--- parser3/src/main/pa_sql_driver_manager.C 2001/04/04 11:47:29 1.2 +++ parser3/src/main/pa_sql_driver_manager.C 2001/10/29 10:06:36 1.44 @@ -2,18 +2,18 @@ Parser: sql driver manager implementation. Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com) - Author: Alexander Petrosyan (http://design.ru/paf) - $Id: pa_sql_driver_manager.C,v 1.2 2001/04/04 11:47:29 paf Exp $ + $Id: pa_sql_driver_manager.C,v 1.44 2001/10/29 10:06:36 paf Exp $ */ -#include "pa_config_includes.h" -#include "ltdl.h" #include "pa_sql_driver_manager.h" +#include "ltdl.h" #include "pa_sql_connection.h" #include "pa_exception.h" #include "pa_common.h" +#include "pa_threads.h" +#include "pa_stack.h" // globals @@ -21,99 +21,208 @@ SQL_Driver_manager *SQL_driver_manager; // consts -const int MAX_PROTOCOL=20; -const char *LIBRARY_CREATE_FUNC_NAME="create"; +const int EXPIRE_UNUSED_CONNECTION_SECONDS=60; +const int CHECK_EXPIRED_CONNECTIONS_SECONDS=EXPIRE_UNUSED_CONNECTION_SECONDS*2; -// url: -// protocol://user:pass@host:port/database -// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this is driver-dependent -SQL_Connection& SQL_Driver_manager::get_connection(const String& url, - Table *protocol2library) { - SYNCHRONIZED(true); - Pool& pool=url.pool(); // request pool +/// SQL_Driver_services Pooled implementation +class SQL_Driver_services_impl : public SQL_Driver_services, public Pooled { +public: + SQL_Driver_services_impl(Pool& apool, const String& aurl) : Pooled(apool), + furl(aurl) { + } - // we have table for locating protocol's library - if(!protocol2library) - PTHROW(0, 0, - &url, - "SQL:drivers table must be defined"); + virtual void *malloc(size_t size) { return Pooled::malloc(size); } + virtual void *calloc(size_t size) { return Pooled::calloc(size); } - // first trying to get cached connection - if(SQL_Connection *result=get_connection_from_cache(url)) - return *result; - // no cached connection - - int pos=url.pos("://", 3); - if(pos<0) - PTHROW(0, 0, - &url, - "no protocol specified"); // NOTE: not THROW, but PTHROW - - // make url string on global pool - char *url_cstr=(char *)malloc(MAX_STRING); - strncpy(url_cstr, url.cstr(String::UL_AS_IS), MAX_STRING); + /** + the idea is to #1 jump to C++ some function to main body, where + every function stack frame has exception unwind information + and from there... #2 propagate_exception() + */ + virtual void _throw(const char *comment) { + e=Exception(0, 0, + &furl, + comment); + + longjmp(mark, 1); + } + virtual void propagate_exception() { + throw e; + } + +private: + const String& furl; + Exception e; +}; + +// helpers + +static void expire_connection(Array::Item *value, void *info) { + SQL_Connection& connection=*static_cast(value); + time_t older_dies=reinterpret_cast(info); + + if(connection.connected() && connection.expired(older_dies)) + connection.disconnect(); +} +static void expire_connections(const Hash::Key& key, Hash::Val *value, void *info) { + Stack& stack=*static_cast(value); + for(int i=0; i<=stack.top_index(); i++) + expire_connection(stack.get(i), info); +} + +// SQL_Driver_manager + +SQL_Driver_manager::SQL_Driver_manager(Pool& pool) : Pooled(pool), + driver_cache(pool), + connection_cache(pool), + prev_expiration_pass_time(0) { - char *protocol_cstr=lsplit(&url_cstr, ':'); - String& protocol=*new(this->pool()) String(this->pool(), protocol_cstr); +} + +SQL_Driver_manager::~SQL_Driver_manager() { + connection_cache.for_each(expire_connections, + reinterpret_cast((time_t)0/*=in past=expire all*/)); +} - // skip // after : - while(*url_cstr=='/') - url_cstr++; - - SQL_Driver *driver; - // first trying to get cached driver - if(!(driver=get_driver_from_cache(protocol))) { - // no cached - const String *library=0; - if(protocol2library->locate(0, protocol)) { - if(!(library=protocol2library->item(1)) || library->size()==0) - PTHROW(0, 0, - protocol2library->origin_string(), - "library column for protocol '%s' is empty", protocol_cstr); - } else - PTHROW(0, 0, - &url, - "undefined protocol '%s'", protocol_cstr); - - const char *filename=library->cstr(String::UL_FILE_NAME); - lt_dlhandle handle=lt_dlopen(filename); - if (!handle) - PTHROW(0, 0, - library, - "can not open the module, %s", lt_dlerror()); - - SQL_Driver_create_func create=(SQL_Driver_create_func)lt_dlsym(handle, - LIBRARY_CREATE_FUNC_NAME); - if(!create) - PTHROW(0, 0, - library, - "function '%s' was not found", LIBRARY_CREATE_FUNC_NAME); - - // create library-driver! - driver=(*create)(); - - // validate driver api version - int driver_api_version=driver->api_version(); - if(driver_api_versionset_services(services); + if(!result->ping()) { // we have some cached connection, is it pingable? + result->disconnect(); // kill unpingabe=dead connection + result=0; + } } + + char *request_url_cstr; + if(result) + request_url_cstr=0; // calm, compiler + else { // no cached connection or it were unpingabe: connect/reconnect + int pos=request_url.pos("://", 3); + if(pos<0) + throw Exception(0, 0, + request_url.size()?&request_url:&request_origin, + "connection string must start with protocol://"); // NOTE: not THROW, but PTHROW + + // make global_url C-string on global pool + request_url_cstr=request_url.cstr(String::UL_AS_IS); + char *global_url_cstr=(char *)malloc(strlen(request_url_cstr)+1); + strcpy(global_url_cstr, request_url_cstr); + // make global_url string on global pool + String& global_url=*new(this->pool()) String(this->pool(), global_url_cstr); + + char *request_protocol_cstr=lsplit(&request_url_cstr, ':'); + // skip "//" after ':' + while(*request_url_cstr=='/') + request_url_cstr++; + // make global_protocol C-string on global pool + char *global_protocol_cstr=(char *)malloc(strlen(request_protocol_cstr)+1); + strcpy(global_protocol_cstr, request_protocol_cstr); + // make global_protocol string on global pool + String& global_protocol=*new(this->pool()) String(this->pool(), + global_protocol_cstr); + + SQL_Driver *driver; + const String *dlopen_file_spec=0; + // first trying to get cached driver + if(!(driver=get_driver_from_cache(global_protocol))) { + // no cached + const String *library=0; + if(protocol2driver_and_client->locate(0, global_protocol)) { + if(!(library=protocol2driver_and_client->item(1)) || library->size()==0) + throw Exception(0, 0, + protocol2driver_and_client->origin_string(), + "driver library column for protocol '%s' is empty", + request_protocol_cstr); + dlopen_file_spec=protocol2driver_and_client->item(2); + } else + throw Exception(0, 0, + &request_url, + "undefined protocol '%s'", + request_protocol_cstr); + + if(lt_dlinit()) + throw Exception(0, 0, + library, + "prepare to dynamic loading failed, %s", lt_dlerror()); + + const char *filename=library->cstr(String::UL_FILE_SPEC); + lt_dlhandle handle=lt_dlopen(filename); + if (!handle) + throw Exception(0, 0, + library, + "can not open the module, %s", lt_dlerror()); + + SQL_Driver_create_func create=(SQL_Driver_create_func)lt_dlsym(handle, + SQL_DRIVER_CREATE_NAME); + if(!create) + throw Exception(0, 0, + library, + "function '"SQL_DRIVER_CREATE_NAME"' was not found"); + + // create library-driver! + driver=(*create)(); + + // validate driver api version + int driver_api_version=driver->api_version(); + if(driver_api_version!=SQL_DRIVER_API_VERSION) + throw Exception(0, 0, + library, + "driver implements API version 0x%04X not equal to 0x%04X", + driver_api_version, SQL_DRIVER_API_VERSION); + + // initialise by connecting to sql client dynamic link library + bool specified_dlopen_file_spec=dlopen_file_spec && dlopen_file_spec->size(); + const char *dlopen_file_spec_cstr= + specified_dlopen_file_spec? + dlopen_file_spec->cstr(String::UL_FILE_SPEC):0; + if(const char *error=driver->initialize( + dlopen_file_spec_cstr)) + throw Exception(0, 0, + library, + "driver failed to initialize client library '%s', %s", + specified_dlopen_file_spec?dlopen_file_spec_cstr:"unspecifed", + error); + + // cache it + put_driver_to_cache(global_protocol, *driver); + } - return *new(this->pool()) SQL_Connection(url.pool(), //< associate with request - *driver, url_cstr, url); + // allocate in global pool + // associate with services[request] + // NOTE: never freed up! + result=new(this->pool()) SQL_Connection(this->pool(), global_url, *driver); + // associate with services[request] (deassociates at close) + result->set_services(services); + } + + // if not connected yet, do that now, when result has services + if(!result->connected()) + result->connect(request_url_cstr); + // return it + return *result; } void SQL_Driver_manager::close_connection(const String& url, SQL_Connection& connection) { - SYNCHRONIZED(true); - - connection.set_pool(0); // deassociate from request + // deassociate from services[request] + connection.set_services(0); put_connection_to_cache(url, connection); } @@ -121,35 +230,54 @@ void SQL_Driver_manager::close_connectio // driver cache SQL_Driver *SQL_Driver_manager::get_driver_from_cache(const String& protocol) { - if(SQL_Driver *result=static_cast(driver_cache.get(protocol))) - return result; + SYNCHRONIZED; - return 0; + return static_cast(driver_cache.get(protocol)); } void SQL_Driver_manager::put_driver_to_cache(const String& protocol, SQL_Driver& driver) { + SYNCHRONIZED; + driver_cache.put(protocol, &driver); } // connection cache - +/// @todo get rid of memory spending Stack [zeros deep inside got accumulated] SQL_Connection *SQL_Driver_manager::get_connection_from_cache(const String& url) { + SYNCHRONIZED; + + maybe_expire_connection_cache(); + if(Stack *connections=static_cast(connection_cache.get(url))) - if(connections->size()) // there are cached connections to that 'url' - return static_cast(connections->pop()); + while(connections->top_index()>=0) { // there are cached connections to that 'url' + SQL_Connection *result=static_cast(connections->pop()); + if(result->connected()) // not expired? + return result; + } return 0; } -/// @todo cache expiration[use SQL_Driver::disconnect], pinging. void SQL_Driver_manager::put_connection_to_cache(const String& url, SQL_Connection& connection) { - Stack *connections; - if(!(connections=static_cast(connection_cache.get(url)))) { - // there are no cached connections to that 'url' yet + SYNCHRONIZED; + + Stack *connections=static_cast(connection_cache.get(url)); + if(!connections) { // there are no cached connections to that 'url' yet? connections=NEW Stack(pool()); // NOTE: never freed up! connection_cache.put(url, connections); } connections->push(&connection); } + +void SQL_Driver_manager::maybe_expire_connection_cache() { + time_t now=time(0); + + if(prev_expiration_pass_time(now-EXPIRE_UNUSED_CONNECTION_SECONDS)); + + prev_expiration_pass_time=now; + } +}