fix threading performance with header cache, r=mscott,a=phil 28233

mailnews/db/msgdb/public/nsMsgDatabase.h

@@ -36,6 +36,7 @@
 #include "nsICollation.h"
 #include "nsIMimeConverter.h"
 #include "nsCOMPtr.h"
+#include "nsHashtable.h"
 
 class ListContext;
 class nsMsgKeyArray;
@@ -346,6 +347,16 @@ protected:
 	mdb_token			m_threadParentColumnToken;
 	mdb_token			m_threadRootKeyColumnToken;
 	nsIMsgHeaderParser	*m_HeaderParser;
+
+	// header caching stuff
+	nsresult			GetHdrFromCache(nsMsgKey key, nsIMsgDBHdr* *result);
+	nsresult			AddHdrToCache(nsIMsgDBHdr *hdr, nsMsgKey key);
+	nsresult			ClearHdrCache();
+	nsresult			RemoveHdrFromCache(nsIMsgDBHdr *hdr, nsMsgKey key);
+
+	nsSupportsHashtable	*m_cachedHeaders;
+	PRBool				m_bCacheHeaders;
+
 };
 
 #endif

mailnews/db/msgdb/public/nsMsgHdr.h

@@ -57,6 +57,7 @@ protected:
     nsresult	GetUInt32Column(mdb_token token, PRUint32 *pvalue, PRUint32 defaultValue = 0);
 
 	// reference and threading stuff.
+	nsresult	ParseReferences(nsCString &references);
 	const char*	GetNextReference(const char *startNextRef, nsCString &reference);
 	const char* GetPrevReference(const char *prevRef, nsCString &reference);
 
@@ -70,7 +71,7 @@ protected:
     PRUint16		m_numReferences;	// x-ref header for threading
     PRInt16			m_csID;			// cs id of message
 	nsCString		m_charSet;		// OK, charset of headers, since cs id's aren't supported.
-	nsCString		m_references;
+	nsCStringArray		m_references;  // avoid parsing references every time we want one
     nsMsgPriority	m_priority;
 
     PRBool m_recipientsIsNewsgroup;

mailnews/db/msgdb/src/nsMsgDatabase.cpp

@@ -70,18 +70,96 @@ static NS_DEFINE_CID(kMsgHeaderParserCID, NS_MSGHEADERPARSER_CID);
 
 
 const int kMsgDBVersion = 1;
+const PRInt32 kMaxHdrsInCache = 200;
 
+nsresult nsMsgDatabase::GetHdrFromCache(nsMsgKey key, nsIMsgDBHdr* *result)
+{
+	if (!result)
+		return NS_ERROR_NULL_POINTER;
+
+	nsresult rv = NS_ERROR_FAILURE;
+
+	*result = nsnull;
+
+	if (m_bCacheHeaders && m_cachedHeaders)
+	{
+		// it would be nice if we had an nsISupports hash table that hashed 32 bit int's
+		nsCAutoString strKey;
+		strKey.Append(key, 10);
+		nsStringKey hashKey(strKey.GetBuffer());
+		// nsSupportsHashtable does an addref
+		*result = (nsIMsgDBHdr *) m_cachedHeaders->Get(&hashKey);
+		if (*result)
+			rv = NS_OK;
+	}
+	return rv;
+}
+
+nsresult nsMsgDatabase::AddHdrToCache(nsIMsgDBHdr *hdr, nsMsgKey key) // do we want key? We could get it from hdr
+{
+	if (m_bCacheHeaders)
+	{
+		if (!m_cachedHeaders)
+			m_cachedHeaders = new nsSupportsHashtable;
+		if (m_cachedHeaders)
+		{
+			nsCOMPtr<nsISupports> supports(do_QueryInterface(hdr));
+			if (m_cachedHeaders->Count() > kMaxHdrsInCache)
+				ClearHdrCache();
+			// it would be nice if we had an nsISupports hash table that hashed 32 bit int's
+			nsCAutoString strKey;
+			strKey.Append(key, 10);
+			nsStringKey hashKey(strKey.GetBuffer());
+			m_cachedHeaders->Put(&hashKey, hdr);
+			return NS_OK;
+		}
+	}
+	return NS_ERROR_FAILURE;
+}
+
+nsresult nsMsgDatabase::ClearHdrCache()
+{
+	if (m_cachedHeaders)
+	{
+		m_cachedHeaders->Reset();
+	}
+	return NS_OK;
+}
+
+nsresult nsMsgDatabase::RemoveHdrFromCache(nsIMsgDBHdr *hdr, nsMsgKey key)
+{
+	if (m_cachedHeaders)
+	{
+		if (key == nsMsgKey_None)
+			hdr->GetMessageKey(&key);
+
+		nsCAutoString strKey;
+		strKey.Append(key, 10);
+		nsStringKey hashKey(strKey.GetBuffer());
+		nsIMsgDBHdr *removedHdr = (nsIMsgDBHdr *) m_cachedHeaders->Remove(&hashKey); // does this release, or do I have to?
+	}
+	return NS_OK;
+}
 
 nsresult
 nsMsgDatabase::CreateMsgHdr(nsIMdbRow* hdrRow, nsMsgKey key, nsIMsgDBHdr* *result)
 {
+	nsresult rv = GetHdrFromCache(key, result);
+	if (NS_SUCCEEDED(rv) && *result)
+	{
+		hdrRow->Release();
+		return rv;
+	}
+
 	nsMsgHdr *msgHdr = new nsMsgHdr(this, hdrRow);
 	if(!msgHdr)
 		return NS_ERROR_OUT_OF_MEMORY;
     msgHdr->SetMessageKey(key);
 	msgHdr->AddRef();
     *result = msgHdr;
-  
+
+	AddHdrToCache(msgHdr, key);  
+
 	return NS_OK;
 }
 
@@ -349,14 +427,20 @@ nsMsgDatabase::nsMsgDatabase()
 	  m_messageCharSetColumnToken(0),
 	  m_threadParentColumnToken(0),
 	  m_threadRootKeyColumnToken(0),
+	  m_bCacheHeaders(PR_FALSE),
+	  m_cachedHeaders(nsnull),
 	  m_HeaderParser(nsnull)
 {
 	NS_INIT_REFCNT();
+	m_bCacheHeaders = PR_TRUE;
 }
 
 nsMsgDatabase::~nsMsgDatabase()
 {
 //	Close(FALSE);	// better have already been closed.
+	ClearHdrCache();
+	delete m_cachedHeaders;
+
 	RemoveFromCache(this);
 #ifdef DEBUG_bienvenu1
 	if (GetNumInCache() != 0)
@@ -946,6 +1030,10 @@ NS_IMETHODIMP nsMsgDatabase::GetMsgHdrForKey(nsMsgKey key, nsIMsgDBHdr **pmsgHdr
 		return NS_ERROR_NULL_POINTER;
 
 	*pmsgHdr = NULL;
+	err = GetHdrFromCache(key, pmsgHdr);
+	if (NS_SUCCEEDED(err) && *pmsgHdr)
+		return err;
+
 	rowObjectId.mOid_Id = key;
 	rowObjectId.mOid_Scope = m_hdrRowScopeToken;
 	err = m_mdbAllMsgHeadersTable->HasOid(GetEnv(), &rowObjectId, &hasOid);
@@ -1098,6 +1186,7 @@ nsresult nsMsgDatabase::RemoveHeaderFromDB(nsMsgHdr *msgHdr)
 	// even if we couldn't find the thread,we should try to remove the header.
 //	if (NS_SUCCEEDED(ret))
 	{
+		RemoveHdrFromCache(msgHdr, nsMsgKey_None);
 		nsIMdbRow* row = msgHdr->GetMDBRow();
 		ret = m_mdbAllMsgHeadersTable->CutRow(GetEnv(), msgHdr->GetMDBRow());
 		row->CutAllColumns(GetEnv());

mailnews/db/msgdb/src/nsMsgHdr.cpp

@@ -300,31 +300,36 @@ NS_IMETHODIMP nsMsgHdr::GetNumReferences(PRUint16 *result)
 	return NS_OK;
 }
 
+nsresult nsMsgHdr::ParseReferences(nsCString &references)
+{
+	const char *startNextRef = references.GetBuffer();
+	nsCAutoString resultReference;
+
+	while (startNextRef && *startNextRef)
+	{
+		startNextRef = GetNextReference(startNextRef, resultReference);
+		m_references.AppendCString(resultReference);
+	}
+	return NS_OK;
+}
+
 NS_IMETHODIMP nsMsgHdr::GetStringReference(PRInt32 refNum, nsCString &resultReference)
 {
 	nsresult err = NS_OK;
 
 	if(!(m_initedValues & REFERENCES_INITED))
 	{
-		m_mdb->RowCellColumnTonsCString(GetMDBRow(), m_mdb->m_referencesColumnToken, m_references);
-
+		nsCAutoString references;
+		err = m_mdb->RowCellColumnTonsCString(GetMDBRow(), m_mdb->m_referencesColumnToken, references);
+		
 		if(NS_SUCCEEDED(err))
+		{
+			ParseReferences(references);
 			m_initedValues |= REFERENCES_INITED;
+		}
 	}
 
-	nsCAutoString cStr(m_references);
-	const char *startNextRef = cStr.GetBuffer();
-	PRInt32 refIndex;
-	for (refIndex = 0; refIndex <= refNum && startNextRef; refIndex++)
-	{
-		startNextRef = GetNextReference(startNextRef, resultReference);
-		if (refIndex == refNum)
-			break;
-	}
-
-	if (refIndex != refNum)
-		resultReference.Truncate(0);
-
+	m_references.CStringAt(refNum, resultReference);
 	return err;
 }
 
@@ -354,20 +359,12 @@ NS_IMETHODIMP nsMsgHdr::SetAuthor(const char *author)
 
 NS_IMETHODIMP nsMsgHdr::SetReferences(const char *references)
 {
-	nsCAutoString reference;
+	nsCAutoString CStrReference(references);
+	ParseReferences(CStrReference);
 
-	for (const char *startNextRef = references; startNextRef != nsnull;)
-	{
-		startNextRef = GetNextReference(startNextRef, reference);
-
-		if (reference.Length() == 0)
-			break;
-		
-		m_numReferences++;
-	}
+	m_numReferences = m_references.Count();
 	SetUInt32Column(m_numReferences, m_mdb->m_numReferencesColumnToken);
 
-	m_references = references;
 	m_initedValues |= REFERENCES_INITED;
 
 	return SetStringColumn(references, m_mdb->m_referencesColumnToken);