Annotation of parser3/src/main/pa_sql_driver_manager.C, revision 1.53
1.53 ! paf 1: /** @file
! 2: Parser: sql driver manager implementation.
! 3:
! 4: Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com)
! 5: Author: Alexander Petrosyan <paf@design.ru> (http://paf.design.ru)
! 6:
! 7: $Id: pa_sql_driver_manager.C,v 1.52 2001/11/08 14:47:32 paf Exp $
! 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,
! 99: reinterpret_cast<void *>((time_t)0/*=in past=expire all*/));
! 100: }
! 101:
! 102: /// @param request_url protocol://[driver-dependent]
! 103: SQL_Connection& SQL_Driver_manager::get_connection(const String& request_url,
! 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
! 118: SQL_Connection *result=get_connection_from_cache(request_url);
! 119: if(result) {
! 120: result->set_services(services);
! 121: if(!result->ping()) { // we have some cached connection, is it pingable?
! 122: result->disconnect(); // kill unpingabe=dead connection
! 123: result=0;
! 124: }
! 125: }
! 126:
! 127: char *request_url_cstr;
! 128: if(result)
! 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!
! 223: result=new(this->pool()) SQL_Connection(this->pool(), global_url, *driver);
! 224: // associate with services[request] (deassociates at close)
! 225: result->set_services(services);
! 226: }
! 227:
! 228: // if not connected yet, do that now, when result has services
! 229: if(!result->connected())
! 230: result->connect(request_url_cstr);
! 231: // return it
! 232: return *result;
! 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
! 307: time_t time_stamp=connection.get_time_stamp();
! 308: const char *unsafe_time_cstr=ctime(&time_stamp);
! 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:
! 324:
! 325: Value& SQL_Driver_manager::get_status(Pool& pool, const String *source) {
! 326: VHash& result=*new(pool) VHash(pool);
! 327:
! 328: // cache
! 329: {
! 330: Array& columns=*new(pool) Array(pool);
! 331: columns+=new(pool) String(pool, "url");
! 332: columns+=new(pool) String(pool, "time");
! 333: Table& table=*new(pool) Table(pool, 0, &columns, connection_cache.size());
! 334:
! 335: connection_cache.for_each(add_connections_to_status_cache_table, &table);
! 336:
! 337: result.hash(source).put(*new(pool) String(pool, "cache"), new(pool) VTable(pool, &table));
! 338: }
! 339:
! 340: return result;
1.49 paf 341: }
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