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pcas/src/dbStatic/dbPvdLib.c
2002-12-13 17:21:50 +00:00

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/*************************************************************************\
* Copyright (c) 2002 The University of Chicago, as Operator of Argonne
* National Laboratory.
* Copyright (c) 2002 The Regents of the University of California, as
* Operator of Los Alamos National Laboratory.
* EPICS BASE Versions 3.13.7
* and higher are distributed subject to a Software License Agreement found
* in file LICENSE that is included with this distribution.
\*************************************************************************/
/*dbPvdLib.c*/
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "dbDefs.h"
#include "ellLib.h"
#include "dbBase.h"
#define epicsExportSharedSymbols
#include "dbStaticLib.h"
#include "dbStaticPvt.h"
int dbPvdHashTableSize = 512;
static int dbPvdHashTableShift;
#define NTABLESIZES 9
static struct {
unsigned int tablesize;
int shift;
}hashTableParms[9] = {
{256,0},
{512,1},
{1024,2},
{2048,3},
{4096,4},
{8192,5},
{16384,6},
{32768,7},
{65536,8}
};
/*The hash algorithm is a modification of the algorithm described in */
/* Fast Hashing of Variable Length Text Strings, Peter K. Pearson, */
/* Communications of the ACM, June 1990 */
/* The modifications were designed by Marty Kraimer */
static unsigned char T[256] = {
39,159,180,252, 71, 6, 13,164,232, 35,226,155, 98,120,154, 69,
157, 24,137, 29,147, 78,121, 85,112, 8,248,130, 55,117,190,160,
176,131,228, 64,211,106, 38, 27,140, 30, 88,210,227,104, 84, 77,
75,107,169,138,195,184, 70, 90, 61,166, 7,244,165,108,219, 51,
9,139,209, 40, 31,202, 58,179,116, 33,207,146, 76, 60,242,124,
254,197, 80,167,153,145,129,233,132, 48,246, 86,156,177, 36,187,
45, 1, 96, 18, 19, 62,185,234, 99, 16,218, 95,128,224,123,253,
42,109, 4,247, 72, 5,151,136, 0,152,148,127,204,133, 17, 14,
182,217, 54,199,119,174, 82, 57,215, 41,114,208,206,110,239, 23,
189, 15, 3, 22,188, 79,113,172, 28, 2,222, 21,251,225,237,105,
102, 32, 56,181,126, 83,230, 53,158, 52, 59,213,118,100, 67,142,
220,170,144,115,205, 26,125,168,249, 66,175, 97,255, 92,229, 91,
214,236,178,243, 46, 44,201,250,135,186,150,221,163,216,162, 43,
11,101, 34, 37,194, 25, 50, 12, 87,198,173,240,193,171,143,231,
111,141,191,103, 74,245,223, 20,161,235,122, 63, 89,149, 73,238,
134, 68, 93,183,241, 81,196, 49,192, 65,212, 94,203, 10,200, 47
};
static unsigned short hash( const char *pname, int length)
{
unsigned char h0=0;
unsigned char h1=0;
unsigned short ind0,ind1;
int isOdd;
int i,n;
isOdd = length%2; /*See if length is odd number of chanacters*/
n = (isOdd ? (length-1) : length);
if(isOdd) h0 = T[h0^*(pname + length -1)];
for(i=0; i<n; i+=2, pname+=2) {
h0 = T[h0^*pname];
h1 = T[h1^*(pname+1)];
}
ind0 = (unsigned short)h0;
ind1 = (unsigned short)h1;
return((ind1<<dbPvdHashTableShift) ^ ind0);
}
int epicsShareAPI dbPvdTableSize(int size)
{
int i;
for(i=0; i< NTABLESIZES; i++) {
if(size==hashTableParms[i].tablesize) {
dbPvdHashTableSize = hashTableParms[i].tablesize;
dbPvdHashTableShift = hashTableParms[i].shift;
return(0);
}
}
printf("Illegal Size for Process Variable Directory\n");
return(-1);
}
void dbPvdInitPvt(dbBase *pdbbase)
{
ELLLIST **ppvd;
int i;
for(i=0; i< NTABLESIZES; i++) {
if((i==NTABLESIZES-1)
||((dbPvdHashTableSize>=hashTableParms[i].tablesize)
&& (dbPvdHashTableSize<hashTableParms[i+1].tablesize))) {
dbPvdHashTableSize = hashTableParms[i].tablesize;
dbPvdHashTableShift = hashTableParms[i].shift;
break;
}
}
ppvd = dbCalloc(dbPvdHashTableSize, sizeof(ELLLIST *));
pdbbase->ppvd = (void *) ppvd;
return;
}
PVDENTRY *dbPvdFind(dbBase *pdbbase,const char *name,int lenName)
{
unsigned short hashInd;
ELLLIST **ppvd = (ELLLIST **) pdbbase->ppvd;
ELLLIST *pvdlist;
PVDENTRY *ppvdNode;
hashInd = hash(name, lenName);
if ((pvdlist=ppvd[hashInd]) == NULL) return (NULL);
ppvdNode = (PVDENTRY *) ellFirst(pvdlist);
while(ppvdNode) {
if(strcmp(name,ppvdNode->precnode->recordname) == 0)
return(ppvdNode);
ppvdNode = (PVDENTRY *) ellNext((ELLNODE*)ppvdNode);
}
return (NULL);
}
PVDENTRY *dbPvdAdd(dbBase *pdbbase,dbRecordType *precordType,dbRecordNode *precnode)
{
unsigned short hashInd;
ELLLIST **ppvd = (ELLLIST **) pdbbase->ppvd;
ELLLIST *ppvdlist;
PVDENTRY *ppvdNode;
int lenName;
char *name=precnode->recordname;
lenName=strlen(name);
hashInd = hash(name, lenName);
if (ppvd[hashInd] == NULL) {
ppvd[hashInd] = dbCalloc(1, sizeof(ELLLIST));
ellInit(ppvd[hashInd]);
}
ppvdlist=ppvd[hashInd];
ppvdNode = (PVDENTRY *) ellFirst(ppvdlist);
while(ppvdNode) {
if(strcmp(name,(char *)ppvdNode->precnode->recordname)==0) return(NULL);
ppvdNode = (PVDENTRY *) ellNext((ELLNODE*)ppvdNode);
}
ppvdNode = dbCalloc(1, sizeof(PVDENTRY));
ellAdd(ppvdlist, (ELLNODE*)ppvdNode);
ppvdNode->precordType = precordType;
ppvdNode->precnode = precnode;
return (ppvdNode);
}
void dbPvdDelete(dbBase *pdbbase,dbRecordNode *precnode)
{
char *name=precnode->recordname;
unsigned short hashInd;
ELLLIST **ppvd = (ELLLIST **) pdbbase->ppvd;
ELLLIST *ppvdlist;
PVDENTRY *ppvdNode;
int lenName;
lenName=strlen(name);
hashInd = hash(name, lenName);
if (ppvd[hashInd] == NULL)return;
ppvdlist=ppvd[hashInd];
ppvdNode = (PVDENTRY *) ellFirst(ppvdlist);
while(ppvdNode) {
if(ppvdNode->precnode && ppvdNode->precnode->recordname
&& strcmp(name,(char *)ppvdNode->precnode->recordname) == 0) {
ellDelete(ppvdlist, (ELLNODE*)ppvdNode);
free((void *)ppvdNode);
return;
}
ppvdNode = (PVDENTRY *) ellNext((ELLNODE*)ppvdNode);
}
return;
}
void dbPvdFreeMem(dbBase *pdbbase)
{
unsigned short hashInd;
ELLLIST **ppvd = (ELLLIST **) pdbbase->ppvd;
ELLLIST *ppvdlist;
PVDENTRY *ppvdNode;
PVDENTRY *next;
if (ppvd == NULL) return;
for (hashInd=0; hashInd<(unsigned short)dbPvdHashTableSize; hashInd++) {
if(ppvd[hashInd] == NULL) continue;
ppvdlist=ppvd[hashInd];
ppvdNode = (PVDENTRY *) ellFirst(ppvdlist);
while(ppvdNode) {
next = (PVDENTRY *) ellNext((ELLNODE*)ppvdNode);
ellDelete(ppvdlist,(ELLNODE*)ppvdNode);
free((void *)ppvdNode);
ppvdNode = next;
}
free((void *)ppvd[hashInd]);
}
free((void *)ppvd);
pdbbase->ppvd = NULL;
}
void epicsShareAPI dbPvdDump(dbBase *pdbbase,int verbose)
{
unsigned short hashInd;
ELLLIST **ppvd = (ELLLIST **) pdbbase->ppvd;
ELLLIST *ppvdlist;
PVDENTRY *ppvdNode;
int number;
if (ppvd == NULL) return;
printf("Process Variable Directory\n");
printf("dbPvdHashTableSize %d dbPvdHashTableShift %d\n",
dbPvdHashTableSize,dbPvdHashTableShift);
for (hashInd=0; hashInd<(unsigned short)dbPvdHashTableSize; hashInd++) {
if(ppvd[hashInd] == NULL) continue;
ppvdlist=ppvd[hashInd];
ppvdNode = (PVDENTRY *) ellFirst(ppvdlist);
printf("\n%3.3hd=%3.3d ",hashInd,ellCount(ppvdlist));
number=0;
while(ppvdNode && verbose) {
printf(" %s",(char *)ppvdNode->precnode->recordname);
if(number++ ==2) {number=0;printf("\n ");}
ppvdNode = (PVDENTRY *) ellNext((ELLNODE*)ppvdNode);
}
}
printf("\nEnd of Process Variable Directory\n");
}