Programming Interface Information: This information is NOT intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only.

HYPMAP

Prolog  

Control Block Contents  

HYPMAP DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

HYPMAP Prolog

Name : HYPMAP Description: Hyperblock Mapping Table DSECT : HYPMAP Function : HYPMAP is the hyperblock mapping table for read-only disks. It contains a header plus an entry for each 4K page of hyperblocks (or FSTs for a STAT) associated with the accessed disk. HYPMAP is used mainly by file management to reduce the paging overhead when searching for a file on a read-only disk. HYPMAP is called by the HYPMAP macro.

 

HYPMAP Control Block Content


HYPMAP DSECT

Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure HYPMAP Hyperblock Mapping Table H E A D E R 0000 0 Signed 4 HYPMSIZE Size of table (DWORDS) 0004 4 Signed 4 HYPMENTS Number of entries in table 00000001 HYPMHSIZ (*-HYPMAP+7)/8 Size of header (DWORDS) T A B L E E N T R I E S 0008 8 Signed 4 HYPTAB (0) Start of table 0008 8 Signed 2 HYPMBLKC Number of hyperblocks/FST's on the page mapped by this table entry 000A 10 Signed 2 * ** Unused ** 000C 12 Address 4 HYPMAHYP Pointer to hyperblock 0010 16 Character 16 HYPMFID (0) ID of last file in this block 0010 16 Character 8 HYPMFN (0) Filename 0010 16 Character 4 HYPMFN1 First half of filename 0014 20 Character 4 HYPMFN2 Second half of filename 0018 24 Character 8 HYPMFT (0) Filetype 0018 24 Character 4 HYPMFT1 First half of filetype 001C 28 Character 4 HYPMFT2 Second half of filetype 0020 32 Character 1 HYPMNEXT (0) Start of next entry 00000018 HYPMLEN *-HYPTAB Length of table entry

 

HYPMAP Storage Layout

*** HYPMAP - Hyperblock Mapping Table
*
*     +---------------------------+---------------------------+
*   0 |         HYPMSIZE          |         HYPMENTS          |
*     +-------------+-------------+---------------------------+
*   8 |  HYPMBLKC   |/////////////|         HYPMAHYP          |
*     +-------------+-------------+---------------------------+
*  10 |         HYPMFN1           |         HYPMFN2           |
*     +---------------------------+---------------------------+
*  18 |         HYPMFT1           |         HYPMFT2           |
*     +---------------------------+---------------------------+
*  20 |                                                       |
*     =                       HYPMNEXT                        =
*     |                                                       |
*     +-------------------------------------------------------+
*
*** HYPMAP - Hyperblock Mapping Table

 

HYPMAP Cross Reference

(contains links to field and bit definitions)
Symbol         Dspl Value
-------------- ---- -----

HYPMAHYP 000C

HYPMBLKC 0008

HYPMENTS 0004

HYPMFID 0010

HYPMFN 0010

HYPMFN1 0010

HYPMFN2 0014

HYPMFT 0018

HYPMFT1 0018

HYPMFT2 001C

HYPMHSIZ 0004 00000001

HYPMLEN 0020 00000018

HYPMNEXT 0020

HYPMSIZE 0000

HYPTAB 0008


This information is based on VM/ESA 2.4.0.
Last updated on 12 Aug 1999 at 11:21:26 EDT.
Copyright IBM Corporation, 1990, 1999