Files
epics-base/src/libCom/gpHash.3
1995-12-07 21:08:25 +00:00

55 lines
1.7 KiB
Groff

.TH gpHash 1 "" "General Purpose Character String Hash Library"
.ad b
.SH VERSION $Id$
.SH NAME
gpHash.c - General Purpose Hash Library
.SH SYNOPSIS
.nf
gphInitPvt - Initialize
gphFind - Find an element taht has been hashed
gphAdd - Add a new entry
gphDelete - Delete an entry
gphFreeMem - Free all memory allocated by gpHash
gphDump - Dump current members
typedef struct{
ELLNODE node;
char *name; /*address of name placed in directory*/
void *pvtid; /*private name for subsystem user*/
void *userPvt; /*private for user*/
} GPHENTRY;
void gphInitPvt(void **ppvt);
GPHENTRY *gphFind(void *pvt,char *name,void *pvtid);
GPHENTRY *gphAdd(void *pvt,char *name,void *pvtid);
void gphDelete(void *pvt,char *name,void *pvtid);
void gphFreeMem(void *pvt);
void gphDump(void *pvt);
where :
pvt - For private use by library. Caller must provide a "void *pvt"
name - The character string that will be hashed and added to table
pvtid - The name plus value of this pointer constitute unique entry
.fi
.SH DESCRIPTION
This library provides a general purpose directory of names that is accessed
via a hash table. The hash table contains 256 entries. Each entry is a list
of members that hash to the same value. The user can maintain seperate directories
via the same table by having a different pvtid for each directory.
.SH RETURNS
.nf
gphFind returns the address of the GPHENTRY describing the entry or NULL if name was not found.
gphAdd returns the address of the new GPHENTRY describing the entry or NULL if name was already
present.
.SH INCLUDES
gpHash.h
.SH REFERENCE
Fast Hashing of Variable Length Text Strings, Peter K. Pearson,
Communications of the ACM, June 1990
.fi