cdev-1.7.2n

include/cdevStrHash.h

@@ -0,0 +1,138 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 1994,1995 Southeastern Universities Research Association,
+//                         Continuous Electron Beam Accelerator Facility
+//
+// This software was developed under a United States Government license
+// described in the NOTICE file included as part of this distribution.
+//
+// CEBAF Data Acquisition Group, 12000 Jefferson Ave., Newport News, VA 23606
+// Email: coda@cebaf.gov  Tel: (804) 249-7101  Fax: (804) 249-7363
+//-----------------------------------------------------------------------------
+// 
+// Description:
+//	 cdevStrHash: cdev hash table keyed by a variable length string
+//                    Open Hash with buckets implemented by single linked lists
+//    
+//              Note: void *s are stored inside the table. This class
+//                    will not manage these pointers. Callers have to
+//                    manage these pointers
+// 
+//              Note: this is unsafe C++ practice. Use at your own risk
+//              
+//            Reason: It is so difficult to use a template class inside
+//                    a shared library. (Cfront based C++ compiler cannot
+//                    instantiate a template class during compilation time
+//	
+// Author:  Jie Chen
+//       CEBAF Data Acquisition Group
+//
+// Revision History:
+//   cdevStrHash.h,v
+// Revision 1.3  1996/08/26  21:12:38  akers
+// Added getData method to iterator
+//
+// Revision 1.2  1995/07/05  18:38:30  chen
+// add simple str hash function
+//
+// Revision 1.1  1995/06/30  15:08:42  chen
+// string hash table
+//
+//
+#ifndef _CDEV_STR_HASH_H
+#define _CDEV_STR_HASH_H
+
+#include <cdevSlist.h>
+
+//======================================================================
+//  One simple string hash function
+//           This hash function is used in cdevDevice and caChannel.
+//           It returns integer value between 0 to MAX_INTEGER_VALUE
+//           and this value will be moded with the size of the hash
+//           table. 
+//           It may be changed to a different hash function in
+//           release 1.1
+//======================================================================
+extern CDEVAPI unsigned int cdevStrHashFunc (char *str);
+
+typedef char* cdevKeyItem;
+typedef void* cdevHashItem;
+
+//======================================================================
+//	class cdevStrHash
+//		collection of buckets indexed by hashed values
+//======================================================================
+class cdevStrHashIterator;
+
+class CDEV_CLASS_SPEC cdevStrHash
+{
+public:
+  // constructor
+  // construct a table with entry max and hash function *f
+  // hash function return any integer from 0 to MAX_INT_VALUE
+  cdevStrHash (unsigned int max, unsigned int (*f)(cdevKeyItem));
+  // destructor
+  virtual ~cdevStrHash (void);
+
+  // operations
+
+  // is the table empty: return 1: yes. return 0: no
+  virtual int   isEmpty();
+
+  // clear the elements of the set
+  virtual void  deleteAllValues();
+
+  // add an element to the collection
+  virtual void  add (cdevKeyItem key, cdevHashItem ele);
+
+  // test to see whether this hash table includes one particular element
+  virtual int   find (cdevKeyItem key, cdevHashItem ele) const;
+
+  // remove an element. return 0: ele is not inside table. return 1: success
+  virtual int   remove (cdevKeyItem key, cdevHashItem ele);
+
+  // return a reference to a particular bucket according to the key
+  cdevSlist&  bucketRef (cdevKeyItem key);
+
+ protected:
+  friend class cdevStrHashIterator;
+
+  // the actual table itself is a vector of buckets
+  const unsigned int    tablesize;
+  cdevSlist*            buckets;
+
+  // convert key into unsigned integer value in range
+  unsigned int          hash(const cdevKeyItem& key) const;
+
+ private:
+  unsigned int          (*hashCode_)(cdevKeyItem);
+};
+
+//======================================================================
+//	class cdevStrHashIterator
+//		iterator protocol for hash tables
+//======================================================================
+class CDEV_CLASS_SPEC cdevStrHashIterator
+{
+public:
+  // constructor and destructor
+  cdevStrHashIterator  (cdevStrHash& v);
+  ~cdevStrHashIterator (void);
+
+  // iterator protocol 
+  int             init       (void);
+  cdevHashItem    operator ()(void);
+  cdevHashItem    getData    (void);       
+  int             operator ! (void);
+  int             operator ++(void);
+  void            operator = (cdevHashItem value);
+
+protected:
+  cdevStrHash&    base;
+  unsigned int    currentIndex;
+  // Single iterator within a bucket
+  cdevSlistIterator*         itr;
+  // getNextIterator used to set internal iterator pointer
+  // return 1: got it. return 0: no more iterator
+  int             getNextIterator (void);
+};
+#endif