AnyHash Class Reference

Macro implementation of universal hash storage method with quick access. More...

#include <AnyHash.H>

Public Member Functions
	AnyHash (unsigned base)
virtual	~AnyHash ()
Logic	known_key (AnyKeyType key_value) const
unsigned	count () const
void	value_list (DynAr &vals) const
AnyType &	hash_fetch (AnyKeyType key)
AnyType	hash_get (AnyKeyType key) const
AnyType &	operator[] (AnyKeyType key)
AnyType	operator() (AnyKeyType key) const
void	add (const AnyType &val)
void	put (const AnyType &val)

Protected Member Functions
Logic	find_key (AnyKeyType key, unsigned &hash_i, unsigned &item_i) const

Protected Attributes
DynAr **	hashItems
unsigned	hashBase

Detailed Description

Macro implementation of universal hash storage method with quick access.

The class is designed to provide hash organized array of items. All items having the same hash value (integer) are stored in unordered manner with linear search, so it's better to increase hash base to improve access performance in case you are planning to store great number of items in the hash.

Specification:

typedef struct
{
#define AnyType     your-item-type
#define AnyHash     your-hash-class
#define AnyKeyType  your-custom-type-for-key
#define AnyItem2Key(x)  extract-key-from-item
#define AnyKey2Hash(k)  convert-key-to-number
#define AnyKeyCmp(k,k_) compare-two-keys
#include <mix/AnyHash.H>

Example 1:

typedef struct
{
  int   val;    //< hash value
  float data;   //< useful data
}   Record;
#define AnyType     Record
#define AnyHash     RecordHash
#define AnyKeyType  int
#define AnyItem2Key(x)  (x).val
#define AnyKey2Hash(k)  (k)
#define AnyKeyCmp(k,k_) COMPAR0((k)-(k_))
#include <mix/AnyHash.H>

Example 2:

class Record
{
private:
  char  *name;  //< hash value
  float data;   //< useful data
public:
  const char*   key () const {
    return name;
  }
  static int    hash (const char* s) {
    int h = 0, i = 0;
    while(s[i] != '\0')
      h += s[i++];
    return h;
  }
};
#define AnyType     Record
#define AnyHash     RecordHash
#define AnyKeyType  const char*
#define AnyItem2Key(x)  (x).key()
#define AnyKey2Hash(k)  Record::hash(k)
#define AnyKeyCmp(k,k_) strcmp((k),(k_))
#include <mix/AnyHash.H>

Constructor & Destructor Documentation

AnyHash::AnyHash ( unsigned  base )

inline

Create the hash object with given number of subclasses (preferred prime number).

virtual AnyHash::~AnyHash ( )

inlinevirtual

Destroy the whole hash object.

Member Function Documentation

void AnyHash::add ( const AnyType &  val )

inline

Add item (with unique key) to the hash.

unsigned AnyHash::count ( ) const

inline

Get number of stored items.

Logic AnyHash::find_key ( AnyKeyType  key, unsigned &  hash_i, unsigned &  item_i  ) const

inlineprotected

Associative operation to find whether the value exist in the hash and where it is.

Logic AnyHash::known_key ( AnyKeyType  key_value ) const

inline

Find whether this key exist in the hash.

void AnyHash::put ( const AnyType &  val )

inline

Add item (unique and non-unique key) to the hash

void AnyHash::value_list ( DynAr &  vals ) const

inline

Get list of stored items.

Member Data Documentation

unsigned AnyHash::hashBase

protected

Number of items - hash base.

DynAr** AnyHash::hashItems

protected

Really the array of pointers to AnyType items with the same hash value.

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The documentation for this class was generated from the following file:

• /net/opt/univers/ubp-i-15.3-centos7-x64.urij/include/mix/AnyHash.H