ToC path:

mco_inmem_load DEPRECATED

Load transient (in-memory) classes from an external file. This function has been deprecated in version 7.1. See mco_db_load().

Prototype

 
    MCO_RET	mco_inmem_load(	/*IN*/ void *stream_handle,
                  /*IN*/ mco_stream_read input_stream_reader,
                  /*IN*/ const char * dbname,
                  /*IN*/ mco_dictionary_h dict,
                  /*IN*/ mco_device_t *devices,
                  /*IN*/ uint2 n_devices,
                  /*IN*/ mco_db_params_t * db_params );

Arguments

stream_handle	Handle to the input stream
input_stream_reader	Handler function called by the runtime to read the input
dbname	Database name passed to `mco_db_open_dev()`
dict	Database dictionary handle passed to `mco_db_open_dev().`
devices	Device structure array passed to `mco_db_open_dev()`
n_devices	The number of device structures passed to `mco_db_open_dev()`.
db_params	The database parameters passed to `mco_db_open_dev()`

Description

While mco_db_load() loads all database objects (both persistent and transient), this function reads the content of only the transient classes. For all-in-memory databases this function is equivalent to mco_db_load(), but for “hybrid” databases this allows the application to load only the transient objects in the database from a previously saved snapshot (see mco_inmem_save() ). After loading the transient classes this function opens the database by calling mco_db_open_dev() with the passed parameters.

The calling application must provide a stream pointer (a pointer to a file, socket, pipe, etc.) and the address of a function that will perform the reading of the stream of bytes representing the database image. The eXtremeDBruntime will call the given function, passing it the stream pointer, a buffer and the size of the buffer to be read. See the control structure stream_reader for further details. (Also see mco_inmem_save()).

Return Codes

MCO_S_OK	The database was closed successfully
MCO_E_NOINSTANCE	The specified database is not opened

Example

 
    Application snippet:
        
     
    mco_size_sig_t file_reader( void *stream_handle /* FILE *  */,  /* OUT */void *to, mco_size_t max_nbytes )
    {
        FILE *f = (FILE *)stream_handle;
        mco_size_sig_t nbs;
        nbs = fread( to, 1, max_nbytes, f );
        return nbs;
    }
     
    int  main(int argc, char** argv)
    {
        MCO_RET             rc;
        sample_memory_t     dbmem;
        mco_db_h            db;
        mco_db_params_t     db_params;
        …
        FILE * fbak;
        …
        rc = mco_inmem_load( (void *)fbak, file_reader, dbname, backupdb_get_dictionary(), dbmem.dev, dbmem.n_dev, &db_params );
        
        fclose( fbak );
        sample_rc_check( "\t Load database", rc );
        if ( MCO_S_OK == rc )
        {
            /* Connect to database */
            rc = mco_db_connect( dbname, &db );
            sample_rc_check( "\t Connect to database", rc );
        }
    }