Annotation of parser3/src/main/pa_sql_driver_manager.C, revision 1.7
1.1 paf 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:
1.7 ! paf 8: $Id: pa_sql_driver_manager.C,v 1.6.2.1 2001/04/17 15:02:04 paf Exp $
1.1 paf 9: */
10:
11: #include "pa_config_includes.h"
12: #include "ltdl.h"
13: #include "pa_sql_driver_manager.h"
1.2 paf 14: #include "pa_sql_connection.h"
1.1 paf 15: #include "pa_exception.h"
16: #include "pa_common.h"
17:
18: // globals
19:
20: SQL_Driver_manager *SQL_driver_manager;
21:
22: // consts
23:
24: const int MAX_PROTOCOL=20;
25: const char *LIBRARY_CREATE_FUNC_NAME="create";
26:
1.3 paf 27:
28: /// Services_for_SQL_driver implementation
29: class Services_for_SQL_driver_impl : public Services_for_SQL_driver, public Pooled {
30: public:
31: Services_for_SQL_driver_impl(Pool& apool, const String& aurl) : Pooled(apool),
32: furl(aurl) {
33: }
34:
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); }
39: /// throw exception
40: void _throw(const char *comment) {
41: THROW(0, 0,
42: &furl,
43: comment);
44: }
45:
46: private:
47: const String& furl;
48: };
49:
50: // SQL_Driver_manager
51:
1.1 paf 52: // url:
53: // protocol://user:pass@host:port/database
54: // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this is driver-dependent
55: SQL_Connection& SQL_Driver_manager::get_connection(const String& url,
1.7 ! paf 56: Table *protocol2driver_and_client) {
1.1 paf 57: SYNCHRONIZED(true);
58:
59: Pool& pool=url.pool(); // request pool
60:
61: // we have table for locating protocol's library
1.7 ! paf 62: if(!protocol2driver_and_client)
1.1 paf 63: PTHROW(0, 0,
64: &url,
1.6 paf 65: "$SQL:drivers table must be defined");
1.1 paf 66:
67: // first trying to get cached connection
68: if(SQL_Connection *result=get_connection_from_cache(url))
1.5 paf 69: if(result->ping())
70: return *result;
71: else
72: result->disconnect(); // kill unpingabe=dead connection
1.1 paf 73: // no cached connection
74:
75: int pos=url.pos("://", 3);
76: if(pos<0)
77: PTHROW(0, 0,
78: &url,
79: "no protocol specified"); // NOTE: not THROW, but PTHROW
80:
81: // make url string on global pool
82: char *url_cstr=(char *)malloc(MAX_STRING);
83: strncpy(url_cstr, url.cstr(String::UL_AS_IS), MAX_STRING);
84:
85: char *protocol_cstr=lsplit(&url_cstr, ':');
86: String& protocol=*new(this->pool()) String(this->pool(), protocol_cstr);
87:
88: // skip // after :
89: while(*url_cstr=='/')
90: url_cstr++;
91:
92: SQL_Driver *driver;
1.7 ! paf 93: const String *dlopen_file_spec=0;
1.1 paf 94: // first trying to get cached driver
95: if(!(driver=get_driver_from_cache(protocol))) {
96: // no cached
97: const String *library=0;
1.7 ! paf 98: if(protocol2driver_and_client->locate(0, protocol)) {
! 99: if(!(library=protocol2driver_and_client->item(1)) || library->size()==0)
1.1 paf 100: PTHROW(0, 0,
1.7 ! paf 101: protocol2driver_and_client->origin_string(),
! 102: "driver library column for protocol '%s' is empty", protocol_cstr);
! 103: if(!(dlopen_file_spec=protocol2driver_and_client->item(2)) || dlopen_file_spec->size()==0)
! 104: PTHROW(0, 0,
! 105: protocol2driver_and_client->origin_string(),
! 106: "client library column for protocol '%s' is empty", protocol_cstr);
1.1 paf 107: } else
108: PTHROW(0, 0,
1.2 paf 109: &url,
110: "undefined protocol '%s'", protocol_cstr);
1.1 paf 111:
112: const char *filename=library->cstr(String::UL_FILE_NAME);
1.2 paf 113: lt_dlhandle handle=lt_dlopen(filename);
1.1 paf 114: if (!handle)
115: PTHROW(0, 0,
116: library,
117: "can not open the module, %s", lt_dlerror());
118:
119: SQL_Driver_create_func create=(SQL_Driver_create_func)lt_dlsym(handle,
120: LIBRARY_CREATE_FUNC_NAME);
121: if(!create)
122: PTHROW(0, 0,
123: library,
124: "function '%s' was not found", LIBRARY_CREATE_FUNC_NAME);
125:
1.2 paf 126: // create library-driver!
1.1 paf 127: driver=(*create)();
128:
129: // validate driver api version
130: int driver_api_version=driver->api_version();
1.7 ! paf 131: if(driver_api_version!=SQL_DRIVER_API_VERSION)
1.1 paf 132: PTHROW(0, 0,
133: library,
1.7 ! paf 134: "driver implements API version 0x%04X not equal to 0x%04X",
1.3 paf 135: driver_api_version, SQL_DRIVER_API_VERSION);
1.1 paf 136:
1.7 ! paf 137: // initialise by connecting to sql client dynamic link library
! 138: const char *dlopen_file_spec_cstr=dlopen_file_spec->cstr(String::UL_FILE_NAME);
! 139: if(const char *error=driver->initialize(
! 140: dlopen_file_spec_cstr))
! 141: PTHROW(0, 0,
! 142: library,
! 143: "driver failed to initialize client library '%s', %s",
! 144: dlopen_file_spec_cstr, error);
! 145:
1.1 paf 146: // cache it
147: put_driver_to_cache(protocol, *driver);
148: }
149:
1.4 paf 150: // services associated with request
1.3 paf 151: Services_for_SQL_driver_impl& services=
152: *new(pool) Services_for_SQL_driver_impl(pool, url);
153:
1.4 paf 154: // allocate in global pool
155: // associate with services[request], deassociates at close
1.3 paf 156: SQL_Connection& result=
1.7 ! paf 157: *new(this->pool()) SQL_Connection(this->pool(),
! 158: url, *driver, services, url_cstr);
1.3 paf 159:
160: return result;
1.1 paf 161: }
162:
163: void SQL_Driver_manager::close_connection(const String& url,
164: SQL_Connection& connection) {
165: SYNCHRONIZED(true);
166:
167: put_connection_to_cache(url, connection);
168: }
169:
170:
171: // driver cache
172:
173: SQL_Driver *SQL_Driver_manager::get_driver_from_cache(const String& protocol) {
174: if(SQL_Driver *result=static_cast<SQL_Driver *>(driver_cache.get(protocol)))
175: return result;
176:
177: return 0;
178: }
179:
180: void SQL_Driver_manager::put_driver_to_cache(const String& protocol,
181: SQL_Driver& driver) {
182: driver_cache.put(protocol, &driver);
183: }
184:
185: // connection cache
186:
187: SQL_Connection *SQL_Driver_manager::get_connection_from_cache(const String& url) {
188: if(Stack *connections=static_cast<Stack *>(connection_cache.get(url)))
189: if(connections->size()) // there are cached connections to that 'url'
190: return static_cast<SQL_Connection *>(connections->pop());
191:
192: return 0;
193: }
194:
1.2 paf 195: /// @todo cache expiration[use SQL_Driver::disconnect], pinging.
1.1 paf 196: void SQL_Driver_manager::put_connection_to_cache(const String& url,
197: SQL_Connection& connection) {
198: Stack *connections;
199: if(!(connections=static_cast<Stack *>(connection_cache.get(url)))) {
200: // there are no cached connections to that 'url' yet
201: connections=NEW Stack(pool()); // NOTE: never freed up!
202: connection_cache.put(url, connections);
203: }
204: connections->push(&connection);
205: }
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