Annotation of parser3/src/main/pa_sql_driver_manager.C, revision 1.61
1.54 paf 1: /** @file
2: Parser: sql driver manager implementation.
3:
1.60 paf 4: Copyright (c) 2001, 2002 ArtLebedev Group (http://www.artlebedev.com)
1.61 ! paf 5: Author: Alexandr Petrosian <paf@design.ru> (http://paf.design.ru)
1.54 paf 6:
1.61 ! paf 7: $Id: pa_sql_driver_manager.C,v 1.60 2002/02/08 07:27:48 paf Exp $
1.54 paf 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: #include "pa_stack.h"
17: #include "pa_vhash.h"
18: #include "pa_vtable.h"
19:
20: // globals
21:
22: SQL_Driver_manager *SQL_driver_manager;
23:
24: // consts
25:
26: const int EXPIRE_UNUSED_CONNECTION_SECONDS=60;
27: const int CHECK_EXPIRED_CONNECTIONS_SECONDS=EXPIRE_UNUSED_CONNECTION_SECONDS*2;
28:
29: // helpers
30:
31: const String& url_without_login(Pool& pool, const String& url) {
32: String& result=*new(pool) String(pool);
33: result << url.mid(0, url.pos(":")) << "://****";
34:
35: int at_pos=url.pos("@");
36: if(at_pos>0)
37: result << url.mid(at_pos, url.size());
38:
39: return result;
40: }
41:
42: /// SQL_Driver_services Pooled implementation
43: class SQL_Driver_services_impl : public SQL_Driver_services, public Pooled {
44: public:
45: SQL_Driver_services_impl(Pool& apool, const String& aurl) : Pooled(apool),
46: furl(aurl) {
47: }
48:
49: virtual void *malloc(size_t size) { return Pooled::malloc(size, 8); }
50: virtual void *calloc(size_t size) { return Pooled::calloc(size); }
51:
52: /**
53: the idea is to #1 jump to C++ some function to main body, where
54: every function stack frame has exception unwind information
55: and from there... #2 propagate_exception()
56: */
57: virtual void _throw(const char *comment) {
58: // hiding passwords and addresses from accidental show [imagine user forgot @exception]
59: e=Exception(0, 0,
60: &url_without_login(pool(), furl),
61: comment);
62:
63: longjmp(mark, 1);
64: }
65: virtual void propagate_exception() {
66: throw e;
67: }
68:
69: private:
70: const String& furl;
71: Exception e;
72: };
73:
74: // helpers
75:
76: static void expire_connection(Array::Item *value, void *info) {
77: SQL_Connection& connection=*static_cast<SQL_Connection *>(value);
78: time_t older_dies=reinterpret_cast<time_t>(info);
79:
80: if(connection.connected() && connection.expired(older_dies))
81: connection.disconnect();
82: }
83: static void expire_connections(const Hash::Key& key, Hash::Val *value, void *info) {
84: Stack& stack=*static_cast<Stack *>(value);
85: for(int i=0; i<=stack.top_index(); i++)
86: expire_connection(stack.get(i), info);
87: }
88:
89: // SQL_Driver_manager
90:
91: SQL_Driver_manager::SQL_Driver_manager(Pool& apool) : Cache_manager(apool),
92: driver_cache(apool),
93: connection_cache(apool),
94: prev_expiration_pass_time(0) {
95: }
96:
97: SQL_Driver_manager::~SQL_Driver_manager() {
98: connection_cache.for_each(expire_connections,
1.56 paf 99: reinterpret_cast<void *>(time(0)+1/*=in future=expire all*/));
1.54 paf 100: }
101:
102: /// @param request_url protocol://[driver-dependent]
1.58 paf 103: SQL_Connection_ptr SQL_Driver_manager::get_connection(const String& request_url,
1.54 paf 104: const String& request_origin,
105: Table *protocol2driver_and_client) {
106: Pool& pool=request_origin.pool(); // request pool
107:
108: // we have table for locating protocol's library
109: if(!protocol2driver_and_client)
110: throw Exception(0, 0,
111: &request_url,
112: "$"MAIN_SQL_NAME":"MAIN_SQL_DRIVERS_NAME" table must be defined");
113:
114: // construct services[request] (deassociates at close)
115: SQL_Driver_services *services=new(pool) SQL_Driver_services_impl(pool, request_url);
116:
117: // first trying to get cached connection
1.58 paf 118: SQL_Connection *connection=get_connection_from_cache(request_url);
119: if(connection) {
120: connection->set_services(services);
121: if(!connection->ping()) { // we have some cached connection, is it pingable?
122: connection->disconnect(); // kill unpingabe=dead connection
123: connection=0;
1.54 paf 124: }
125: }
126:
127: char *request_url_cstr;
1.58 paf 128: if(connection)
1.54 paf 129: request_url_cstr=0; // calm, compiler
130: else { // no cached connection or it were unpingabe: connect/reconnect
131: int pos=request_url.pos("://", 3);
132: if(pos<0)
133: throw Exception(0, 0,
134: request_url.size()?&request_url:&request_origin,
135: "connection string must start with protocol://"); // NOTE: not THROW, but PTHROW
136:
137: // make global_url C-string on global pool
138: request_url_cstr=request_url.cstr();
139: char *global_url_cstr=(char *)malloc(strlen(request_url_cstr)+1);
140: strcpy(global_url_cstr, request_url_cstr);
141: // make global_url string on global pool
142: String& global_url=*new(this->pool()) String(this->pool(), global_url_cstr);
143:
144: char *request_protocol_cstr=lsplit(&request_url_cstr, ':');
145: // skip "//" after ':'
146: while(*request_url_cstr=='/')
147: request_url_cstr++;
148: // make global_protocol C-string on global pool
149: char *global_protocol_cstr=(char *)malloc(strlen(request_protocol_cstr)+1);
150: strcpy(global_protocol_cstr, request_protocol_cstr);
151: // make global_protocol string on global pool
152: String& global_protocol=*new(this->pool()) String(this->pool(),
153: global_protocol_cstr);
154:
155: SQL_Driver *driver;
156: // first trying to get cached driver
157: if(!(driver=get_driver_from_cache(global_protocol))) {
158: // no cached
159: const String *library=0;
160: const String *dlopen_file_spec=0;
161: if(protocol2driver_and_client->locate(0, global_protocol)) {
162: if(!(library=protocol2driver_and_client->item(1)) || library->size()==0)
163: throw Exception(0, 0,
164: protocol2driver_and_client->origin_string(),
165: "driver library column for protocol '%s' is empty",
166: request_protocol_cstr);
167: dlopen_file_spec=protocol2driver_and_client->item(2);
168: } else
169: throw Exception(0, 0,
170: &request_url,
171: "undefined protocol '%s'",
172: request_protocol_cstr);
173:
174: if(lt_dlinit())
175: throw Exception(0, 0,
176: library,
177: "prepare to dynamic loading failed, %s", lt_dlerror());
178:
179: const char *filename=library->cstr(String::UL_FILE_SPEC);
180: lt_dlhandle handle=lt_dlopen(filename);
181: if (!handle)
182: throw Exception(0, 0,
183: library,
184: "can not open the module, %s", lt_dlerror());
185:
186: SQL_Driver_create_func create=(SQL_Driver_create_func)lt_dlsym(handle,
187: SQL_DRIVER_CREATE_NAME);
188: if(!create)
189: throw Exception(0, 0,
190: library,
191: "function '"SQL_DRIVER_CREATE_NAME"' was not found");
192:
193: // create library-driver!
194: driver=(*create)();
195:
196: // validate driver api version
197: int driver_api_version=driver->api_version();
198: if(driver_api_version!=SQL_DRIVER_API_VERSION)
199: throw Exception(0, 0,
200: library,
201: "driver implements API version 0x%04X not equal to 0x%04X",
202: driver_api_version, SQL_DRIVER_API_VERSION);
203:
204: // initialise by connecting to sql client dynamic link library
205: char *dlopen_file_spec_cstr=
206: dlopen_file_spec && dlopen_file_spec->size()?
207: dlopen_file_spec->cstr(String::UL_AS_IS):0;
208: if(const char *error=driver->initialize(
209: dlopen_file_spec_cstr))
210: throw Exception(0, 0,
211: library,
212: "driver failed to initialize client library '%s', %s",
213: dlopen_file_spec_cstr?dlopen_file_spec_cstr:"unspecifed",
214: error);
215:
216: // cache it
217: put_driver_to_cache(global_protocol, *driver);
218: }
219:
220: // allocate in global pool
221: // associate with services[request]
222: // NOTE: never freed up!
1.58 paf 223: connection=new(this->pool()) SQL_Connection(this->pool(), global_url, *driver);
1.54 paf 224: // associate with services[request] (deassociates at close)
1.58 paf 225: connection->set_services(services);
1.54 paf 226: }
227:
1.58 paf 228: // if not connected yet, do that now, when connection has services
229: if(!connection->connected())
230: connection->connect(request_url_cstr);
231: // return autoclosing object for it
1.59 paf 232: return SQL_Connection_ptr(connection);
1.54 paf 233: }
234:
235: void SQL_Driver_manager::close_connection(const String& url,
236: SQL_Connection& connection) {
237: // deassociate from services[request]
238: connection.set_services(0);
239: put_connection_to_cache(url, connection);
240: }
241:
242:
243: // driver cache
244:
245: SQL_Driver *SQL_Driver_manager::get_driver_from_cache(const String& protocol) {
246: SYNCHRONIZED;
247:
248: return static_cast<SQL_Driver *>(driver_cache.get(protocol));
249: }
250:
251: void SQL_Driver_manager::put_driver_to_cache(const String& protocol,
252: SQL_Driver& driver) {
253: SYNCHRONIZED;
254:
255: driver_cache.put(protocol, &driver);
256: }
257:
258: // connection cache
259: /// @todo get rid of memory spending Stack [zeros deep inside got accumulated]
260: SQL_Connection *SQL_Driver_manager::get_connection_from_cache(const String& url) {
261: SYNCHRONIZED;
262:
263: if(Stack *connections=static_cast<Stack *>(connection_cache.get(url)))
264: while(connections->top_index()>=0) { // there are cached connections to that 'url'
265: SQL_Connection *result=static_cast<SQL_Connection *>(connections->pop());
266: if(result->connected()) // not expired?
267: return result;
268: }
269:
270: return 0;
271: }
272:
273: void SQL_Driver_manager::put_connection_to_cache(const String& url,
274: SQL_Connection& connection) {
275: SYNCHRONIZED;
276:
277: Stack *connections=static_cast<Stack *>(connection_cache.get(url));
278: if(!connections) { // there are no cached connections to that 'url' yet?
279: connections=NEW Stack(pool()); // NOTE: never freed up!
280: connection_cache.put(url, connections);
281: }
282: connections->push(&connection);
283: }
284:
285: void SQL_Driver_manager::maybe_expire_cache() {
286: time_t now=time(0);
287:
288: if(prev_expiration_pass_time<now-CHECK_EXPIRED_CONNECTIONS_SECONDS) {
289: connection_cache.for_each(expire_connections,
290: reinterpret_cast<void *>(now-EXPIRE_UNUSED_CONNECTION_SECONDS));
291:
292: prev_expiration_pass_time=now;
293: }
294: }
295:
296: static void add_connection_to_status_cache_table(Array::Item *value, void *info) {
297: SQL_Connection& connection=*static_cast<SQL_Connection *>(value);
298: Table& table=*static_cast<Table *>(info);
299:
300: if(connection.connected()) {
301: Pool& pool=table.pool();
302: Array& row=*new(pool) Array(pool);
303:
304: // url
305: row+=&url_without_login(pool, connection.get_url());
306: // time
1.58 paf 307: time_t time_used=connection.get_time_used();
308: const char *unsafe_time_cstr=ctime(&time_used);
1.54 paf 309: int time_buf_size=strlen(unsafe_time_cstr);
310: char *safe_time_buf=(char *)pool.malloc(time_buf_size);
311: memcpy(safe_time_buf, unsafe_time_cstr, time_buf_size);
312: row+=new(pool) String(pool, safe_time_buf, time_buf_size);
313:
314: table+=&row;
315: }
316: }
317: static void add_connections_to_status_cache_table(const Hash::Key& key, Hash::Val *value, void *info) {
318: Stack& stack=*static_cast<Stack *>(value);
319: Array_iter iter(stack);
320: for(int countdown=stack.top_index(); countdown-->=0; )
321: add_connection_to_status_cache_table(iter.next(), info);
322: }
323: Value& SQL_Driver_manager::get_status(Pool& pool, const String *source) {
324: VHash& result=*new(pool) VHash(pool);
325:
326: // cache
327: {
328: Array& columns=*new(pool) Array(pool);
329: columns+=new(pool) String(pool, "url");
330: columns+=new(pool) String(pool, "time");
331: Table& table=*new(pool) Table(pool, 0, &columns, connection_cache.size());
332:
333: connection_cache.for_each(add_connections_to_status_cache_table, &table);
334:
335: result.hash(source).put(*new(pool) String(pool, "cache"), new(pool) VTable(pool, &table));
336: }
337:
338: return result;
1.57 paf 339: }
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