Annotation of parser3/src/main/pa_sql_driver_manager.C, revision 1.33.4.1
1.29 parser 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: */
1.33.4.1! parser 8: static const char *RCSId="$Id: pa_sql_driver_manager.C,v 1.33 2001/09/05 09:32:40 parser Exp $";
1.29 parser 9:
10: #include "pa_sql_driver_manager.h"
11: #include "ltdl.h"
12: #include "pa_sql_connection.h"
13: #include "pa_exception.h"
14: #include "pa_common.h"
15: #include "pa_threads.h"
16:
17: #include "pa_sapi.h"
18:
19: // globals
20:
21: SQL_Driver_manager *SQL_driver_manager;
22:
23: // consts
24:
25: const int EXPIRE_UNUSED_CONNECTION_SECONDS=60;
1.30 parser 26: const int CHECK_EXPIRED_CONNECTIONS_SECONDS=EXPIRE_UNUSED_CONNECTION_SECONDS*2;
1.29 parser 27:
28:
29: /// SQL_Driver_services Pooled implementation
30: class SQL_Driver_services_impl : public SQL_Driver_services, public Pooled {
31: public:
32: SQL_Driver_services_impl(Pool& apool, const String& aurl) : Pooled(apool),
33: furl(aurl) {
34: }
35:
36: /// allocates some bytes on pool
37: void *malloc(size_t size) { return Pooled::malloc(size); }
38: /// allocates some bytes clearing them with zeros
39: void *calloc(size_t size) { return Pooled::calloc(size); }
40: /// throw exception
41: void _throw(const char *comment) {
42: THROW(0, 0,
43: &furl,
44: comment);
45: }
46:
47: private:
48: const String& furl;
49: };
50:
51: // SQL_Driver_manager
52:
53: /// @param request_url protocol://[driver-dependent]
1.33.4.1! parser 54: SQL_Connection& SQL_Driver_manager::get_connection(const String& request_url,
! 55: const String& request_origin,
1.29 parser 56: Table *protocol2driver_and_client) {
1.33.4.1! parser 57: Pool& pool=request_origin.pool(); // request pool
1.29 parser 58:
59: // we have table for locating protocol's library
60: if(!protocol2driver_and_client)
61: PTHROW(0, 0,
62: &request_url,
1.31 parser 63: "$"MAIN_SQL_NAME":"MAIN_SQL_DRIVERS_NAME" table must be defined");
1.29 parser 64:
65: // first trying to get cached connection
66: SQL_Connection *result=get_connection_from_cache(request_url);
67: if(result && !result->ping()) { // we have some cached connection, is it pingable?
68: result->disconnect(); // kill unpingabe=dead connection
69: result=0;
70: }
71:
72: char *request_url_cstr;
73: if(result)
74: request_url_cstr=0; // calm, compiler
75: else { // no cached connection or it were unpingabe: connect/reconnect
76: int pos=request_url.pos("://", 3);
77: if(pos<0)
78: PTHROW(0, 0,
1.33.4.1! parser 79: request_url.size()?&request_url:&request_origin,
! 80: "connection string must start with protocol://"); // NOTE: not THROW, but PTHROW
1.29 parser 81:
82: // make global_url C-string on global pool
83: request_url_cstr=request_url.cstr(String::UL_AS_IS);
84: char *global_url_cstr=(char *)malloc(strlen(request_url_cstr)+1);
85: strcpy(global_url_cstr, request_url_cstr);
86: // make global_url string on global pool
87: String& global_url=*new(this->pool()) String(this->pool(), global_url_cstr);
88:
89: char *request_protocol_cstr=lsplit(&request_url_cstr, ':');
90: // skip "//" after ':'
91: while(*request_url_cstr=='/')
92: request_url_cstr++;
93: // make global_protocol C-string on global pool
94: char *global_protocol_cstr=(char *)malloc(strlen(request_protocol_cstr)+1);
95: strcpy(global_protocol_cstr, request_protocol_cstr);
96: // make global_protocol string on global pool
97: String& global_protocol=*new(this->pool()) String(this->pool(),
98: global_protocol_cstr);
99:
100: SQL_Driver *driver;
101: const String *dlopen_file_spec=0;
102: // first trying to get cached driver
103: if(!(driver=get_driver_from_cache(global_protocol))) {
104: // no cached
105: const String *library=0;
106: if(protocol2driver_and_client->locate(0, global_protocol)) {
107: if(!(library=protocol2driver_and_client->item(1)) || library->size()==0)
108: PTHROW(0, 0,
109: protocol2driver_and_client->origin_string(),
110: "driver library column for protocol '%s' is empty",
111: request_protocol_cstr);
112: dlopen_file_spec=protocol2driver_and_client->item(2);
113: } else
114: PTHROW(0, 0,
115: &request_url,
116: "undefined protocol '%s'",
117: request_protocol_cstr);
118:
119: if(lt_dlinit())
120: PTHROW(0, 0,
121: library,
122: "prepare to dynamic loading failed, %s", lt_dlerror());
123:
124: const char *filename=library->cstr(String::UL_FILE_NAME);
125: lt_dlhandle handle=lt_dlopen(filename);
126: if (!handle)
127: PTHROW(0, 0,
128: library,
129: "can not open the module, %s", lt_dlerror());
130:
131: SQL_Driver_create_func create=(SQL_Driver_create_func)lt_dlsym(handle,
1.33 parser 132: SQL_DRIVER_CREATE_NAME);
1.29 parser 133: if(!create)
134: PTHROW(0, 0,
135: library,
1.33 parser 136: "function '"SQL_DRIVER_CREATE_NAME"' was not found");
1.29 parser 137:
138: // create library-driver!
139: driver=(*create)();
140:
141: // validate driver api version
142: int driver_api_version=driver->api_version();
143: if(driver_api_version!=SQL_DRIVER_API_VERSION)
144: PTHROW(0, 0,
145: library,
146: "driver implements API version 0x%04X not equal to 0x%04X",
147: driver_api_version, SQL_DRIVER_API_VERSION);
148:
149: // initialise by connecting to sql client dynamic link library
150: bool specified_dlopen_file_spec=dlopen_file_spec && dlopen_file_spec->size();
151: const char *dlopen_file_spec_cstr=
152: specified_dlopen_file_spec?
153: dlopen_file_spec->cstr(String::UL_FILE_NAME):0;
154: if(const char *error=driver->initialize(
155: dlopen_file_spec_cstr))
156: PTHROW(0, 0,
157: library,
158: "driver failed to initialize client library '%s', %s",
159: specified_dlopen_file_spec?dlopen_file_spec_cstr:"unspecifed",
160: error);
161:
162: // cache it
163: put_driver_to_cache(global_protocol, *driver);
164: }
165:
166: // allocate in global pool
167: // associate with services[request]
168: // NOTE: never freed up!
169: result=new(this->pool()) SQL_Connection(this->pool(), global_url, *driver);
170: }
171:
172: // associate with services[request] (deassociates at close)
173: result->set_services(new(pool) SQL_Driver_services_impl(pool, request_url));
174: // if not connected yet, do that now, when result has services
175: if(!result->connected())
176: result->connect(request_url_cstr);
177: // return it
178: return *result;
179: }
180:
181: void SQL_Driver_manager::close_connection(const String& url,
182: SQL_Connection& connection) {
183: // deassociate from services[request]
184: connection.set_services(0);
185: put_connection_to_cache(url, connection);
186: }
187:
188:
189: // driver cache
190:
191: SQL_Driver *SQL_Driver_manager::get_driver_from_cache(const String& protocol) {
192: SYNCHRONIZED;
193:
194: return static_cast<SQL_Driver *>(driver_cache.get(protocol));
195: }
196:
197: void SQL_Driver_manager::put_driver_to_cache(const String& protocol,
198: SQL_Driver& driver) {
199: SYNCHRONIZED;
200:
201: driver_cache.put(protocol, &driver);
202: }
203:
204: // connection cache
205: /// @todo get rid of memory spending Stack [zeros deep inside got accumulated]
206: SQL_Connection *SQL_Driver_manager::get_connection_from_cache(const String& url) {
207: SYNCHRONIZED;
208:
209: maybe_expire_connection_cache();
210:
211: if(Stack *connections=static_cast<Stack *>(connection_cache.get(url)))
212: while(connections->top_index()>=0) { // there are cached connections to that 'url'
213: SQL_Connection *result=static_cast<SQL_Connection *>(connections->pop());
214: if(result->connected()) // not expired?
215: return result;
216: }
217:
218: return 0;
219: }
220:
221: void SQL_Driver_manager::put_connection_to_cache(const String& url,
222: SQL_Connection& connection) {
223: SYNCHRONIZED;
224:
225: Stack *connections=static_cast<Stack *>(connection_cache.get(url));
226: if(!connections) { // there are no cached connections to that 'url' yet?
227: connections=NEW Stack(pool()); // NOTE: never freed up!
228: connection_cache.put(url, connections);
229: }
230: connections->push(&connection);
231: }
232:
233: static void expire_connection(Array::Item *value, void *info) {
234: SQL_Connection& connection=*static_cast<SQL_Connection *>(value);
235: time_t older_dies=reinterpret_cast<time_t>(info);
236:
237: if(connection.connected() && connection.expired(older_dies))
238: connection.disconnect();
239: }
240: static void expire_connections(const Hash::Key& key, Hash::Val *value, void *info) {
241: Stack& stack=*static_cast<Stack *>(value);
242: for(int i=0; i<=stack.top_index(); i++)
243: expire_connection(stack.get(i), info);
244: }
245: void SQL_Driver_manager::maybe_expire_connection_cache() {
246: time_t now=time(0);
247:
248: if(prev_expiration_pass_time<now-CHECK_EXPIRED_CONNECTIONS_SECONDS) {
249: connection_cache.for_each(expire_connections,
250: reinterpret_cast<void *>(now-EXPIRE_UNUSED_CONNECTION_SECONDS));
251:
252: prev_expiration_pass_time=now;
253: }
254: }
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