Leaked source code of windows server 2003
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/////////////////////////////////////////////////////////////////////////////
// class CMapKeyToValue - a mapping from 'KEY's to 'VALUE's, passed in as
// pv/cb pairs. The keys can be variable length, although we optmizize the
// case when they are all the same.
//
/////////////////////////////////////////////////////////////////////////////
#include <windows.h>
#include <ole2.h>
#include <ole2sp.h>
#include <olecoll.h>
#include <memctx.hxx>
#include "map_kv.h"
#include "plex.h"
ASSERTDATA
/////////////////////////////////////////////////////////////////////////////
CMapKeyToValue::CMapKeyToValue(DWORD memctx, UINT cbValue, UINT cbKey,
int nBlockSize, LPFNHASHKEY lpfnHashKey, UINT nHashSize)
{
Assert(nBlockSize > 0);
m_cbValue = cbValue;
m_cbKey = cbKey;
m_cbKeyInAssoc = cbKey == 0 ? sizeof(CKeyWrap) : cbKey;
m_pHashTable = NULL;
m_nHashTableSize = nHashSize;
m_lpfnHashKey = lpfnHashKey;
m_nCount = 0;
m_pFreeList = NULL;
m_pBlocks = NULL;
m_nBlockSize = nBlockSize;
if (memctx == MEMCTX_SAME)
memctx = CoMemctxOf(this);
m_memctx = memctx;
Assert(m_memctx != MEMCTX_UNKNOWN);
}
CMapKeyToValue::~CMapKeyToValue()
{
ASSERT_VALID(this);
RemoveAll();
Assert(m_nCount == 0);
}
// simple, default hash function
// REVIEW: need to check the value in this for GUIDs and strings
STDAPI_(UINT) MKVDefaultHashKey(LPVOID pKey, UINT cbKey)
{
UINT hash = 0;
BYTE FAR* lpb = (BYTE FAR*)pKey;
while (cbKey-- != 0)
hash = 257 * hash + *lpb++;
return hash;
}
BOOL CMapKeyToValue::InitHashTable()
{
ASSERT_VALID(this);
Assert(m_nHashTableSize > 0);
if (m_pHashTable != NULL)
return TRUE;
Assert(m_nCount == 0);
if ((m_pHashTable = (CAssoc FAR* FAR*)CoMemAlloc(m_nHashTableSize * sizeof(CAssoc FAR*), m_memctx, NULL)) == NULL)
return FALSE;
_fmemset(m_pHashTable, 0, sizeof(CAssoc FAR*) * m_nHashTableSize);
ASSERT_VALID(this);
return TRUE;
}
void CMapKeyToValue::RemoveAll()
{
ASSERT_VALID(this);
// free all key values and then hash table
if (m_pHashTable != NULL)
{
// destroy assocs
for (UINT nHash = 0; nHash < m_nHashTableSize; nHash++)
{
register CAssoc FAR* pAssoc;
for (pAssoc = m_pHashTable[nHash]; pAssoc != NULL;
pAssoc = pAssoc->pNext)
// assoc itself is freed by FreeDataChain below
FreeAssocKey(pAssoc);
}
// free hash table
CoMemFree(m_pHashTable, m_memctx);
m_pHashTable = NULL;
}
m_nCount = 0;
m_pFreeList = NULL;
m_pBlocks->FreeDataChain(m_memctx);
m_pBlocks = NULL;
ASSERT_VALID(this);
}
/////////////////////////////////////////////////////////////////////////////
// Assoc helpers
// CAssoc's are singly linked all the time
CMapKeyToValue::CAssoc FAR*
CMapKeyToValue::NewAssoc(UINT hash, LPVOID pKey, UINT cbKey, LPVOID pValue)
{
if (m_pFreeList == NULL)
{
// add another block
CPlex FAR* newBlock = CPlex::Create(m_pBlocks, m_memctx, m_nBlockSize, SizeAssoc());
if (newBlock == NULL)
return NULL;
// chain them into free list
register BYTE FAR* pbAssoc = (BYTE FAR*) newBlock->data();
// free in reverse order to make it easier to debug
pbAssoc += (m_nBlockSize - 1) * SizeAssoc();
for (int i = m_nBlockSize-1; i >= 0; i--, pbAssoc -= SizeAssoc())
{
((CAssoc FAR*)pbAssoc)->pNext = m_pFreeList;
m_pFreeList = (CAssoc FAR*)pbAssoc;
}
}
Assert(m_pFreeList != NULL); // we must have something
CMapKeyToValue::CAssoc FAR* pAssoc = m_pFreeList;
// init all fields except pNext while still on free list
pAssoc->nHashValue = hash;
if (!SetAssocKey(pAssoc, pKey, cbKey))
return NULL;
SetAssocValue(pAssoc, pValue);
// remove from free list after successfully initializing it (except pNext)
m_pFreeList = m_pFreeList->pNext;
m_nCount++;
Assert(m_nCount > 0); // make sure we don't overflow
return pAssoc;
}
// free individual assoc by freeing key and putting on free list
void CMapKeyToValue::FreeAssoc(CMapKeyToValue::CAssoc FAR* pAssoc)
{
pAssoc->pNext = m_pFreeList;
m_pFreeList = pAssoc;
m_nCount--;
Assert(m_nCount >= 0); // make sure we don't underflow
FreeAssocKey(pAssoc);
}
// find association (or return NULL)
CMapKeyToValue::CAssoc FAR*
CMapKeyToValue::GetAssocAt(LPVOID pKey, UINT cbKey, UINT FAR& nHash) const
{
if (m_lpfnHashKey)
nHash = (*m_lpfnHashKey)(pKey, cbKey) % m_nHashTableSize;
else {
Assert(m_lpfnHashKey);
return NULL;
}
if (m_pHashTable == NULL)
return NULL;
// see if it exists
register CAssoc FAR* pAssoc;
for (pAssoc = m_pHashTable[nHash]; pAssoc != NULL; pAssoc = pAssoc->pNext)
{
if (CompareAssocKey(pAssoc, pKey, cbKey))
return pAssoc;
}
return NULL;
}
BOOL CMapKeyToValue::CompareAssocKey(CAssoc FAR* pAssoc, LPVOID pKey2, UINT cbKey2) const
{
LPVOID pKey1;
UINT cbKey1;
GetAssocKeyPtr(pAssoc, &pKey1, &cbKey1);
return cbKey1 == cbKey2 && _fmemcmp(pKey1, pKey2, cbKey1) == 0;
}
BOOL CMapKeyToValue::SetAssocKey(CAssoc FAR* pAssoc, LPVOID pKey, UINT cbKey) const
{
Assert(cbKey == m_cbKey || m_cbKey == 0);
if (m_cbKey == 0)
{
Assert(m_cbKeyInAssoc == sizeof(CKeyWrap));
// alloc, set size and pointer
if ((pAssoc->key.pKey = CoMemAlloc(cbKey, m_memctx, NULL)) == NULL)
return FALSE;
pAssoc->key.cbKey = cbKey;
}
LPVOID pKeyTo;
GetAssocKeyPtr(pAssoc, &pKeyTo, &cbKey);
_fmemcpy(pKeyTo, pKey, cbKey);
return TRUE;
}
// gets pointer to key and its length
void CMapKeyToValue::GetAssocKeyPtr(CAssoc FAR* pAssoc, LPVOID FAR* ppKey,UINT FAR* pcbKey) const
{
if (m_cbKey == 0)
{
// variable length key; go indirect
*ppKey = pAssoc->key.pKey;
*pcbKey = pAssoc->key.cbKey;
}
else
{
// fixed length key; key in assoc
*ppKey = (LPVOID)&pAssoc->key;
*pcbKey = m_cbKey;
}
}
void CMapKeyToValue::FreeAssocKey(CAssoc FAR* pAssoc) const
{
if (m_cbKey == 0)
CoMemFree(pAssoc->key.pKey, m_memctx);
}
void CMapKeyToValue::GetAssocValuePtr(CAssoc FAR* pAssoc, LPVOID FAR* ppValue) const
{
*ppValue = (char FAR*)&pAssoc->key + m_cbKeyInAssoc;
}
void CMapKeyToValue::GetAssocValue(CAssoc FAR* pAssoc, LPVOID pValue) const
{
LPVOID pValueFrom;
GetAssocValuePtr(pAssoc, &pValueFrom);
Assert(pValue != NULL);
_fmemcpy(pValue, pValueFrom, m_cbValue);
}
void CMapKeyToValue::SetAssocValue(CAssoc FAR* pAssoc, LPVOID pValue) const
{
LPVOID pValueTo;
GetAssocValuePtr(pAssoc, &pValueTo);
if (pValue == NULL)
_fmemset(pValueTo, 0, m_cbValue);
else
_fmemcpy(pValueTo, pValue, m_cbValue);
}
/////////////////////////////////////////////////////////////////////////////
// lookup value given key; return FALSE if key not found; in that
// case, the value is set to all zeros
BOOL CMapKeyToValue::Lookup(LPVOID pKey, UINT cbKey, LPVOID pValue) const
{
UINT nHash;
return LookupHKey((HMAPKEY)GetAssocAt(pKey, cbKey, nHash), pValue);
}
// lookup value given key; return FALSE if NULL (or bad) key; in that
// case, the value is set to all zeros
BOOL CMapKeyToValue::LookupHKey(HMAPKEY hKey, LPVOID pValue) const
{
// REVIEW: would like some way to verify that hKey is valid
register CAssoc FAR* pAssoc = (CAssoc FAR*)hKey;
if (pAssoc == NULL)
{
_fmemset(pValue, 0, m_cbValue);
return FALSE; // not in map
}
ASSERT_VALID(this);
GetAssocValue(pAssoc, pValue);
return TRUE;
}
// lookup and if not found add; returns FALSE only if OOM; if added,
// value added and pointer passed are set to zeros.
BOOL CMapKeyToValue::LookupAdd(LPVOID pKey, UINT cbKey, LPVOID pValue) const
{
if (Lookup(pKey, cbKey, pValue))
return TRUE;
// value set to zeros since lookup failed
return ((CMapKeyToValue FAR*)this)->SetAt(pKey, cbKey, NULL);
}
// the only place new assocs are created; return FALSE if OOM;
// never returns FALSE if keys already exists
BOOL CMapKeyToValue::SetAt(LPVOID pKey, UINT cbKey, LPVOID pValue)
{
UINT nHash;
register CAssoc FAR* pAssoc;
ASSERT_VALID(this);
if ((pAssoc = GetAssocAt(pKey, cbKey, nHash)) == NULL)
{
if (!InitHashTable())
// out of memory
return FALSE;
// it doesn't exist, add a new Association
if ((pAssoc = NewAssoc(nHash, pKey, cbKey, pValue)) == NULL)
return FALSE;
// put into hash table
pAssoc->pNext = m_pHashTable[nHash];
m_pHashTable[nHash] = pAssoc;
ASSERT_VALID(this);
}
else
{
SetAssocValue(pAssoc, pValue);
}
return TRUE;
}
// set existing hkey to value; return FALSE if NULL or bad key
BOOL CMapKeyToValue::SetAtHKey(HMAPKEY hKey, LPVOID pValue)
{
// REVIEW: would like some way to verify that hKey is valid
register CAssoc FAR* pAssoc = (CAssoc FAR*)hKey;
if (pAssoc == NULL)
return FALSE; // not in map
ASSERT_VALID(this);
SetAssocValue(pAssoc, pValue);
return TRUE;
}
// remove key - return TRUE if removed
BOOL CMapKeyToValue::RemoveKey(LPVOID pKey, UINT cbKey)
{
ASSERT_VALID(this);
if (m_pHashTable == NULL)
return FALSE; // nothing in the table
register CAssoc FAR* FAR* ppAssocPrev;
ppAssocPrev = &m_pHashTable[(*m_lpfnHashKey)(pKey, cbKey) % m_nHashTableSize];
CAssoc FAR* pAssoc;
for (pAssoc = *ppAssocPrev; pAssoc != NULL; pAssoc = pAssoc->pNext)
{
if (CompareAssocKey(pAssoc, pKey, cbKey))
{
// remove it
*ppAssocPrev = pAssoc->pNext; // remove from list
FreeAssoc(pAssoc);
ASSERT_VALID(this);
return TRUE;
}
ppAssocPrev = &pAssoc->pNext;
}
return FALSE; // not found
}
// remove key based on pAssoc (HMAPKEY)
BOOL CMapKeyToValue::RemoveHKey(HMAPKEY hKey)
{
ASSERT_VALID(this);
if (m_pHashTable == NULL)
return FALSE; // nothing in the table
// REVIEW: would like some way to verify that hKey is valid
CAssoc FAR* pAssoc = (CAssoc FAR*)hKey;
if (pAssoc == NULL || pAssoc->nHashValue >= m_nHashTableSize)
// null hkey or bad hash value
return FALSE;
register CAssoc FAR* FAR* ppAssocPrev;
ppAssocPrev = &m_pHashTable[pAssoc->nHashValue];
while (*ppAssocPrev != NULL)
{
if (*ppAssocPrev == pAssoc)
{
// remove it
*ppAssocPrev = pAssoc->pNext; // remove from list
FreeAssoc(pAssoc);
ASSERT_VALID(this);
return TRUE;
}
ppAssocPrev = &(*ppAssocPrev)->pNext;
}
return FALSE; // not found (must have a messed up list or passed
// a key from another list)
}
HMAPKEY CMapKeyToValue::GetHKey(LPVOID pKey, UINT cbKey) const
{
UINT nHash;
ASSERT_VALID(this);
return (HMAPKEY)GetAssocAt(pKey, cbKey, nHash);
}
/////////////////////////////////////////////////////////////////////////////
// Iterating
// for fixed length keys, copies key to pKey; pcbKey can be NULL;
// for variable length keys, copies pointer to key to pKey; sets pcbKey.
void CMapKeyToValue::GetNextAssoc(POSITION FAR* pNextPosition,
LPVOID pKey, UINT FAR* pcbKey, LPVOID pValue) const
{
ASSERT_VALID(this);
Assert(m_pHashTable != NULL); // never call on empty map
register CAssoc FAR* pAssocRet = (CAssoc FAR*)*pNextPosition;
Assert(pAssocRet != NULL);
if (pAssocRet == (CAssoc FAR*) 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
CAssoc FAR* pAssocNext;
if ((pAssocNext = pAssocRet->pNext) == NULL)
{
// go to next bucket
for (UINT nBucket = pAssocRet->nHashValue + 1;
nBucket < m_nHashTableSize; nBucket++)
if ((pAssocNext = m_pHashTable[nBucket]) != NULL)
break;
}
// fill in return data
*pNextPosition = (POSITION) pAssocNext;
// fill in key/pointer to key
LPVOID pKeyFrom;
UINT cbKey;
GetAssocKeyPtr(pAssocRet, &pKeyFrom, &cbKey);
if (m_cbKey == 0)
// variable length key; just return pointer to key itself
*(void FAR* FAR*)pKey = pKeyFrom;
else
_fmemcpy(pKey, pKeyFrom, cbKey);
if (pcbKey != NULL)
*pcbKey = cbKey;
// get value
GetAssocValue(pAssocRet, pValue);
}
/////////////////////////////////////////////////////////////////////////////
void CMapKeyToValue::AssertValid() const
{
#ifdef _DEBUG
Assert(m_cbKeyInAssoc == (m_cbKey == 0 ? sizeof(CKeyWrap) : m_cbKey));
Assert(m_nHashTableSize > 0);
Assert(m_nCount == 0 || m_pHashTable != NULL);
if (m_pHashTable != NULL)
Assert(!IsBadReadPtr(m_pHashTable, m_nHashTableSize * sizeof(CAssoc FAR*)));
Assert(!IsBadCodePtr((FARPROC)m_lpfnHashKey));
if (m_pFreeList != NULL)
Assert(!IsBadReadPtr(m_pFreeList, SizeAssoc()));
if (m_pBlocks != NULL)
Assert(!IsBadReadPtr(m_pBlocks, SizeAssoc() * m_nBlockSize));
// some collections live as global variables in the libraries, but
// have their existance in some context. Also, we can't check shared
// collections since we might be checking the etask collection
// which would cause an infinite recursion.
Assert(m_memctx == MEMCTX_SHARED || CoMemctxOf(this) == MEMCTX_UNKNOWN || CoMemctxOf(this) == m_memctx);
#endif //_DEBUG
}