src/misc/hash/hashPtr.h

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#ifndef __HASH_PTR_H__
#define __HASH_PTR_H__


#include <stdio.h>
#include "extra.h"

extern int Hash_DefaultHashFunc(int key, int nBins);



typedef struct Hash_Ptr_t_       Hash_Ptr_t;
typedef struct Hash_Ptr_Entry_t_ Hash_Ptr_Entry_t;

struct Hash_Ptr_Entry_t_
{
  int                              key;
  void *                           data;
  struct Hash_Ptr_Entry_t_ *       pNext;
};

struct Hash_Ptr_t_ 
{
  int                             nSize;
  int                             nBins;
  int (* fHash)(int key, int nBins);
  Hash_Ptr_Entry_t **             pArray;
};




#define Hash_PtrForEachEntry( pHash, pEntry, bin )   \
  for(bin=-1, pEntry=NULL; bin < pHash->nBins; (!pEntry)?(pEntry=pHash->pArray[++bin]):(pEntry=pEntry->pNext)) \
    if (pEntry)


static inline Hash_Ptr_t * Hash_PtrAlloc( int nBins )
{
  Hash_Ptr_t * p;
  int i;
  assert(nBins > 0);
  p = ALLOC( Hash_Ptr_t, 1);
  p->nBins = nBins;
  p->fHash = Hash_DefaultHashFunc;
  p->nSize  = 0;
  p->pArray = ALLOC( Hash_Ptr_Entry_t *, nBins );
  for(i=0; i<nBins; i++)
    p->pArray[i] = NULL;

  return p;
}

static inline int Hash_PtrExists( Hash_Ptr_t *p, int key )
{
  int bin;
  Hash_Ptr_Entry_t *pEntry, **pLast;

  // find the bin where this key would live
  bin = (*(p->fHash))(key, p->nBins);

  // search for key
  pLast = &(p->pArray[bin]);
  pEntry = p->pArray[bin];
  while(pEntry) {
    if (pEntry->key == key) {
      return 1;
    }
    pLast = &(pEntry->pNext);
    pEntry = pEntry->pNext;
  }

  return 0;
}

static inline void Hash_PtrWriteEntry( Hash_Ptr_t *p, int key, void * data )
{
  int bin;
  Hash_Ptr_Entry_t *pEntry, **pLast;

  // find the bin where this key would live
  bin = (*(p->fHash))(key, p->nBins);

  // search for key
  pLast = &(p->pArray[bin]);
  pEntry = p->pArray[bin];
  while(pEntry) {
    if (pEntry->key == key) {
      pEntry->data = data;
      return;
    }
    pLast = &(pEntry->pNext);
    pEntry = pEntry->pNext;
  }

  // this key does not currently exist
  // create a new entry and add to bin
  p->nSize++;
  (*pLast) = pEntry = ALLOC( Hash_Ptr_Entry_t, 1 );
  pEntry->pNext = NULL;
  pEntry->key = key;
  pEntry->data = data;

  return;
}


static inline void * Hash_PtrEntry( Hash_Ptr_t *p, int key, int fCreate )
{
  int bin;
  Hash_Ptr_Entry_t *pEntry, **pLast;

  // find the bin where this key would live
  bin = (*(p->fHash))(key, p->nBins);

  // search for key
  pLast = &(p->pArray[bin]);
  pEntry = p->pArray[bin];
  while(pEntry) {
    if (pEntry->key == key)
      return pEntry->data;
    pLast = &(pEntry->pNext);
    pEntry = pEntry->pNext;
  }

  // this key does not currently exist
  if (fCreate) {
    // create a new entry and add to bin
    p->nSize++;
    (*pLast) = pEntry = ALLOC( Hash_Ptr_Entry_t, 1 );
    pEntry->pNext = NULL;
    pEntry->key = key;
    pEntry->data = NULL;
    return pEntry->data;
  }

  return NULL;
}


static inline void** Hash_PtrEntryPtr( Hash_Ptr_t *p, int key )
{
  int bin;
  Hash_Ptr_Entry_t *pEntry, **pLast;

  // find the bin where this key would live
  bin = (*(p->fHash))(key, p->nBins);

  // search for key
  pLast = &(p->pArray[bin]);
  pEntry = p->pArray[bin];
  while(pEntry) {
    if (pEntry->key == key)
      return &(pEntry->data);
    pLast = &(pEntry->pNext);
    pEntry = pEntry->pNext;
  }

  // this key does not currently exist
  // create a new entry and add to bin
  p->nSize++;
  (*pLast) = pEntry = ALLOC( Hash_Ptr_Entry_t, 1 );
  pEntry->pNext = NULL;
  pEntry->key = key;
  pEntry->data = NULL;

  return &(pEntry->data);
}

static inline void* Hash_PtrRemove( Hash_Ptr_t *p, int key )
{
  int    bin;
  void * data;
  Hash_Ptr_Entry_t *pEntry, **pLast;

  // find the bin where this key would live
  bin = (*(p->fHash))(key, p->nBins);

  // search for key
  pLast = &(p->pArray[bin]);
  pEntry = p->pArray[bin];
  while(pEntry) {
    if (pEntry->key == key) {
      p->nSize--;
      data = pEntry->data;
      *pLast = pEntry->pNext;
      return data;
    }
    pLast = &(pEntry->pNext);
    pEntry = pEntry->pNext;
  }
    
  // could not find key
  return NULL;
}

static inline void Hash_PtrFree( Hash_Ptr_t *p ) {
  int bin;
  Hash_Ptr_Entry_t *pEntry;

  // free bins
  for(bin = 0; bin < p->nBins; bin++) {
    pEntry = p->pArray[bin];
    while(pEntry) {
      pEntry = pEntry->pNext;
      FREE( pEntry );
    }
  }
 
  // free hash
  FREE( p->pArray );
  FREE( p );
}


#endif

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