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/** BEGIN COPYRIGHT BLOCK
* Copyright (C) 2001 Sun Microsystems, Inc. Used by permission.
* Copyright (C) 2005 Red Hat, Inc.
* All rights reserved.
* END COPYRIGHT BLOCK **/
#include <stdio.h>
#include <string.h>
#define COMPILE_STRINGS_IN_MEMORY
static char emptyString[] = "";
#ifdef COMPILE_STRINGS_IN_MEMORY
typedef struct DATABIN {
char* pLibraryName;
char** pArrayOfLibraryStrings;
unsigned numberOfStringsInLibrary;
} DATABIN;
#include "getstrmem.h"
#endif
#if 0 /* Example of getstrmem.h */
/* It is intended that this header file be generated by program dblink */
#define NUM_BUCKETS 2 /* must be power of 2 */
/* strings in library libalpha */
static char* libalpha[] = {
"",
"libalpha string 1",
"libalpha string 2",
"libalpha string 3",
"libalpha string 4",
emptyString };
/* strings in library libbeta */
static char* libbeta[] = {
"",
"libbeta string 1",
"libbeta string 2",
emptyString };
/* libraries in bucket for hashKey==0 */
static struct DATABIN bucket0[] = {
{emptyString, NULL, 0}};
/* libraries in bucket for hashKey==1 */
static struct DATABIN bucket1[] = {
{"libalpha", libalpha, 5},
{"libbeta", libbeta, 3},
{emptyString, NULL, 0}};
/* array of buckets */
static struct DATABIN* buckets[NUM_BUCKETS] = {
bucket0,
bucket1 };
#endif /* end of example getstrmem.h */
#define BUCKET_MASK NUM_BUCKETS-1
char*
XP_GetStringFromMemory(char* strLibraryName,int iToken)
{
/*
* In memory model called by XP_GetStringFromDatabase
* does not use database (nsres, et al.).
*
* This function uses hash table for library lookup
* and direct lookup for string.
*
* This function is thread safe.
*/
#ifdef COMPILE_STRINGS_IN_MEMORY
unsigned hashKey;
int found = 0;
unsigned uToken = iToken;
char* cPtr;
DATABIN* pBucket;
/* calculate hash key */
hashKey = 0;
cPtr = strLibraryName;
while (*cPtr) {
hashKey += *(cPtr++);
}
hashKey &= BUCKET_MASK;
/* get bucket for this hash key */
pBucket = buckets[hashKey];
/* search overflow buckets */
while (*(pBucket->pLibraryName)!='\0') {
if (strcmp(pBucket->pLibraryName,strLibraryName)==0) {
found = 1;
break;
}
pBucket++;
}
if (!found) {
return emptyString;
}
if (uToken<=pBucket->numberOfStringsInLibrary) {
return pBucket->pArrayOfLibraryStrings[uToken];
} else {
/* string token out of range */
return emptyString;
}
#else
return emptyString;
#endif
}
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