Annotation of parser3/src/main/pa_sql_driver_manager.C, revision 1.38
1.29 parser 1: /** @file
2: Parser: sql driver manager implementation.
3:
4: Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com)
1.38 ! parser 5: Author: Alexander Petrosyan <paf@design.ru> (http://design.ru/paf)
1.29 parser 6:
1.38 ! parser 7: $Id: $
1.29 parser 8: */
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: // globals
18:
19: SQL_Driver_manager *SQL_driver_manager;
20:
21: // consts
22:
23: const int EXPIRE_UNUSED_CONNECTION_SECONDS=60;
1.30 parser 24: const int CHECK_EXPIRED_CONNECTIONS_SECONDS=EXPIRE_UNUSED_CONNECTION_SECONDS*2;
1.29 parser 25:
26:
27: /// SQL_Driver_services Pooled implementation
28: class SQL_Driver_services_impl : public SQL_Driver_services, public Pooled {
29: public:
30: SQL_Driver_services_impl(Pool& apool, const String& aurl) : Pooled(apool),
31: furl(aurl) {
32: }
33:
34: /// allocates some bytes on pool
35: void *malloc(size_t size) { return Pooled::malloc(size); }
36: /// allocates some bytes clearing them with zeros
37: void *calloc(size_t size) { return Pooled::calloc(size); }
38: /// throw exception
39: void _throw(const char *comment) {
40: THROW(0, 0,
41: &furl,
42: comment);
43: }
44:
45: private:
46: const String& furl;
47: };
48:
49: // SQL_Driver_manager
50:
51: /// @param request_url protocol://[driver-dependent]
1.36 parser 52: SQL_Connection& SQL_Driver_manager::get_connection(const String& request_url,
53: const String& request_origin,
1.29 parser 54: Table *protocol2driver_and_client) {
1.36 parser 55: Pool& pool=request_origin.pool(); // request pool
1.29 parser 56:
57: // we have table for locating protocol's library
58: if(!protocol2driver_and_client)
59: PTHROW(0, 0,
60: &request_url,
1.31 parser 61: "$"MAIN_SQL_NAME":"MAIN_SQL_DRIVERS_NAME" table must be defined");
1.29 parser 62:
63: // first trying to get cached connection
64: SQL_Connection *result=get_connection_from_cache(request_url);
65: if(result && !result->ping()) { // we have some cached connection, is it pingable?
66: result->disconnect(); // kill unpingabe=dead connection
67: result=0;
68: }
69:
70: char *request_url_cstr;
71: if(result)
72: request_url_cstr=0; // calm, compiler
73: else { // no cached connection or it were unpingabe: connect/reconnect
74: int pos=request_url.pos("://", 3);
75: if(pos<0)
76: PTHROW(0, 0,
1.36 parser 77: request_url.size()?&request_url:&request_origin,
78: "connection string must start with protocol://"); // NOTE: not THROW, but PTHROW
1.29 parser 79:
80: // make global_url C-string on global pool
81: request_url_cstr=request_url.cstr(String::UL_AS_IS);
82: char *global_url_cstr=(char *)malloc(strlen(request_url_cstr)+1);
83: strcpy(global_url_cstr, request_url_cstr);
84: // make global_url string on global pool
85: String& global_url=*new(this->pool()) String(this->pool(), global_url_cstr);
86:
87: char *request_protocol_cstr=lsplit(&request_url_cstr, ':');
88: // skip "//" after ':'
89: while(*request_url_cstr=='/')
90: request_url_cstr++;
91: // make global_protocol C-string on global pool
92: char *global_protocol_cstr=(char *)malloc(strlen(request_protocol_cstr)+1);
93: strcpy(global_protocol_cstr, request_protocol_cstr);
94: // make global_protocol string on global pool
95: String& global_protocol=*new(this->pool()) String(this->pool(),
96: global_protocol_cstr);
97:
98: SQL_Driver *driver;
99: const String *dlopen_file_spec=0;
100: // first trying to get cached driver
101: if(!(driver=get_driver_from_cache(global_protocol))) {
102: // no cached
103: const String *library=0;
104: if(protocol2driver_and_client->locate(0, global_protocol)) {
105: if(!(library=protocol2driver_and_client->item(1)) || library->size()==0)
106: PTHROW(0, 0,
107: protocol2driver_and_client->origin_string(),
108: "driver library column for protocol '%s' is empty",
109: request_protocol_cstr);
110: dlopen_file_spec=protocol2driver_and_client->item(2);
111: } else
112: PTHROW(0, 0,
113: &request_url,
114: "undefined protocol '%s'",
115: request_protocol_cstr);
116:
117: if(lt_dlinit())
118: PTHROW(0, 0,
119: library,
120: "prepare to dynamic loading failed, %s", lt_dlerror());
121:
1.34 parser 122: const char *filename=library->cstr(String::UL_FILE_SPEC);
1.29 parser 123: lt_dlhandle handle=lt_dlopen(filename);
124: if (!handle)
125: PTHROW(0, 0,
126: library,
127: "can not open the module, %s", lt_dlerror());
128:
129: SQL_Driver_create_func create=(SQL_Driver_create_func)lt_dlsym(handle,
1.33 parser 130: SQL_DRIVER_CREATE_NAME);
1.29 parser 131: if(!create)
132: PTHROW(0, 0,
133: library,
1.33 parser 134: "function '"SQL_DRIVER_CREATE_NAME"' was not found");
1.29 parser 135:
136: // create library-driver!
137: driver=(*create)();
138:
139: // validate driver api version
140: int driver_api_version=driver->api_version();
141: if(driver_api_version!=SQL_DRIVER_API_VERSION)
142: PTHROW(0, 0,
143: library,
144: "driver implements API version 0x%04X not equal to 0x%04X",
145: driver_api_version, SQL_DRIVER_API_VERSION);
146:
147: // initialise by connecting to sql client dynamic link library
148: bool specified_dlopen_file_spec=dlopen_file_spec && dlopen_file_spec->size();
149: const char *dlopen_file_spec_cstr=
150: specified_dlopen_file_spec?
1.34 parser 151: dlopen_file_spec->cstr(String::UL_FILE_SPEC):0;
1.29 parser 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: specified_dlopen_file_spec?dlopen_file_spec_cstr:"unspecifed",
158: error);
159:
160: // cache it
161: put_driver_to_cache(global_protocol, *driver);
162: }
163:
164: // allocate in global pool
165: // associate with services[request]
166: // NOTE: never freed up!
167: result=new(this->pool()) SQL_Connection(this->pool(), global_url, *driver);
168: }
169:
170: // associate with services[request] (deassociates at close)
171: result->set_services(new(pool) SQL_Driver_services_impl(pool, request_url));
172: // if not connected yet, do that now, when result has services
173: if(!result->connected())
174: result->connect(request_url_cstr);
175: // return it
176: return *result;
177: }
178:
179: void SQL_Driver_manager::close_connection(const String& url,
180: SQL_Connection& connection) {
181: // deassociate from services[request]
182: connection.set_services(0);
183: put_connection_to_cache(url, connection);
184: }
185:
186:
187: // driver cache
188:
189: SQL_Driver *SQL_Driver_manager::get_driver_from_cache(const String& protocol) {
190: SYNCHRONIZED;
191:
192: return static_cast<SQL_Driver *>(driver_cache.get(protocol));
193: }
194:
195: void SQL_Driver_manager::put_driver_to_cache(const String& protocol,
196: SQL_Driver& driver) {
197: SYNCHRONIZED;
198:
199: driver_cache.put(protocol, &driver);
200: }
201:
202: // connection cache
203: /// @todo get rid of memory spending Stack [zeros deep inside got accumulated]
204: SQL_Connection *SQL_Driver_manager::get_connection_from_cache(const String& url) {
205: SYNCHRONIZED;
206:
207: maybe_expire_connection_cache();
208:
209: if(Stack *connections=static_cast<Stack *>(connection_cache.get(url)))
210: while(connections->top_index()>=0) { // there are cached connections to that 'url'
211: SQL_Connection *result=static_cast<SQL_Connection *>(connections->pop());
212: if(result->connected()) // not expired?
213: return result;
214: }
215:
216: return 0;
217: }
218:
219: void SQL_Driver_manager::put_connection_to_cache(const String& url,
220: SQL_Connection& connection) {
221: SYNCHRONIZED;
222:
223: Stack *connections=static_cast<Stack *>(connection_cache.get(url));
224: if(!connections) { // there are no cached connections to that 'url' yet?
225: connections=NEW Stack(pool()); // NOTE: never freed up!
226: connection_cache.put(url, connections);
227: }
228: connections->push(&connection);
229: }
230:
231: static void expire_connection(Array::Item *value, void *info) {
232: SQL_Connection& connection=*static_cast<SQL_Connection *>(value);
233: time_t older_dies=reinterpret_cast<time_t>(info);
234:
235: if(connection.connected() && connection.expired(older_dies))
236: connection.disconnect();
237: }
238: static void expire_connections(const Hash::Key& key, Hash::Val *value, void *info) {
239: Stack& stack=*static_cast<Stack *>(value);
240: for(int i=0; i<=stack.top_index(); i++)
241: expire_connection(stack.get(i), info);
242: }
243: void SQL_Driver_manager::maybe_expire_connection_cache() {
244: time_t now=time(0);
245:
246: if(prev_expiration_pass_time<now-CHECK_EXPIRED_CONNECTIONS_SECONDS) {
247: connection_cache.for_each(expire_connections,
248: reinterpret_cast<void *>(now-EXPIRE_UNUSED_CONNECTION_SECONDS));
249:
250: prev_expiration_pass_time=now;
251: }
252: }
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