windows-nt/Source/XPSP1/NT/termsrv/remdsk/rds/t120/h/hash.h
2020-09-26 16:20:57 +08:00

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3.7 KiB
C++

/* hash.h
*
* Copyright (c) 1996 by Microsoft Corporation
*
* Written by: Christos Tsollis
*
* Revisions:
*
* Abstract:
*
* This is the interface to a dictionary data structure.
* Both the key and the value in a dictionary entry are DWORD values. So, for example, if the
* value is really a pointer it has to be converted into a DWORD before being passed into a
* member dictionary function.
*
*/
#ifndef _HASH_
#define _HASH_
#include <windows.h>
#define DEFAULT_NUMBER_OF_BUCKETS 3
typedef enum {
DWORD_DICTIONARY, /* The key is a 32-bit unsigned value */
STRING_DICTIONARY, /* The key is a NULL-terminated string that is being pointed by
* the "key" field in the structure below */
LENGTH_STRING_DICTIONARY /* The key is a string with a specific length. The "key" field
* in the structure below, points to memory space containing
* the length and a string of that length. */
} DictionaryType;
typedef struct _dictionary_item {
DWORD key; // The key value, or a pointer to a string (depending on the dictionary type)
DWORD value; // This is always a 32-bit unsigned value
struct _dictionary_item *next; // Pointer to the next structure in the dictionary bucket
} DICTIONARY_ITEM, *PDICTIONARY_ITEM;
class DictionaryClass
{
public:
DictionaryClass (ULong num_of_buckets = DEFAULT_NUMBER_OF_BUCKETS, DictionaryType dtype = DWORD_DICTIONARY);
DictionaryClass (const DictionaryClass& original);
~DictionaryClass ();
BOOL insert (DWORD new_key, DWORD new_value, ULong length = 0);
BOOL remove (DWORD Key, ULong length = 0);
BOOL find (DWORD Key, LPDWORD pValue = NULL, ULong length = 0);
BOOL isEmpty ();
void clear ();
ULong entries () {
return (3 * NumOfBuckets - ItemCount + NumOfExternItems);
};
BOOL iterate (LPDWORD pValue = NULL, LPDWORD pKey = NULL);
void reset () { pCurrent = NULL; }; // Resets the dictionary iterator
BOOL Insert(DWORD new_key, LPVOID new_value, UINT length = 0) { ASSERT(new_value != NULL); return insert(new_key, (DWORD) new_value, (ULONG) length); }
BOOL Remove(DWORD Key, UINT length = 0) { return remove(Key, (ULONG) length); }
LPVOID Find(DWORD Key, UINT length = 0);
LPVOID Iterate(LPDWORD pKey = NULL);
BOOL IsEmpty(void) { return isEmpty(); }
void Clear(void) { clear(); }
UINT GetCount(void) { return (UINT) entries(); }
void Reset(void) { reset(); }
private:
DWORD hashFunction (DWORD key);
int LengthStrcmp (DWORD DictionaryKey, DWORD ChallengeKey, ULong length);
ULong NumOfBuckets; // Number of dictionary buckets. Specified during object construction.
DWORD dwNormalSize; // Initial space allocated for the dictionary
PDICTIONARY_ITEM *Buckets; // Address of the Buckets array
PDICTIONARY_ITEM *ItemArray; // Pointer to the array of initially allocated dictionary items
ULong ItemCount; // Number of dictionary items left in the ItemArray
PDICTIONARY_ITEM pCurrent; // Points to the current dictionary item while we iterate through the dictionary
ULong ulCurrentBucket; // Id of the current bucket while we iterate
DictionaryType Type; // Dictionary type
ULong NumOfExternItems; // Number of external dictionary items
};
typedef DictionaryClass * PDictionaryClass;
#define DEFINE_DICTIONARY_FRIENDLY_METHODS(_ClassName_) \
BOOL Insert(DWORD new_key, _ClassName_ *new_value, UINT length = 0) { return DictionaryClass::Insert(new_key, (LPVOID) new_value, length); } \
BOOL Remove(DWORD Key, UINT length = 0) { return DictionaryClass::Remove(Key, length); } \
_ClassName_ *Find(DWORD Key, UINT length = 0) { return (_ClassName_ *) DictionaryClass::Find(Key, length); } \
_ClassName_ *Iterate(LPDWORD pKey = NULL) { return (_ClassName_ *) DictionaryClass::Iterate(pKey); }
#endif