1 // Copyright 2016 PDFium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6
7 #include "core/fpdfapi/render/cpdf_pagerendercache.h"
8
9 #include <algorithm>
10 #include <vector>
11
12 #include "core/fpdfapi/page/cpdf_image.h"
13 #include "core/fpdfapi/page/cpdf_page.h"
14 #include "core/fpdfapi/render/cpdf_imagecacheentry.h"
15 #include "core/fpdfapi/render/cpdf_renderstatus.h"
16 #include "core/fxge/dib/cfx_dibitmap.h"
17
18 namespace {
19
20 struct CacheInfo {
CacheInfo__anon094f5c200111::CacheInfo21 CacheInfo(uint32_t t, CPDF_Stream* stream) : time(t), pStream(stream) {}
22
23 uint32_t time;
24 CPDF_Stream* pStream;
25
operator <__anon094f5c200111::CacheInfo26 bool operator<(const CacheInfo& other) const { return time < other.time; }
27 };
28
29 } // namespace
30
CPDF_PageRenderCache(CPDF_Page * pPage)31 CPDF_PageRenderCache::CPDF_PageRenderCache(CPDF_Page* pPage) : m_pPage(pPage) {}
32
33 CPDF_PageRenderCache::~CPDF_PageRenderCache() = default;
34
CacheOptimization(int32_t dwLimitCacheSize)35 void CPDF_PageRenderCache::CacheOptimization(int32_t dwLimitCacheSize) {
36 if (m_nCacheSize <= (uint32_t)dwLimitCacheSize)
37 return;
38
39 size_t nCount = m_ImageCache.size();
40 std::vector<CacheInfo> cache_info;
41 cache_info.reserve(nCount);
42 for (const auto& it : m_ImageCache) {
43 cache_info.emplace_back(it.second->GetTimeCount(),
44 it.second->GetImage()->GetStream());
45 }
46 std::sort(cache_info.begin(), cache_info.end());
47
48 // Check if time value is about to roll over and reset all entries.
49 // The comparision is legal because uint32_t is an unsigned type.
50 uint32_t nTimeCount = m_nTimeCount;
51 if (nTimeCount + 1 < nTimeCount) {
52 for (size_t i = 0; i < nCount; i++)
53 m_ImageCache[cache_info[i].pStream]->m_dwTimeCount = i;
54 m_nTimeCount = nCount;
55 }
56
57 size_t i = 0;
58 while (i + 15 < nCount)
59 ClearImageCacheEntry(cache_info[i++].pStream);
60
61 while (i < nCount && m_nCacheSize > (uint32_t)dwLimitCacheSize)
62 ClearImageCacheEntry(cache_info[i++].pStream);
63 }
64
ClearImageCacheEntry(CPDF_Stream * pStream)65 void CPDF_PageRenderCache::ClearImageCacheEntry(CPDF_Stream* pStream) {
66 auto it = m_ImageCache.find(pStream);
67 if (it == m_ImageCache.end())
68 return;
69
70 m_nCacheSize -= it->second->EstimateSize();
71 m_ImageCache.erase(it);
72 }
73
StartGetCachedBitmap(const RetainPtr<CPDF_Image> & pImage,const CPDF_RenderStatus * pRenderStatus,bool bStdCS)74 bool CPDF_PageRenderCache::StartGetCachedBitmap(
75 const RetainPtr<CPDF_Image>& pImage,
76 const CPDF_RenderStatus* pRenderStatus,
77 bool bStdCS) {
78 CPDF_Stream* pStream = pImage->GetStream();
79 const auto it = m_ImageCache.find(pStream);
80 m_bCurFindCache = it != m_ImageCache.end();
81 if (m_bCurFindCache) {
82 m_pCurImageCacheEntry = it->second.get();
83 } else {
84 m_pCurImageCacheEntry =
85 std::make_unique<CPDF_ImageCacheEntry>(m_pPage->GetDocument(), pImage);
86 }
87 CPDF_DIB::LoadState ret = m_pCurImageCacheEntry->StartGetCachedBitmap(
88 m_pPage->m_pPageResources.Get(), pRenderStatus, bStdCS);
89 if (ret == CPDF_DIB::LoadState::kContinue)
90 return true;
91
92 m_nTimeCount++;
93 if (!m_bCurFindCache)
94 m_ImageCache[pStream] = m_pCurImageCacheEntry.Release();
95
96 if (ret == CPDF_DIB::LoadState::kFail)
97 m_nCacheSize += m_pCurImageCacheEntry->EstimateSize();
98
99 return false;
100 }
101
Continue(PauseIndicatorIface * pPause,CPDF_RenderStatus * pRenderStatus)102 bool CPDF_PageRenderCache::Continue(PauseIndicatorIface* pPause,
103 CPDF_RenderStatus* pRenderStatus) {
104 bool ret = m_pCurImageCacheEntry->Continue(pPause, pRenderStatus);
105 if (ret)
106 return true;
107
108 m_nTimeCount++;
109 if (!m_bCurFindCache) {
110 m_ImageCache[m_pCurImageCacheEntry->GetImage()->GetStream()] =
111 m_pCurImageCacheEntry.Release();
112 }
113 m_nCacheSize += m_pCurImageCacheEntry->EstimateSize();
114 return false;
115 }
116
ResetBitmapForImage(const RetainPtr<CPDF_Image> & pImage)117 void CPDF_PageRenderCache::ResetBitmapForImage(
118 const RetainPtr<CPDF_Image>& pImage) {
119 CPDF_ImageCacheEntry* pEntry;
120 CPDF_Stream* pStream = pImage->GetStream();
121 const auto it = m_ImageCache.find(pStream);
122 if (it == m_ImageCache.end())
123 return;
124
125 pEntry = it->second.get();
126 m_nCacheSize -= pEntry->EstimateSize();
127 pEntry->Reset();
128 m_nCacheSize += pEntry->EstimateSize();
129 }
130