/** BEGIN COPYRIGHT BLOCK
 * Copyright 2001 Sun Microsystems, Inc.
 * Portions copyright 1999, 2001-2003 Netscape Communications Corporation.
 * 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
}