Annotation of parser3/src/main/pa_sql_driver_manager.C, revision 1.42
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:
1.42 ! parser 7: $Id: pa_sql_driver_manager.C,v 1.41 2001/10/19 12:43:30 parser Exp $
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"
1.42 ! parser 16: #include "pa_stack.h"
1.29 parser 17:
18: // globals
19:
20: SQL_Driver_manager *SQL_driver_manager;
21:
22: // consts
23:
24: const int EXPIRE_UNUSED_CONNECTION_SECONDS=60;
1.30 parser 25: const int CHECK_EXPIRED_CONNECTIONS_SECONDS=EXPIRE_UNUSED_CONNECTION_SECONDS*2;
1.29 parser 26:
27:
28: /// SQL_Driver_services Pooled implementation
29: class SQL_Driver_services_impl : public SQL_Driver_services, public Pooled {
30: public:
31: SQL_Driver_services_impl(Pool& apool, const String& aurl) : Pooled(apool),
32: furl(aurl) {
33: }
1.40 parser 34:
1.29 parser 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); }
1.40 parser 39:
1.29 parser 40: /// throw exception
41: void _throw(const char *comment) {
1.41 parser 42: throw Exception(0, 0,
1.29 parser 43: &furl,
44: comment);
45: }
46:
47: private:
48: const String& furl;
49: };
50:
1.42 ! parser 51: // helpers
! 52:
! 53: static void expire_connection(Array::Item *value, void *info) {
! 54: SQL_Connection& connection=*static_cast<SQL_Connection *>(value);
! 55: time_t older_dies=reinterpret_cast<time_t>(info);
! 56:
! 57: if(connection.connected() && connection.expired(older_dies))
! 58: connection.disconnect();
! 59: }
! 60: static void expire_connections(const Hash::Key& key, Hash::Val *value, void *info) {
! 61: Stack& stack=*static_cast<Stack *>(value);
! 62: for(int i=0; i<=stack.top_index(); i++)
! 63: expire_connection(stack.get(i), info);
! 64: }
! 65:
1.29 parser 66: // SQL_Driver_manager
67:
1.42 ! parser 68: SQL_Driver_manager::SQL_Driver_manager(Pool& pool) : Pooled(pool),
! 69: driver_cache(pool),
! 70: connection_cache(pool),
! 71: prev_expiration_pass_time(0) {
! 72:
! 73: }
! 74:
! 75: SQL_Driver_manager::~SQL_Driver_manager() {
! 76: connection_cache.for_each(expire_connections,
! 77: reinterpret_cast<void *>((time_t)0/*=in past=expire all*/));
! 78: }
! 79:
1.29 parser 80: /// @param request_url protocol://[driver-dependent]
1.36 parser 81: SQL_Connection& SQL_Driver_manager::get_connection(const String& request_url,
82: const String& request_origin,
1.29 parser 83: Table *protocol2driver_and_client) {
1.36 parser 84: Pool& pool=request_origin.pool(); // request pool
1.29 parser 85:
86: // we have table for locating protocol's library
87: if(!protocol2driver_and_client)
1.41 parser 88: throw Exception(0, 0,
1.29 parser 89: &request_url,
1.31 parser 90: "$"MAIN_SQL_NAME":"MAIN_SQL_DRIVERS_NAME" table must be defined");
1.29 parser 91:
92: // first trying to get cached connection
93: SQL_Connection *result=get_connection_from_cache(request_url);
94: if(result && !result->ping()) { // we have some cached connection, is it pingable?
95: result->disconnect(); // kill unpingabe=dead connection
96: result=0;
97: }
98:
99: char *request_url_cstr;
100: if(result)
101: request_url_cstr=0; // calm, compiler
102: else { // no cached connection or it were unpingabe: connect/reconnect
103: int pos=request_url.pos("://", 3);
104: if(pos<0)
1.41 parser 105: throw Exception(0, 0,
1.36 parser 106: request_url.size()?&request_url:&request_origin,
107: "connection string must start with protocol://"); // NOTE: not THROW, but PTHROW
1.29 parser 108:
109: // make global_url C-string on global pool
110: request_url_cstr=request_url.cstr(String::UL_AS_IS);
111: char *global_url_cstr=(char *)malloc(strlen(request_url_cstr)+1);
112: strcpy(global_url_cstr, request_url_cstr);
113: // make global_url string on global pool
114: String& global_url=*new(this->pool()) String(this->pool(), global_url_cstr);
115:
116: char *request_protocol_cstr=lsplit(&request_url_cstr, ':');
117: // skip "//" after ':'
118: while(*request_url_cstr=='/')
119: request_url_cstr++;
120: // make global_protocol C-string on global pool
121: char *global_protocol_cstr=(char *)malloc(strlen(request_protocol_cstr)+1);
122: strcpy(global_protocol_cstr, request_protocol_cstr);
123: // make global_protocol string on global pool
124: String& global_protocol=*new(this->pool()) String(this->pool(),
125: global_protocol_cstr);
126:
127: SQL_Driver *driver;
128: const String *dlopen_file_spec=0;
129: // first trying to get cached driver
130: if(!(driver=get_driver_from_cache(global_protocol))) {
131: // no cached
132: const String *library=0;
133: if(protocol2driver_and_client->locate(0, global_protocol)) {
134: if(!(library=protocol2driver_and_client->item(1)) || library->size()==0)
1.41 parser 135: throw Exception(0, 0,
1.29 parser 136: protocol2driver_and_client->origin_string(),
137: "driver library column for protocol '%s' is empty",
138: request_protocol_cstr);
139: dlopen_file_spec=protocol2driver_and_client->item(2);
140: } else
1.41 parser 141: throw Exception(0, 0,
1.29 parser 142: &request_url,
143: "undefined protocol '%s'",
144: request_protocol_cstr);
145:
146: if(lt_dlinit())
1.41 parser 147: throw Exception(0, 0,
1.29 parser 148: library,
149: "prepare to dynamic loading failed, %s", lt_dlerror());
150:
1.34 parser 151: const char *filename=library->cstr(String::UL_FILE_SPEC);
1.29 parser 152: lt_dlhandle handle=lt_dlopen(filename);
153: if (!handle)
1.41 parser 154: throw Exception(0, 0,
1.29 parser 155: library,
156: "can not open the module, %s", lt_dlerror());
157:
158: SQL_Driver_create_func create=(SQL_Driver_create_func)lt_dlsym(handle,
1.33 parser 159: SQL_DRIVER_CREATE_NAME);
1.29 parser 160: if(!create)
1.41 parser 161: throw Exception(0, 0,
1.29 parser 162: library,
1.33 parser 163: "function '"SQL_DRIVER_CREATE_NAME"' was not found");
1.29 parser 164:
165: // create library-driver!
166: driver=(*create)();
167:
168: // validate driver api version
169: int driver_api_version=driver->api_version();
170: if(driver_api_version!=SQL_DRIVER_API_VERSION)
1.41 parser 171: throw Exception(0, 0,
1.29 parser 172: library,
173: "driver implements API version 0x%04X not equal to 0x%04X",
174: driver_api_version, SQL_DRIVER_API_VERSION);
175:
176: // initialise by connecting to sql client dynamic link library
177: bool specified_dlopen_file_spec=dlopen_file_spec && dlopen_file_spec->size();
178: const char *dlopen_file_spec_cstr=
179: specified_dlopen_file_spec?
1.34 parser 180: dlopen_file_spec->cstr(String::UL_FILE_SPEC):0;
1.29 parser 181: if(const char *error=driver->initialize(
182: dlopen_file_spec_cstr))
1.41 parser 183: throw Exception(0, 0,
1.29 parser 184: library,
185: "driver failed to initialize client library '%s', %s",
186: specified_dlopen_file_spec?dlopen_file_spec_cstr:"unspecifed",
187: error);
188:
189: // cache it
190: put_driver_to_cache(global_protocol, *driver);
191: }
192:
193: // allocate in global pool
194: // associate with services[request]
195: // NOTE: never freed up!
196: result=new(this->pool()) SQL_Connection(this->pool(), global_url, *driver);
197: }
198:
199: // associate with services[request] (deassociates at close)
200: result->set_services(new(pool) SQL_Driver_services_impl(pool, request_url));
201: // if not connected yet, do that now, when result has services
202: if(!result->connected())
203: result->connect(request_url_cstr);
204: // return it
205: return *result;
206: }
207:
208: void SQL_Driver_manager::close_connection(const String& url,
209: SQL_Connection& connection) {
210: // deassociate from services[request]
211: connection.set_services(0);
212: put_connection_to_cache(url, connection);
213: }
214:
215:
216: // driver cache
217:
218: SQL_Driver *SQL_Driver_manager::get_driver_from_cache(const String& protocol) {
219: SYNCHRONIZED;
220:
221: return static_cast<SQL_Driver *>(driver_cache.get(protocol));
222: }
223:
224: void SQL_Driver_manager::put_driver_to_cache(const String& protocol,
225: SQL_Driver& driver) {
226: SYNCHRONIZED;
227:
228: driver_cache.put(protocol, &driver);
229: }
230:
231: // connection cache
232: /// @todo get rid of memory spending Stack [zeros deep inside got accumulated]
233: SQL_Connection *SQL_Driver_manager::get_connection_from_cache(const String& url) {
234: SYNCHRONIZED;
235:
236: maybe_expire_connection_cache();
237:
238: if(Stack *connections=static_cast<Stack *>(connection_cache.get(url)))
239: while(connections->top_index()>=0) { // there are cached connections to that 'url'
240: SQL_Connection *result=static_cast<SQL_Connection *>(connections->pop());
241: if(result->connected()) // not expired?
242: return result;
243: }
244:
245: return 0;
246: }
247:
248: void SQL_Driver_manager::put_connection_to_cache(const String& url,
249: SQL_Connection& connection) {
250: SYNCHRONIZED;
251:
252: Stack *connections=static_cast<Stack *>(connection_cache.get(url));
253: if(!connections) { // there are no cached connections to that 'url' yet?
254: connections=NEW Stack(pool()); // NOTE: never freed up!
255: connection_cache.put(url, connections);
256: }
257: connections->push(&connection);
258: }
259:
260: void SQL_Driver_manager::maybe_expire_connection_cache() {
261: time_t now=time(0);
262:
263: if(prev_expiration_pass_time<now-CHECK_EXPIRED_CONNECTIONS_SECONDS) {
264: connection_cache.for_each(expire_connections,
265: reinterpret_cast<void *>(now-EXPIRE_UNUSED_CONNECTION_SECONDS));
266:
267: prev_expiration_pass_time=now;
268: }
269: }
E-mail:
![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to pa_sql_driver_manager.C CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [parser3project] / parser3 / src / main