Procedure

     DAFNRR ( DAF number of reads, requests )

     ENTRY DAFNRR ( READS, REQS )

Abstract

     Return the number of reads and requests fielded by DAFRDR.

Required_Reading

     DAF

Keywords

     FILES

Declarations

    INTEGER               READS
    INTEGER               REQS

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     READS,
     REQS       O   Reads, requests in this execution.

Detailed_Input

     None.

Detailed_Output

     READS,
     REQS     are the number of physical reads and the number
              of requests processed by DAFRDR during the current
              execution of the calling program.

Parameters

     None.

Exceptions

     Error free.

Files

     None.

Particulars

     The ratio of reads to requests tells you something about
     the effectiveness with which the record buffer is preventing
     unwanted disk access. In the ideal case, most of the records
     needed by the calling program can be returned directly from
     the buffer, and the ratio of reads to requests approaches zero.
     More realistically, it should be be somewhere between 1/10
     and 1/2.

     If the ratio is greater than 1/2, you should consider increasing
     the size of the record buffer (which is controlled by parameter
     RBSIZE) in order to improve the performance of the DAF package,
     unless your application is strapped for space.

Examples

     In the following code fragment, the ratio of reads to requests
     is determined following a series of calls to the reader DAFEZ.

        DO I = 1, N
           CALL DAFEZ ( ..., STATES(1,I), ... )
        END DO

        CALL DAFNRR ( READS, REQS )

        WRITE (*,*) 'Reads/requests = ', FLOAT( READS ) / FLOAT( REQS )

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

     N.J. Bachman       (JPL)
     J.M. Lynch         (JPL)
     H.A. Neilan        (JPL)
     W.L. Taber         (JPL)
     I.M. Underwood     (JPL)

Version

    SPICELIB Version 1.3.1, 09-AUG-2021 (NJB)

        Re-ordered header sections. Corrected typos in comments.
        Edited the header to comply with NAIF standard.

        Removed DAF required reading from $Literature_References.

    SPICELIB Version 1.3.0, 24-MAR-2000 (WLT)

        The loop in DAFRDR that moved buffered d.p.s into the output
        array DATA was modified to use the routine MOVED.

    SPICELIB Version 1.1.0, 25-NOV-1992 (JML)

        A cut and paste error in the literature references
        section of the header was fixed.

    SPICELIB Version 1.0.2, 10-MAR-1992 (WLT)

        Comment section for permuted index source lines was added
        following the header.

    SPICELIB Version 1.0.1, 22-MAR-1990 (HAN)

        Literature references added to the header.

    SPICELIB Version 1.0.0, 31-JAN-1990 (IMU)