mozilla-history/netwerk/cache/filecache/nsDBEnumerator.cpp

109 строки
2.8 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is Mozilla Communicator.
*
* The Initial Developer of the Original Code is Intel Corp.
* Portions created by Intel Corp. are
* Copyright (C) 1999, 1999 Intel Corp. All
* Rights Reserved.
*
* Contributor(s): Yixiong Zou <yixiong.zou@intel.com>
* Carl Wong <carl.wong@intel.com>
*/
/*
* This file is part of filecache implementation.
*
* It implements a simple iterator for the database, see nsDBAccessor.
*/
#include "nsDBEnumerator.h"
#include "nsDiskCacheRecord.h"
nsDBEnumerator::nsDBEnumerator(nsIDBAccessor* aDB, nsNetDiskCache* aCache) :
m_DB(aDB) ,
m_DiskCache(aCache) ,
m_tempEntry(0) ,
m_tempEntry_length(0) ,
m_CacheEntry(0) ,
m_bReset(PR_TRUE)
{
NS_INIT_REFCNT();
}
nsDBEnumerator::~nsDBEnumerator()
{
NS_IF_RELEASE(m_CacheEntry) ;
}
//
// Implement nsISupports methods
//
NS_IMPL_ISUPPORTS(nsDBEnumerator, NS_GET_IID(nsIEnumerator))
/////////////////////////////////////////////////////////////////
// nsISimpleEnumerator methods
NS_IMETHODIMP
nsDBEnumerator::HasMoreElements(PRBool *_retval)
{
*_retval = PR_FALSE ;
nsresult rv = m_DB->EnumEntry(&m_tempEntry, &m_tempEntry_length, m_bReset) ;
if(NS_FAILED(rv)) {
// do some error recovery
m_DiskCache->DBRecovery() ;
return rv ;
}
m_bReset = PR_FALSE ;
if(m_tempEntry && m_tempEntry_length != 0)
*_retval = PR_TRUE ;
return NS_OK ;
}
// this routine does not create a new item by itself
// Rather it reuses the item inside the object. So if you need to use the
// item later, you have to
// create a new item specifically, using copy constructor or some other dup
// function. And don't forget to release it after you're done
//
NS_IMETHODIMP
nsDBEnumerator::GetNext(nsISupports **_retval)
{
if(!m_CacheEntry) {
m_CacheEntry = new nsDiskCacheRecord(m_DB, m_DiskCache) ;
if(m_CacheEntry)
NS_ADDREF(m_CacheEntry) ;
else
return NS_ERROR_OUT_OF_MEMORY ;
}
if(!_retval)
return NS_ERROR_NULL_POINTER ;
*_retval = nsnull ;
nsresult rv = m_CacheEntry->RetrieveInfo(m_tempEntry, m_tempEntry_length) ;
if(NS_FAILED(rv))
return rv ;
*_retval = NS_STATIC_CAST(nsISupports*, m_CacheEntry) ;
NS_ADDREF(*_retval) ; // all good getter addref
return NS_OK ;
}