123 lines
2.5 KiB
C
123 lines
2.5 KiB
C
#include <string.h>
|
|
|
|
#include "picoc.h"
|
|
|
|
|
|
#ifdef USE_MALLOC
|
|
#include <stdlib.h>
|
|
|
|
|
|
static unsigned int TableHash(const Str *Key)
|
|
{
|
|
unsigned int Hash;
|
|
int Count;
|
|
int Offset;
|
|
const char *KeyPos;
|
|
|
|
Hash = Key->Len;
|
|
KeyPos = Key->Str;
|
|
Offset = 8;
|
|
for (Count = 0; Count < Key->Len; Count++, Offset+=7)
|
|
{
|
|
if (Offset > sizeof(unsigned int) * 8 - 7)
|
|
Offset -= (sizeof(unsigned int)-1) * 8;
|
|
|
|
Hash ^= *KeyPos++ << Offset;
|
|
}
|
|
|
|
return Hash;
|
|
}
|
|
|
|
|
|
void TableInit(struct Table *Tbl, struct TableEntry *HashTable, const char *Name, int Size)
|
|
{
|
|
Tbl->Name = Name;
|
|
Tbl->Size = Size;
|
|
Tbl->HashTable = HashTable;
|
|
memset(HashTable, '\0', sizeof(struct TableEntry) * Size);
|
|
}
|
|
|
|
|
|
static int TableCheckEntry(struct Table *Tbl, const Str *Key, int HashPos)
|
|
{
|
|
struct TableEntry *Entry = &Tbl->HashTable[HashPos];
|
|
|
|
if (Entry->Key.Len == 0)
|
|
return -1; /* empty */
|
|
|
|
else if (StrEqual(&Entry->Key, Key))
|
|
return HashPos; /* found */
|
|
|
|
else
|
|
return -2; /* wrong key */
|
|
}
|
|
|
|
|
|
static int TableSearch(struct Table *Tbl, const Str *Key, int *AddAt)
|
|
{
|
|
int HashValue;
|
|
int HashPos;
|
|
int Result;
|
|
|
|
HashValue = TableHash(Key) % Tbl->Size;
|
|
|
|
for (HashPos = HashValue; HashPos < Tbl->Size; HashPos++)
|
|
{
|
|
*AddAt = HashPos;
|
|
if ( (Result = TableCheckEntry(Tbl, Key, HashPos)) != -2)
|
|
return Result;
|
|
}
|
|
|
|
for (HashPos = 0; HashPos < HashValue; HashPos++)
|
|
{
|
|
*AddAt = HashPos;
|
|
if ( (Result = TableCheckEntry(Tbl, Key, HashPos)) != -2)
|
|
return Result;
|
|
}
|
|
|
|
/* not found and table is full */
|
|
*AddAt = -1;
|
|
return -1;
|
|
}
|
|
|
|
|
|
void TableSet(struct Table *Tbl, const Str *Key, void *Value)
|
|
{
|
|
int HashPos;
|
|
int AddAt;
|
|
|
|
HashPos = TableSearch(Tbl, Key, &AddAt);
|
|
|
|
if (HashPos != -1)
|
|
Tbl->HashTable[HashPos].Value = Value; /* found - update value */
|
|
else
|
|
{
|
|
if (AddAt == -1)
|
|
Fail("table '%s' is full\n", Tbl->Name);
|
|
|
|
else
|
|
{ /* add it to the table */
|
|
struct TableEntry *Entry = &Tbl->HashTable[AddAt];
|
|
Entry->Key = *Key;
|
|
Entry->Value = Value;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
void *TableLookup(struct Table *Tbl, const Str *Key)
|
|
{
|
|
int HashPos;
|
|
int AddAt;
|
|
|
|
HashPos = TableSearch(Tbl, Key, &AddAt);
|
|
|
|
if (HashPos == -1)
|
|
return NULL;
|
|
else
|
|
return Tbl->HashTable[HashPos].Value;
|
|
}
|
|
|
|
#endif
|
|
|