static HashElem FindElementGivenHash(Hash hash, string key, int keyLength, uint h)
{
HashElem elem; // Used to loop thru the element list
int count; // Number of elements left to test
if (hash.Table != null && hash.Table[h] != null)
{
HTable entry = hash.Table[h];
elem = entry.Chain;
count = entry.Count;
}
else
{
elem = hash.First;
count = (int)hash.Count;
}
while (count-- > 0 && C._ALWAYS(elem != null))
{
if (elem.KeyLength == keyLength && elem.Key.Equals(key, StringComparison.OrdinalIgnoreCase))
{
return(elem);
}
elem = elem.Next;
}
return(null);
}
static bool Rehash(Hash hash, uint newSize)
{
#if MALLOC_SOFT_LIMIT
if (newSize * sizeof(HTable) > MALLOC_SOFT_LIMIT)
{
newSize = MALLOC_SOFT_LIMIT / sizeof(HTable);
}
if (newSize == hash.TableSize)
{
return(false);
}
#endif
// The inability to allocates space for a larger hash table is a performance hit but it is not a fatal error. So mark the
// allocation as a benign. Use sqlite3Malloc()/memset(0) instead of sqlite3MallocZero() to make the allocation, as sqlite3MallocZero()
// only zeroes the requested number of bytes whereas this module will use the actual amount of space allocated for the hash table (which
// may be larger than the requested amount).
C._benignalloc_begin();
HTable[] newTable = new HTable[newSize]; // The new hash table
for (int i = 0; i < newSize; i++)
{
newTable[i] = new HTable();
}
C._benignalloc_end();
if (newTable == null)
{
return(false);
}
C._free(ref hash.Table);
hash.Table = newTable;
//hash.TableSize = newSize = SysEx.AllocSize(newTable) / sizeof(HTable);
hash.TableSize = newSize;
HashElem elem, nextElem;
for (elem = hash.First, hash.First = null; elem != null; elem = nextElem)
{
uint h = GetHashCode(elem.Key, elem.KeyLength) % newSize;
nextElem = elem.Next;
InsertElement(hash, newTable[h], elem);
}
return(true);
}
static void InsertElement(Hash hash, HTable entry, HashElem newElem)
{
HashElem headElem; // First element already in entry
if (entry != null)
{
headElem = (entry.Count != 0 ? entry.Chain : null);
entry.Count++;
entry.Chain = newElem;
}
else
{
headElem = null;
}
if (headElem != null)
{
newElem.Next = headElem;
newElem.Prev = headElem.Prev;
if (headElem.Prev != null)
{
headElem.Prev.Next = newElem;
}
else
{
hash.First = newElem;
}
headElem.Prev = newElem;
}
else
{
newElem.Next = hash.First;
if (hash.First != null)
{
hash.First.Prev = newElem;
}
newElem.Prev = null;
hash.First = newElem;
}
}
