add MessageHdrStruct and db cache apis

mailnews/db/msgdb/public/nsMsgDatabase.h

@@ -18,9 +18,42 @@
 
 
 #include "nsMsgHdr.h"
+#include "nsMsgPtrArray.h"
+#include "nsString.h"
 
 class ListContext;
 
+
+// used to cache open db's.
+class nsMsgDatabaseArray : public XPPtrArray
+{
+public:
+	nsMsgDatabaseArray();
+	
+	// overrides with proper types to avoid casting
+	nsMsgDatabase* GetAt(int nIndex) const {return((nsMsgDatabase*)XPPtrArray::GetAt(nIndex));}
+	void* operator[](int nIndex) const {return((nsMsgDatabase*)XPPtrArray::operator[](nIndex));}
+};
+
+// This is to be used as an interchange object, to make creating nsMsgHeaders easier.
+struct MessageHdrStruct
+{
+	MessageKey   m_threadId; 
+	MessageKey	m_messageKey; 	
+	nsString	m_subject;
+	nsString	m_author;
+	nsString	m_messageId;
+	nsString	m_references; 
+	nsString	m_recipients;
+	time_t 		m_date;         // is there some sort of PR type I should use for this?
+	PRUInt32	m_messageSize;	// lines for news articles, bytes for local mail and imap messages
+	PRUInt32	m_flags;
+	PRInt16		m_numChildren;		// for top-level threads
+	PRInt16		m_numNewChildren;	// for top-level threads
+	MSG_PRIORITY m_priority;
+public:
+};
+
 // I don't think this is going to be an interface, actually, since it's just
 // a thin layer above MDB that defines the msg db schema.
 
@@ -30,10 +63,12 @@ public:
 	nsMsgDatabase();
 	virtual ~nsMsgDatabase();
 
-	nsresult OpenMDB(const char *dbName, PR_Bool create);
-	nsresult CloseMDB(PR_Bool commit = TRUE);
+	virtual nsresult	OpenMDB(const char *dbName, PRBool create);
+	virtual nsresult	CloseMDB(PR_Bool commit = TRUE);
 	// get a message header for the given key. Caller must release()!
-	nsresult GetMsgHdrForKey(MessageKey messageKey, nsMsgHdr **msgHdr);
+	virtual nsresult	GetMsgHdrForKey(MessageKey messageKey, nsMsgHdr **msgHdr);
+
+	virtual nsresult	CreateNewHdr(PRBool *newThread, PRBool notify = FALSE, nsMsgHdr **newHdr);
 
 	// iterator methods
 	// iterate through message headers, in no particular order
@@ -43,6 +78,12 @@ public:
 	nsresult	ListFirst(ListContext **pContext, nsMsgHdr **pResult);
 	nsresult	ListNext(ListContext *pContext, nsMsgHdr **pResult);
 	nsresult	ListDone(ListContext *pContext);
+	static nsMsgDatabase* FindInCache(const char * pDBName);
 protected:
 	mdbEnv		*m_mdbEnv;	// to be used in all the db calls.
+	static void		AddToCache(nsMsgDatabase* pMessageDB) 
+						{GetDBCache()->Add(pMessageDB);}
+	static void		RemoveFromCache(nsMsgDatabase* pMessageDB);
+	static int		FindInCache(nsMsgDatabase* pMessageDB);
+	static nsMsgDatabaseArray*	GetDBCache();
 };