/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0 .
*/
#include <svl/inethist.hxx>
#include <algorithm>
#include <string.h>
#include <rtl/crc.h>
#include <tools/debug.hxx>
#include <tools/urlobj.hxx>
/*
* INetURLHistory internals.
*/
#define INETHIST_DEF_FTP_PORT 21
#define INETHIST_DEF_HTTP_PORT 80
#define INETHIST_DEF_HTTPS_PORT 443
#define INETHIST_SIZE_LIMIT 1024
#define INETHIST_MAGIC_HEAD 0x484D4849UL
class INetURLHistory_Impl
{
struct head_entry
{
/** Representation.
*/
sal_uInt32 m_nMagic;
sal_uInt16 m_nNext;
/** Initialization.
*/
void initialize()
{
m_nMagic = INETHIST_MAGIC_HEAD;
m_nNext = 0;
}
};
struct hash_entry
{
/** Representation.
*/
sal_uInt32 m_nHash;
sal_uInt16 m_nLru;
/** Initialization.
*/
void initialize (sal_uInt16 nLru)
{
m_nHash = 0;
m_nLru = nLru;
}
/** Comparison.
*/
bool operator== (sal_uInt32 nHash)
const
{
return (m_nHash == nHash);
}
bool operator< (sal_uInt32 nHash)
const
{
return (m_nHash < nHash);
}
};
struct lru_entry
{
/** Representation.
*/
sal_uInt32 m_nHash;
sal_uInt16 m_nNext;
sal_uInt16 m_nPrev;
/** Initialization.
*/
void initialize (sal_uInt16 nThis)
{
m_nHash = 0;
m_nNext = nThis;
m_nPrev = nThis;
}
};
/** Representation.
*/
head_entry m_aHead;
hash_entry m_pHash[INETHIST_SIZE_LIMIT];
lru_entry m_pList[INETHIST_SIZE_LIMIT];
/** Initialization.
*/
void initialize();
static sal_uInt16 capacity()
{
return sal_uInt16(INETHIST_SIZE_LIMIT);
}
static sal_uInt32 crc32 (OUString
const & rData)
{
return rtl_crc32 (0, rData.getStr(), rData.getLength() *
sizeof(sal_Unicode));
}
sal_uInt16 find (sal_uInt32 nHash)
const;
void move (sal_uInt16 nSI, sal_uInt16 nDI);
void backlink (sal_uInt16 nThis, sal_uInt16 nTail)
{
lru_entry &rThis = m_pList[nThis];
lru_entry &rTail = m_pList[nTail];
rTail.m_nNext = nThis;
rTail.m_nPrev = rThis.m_nPrev;
rThis.m_nPrev = nTail;
m_pList[rTail.m_nPrev].m_nNext = nTail;
}
void unlink (sal_uInt16 nThis)
{
lru_entry &rThis = m_pList[nThis];
m_pList[rThis.m_nPrev].m_nNext = rThis.m_nNext;
m_pList[rThis.m_nNext].m_nPrev = rThis.m_nPrev;
rThis.m_nNext = nThis;
rThis.m_nPrev = nThis;
}
public:
INetURLHistory_Impl();
INetURLHistory_Impl(
const INetURLHistory_Impl&) =
delete;
INetURLHistory_Impl&
operator=(
const INetURLHistory_Impl&) =
delete;
/** putUrl/queryUrl.
*/
void putUrl (
const OUString &rUrl);
bool queryUrl (
const OUString &rUrl)
const;
};
INetURLHistory_Impl::INetURLHistory_Impl()
{
initialize();
}
void INetURLHistory_Impl::initialize()
{
m_aHead.initialize();
sal_uInt16 i, n = capacity();
for (i = 0; i < n; i++)
m_pHash[i].initialize(i);
for (i = 0; i < n; i++)
m_pList[i].initialize(i);
for (i = 1; i < n; i++)
backlink (m_aHead.m_nNext, i);
}
sal_uInt16 INetURLHistory_Impl::find (sal_uInt32 nHash)
const
{
sal_uInt16 l = 0;
sal_uInt16 r = capacity() - 1;
sal_uInt16 c = capacity();
while ((l < r) && (r < c))
{
sal_uInt16 m = ((l + r) / 2) & 0xFFFF;
if (m_pHash[m] == nHash)
return m;
if (m_pHash[m] < nHash)
l = m + 1;
else
r = m - 1;
}
return l;
}
void INetURLHistory_Impl::move (sal_uInt16 nSI, sal_uInt16 nDI)
{
hash_entry e = m_pHash[nSI];
if (nSI < nDI)
{
// shift left.
memmove (
&m_pHash[nSI ],
&m_pHash[nSI + 1],
(nDI - nSI) *
sizeof(hash_entry));
}
if (nSI > nDI)
{
// shift right.
memmove (
&m_pHash[nDI + 1],
&m_pHash[nDI ],
(nSI - nDI) *
sizeof(hash_entry));
}
m_pHash[nDI] = e;
}
void INetURLHistory_Impl::putUrl (
const OUString &rUrl)
{
sal_uInt32 h = crc32 (rUrl);
sal_uInt16 k = find (h);
if ((k < capacity()) && (m_pHash[k] == h))
{
// Cache hit.
sal_uInt16 nMRU = m_pHash[k].m_nLru;
if (nMRU != m_aHead.m_nNext)
{
// Update LRU chain.
unlink (nMRU);
backlink (m_aHead.m_nNext, nMRU);
// Rotate LRU chain.
m_aHead.m_nNext = m_pList[m_aHead.m_nNext].m_nPrev;
}
}
else
{
// Cache miss. Obtain least recently used.
sal_uInt16 nLRU = m_pList[m_aHead.m_nNext].m_nPrev;
sal_uInt16 nSI = find (m_pList[nLRU].m_nHash);
if (nLRU != m_pHash[nSI].m_nLru)
{
// Update LRU chain.
nLRU = m_pHash[nSI].m_nLru;
unlink (nLRU);
backlink (m_aHead.m_nNext, nLRU);
}
// Rotate LRU chain.
m_aHead.m_nNext = m_pList[m_aHead.m_nNext].m_nPrev;
// Check source and destination.
sal_uInt16 nDI = std::min (k, sal_uInt16(capacity() - 1));
if (nSI < nDI && !(m_pHash[nDI] < h))
nDI -= 1;
if (nDI < nSI && m_pHash[nDI] < h)
nDI += 1;
// Assign data.
m_pList[m_aHead.m_nNext].m_nHash = m_pHash[nSI].m_nHash = h;
move (nSI, nDI);
}
}
bool INetURLHistory_Impl::queryUrl (
const OUString &rUrl)
const
{
sal_uInt32 h = crc32 (rUrl);
sal_uInt16 k = find (h);
// true if cache hit
return (k < capacity()) && (m_pHash[k] == h);
}
INetURLHistory::INetURLHistory() : m_pImpl (
new INetURLHistory_Impl())
{
}
INetURLHistory::~INetURLHistory()
{
}
/*
* GetOrCreate.
*/
INetURLHistory* INetURLHistory::GetOrCreate()
{
static INetURLHistory instance;
return &instance;
}
void INetURLHistory::NormalizeUrl_Impl (INetURLObject &rUrl)
{
switch (rUrl.GetProtocol())
{
case INetProtocol::File:
if (!INetURLObject::IsCaseSensitive())
{
OUString aPath (rUrl.GetURLPath(INetURLObject::DecodeMechanism::NONE).toAsciiLower
Case());
rUrl.SetURLPath (aPath, INetURLObject::EncodeMechanism::NotCanonical);
}
break;
case INetProtocol::Ftp:
if (!rUrl.HasPort())
rUrl.SetPort (INETHIST_DEF_FTP_PORT);
break;
case INetProtocol::Http:
if (!rUrl.HasPort())
rUrl.SetPort (INETHIST_DEF_HTTP_PORT);
if (!rUrl.HasURLPath())
rUrl.SetURLPath(u"/");
break;
case INetProtocol::Https:
if (!rUrl.HasPort())
rUrl.SetPort (INETHIST_DEF_HTTPS_PORT);
if (!rUrl.HasURLPath())
rUrl.SetURLPath(u"/");
break;
default:
break;
}
}
void INetURLHistory::PutUrl_Impl (const INetURLObject &rUrl)
{
DBG_ASSERT (m_pImpl, "PutUrl_Impl(): no Implementation");
if (!m_pImpl)
return;
INetURLObject aHistUrl (rUrl);
NormalizeUrl_Impl (aHistUrl);
m_pImpl->putUrl (aHistUrl.GetMainURL(INetURLObject::DecodeMechanism::NONE));
Broadcast (INetURLHistoryHint (&rUrl));
if (aHistUrl.HasMark())
{
aHistUrl.SetURL (aHistUrl.GetURLNoMark(INetURLObject::DecodeMechanism::NONE),
INetURLObject::EncodeMechanism::NotCanonical);
m_pImpl->putUrl (aHistUrl.GetMainURL(INetURLObject::DecodeMechanism::NONE));
Broadcast (INetURLHistoryHint (&aHistUrl));
}
}
bool INetURLHistory::QueryUrl(std::u16string_view rUrl) const
{
INetProtocol eProto = INetURLObject::CompareProtocolScheme (rUrl);
if (!QueryProtocol (eProto))
return false;
return QueryUrl_Impl( INetURLObject(rUrl) );
}
bool INetURLHistory::QueryUrl_Impl (INetURLObject rUrl) const
{
DBG_ASSERT (m_pImpl, "QueryUrl_Impl(): no Implementation");
if (m_pImpl)
{
NormalizeUrl_Impl (rUrl);
return m_pImpl->queryUrl (rUrl.GetMainURL(INetURLObject::DecodeMechanism::NONE));
}
return false;
}
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