa_sql_driver_manager.C,v 1.11 2001/05/16 08:10:22 parser Exp $
1.1 paf 9: */
10:
11: #include "pa_config_includes.h"
12: #include "ltdl.h"
13: #include "pa_sql_driver_manager.h"
1.2 paf 14: #include "pa_sql_connection.h"
1.1 paf 15: #include "pa_exception.h"
16: #include "pa_common.h"
17:
18: // globals
19:
20: SQL_Driver_manager *SQL_driver_manager;
21:
22: // consts
23:
24: const int MAX_PROTOCOL=20;
25: const char *LIBRARY_CREATE_FUNC_NAME="create";
26:
1.3 paf 27:
1.8 paf 28: /// SQL_Driver_services Pooled implementation
29: class SQL_Driver_services_impl : public SQL_Driver_services, public Pooled {
1.3 paf 30: public:
1.8 paf 31: SQL_Driver_services_impl(Pool& apool, const String& aurl) : Pooled(apool),
1.3 paf 32: furl(aurl) {
33: }
34:
35: /// allocates some bytes on pool
36: void *malloc(size_t size) { return Pooled::malloc(size); }
37: /// allocates some bytes clearing them with zeros
38: void *calloc(size_t size) { return Pooled::calloc(size); }
39: /// throw exception
40: void _throw(const char *comment) {
41: THROW(0, 0,
42: &furl,
43: comment);
44: }
45:
46: private:
47: const String& furl;
48: };
49:
50: // SQL_Driver_manager
51:
1.12 ! parser 52: /// @param request_url protocol://[driver-dependent]
! 53: SQL_Connection& SQL_Driver_manager::get_connection(const String& request_url,
1.7 paf 54: Table *protocol2driver_and_client) {
1.1 paf 55: SYNCHRONIZED(true);
56:
1.12 ! parser 57: Pool& pool=request_url.pool(); // request pool
1.1 paf 58:
59: // we have table for locating protocol's library
1.7 paf 60: if(!protocol2driver_and_client)
1.1 paf 61: PTHROW(0, 0,
1.12 ! parser 62: &request_url,
1.6 paf 63: "$SQL:drivers table must be defined");
1.1 paf 64:
1.12 ! parser 65: // services associated with request
! 66: SQL_Driver_services_impl& services=
! 67: *new(pool) SQL_Driver_services_impl(pool, request_url);
! 68:
1.1 paf 69: // first trying to get cached connection
1.12 ! parser 70: if(SQL_Connection *result=get_connection_from_cache(request_url))
! 71: if(result->ping()) {
! 72: result->set_services(&services);
1.5 paf 73: return *result;
1.12 ! parser 74: } else
1.5 paf 75: result->disconnect(); // kill unpingabe=dead connection
1.1 paf 76: // no cached connection
77:
1.12 ! parser 78: int pos=request_url.pos("://", 3);
1.1 paf 79: if(pos<0)
80: PTHROW(0, 0,
1.12 ! parser 81: &request_url,
1.1 paf 82: "no protocol specified"); // NOTE: not THROW, but PTHROW
83:
1.12 ! parser 84: // make global_url C-string on global pool
! 85: char *request_url_cstr=request_url.cstr(String::UL_AS_IS);
! 86: char *global_url_cstr=(char *)malloc(strlen(request_url_cstr)+1);
! 87: strcpy(global_url_cstr, request_url_cstr);
! 88: // make global_url string on global pool
! 89: String& global_url=*new(this->pool()) String(this->pool(), global_url_cstr);
1.1 paf 90:
1.12 ! parser 91: char *request_protocol_cstr=lsplit(&request_url_cstr, ':');
! 92: // skip "//" after ':'
! 93: while(*request_url_cstr=='/')
! 94: request_url_cstr++;
! 95: // make global_protocol C-string on global pool
! 96: char *global_protocol_cstr=(char *)malloc(strlen(request_protocol_cstr)+1);
! 97: strcpy(global_protocol_cstr, request_protocol_cstr);
! 98: // make global_protocol string on global pool
! 99: String& global_protocol=*new(this->pool()) String(this->pool(),
! 100: global_protocol_cstr);
1.1 paf 101:
102: SQL_Driver *driver;
1.7 paf 103: const String *dlopen_file_spec=0;
1.1 paf 104: // first trying to get cached driver
1.12 ! parser 105: if(!(driver=get_driver_from_cache(global_protocol))) {
1.1 paf 106: // no cached
107: const String *library=0;
1.12 ! parser 108: if(protocol2driver_and_client->locate(0, global_protocol)) {
1.7 paf 109: if(!(library=protocol2driver_and_client->item(1)) || library->size()==0)
1.1 paf 110: PTHROW(0, 0,
1.7 paf 111: protocol2driver_and_client->origin_string(),
1.12 ! parser 112: "driver library column for protocol '%s' is empty",
! 113: request_protocol_cstr);
1.7 paf 114: if(!(dlopen_file_spec=protocol2driver_and_client->item(2)) || dlopen_file_spec->size()==0)
115: PTHROW(0, 0,
116: protocol2driver_and_client->origin_string(),
1.12 ! parser 117: "client library column for protocol '%s' is empty",
! 118: request_protocol_cstr);
1.1 paf 119: } else
120: PTHROW(0, 0,
1.12 ! parser 121: &request_url,
! 122: "undefined protocol '%s'",
! 123: request_protocol_cstr);
1.1 paf 124:
125: const char *filename=library->cstr(String::UL_FILE_NAME);
1.2 paf 126: lt_dlhandle handle=lt_dlopen(filename);
1.1 paf 127: if (!handle)
128: PTHROW(0, 0,
129: library,
130: "can not open the module, %s", lt_dlerror());
131:
132: SQL_Driver_create_func create=(SQL_Driver_create_func)lt_dlsym(handle,
133: LIBRARY_CREATE_FUNC_NAME);
134: if(!create)
135: PTHROW(0, 0,
136: library,
137: "function '%s' was not found", LIBRARY_CREATE_FUNC_NAME);
138:
1.2 paf 139: // create library-driver!
1.1 paf 140: driver=(*create)();
141:
142: // validate driver api version
143: int driver_api_version=driver->api_version();
1.7 paf 144: if(driver_api_version!=SQL_DRIVER_API_VERSION)
1.1 paf 145: PTHROW(0, 0,
146: library,
1.7 paf 147: "driver implements API version 0x%04X not equal to 0x%04X",
1.3 paf 148: driver_api_version, SQL_DRIVER_API_VERSION);
1.1 paf 149:
1.7 paf 150: // initialise by connecting to sql client dynamic link library
151: const char *dlopen_file_spec_cstr=dlopen_file_spec->cstr(String::UL_FILE_NAME);
152: if(const char *error=driver->initialize(
153: dlopen_file_spec_cstr))
154: PTHROW(0, 0,
155: library,
156: "driver failed to initialize client library '%s', %s",
157: dlopen_file_spec_cstr, error);
158:
1.1 paf 159: // cache it
1.12 ! parser 160: put_driver_to_cache(global_protocol, *driver);
1.1 paf 161: }
162:
1.4 paf 163: // allocate in global pool
164: // associate with services[request], deassociates at close
1.3 paf 165: SQL_Connection& result=
1.7 paf 166: *new(this->pool()) SQL_Connection(this->pool(),
1.12 ! parser 167: global_url, *driver, services, request_url_cstr);
1.3 paf 168:
169: return result;
1.1 paf 170: }
171:
172: void SQL_Driver_manager::close_connection(const String& url,
173: SQL_Connection& connection) {
174: SYNCHRONIZED(true);
175:
176: put_connection_to_cache(url, connection);
177: }
178:
179:
180: // driver cache
181:
182: SQL_Driver *SQL_Driver_manager::get_driver_from_cache(const String& protocol) {
183: if(SQL_Driver *result=static_cast<SQL_Driver *>(driver_cache.get(protocol)))
184: return result;
185:
186: return 0;
187: }
188:
189: void SQL_Driver_manager::put_driver_to_cache(const String& protocol,
190: SQL_Driver& driver) {
191: driver_cache.put(protocol, &driver);
192: }
193:
194: // connection cache
195:
196: SQL_Connection *SQL_Driver_manager::get_connection_from_cache(const String& url) {
197: if(Stack *connections=static_cast<Stack *>(connection_cache.get(url)))
198: if(connections->size()) // there are cached connections to that 'url'
199: return static_cast<SQL_Connection *>(connections->pop());
200:
201: return 0;
202: }
203:
1.10 paf 204: /// @todo cache expiration[use SQL_Driver::disconnect]
1.1 paf 205: void SQL_Driver_manager::put_connection_to_cache(const String& url,
206: SQL_Connection& connection) {
207: Stack *connections;
208: if(!(connections=static_cast<Stack *>(connection_cache.get(url)))) {
209: // there are no cached connections to that 'url' yet
210: connections=NEW Stack(pool()); // NOTE: never freed up!
211: connection_cache.put(url, connections);
212: }
213: connections->push(&connection);
214: }
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