Annotation of parser3/src/sql/pa_sql_driver.h, revision 1.29

1.22      paf         1: /** @file
                      2:        Parser: sql driver interface.
                      3: 
1.25      paf         4:        Copyright (c) 2001, 2002 ArtLebedev Group (http://www.artlebedev.com)
1.26      paf         5:        Author: Alexandr Petrosian <paf@design.ru> (http://paf.design.ru)
1.22      paf         6: 
                      7: 
                      8:        driver dynamic library must look like this:
                      9:        @code
                     10:                class X_SQL_Driver : public SQL_Driver {
                     11:                public:
                     12: 
                     13:                        X_SQL_Driver() : SQL_driver() {}
                     14: 
                     15:                        int api_version() { return SQL_DRIVER_API_VERSION; }
                     16:                        
                     17:                        //...
                     18:                };
                     19: 
                     20:                extern "C" SQL_Driver *create() {
                     21:                        return new X_SQL_Driver();
                     22:                }       
                     23:        @endcode
                     24: */
                     25: 
                     26: #ifndef PA_SQL_DRIVER_H
                     27: #define PA_SQL_DRIVER_H
1.27      paf        28: 
1.29    ! paf        29: static const char* IDENT_SQL_DRIVER_H="$Date: 2002/08/01 11:41:20 $";
1.22      paf        30: 
                     31: #include <sys/types.h>
                     32: 
1.29    ! paf        33: #define SQL_DRIVER_API_VERSION 0x0004
        !            34: #define SQL_DRIVER_CREATE create /* used in driver implementation */
        !            35: #define SQL_DRIVER_CREATE_NAME "create" /* could not figure out how to # it :( */
        !            36: 
        !            37: /// fields are freed elsewhere
        !            38: class SQL_Exception {
        !            39:        friend class SQL_Driver_services_impl;
        !            40: 
        !            41:        bool fdefined;
        !            42:        const char *ftype;
        !            43:        const void *fproblem_source;
        !            44:        const char *fcomment;
        !            45: public:
        !            46:        SQL_Exception():
        !            47:                fdefined(false) {}
        !            48:        SQL_Exception(
        !            49:                const char *atype,
        !            50:                const void *aproblem_source, 
        !            51:                const char *acomment):
        !            52:                fdefined(true),
        !            53:                ftype(atype),
        !            54:                fproblem_source(aproblem_source),
        !            55:                fcomment(acomment) {}
        !            56:        SQL_Exception(const char *acomment):
        !            57:                fdefined(true),
        !            58:                ftype(0),
        !            59:                fproblem_source(0),
        !            60:                fcomment(acomment) {}
        !            61: /*
        !            62:        SQL_Exception(const SQL_Exception& src) : 
        !            63:                fdefined(src.fdefined),
        !            64:                ftype(src.ftype),
        !            65:                fproblem_source(src.fproblem_source),
        !            66:                fcomment(src.fcomment) {}
        !            67: */
        !            68:        SQL_Exception& operator =(const SQL_Exception& src) {
        !            69:                fdefined=src.fdefined;
        !            70:                ftype=src.ftype;
        !            71:                fproblem_source=src.fproblem_source;
        !            72:                fcomment=src.fcomment;
        !            73:                return *this;
        !            74:        }
        !            75: 
        !            76:        bool defined() { return fdefined; }
        !            77:        const char *type() { return ftype; }
        !            78:        const void *problem_source() { return fproblem_source; }
        !            79:        const char *comment() { return fcomment; }
        !            80: };
        !            81: 
1.22      paf        82: /// service functions for SQL driver to use
                     83: class SQL_Driver_services {
                     84: public:
                     85:        /// allocates some bytes on pool
                     86:        virtual void *malloc(size_t size) =0;
                     87:        /// allocates some bytes clearing them with zeros
                     88:        virtual void *calloc(size_t size) =0;
                     89:        /// prepare throw exception
1.29    ! paf        90:        virtual void _throw(const SQL_Exception& e) =0;
1.22      paf        91:        /// throw C++ exception from prepared
                     92:        virtual void propagate_exception() =0;
1.29    ! paf        93:        /// helper func
        !            94:        void _throw(const char *comment) { _throw(SQL_Exception(0, 0, comment)); }
1.22      paf        95: public:
                     96:        /// regretrully public, because can't make stack frames: "nowhere to return to"
                     97:        jmp_buf mark;
                     98: };
                     99: 
                    100: /// events, occuring when SQL_Driver::query()-ing
                    101: class SQL_Driver_query_event_handlers {
                    102: public:
                    103:        virtual void add_column(void *ptr, size_t size) =0;
                    104:        virtual void before_rows() =0;
                    105:        virtual void add_row() =0;
                    106:        virtual void add_row_cell(void *ptr, size_t size) =0;
                    107: };
                    108: 
                    109: /// SQL driver API
                    110: class SQL_Driver {
                    111: public:
                    112: 
                    113:        /// get api version
                    114:        virtual int api_version() =0;
                    115:        /// initialize driver by loading sql dynamic link library
                    116:        virtual const char *initialize(char *dlopen_file_spec) =0;
                    117:        /**     connect to sql database using 
                    118:                @param used_only_to_connect_url 
                    119:                        format is driver specific
                    120:                        WARNING: must be used only to connect, for buffer doesn't live long enough
                    121: 
                    122:                @returns true+'connection' on success. 'error' on failure
                    123:        */
                    124:        virtual void connect(char *used_only_in_connect_url_cstr, 
                    125:                SQL_Driver_services& services, void **connection) =0;
                    126:        virtual void disconnect(void *connection) =0;
                    127:        virtual void commit(
                    128:                SQL_Driver_services& services, void *connection) =0;
                    129:        virtual void rollback(
                    130:                SQL_Driver_services& services, void *connection) =0;
                    131:        /// @returns true to indicate that connection still alive 
                    132:        virtual bool ping(
                    133:                SQL_Driver_services& services, void *connection) =0;
                    134:        /// encodes the string in 'from' to an escaped SQL string
                    135:        virtual unsigned int quote(
                    136:                SQL_Driver_services& services, void *connection,
                    137:                char *to, const char *from, unsigned int length) =0;
                    138:        virtual void query(
                    139:                SQL_Driver_services& services, void *connection,
                    140:                const char *statement, unsigned long offset, unsigned long limit,
                    141:                SQL_Driver_query_event_handlers& handlers) =0;
                    142: };
                    143: 
                    144: typedef SQL_Driver *(*SQL_Driver_create_func)();
                    145: 
                    146: #endif

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