windows-nt/Source/XPSP1/NT/inetsrv/iis/svcs/cmp/asp/smhash.cpp
2020-09-26 16:20:57 +08:00

180 lines
4.2 KiB
C++

/*===================================================================
Microsoft Denali
Microsoft Confidential.
Copyright 1996 Microsoft Corporation. All Rights Reserved.
Component: Hash table for Script Manager
File: SMHash.cpp
Owner: AndrewS
This is the Link list and Hash table for use by the Script Manager only
===================================================================*/
#include "denpre.h"
#pragma hdrstop
#include "memchk.h"
/*===================================================================
CSMHash::AddElem
Adds a CLruLinkElem to the SM Hash table.
User is responsible for allocating the Element to be added.
Note: This is identical to the standard CHashTable::AddElem, except
that it allows for elements with duplicate names
Parameters:
CLruLinkElem *pElem Object to be added
Returns:
Pointer to element added/found.
===================================================================*/
CLruLinkElem *CSMHash::AddElem
(
CLruLinkElem *pElem
)
{
AssertValid();
if (m_rgpBuckets == NULL)
{
if (FAILED(AllocateBuckets()))
return NULL;
}
if (pElem == NULL)
return NULL;
UINT iBucket = m_pfnHash(pElem->m_pKey, pElem->m_cbKey) % m_cBuckets;
CLruLinkElem * pT = static_cast<CLruLinkElem *>(m_rgpBuckets[iBucket]);
while (pT)
{
if (pT->m_Info > 0)
pT = static_cast<CLruLinkElem *>(pT->m_pNext);
else
break;
}
if (pT)
{
// There are other elements in bucket
pT = static_cast<CLruLinkElem *>(m_rgpBuckets[iBucket]);
m_rgpBuckets[iBucket] = pElem;
pElem->m_Info = pT->m_Info + 1;
pElem->m_pNext = pT;
pElem->m_pPrev = pT->m_pPrev;
pT->m_pPrev = pElem;
if (pElem->m_pPrev == NULL)
m_pHead = pElem;
else
pElem->m_pPrev->m_pNext = pElem;
}
else
{
// This is the first element in the bucket
m_rgpBuckets[iBucket] = pElem;
pElem->m_pPrev = NULL;
pElem->m_pNext = m_pHead;
pElem->m_Info = 0;
if (m_pHead)
m_pHead->m_pPrev = pElem;
else
m_pTail = pElem;
m_pHead = pElem;
}
m_Count++;
pElem->PrependTo(m_lruHead);
AssertValid();
return pElem;
}
/*===================================================================
CSMHash::FindElem
Finds a script engine element in the hash table based on the name
and language type.
Parameters:
void * pKey - the key to look for
int cbKey - length of the key to look for
PROGLANG_ID proglang_id - program language name
DWORD dwInstanceID - instance ID to find
BOOL fCheckLoaded - if true, only return engines flagged as "loaded"
Returns:
Pointer to CLruLinkElem if found, otherwise NULL.
===================================================================*/
CLruLinkElem * CSMHash::FindElem
(
const void *pKey,
int cbKey,
PROGLANG_ID proglang_id,
DWORD dwInstanceID,
BOOL fCheckLoaded
)
{
AssertValid();
if (m_rgpBuckets == NULL || pKey == NULL)
return NULL;
UINT iBucket = m_pfnHash(static_cast<const BYTE *>(pKey), cbKey) % m_cBuckets;
CLruLinkElem * pT = static_cast<CLruLinkElem *>(m_rgpBuckets[iBucket]);
CLruLinkElem * pRet = NULL;
/*
* We have the right bucket based on the hashed name.
* Search through the bucket chain looking for elements whose name
* is correct (multiple names can hash to the same bucket), and
* whose language is the one we want, and (optionally) skip
* elements that are not fully "loaded"
*
* Note: This all relys on intimate knowlege of the format of an ActiveScriptEngine.
* these elements better be ASE's.
*/
while (pT && pRet == NULL)
{
if (FIsEqual(pT->m_pKey, pT->m_cbKey, pKey, cbKey))
{
CASEElem *pASEElem = static_cast<CASEElem *>(pT);
Assert(pASEElem != NULL);
CActiveScriptEngine *pASE = pASEElem->PASE();
Assert(pASE != NULL);
// Element has the right name. Is it really the one we want?
if (proglang_id != pASE->ProgLang_Id())
goto LNext;
if (dwInstanceID != pASE->DWInstanceID())
goto LNext;
if (fCheckLoaded && !pASE->FFullyLoaded())
goto LNext;
// Yup, its the right one!
pRet = pT;
break;
}
LNext:
if (pT->m_Info > 0)
pT = static_cast<CLruLinkElem *>(pT->m_pNext);
else
{
// got to the last element in this bucket chain
break;
}
}
if (pRet)
pRet->PrependTo(m_lruHead);
AssertValid();
return pRet;
}