Annotation of parser3/src/sql/pa_sql_driver.h, revision 1.37

1.22      paf         1: /** @file
                      2:        Parser: sql driver interface.
                      3: 
1.35      paf         4:        Copyright (c) 2001-2003 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
1.35      paf        10:                class X_SQL_Driver: public SQL_Driver {
1.22      paf        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: 
1.37    ! paf        29: static const char * const IDENT_SQL_DRIVER_H="$Date: 2003/11/20 16:34:27 $";
1.22      paf        30: 
                     31: #include <sys/types.h>
1.35      paf        32: #include <setjmp.h>
                     33: #include <stdlib.h>
1.22      paf        34: 
1.37    ! paf        35: #define SQL_DRIVER_API_VERSION 0x0008
1.29      paf        36: #define SQL_DRIVER_CREATE create /* used in driver implementation */
                     37: #define SQL_DRIVER_CREATE_NAME "create" /* could not figure out how to # it :( */
                     38: 
                     39: /// fields are freed elsewhere
1.32      paf        40: class SQL_Error {
1.29      paf        41:        bool fdefined;
1.35      paf        42:        const char* ftype;
                     43:        const char* fcomment;
1.29      paf        44: public:
1.32      paf        45:        SQL_Error():
1.29      paf        46:                fdefined(false) {}
1.32      paf        47:        SQL_Error(
1.35      paf        48:                const char* atype,
                     49:                const char* acomment):
1.29      paf        50:                fdefined(true),
                     51:                ftype(atype),
                     52:                fcomment(acomment) {}
1.35      paf        53:        SQL_Error(const char* acomment):
1.29      paf        54:                fdefined(true),
                     55:                ftype(0),
                     56:                fcomment(acomment) {}
1.32      paf        57:        SQL_Error& operator =(const SQL_Error& src) {
1.29      paf        58:                fdefined=src.fdefined;
                     59:                ftype=src.ftype;
                     60:                fcomment=src.fcomment;
                     61:                return *this;
                     62:        }
                     63: 
1.32      paf        64:        bool defined() const { return fdefined; }
1.35      paf        65:        const char* type() const { return ftype; }
                     66:        const char* comment() const { return fcomment; }
1.29      paf        67: };
                     68: 
1.22      paf        69: /// service functions for SQL driver to use
                     70: class SQL_Driver_services {
                     71: public:
1.35      paf        72:        /// allocates some bytes
1.22      paf        73:        virtual void *malloc(size_t size) =0;
1.35      paf        74:        /// allocates some bytes, user promises: no pointers inside
                     75:        virtual void *malloc_atomic(size_t size) =0;
                     76:        /// reallocates bytes 
                     77:        virtual void *realloc(void *ptr, size_t size) =0;
1.37    ! paf        78:        /// $request:charset
        !            79:        virtual const char* request_charset() =0;
        !            80:        /// transcoder
        !            81:        virtual void transcode(const char* src, size_t src_length,
        !            82:                const char*& dst, size_t& dst_length,
        !            83:                const char* charset_from_name,
        !            84:                const char* charset_to_name
        !            85:                ) =0;
1.22      paf        86:        /// prepare throw exception
1.32      paf        87:        virtual void _throw(const SQL_Error& e) =0;
1.22      paf        88:        /// throw C++ exception from prepared
                     89:        virtual void propagate_exception() =0;
1.29      paf        90:        /// helper func
1.35      paf        91:        void _throw(const char* comment) { _throw(SQL_Error("sql.connect", comment)); }
1.22      paf        92: public:
                     93:        /// regretrully public, because can't make stack frames: "nowhere to return to"
                     94:        jmp_buf mark;
                     95: };
                     96: 
1.32      paf        97: /** events, occuring when SQL_Driver::query()-ing. 
                     98: 
                     99:                when OK must return false.
                    100:                must NOT throw exceptions, must store them to error & return true.
                    101: */
1.22      paf       102: class SQL_Driver_query_event_handlers {
                    103: public:
1.35      paf       104:        virtual bool add_column(SQL_Error& error, const char* str, size_t length) =0;
1.32      paf       105:        virtual bool before_rows(SQL_Error& error) =0;
                    106:        virtual bool add_row(SQL_Error& error) =0;
1.35      paf       107:        virtual bool add_row_cell(SQL_Error& error, const char* str, size_t length) =0;
1.22      paf       108: };
                    109: 
                    110: /// SQL driver API
                    111: class SQL_Driver {
                    112: public:
                    113: 
1.35      paf       114:        /** allocated using our allocator,
                    115:                @todo never freed
                    116:        */
                    117:        static void *operator new(size_t size) { 
                    118:                void *result=::malloc(size);
                    119:                if(!result)
                    120:                        abort();
                    121: 
                    122:                return result;
                    123:        }
1.22      paf       124:        /// get api version
                    125:        virtual int api_version() =0;
                    126:        /// initialize driver by loading sql dynamic link library
1.35      paf       127:        virtual const char* initialize(char *dlopen_file_spec) =0;
1.22      paf       128:        /**     connect to sql database using 
                    129:                @param used_only_to_connect_url 
                    130:                        format is driver specific
                    131:                        WARNING: must be used only to connect, for buffer doesn't live long enough
                    132: 
                    133:                @returns true+'connection' on success. 'error' on failure
                    134:        */
                    135:        virtual void connect(char *used_only_in_connect_url_cstr, 
                    136:                SQL_Driver_services& services, void **connection) =0;
                    137:        virtual void disconnect(void *connection) =0;
1.37    ! paf       138:        virtual void commit(void *connection) =0;
        !           139:        virtual void rollback(void *connection) =0;
1.22      paf       140:        /// @returns true to indicate that connection still alive 
1.37    ! paf       141:        virtual bool ping(void *connection) =0;
1.22      paf       142:        /// encodes the string in 'from' to an escaped SQL string
1.37    ! paf       143:        virtual const char* quote(void *connection,
1.35      paf       144:                const char* str, unsigned int length) =0;
1.37    ! paf       145:        virtual void query(void *connection,
1.35      paf       146:                const char* statement, unsigned long offset, unsigned long limit,
1.22      paf       147:                SQL_Driver_query_event_handlers& handlers) =0;
                    148: };
                    149: 
                    150: typedef SQL_Driver *(*SQL_Driver_create_func)();
                    151: 
                    152: #endif

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