Windows2000/private/inet/urlmon/utils/map_pp.cxx
2020-09-30 17:12:32 +02:00

355 lines
8.5 KiB
C++

// This is a part of the Microsoft Foundation Classes C++ library.
// Copyright (C) 1992-1995 Microsoft Corporation
// All rights reserved.
// This source code is only intended as a supplement to the
// Microsoft Foundation Classes Reference and related
// electronic documentation provided with the library.
// See these sources for detailed information regarding the
// Microsoft Foundation Classes product.
// Implementation of parmeterized Map
#include <urlint.h>
#include <map_kv.h>
#include "coll.hxx"
#define ASSERT(x)
/*
#include "stdafx.h"
#ifdef AFX_COLL2_SEG
#pragma code_seg(AFX_COLL2_SEG)
#endif
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
//#define new DEBUG_NEW
*/
CMapPtrToPtr::CMapPtrToPtr(int nBlockSize)
{
ASSERT(nBlockSize > 0);
m_pHashTable = NULL;
m_nHashTableSize = 17; // default size
m_nCount = 0;
m_pFreeList = NULL;
m_pBlocks = NULL;
m_nBlockSize = nBlockSize;
}
inline UINT CMapPtrToPtr::HashKey(void* key) const
{
// default identity hash - works for most primitive values
return PtrToUlong((void*)(DWORD_PTR)key) >> 4;
}
void CMapPtrToPtr::InitHashTable(
UINT nHashSize, BOOL bAllocNow)
// Used to force allocation of a hash table or to override the default
// hash table size of (which is fairly small)
{
ASSERT_VALID(this);
ASSERT(m_nCount == 0);
ASSERT(nHashSize > 0);
if (m_pHashTable != NULL)
{
// free hash table
delete[] m_pHashTable;
m_pHashTable = NULL;
}
if (bAllocNow)
{
m_pHashTable = new CAssoc* [nHashSize];
memset(m_pHashTable, 0, sizeof(CAssoc*) * nHashSize);
}
m_nHashTableSize = nHashSize;
}
void CMapPtrToPtr::RemoveAll()
{
ASSERT_VALID(this);
if (m_pHashTable != NULL)
{
// free hash table
delete[] m_pHashTable;
m_pHashTable = NULL;
}
m_nCount = 0;
m_pFreeList = NULL;
m_pBlocks->FreeDataChain();
m_pBlocks = NULL;
}
CMapPtrToPtr::~CMapPtrToPtr()
{
RemoveAll();
ASSERT(m_nCount == 0);
}
// Assoc helpers
// same as CList implementation except we store CAssoc's not CNode's
// and CAssoc's are singly linked all the time
CMapPtrToPtr::CAssoc*
CMapPtrToPtr::NewAssoc()
{
if (m_pFreeList == NULL)
{
// add another block
CPlex* newBlock = CPlex::Create(m_pBlocks, m_nBlockSize, sizeof(CMapPtrToPtr::CAssoc));
// chain them into free list
CMapPtrToPtr::CAssoc* pAssoc = (CMapPtrToPtr::CAssoc*) newBlock->data();
// free in reverse order to make it easier to debug
pAssoc += m_nBlockSize - 1;
for (int i = m_nBlockSize-1; i >= 0; i--, pAssoc--)
{
pAssoc->pNext = m_pFreeList;
m_pFreeList = pAssoc;
}
}
ASSERT(m_pFreeList != NULL); // we must have something
CMapPtrToPtr::CAssoc* pAssoc = m_pFreeList;
m_pFreeList = m_pFreeList->pNext;
m_nCount++;
ASSERT(m_nCount > 0); // make sure we don't overflow
pAssoc->key = 0;
pAssoc->value = 0;
return pAssoc;
}
void CMapPtrToPtr::FreeAssoc(CMapPtrToPtr::CAssoc* pAssoc)
{
pAssoc->pNext = m_pFreeList;
m_pFreeList = pAssoc;
m_nCount--;
ASSERT(m_nCount >= 0); // make sure we don't underflow
// if no more elements, cleanup completely
if (m_nCount == 0)
RemoveAll();
}
CMapPtrToPtr::CAssoc*
CMapPtrToPtr::GetAssocAt(void* key, UINT& nHash) const
// find association (or return NULL)
{
nHash = HashKey(key) % m_nHashTableSize;
if (m_pHashTable == NULL)
return NULL;
// see if it exists
CAssoc* pAssoc;
for (pAssoc = m_pHashTable[nHash]; pAssoc != NULL; pAssoc = pAssoc->pNext)
{
if (pAssoc->key == key)
return pAssoc;
}
return NULL;
}
void* CMapPtrToPtr::GetValueAt(void* key) const
// find value (or return NULL -- NULL values not different as a result)
{
if (m_pHashTable == NULL)
return NULL;
UINT nHash = HashKey(key) % m_nHashTableSize;
// see if it exists
CAssoc* pAssoc;
for (pAssoc = m_pHashTable[nHash]; pAssoc != NULL; pAssoc = pAssoc->pNext)
{
if (pAssoc->key == key)
return pAssoc->value;
}
return NULL;
}
BOOL CMapPtrToPtr::Lookup(void* key, void*& rValue) const
{
ASSERT_VALID(this);
UINT nHash;
CAssoc* pAssoc = GetAssocAt(key, nHash);
if (pAssoc == NULL)
return FALSE; // not in map
rValue = pAssoc->value;
return TRUE;
}
void*& CMapPtrToPtr::operator[](void* key)
{
ASSERT_VALID(this);
UINT nHash;
CAssoc* pAssoc;
if ((pAssoc = GetAssocAt(key, nHash)) == NULL)
{
if (m_pHashTable == NULL)
InitHashTable(m_nHashTableSize);
// it doesn't exist, add a new Association
pAssoc = NewAssoc();
pAssoc->key = key;
// 'pAssoc->value' is a constructed object, nothing more
// put into hash table
pAssoc->pNext = m_pHashTable[nHash];
m_pHashTable[nHash] = pAssoc;
}
return pAssoc->value; // return new reference
}
BOOL CMapPtrToPtr::RemoveKey(void* key)
// remove key - return TRUE if removed
{
ASSERT_VALID(this);
if (m_pHashTable == NULL)
return FALSE; // nothing in the table
CAssoc** ppAssocPrev;
ppAssocPrev = &m_pHashTable[HashKey(key) % m_nHashTableSize];
CAssoc* pAssoc;
for (pAssoc = *ppAssocPrev; pAssoc != NULL; pAssoc = pAssoc->pNext)
{
if (pAssoc->key == key)
{
// remove it
*ppAssocPrev = pAssoc->pNext; // remove from list
FreeAssoc(pAssoc);
return TRUE;
}
ppAssocPrev = &pAssoc->pNext;
}
return FALSE; // not found
}
// Iterating
void CMapPtrToPtr::GetNextAssoc(POSITION& rNextPosition,
void*& rKey, void*& rValue) const
{
ASSERT_VALID(this);
ASSERT(m_pHashTable != NULL); // never call on empty map
CAssoc* pAssocRet = (CAssoc*)rNextPosition;
ASSERT(pAssocRet != NULL);
if (pAssocRet == (CAssoc*) BEFORE_START_POSITION)
{
// find the first association
for (UINT nBucket = 0; nBucket < m_nHashTableSize; nBucket++)
if ((pAssocRet = m_pHashTable[nBucket]) != NULL)
break;
ASSERT(pAssocRet != NULL); // must find something
}
// find next association
ASSERT(AfxIsValidAddress(pAssocRet, sizeof(CAssoc)));
CAssoc* pAssocNext;
if ((pAssocNext = pAssocRet->pNext) == NULL)
{
// go to next bucket
for (UINT nBucket = (HashKey(pAssocRet->key) % m_nHashTableSize) + 1;
nBucket < m_nHashTableSize; nBucket++)
if ((pAssocNext = m_pHashTable[nBucket]) != NULL)
break;
}
rNextPosition = (POSITION) pAssocNext;
// fill in return data
rKey = pAssocRet->key;
rValue = pAssocRet->value;
}
// Diagnostics
#ifdef _DEBUG
void CMapPtrToPtr::Dump(CDumpContext& dc) const
{
CObject::Dump(dc);
dc << "with " << m_nCount << " elements";
if (dc.GetDepth() > 0)
{
// Dump in format "[key] -> value"
void* key;
void* val;
POSITION pos = GetStartPosition();
while (pos != NULL)
{
GetNextAssoc(pos, key, val);
dc << "\n\t[" << key << "] = " << val;
}
}
dc << "\n";
}
void CMapPtrToPtr::AssertValid() const
{
CObject::AssertValid();
ASSERT(m_nHashTableSize > 0);
ASSERT(m_nCount == 0 || m_pHashTable != NULL);
// non-empty map should have hash table
}
#endif //_DEBUG
#ifdef AFX_INIT_SEG
#pragma code_seg(AFX_INIT_SEG)
#endif
//IMPLEMENT_DYNAMIC(CMapPtrToPtr, CObject)