Annotation of parser3/src/main/pa_sql_driver_manager.C, revision 1.13
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:
1.13 ! parser 8: $Id: pa_sql_driver_manager.C,v 1.12 2001/05/17 08:42:22 parser 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:
1.8 paf 28: /// SQL_Driver_services Pooled implementation
29: class SQL_Driver_services_impl : public SQL_Driver_services, public Pooled {
1.3 paf 30: public:
1.8 paf 31: SQL_Driver_services_impl(Pool& apool, const String& aurl) : Pooled(apool),
1.3 paf 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:
1.12 parser 52: /// @param request_url protocol://[driver-dependent]
53: SQL_Connection& SQL_Driver_manager::get_connection(const String& request_url,
1.7 paf 54: Table *protocol2driver_and_client) {
1.12 parser 55: Pool& pool=request_url.pool(); // request pool
1.1 paf 56:
57: // we have table for locating protocol's library
1.7 paf 58: if(!protocol2driver_and_client)
1.1 paf 59: PTHROW(0, 0,
1.12 parser 60: &request_url,
1.6 paf 61: "$SQL:drivers table must be defined");
1.1 paf 62:
1.12 parser 63: // services associated with request
64: SQL_Driver_services_impl& services=
65: *new(pool) SQL_Driver_services_impl(pool, request_url);
66:
1.1 paf 67: // first trying to get cached connection
1.12 parser 68: if(SQL_Connection *result=get_connection_from_cache(request_url))
69: if(result->ping()) {
70: result->set_services(&services);
1.5 paf 71: return *result;
1.12 parser 72: } else
1.5 paf 73: result->disconnect(); // kill unpingabe=dead connection
1.1 paf 74: // no cached connection
75:
1.12 parser 76: int pos=request_url.pos("://", 3);
1.1 paf 77: if(pos<0)
78: PTHROW(0, 0,
1.12 parser 79: &request_url,
1.1 paf 80: "no protocol specified"); // NOTE: not THROW, but PTHROW
81:
1.12 parser 82: // make global_url C-string on global pool
83: char *request_url_cstr=request_url.cstr(String::UL_AS_IS);
84: char *global_url_cstr=(char *)malloc(strlen(request_url_cstr)+1);
85: strcpy(global_url_cstr, request_url_cstr);
86: // make global_url string on global pool
87: String& global_url=*new(this->pool()) String(this->pool(), global_url_cstr);
1.1 paf 88:
1.12 parser 89: char *request_protocol_cstr=lsplit(&request_url_cstr, ':');
90: // skip "//" after ':'
91: while(*request_url_cstr=='/')
92: request_url_cstr++;
93: // make global_protocol C-string on global pool
94: char *global_protocol_cstr=(char *)malloc(strlen(request_protocol_cstr)+1);
95: strcpy(global_protocol_cstr, request_protocol_cstr);
96: // make global_protocol string on global pool
97: String& global_protocol=*new(this->pool()) String(this->pool(),
98: global_protocol_cstr);
1.1 paf 99:
100: SQL_Driver *driver;
1.7 paf 101: const String *dlopen_file_spec=0;
1.1 paf 102: // first trying to get cached driver
1.12 parser 103: if(!(driver=get_driver_from_cache(global_protocol))) {
1.1 paf 104: // no cached
105: const String *library=0;
1.12 parser 106: if(protocol2driver_and_client->locate(0, global_protocol)) {
1.7 paf 107: if(!(library=protocol2driver_and_client->item(1)) || library->size()==0)
1.1 paf 108: PTHROW(0, 0,
1.7 paf 109: protocol2driver_and_client->origin_string(),
1.12 parser 110: "driver library column for protocol '%s' is empty",
111: request_protocol_cstr);
1.7 paf 112: if(!(dlopen_file_spec=protocol2driver_and_client->item(2)) || dlopen_file_spec->size()==0)
113: PTHROW(0, 0,
114: protocol2driver_and_client->origin_string(),
1.12 parser 115: "client library column for protocol '%s' is empty",
116: request_protocol_cstr);
1.1 paf 117: } else
118: PTHROW(0, 0,
1.12 parser 119: &request_url,
120: "undefined protocol '%s'",
121: request_protocol_cstr);
1.1 paf 122:
123: const char *filename=library->cstr(String::UL_FILE_NAME);
1.2 paf 124: lt_dlhandle handle=lt_dlopen(filename);
1.1 paf 125: if (!handle)
126: PTHROW(0, 0,
127: library,
128: "can not open the module, %s", lt_dlerror());
129:
130: SQL_Driver_create_func create=(SQL_Driver_create_func)lt_dlsym(handle,
131: LIBRARY_CREATE_FUNC_NAME);
132: if(!create)
133: PTHROW(0, 0,
134: library,
135: "function '%s' was not found", LIBRARY_CREATE_FUNC_NAME);
136:
1.2 paf 137: // create library-driver!
1.1 paf 138: driver=(*create)();
139:
140: // validate driver api version
141: int driver_api_version=driver->api_version();
1.7 paf 142: if(driver_api_version!=SQL_DRIVER_API_VERSION)
1.1 paf 143: PTHROW(0, 0,
144: library,
1.7 paf 145: "driver implements API version 0x%04X not equal to 0x%04X",
1.3 paf 146: driver_api_version, SQL_DRIVER_API_VERSION);
1.1 paf 147:
1.7 paf 148: // initialise by connecting to sql client dynamic link library
149: const char *dlopen_file_spec_cstr=dlopen_file_spec->cstr(String::UL_FILE_NAME);
150: if(const char *error=driver->initialize(
151: dlopen_file_spec_cstr))
152: PTHROW(0, 0,
153: library,
154: "driver failed to initialize client library '%s', %s",
155: dlopen_file_spec_cstr, error);
156:
1.1 paf 157: // cache it
1.12 parser 158: put_driver_to_cache(global_protocol, *driver);
1.1 paf 159: }
160:
1.4 paf 161: // allocate in global pool
162: // associate with services[request], deassociates at close
1.3 paf 163: SQL_Connection& result=
1.7 paf 164: *new(this->pool()) SQL_Connection(this->pool(),
1.12 parser 165: global_url, *driver, services, request_url_cstr);
1.3 paf 166:
167: return result;
1.1 paf 168: }
169:
170: void SQL_Driver_manager::close_connection(const String& url,
171: SQL_Connection& connection) {
172: put_connection_to_cache(url, connection);
173: }
174:
175:
176: // driver cache
177:
178: SQL_Driver *SQL_Driver_manager::get_driver_from_cache(const String& protocol) {
1.13 ! parser 179: SYNCHRONIZED;
! 180:
1.1 paf 181: if(SQL_Driver *result=static_cast<SQL_Driver *>(driver_cache.get(protocol)))
182: return result;
183:
184: return 0;
185: }
186:
187: void SQL_Driver_manager::put_driver_to_cache(const String& protocol,
188: SQL_Driver& driver) {
1.13 ! parser 189: SYNCHRONIZED;
! 190:
1.1 paf 191: driver_cache.put(protocol, &driver);
192: }
193:
194: // connection cache
195:
196: SQL_Connection *SQL_Driver_manager::get_connection_from_cache(const String& url) {
1.13 ! parser 197: SYNCHRONIZED;
! 198:
1.1 paf 199: if(Stack *connections=static_cast<Stack *>(connection_cache.get(url)))
200: if(connections->size()) // there are cached connections to that 'url'
201: return static_cast<SQL_Connection *>(connections->pop());
202:
203: return 0;
204: }
205:
1.10 paf 206: /// @todo cache expiration[use SQL_Driver::disconnect]
1.1 paf 207: void SQL_Driver_manager::put_connection_to_cache(const String& url,
208: SQL_Connection& connection) {
1.13 ! parser 209: SYNCHRONIZED;
! 210:
1.1 paf 211: Stack *connections;
212: if(!(connections=static_cast<Stack *>(connection_cache.get(url)))) {
213: // there are no cached connections to that 'url' yet
214: connections=NEW Stack(pool()); // NOTE: never freed up!
215: connection_cache.put(url, connections);
216: }
217: connections->push(&connection);
218: }
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