1 /*
2 dspdfviewer - Dual Screen PDF Viewer for LaTeX-Beamer
3 Copyright (C) 2012 Danny Edel <mail@danny-edel.de>
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20
21 #include "pdfrenderfactory.h"
22 #include "renderthread.h"
23 #include "sconnect.h"
24
25 #include <QMutexLocker>
26 #include <QThreadPool>
27 #include <stdexcept>
28 #include "debug.h"
29 #include "renderutils.h"
30
31 #include <boost/cast.hpp>
32
33 namespace {
34 /** Estimates size in bytes of a rendered Page
35 *
36 * This currently assumes 32 bit (4 byte) per pixel, and no
37 * overhead.
38 */
cacheCost(const RenderedPage & renderedPage)39 int cacheCost(const RenderedPage& renderedPage) {
40 const QSize& imageSize = renderedPage.getImage().size();
41 return boost::numeric_cast<int>(sizeof(RenderedPage)) +
42 4 * imageSize.width() * imageSize.height();
43 }
44 }
45
pageThreadFinishedRendering(QSharedPointer<RenderedPage> renderedPage)46 void PdfRenderFactory::pageThreadFinishedRendering(QSharedPointer<RenderedPage> renderedPage)
47 {
48 {
49 QMutexLocker lock(&mutex);
50 const RenderingIdentifier ident( renderedPage->getIdentifier() );
51 // Ignore this incoming rendering if it was from an old version
52 if ( ident.theVersion != currentVersion )
53 return;
54
55 renderedPages.insert(ident, new RenderedPage(*renderedPage), cacheCost(*renderedPage) );
56 currentlyRenderingPages.remove(ident);
57 if ( renderedPages.contains(ident) ) {
58 DEBUGOUT << "Stored" << ident << "into cache";
59 } else {
60 WARNINGOUT << "Unable to store" << ident << "into the cache! It would cost" <<
61 cacheCost(*renderedPage) << "but Current load is" <<
62 renderedPages.totalCost() << "/" << renderedPages.maxCost();
63 }
64
65 DEBUGOUT << "Current cache fill is " <<
66 renderedPages.totalCost() << "/" << renderedPages.maxCost() << '(' <<
67 100.0 * renderedPages.totalCost() / renderedPages.maxCost() << "% )";
68 }
69
70 emit pageRendered(renderedPage);
71 }
72
rewatchFile()73 void PdfRenderFactory::rewatchFile()
74 {
75 if ( ! fileWatcher.files().contains( documentReference.filename() ) ) {
76 fileWatcher.addPath( documentReference.filename() );
77 // Check if it has been added (i.e. if it exists)
78 if ( fileWatcher.files().contains( documentReference.filename() ) ) {
79 // The file was created in the meantime. FileWatcher does not report this as a "change",
80 // So we have to check it manually.
81 fileOnDiskChanged(documentReference.filename());
82 }
83 }
84 }
85
86
87
PdfRenderFactory(const RuntimeConfiguration & rc)88 PdfRenderFactory::PdfRenderFactory( const RuntimeConfiguration& rc):
89 QObject(),
90 documentReference(rc.filePathQString(), rc.cacheSetting()),
91 fileWatcher(),
92 fileWatcherRewatchTimer(),
93 currentlyRenderingPages(),
94 renderedPages( boost::numeric_cast<int>(rc.cacheSizeBytes()) ),
95 mutex(),
96 currentVersion(0),
97 // Attempt to read the document to get the number of pages within.
98 // This will throw an error if the document is unreadable.
99 numberOfPages_(documentReference.popplerDocument()->numPages())
100 {
101
102 rewatchFile();
103
104 // register the on-change function
105 sconnect(&fileWatcher, SIGNAL(fileChanged(QString)), this, SLOT(fileOnDiskChanged(QString)));
106
107 // Make sure it re-watches the file
108 fileWatcherRewatchTimer.setInterval(1000);
109 sconnect(&fileWatcherRewatchTimer, SIGNAL(timeout()), this, SLOT(rewatchFile()));
110 fileWatcherRewatchTimer.start();
111 }
112
requestPageRendering(const RenderingIdentifier & originalIdentifier,QThread::Priority priority)113 void PdfRenderFactory::requestPageRendering(const RenderingIdentifier& originalIdentifier, QThread::Priority priority)
114 {
115 QMutexLocker lock(&mutex);
116
117 RenderingIdentifier renderingIdentifier(originalIdentifier);
118
119 renderingIdentifier.theVersion = currentVersion;
120
121 if ( renderedPages.contains(renderingIdentifier) )
122 {
123 /* Page is ready. Take a copy and lets go. */
124 QSharedPointer<RenderedPage> page( new RenderedPage( * renderedPages.object(renderingIdentifier) ));
125 emit pageRendered(page);
126 return;
127 }
128 /* Page was not in cache. Check if its currently in the render stage. */
129 if ( currentlyRenderingPages.contains(renderingIdentifier) )
130 {
131 /* Page is already rendering, so there is nothing to do. */
132 return;
133 }
134 /* Nobody is working on the page right now. Lets create it. */
135
136 RenderThread* t = new RenderThread( documentReference, renderingIdentifier );
137 sconnect(t, SIGNAL(renderingFinished(QSharedPointer<RenderedPage>)), this, SLOT(pageThreadFinishedRendering(QSharedPointer<RenderedPage>)));
138 currentlyRenderingPages.insert(renderingIdentifier);
139 QThreadPool::globalInstance()->start(t, priority);
140
141 }
142
fileOnDiskChanged(const QString & filename)143 void PdfRenderFactory::fileOnDiskChanged(const QString& filename)
144 {
145 DEBUGOUT << "File" << filename << "has changed on disk";
146
147 if ( filename != documentReference.filename() ) {
148 DEBUGOUT << "Ignoring that file.";
149 return;
150 }
151
152 // Add path back in case it was modified via "move temporary onto filename",
153 // which filewatcher treats as a remove and stops watching
154
155 try {
156 emit pdfFileChanged();
157
158 {
159
160 // Lock mutex
161 QMutexLocker locker(&mutex);
162
163 // Create a new File Reference
164 PDFDocumentReference newDoc(filename, documentReference.cacheOption());
165
166 if ( documentReference.cacheOption() == PDFCacheOption::keepPDFinMemory ) {
167 // If we keep them in memory, a byte-by-byte compare should be resonably fast.
168 // If they are *identical*, we can skip the reloading.
169
170 if( documentReference == newDoc ) {
171 DEBUGOUT << "The new document compares identical to the old one, not doing anything.";
172 return;
173 }
174
175 }
176 DEBUGOUT << "The file on disk has different contents. Trying to parse it as PDF.";
177
178 // Verify poppler can read this
179 newDoc.popplerDocument();
180
181 // replace the current reference with the new one
182 documentReference = newDoc;
183
184 numberOfPages_ = documentReference.popplerDocument()->numPages();
185 DEBUGOUT << "New document has" << numberOfPages_ << "pages.";
186
187 // clear the page cache
188 clearAllCaches();
189 }
190
191 emit pdfFileRereadSuccesfully();
192 } catch( std::runtime_error& ) {
193 DEBUGOUT << "Unable to read the new reference. keeping the old one.";
194 emit pdfFileRereadFailed();
195 }
196 }
197
clearAllCaches()198 void PdfRenderFactory::clearAllCaches()
199 {
200
201 // Increment version, so that incoming "old" renders will get ignored
202 /// TODO: Send a termination signal to these lingering threads
203
204 ++currentVersion;
205
206 // No renders of the current version are taking place, incoming old renders
207 // will be ignored.
208 currentlyRenderingPages.clear();
209
210 // Remove the caches. Since we use explicit copy semantics, its safe to empty
211 // these.
212 renderedPages.clear();
213
214 }
215
numberOfPages() const216 int PdfRenderFactory::numberOfPages() const
217 {
218 QMutexLocker lock(&mutex);
219 return numberOfPages_;
220 }
221
~PdfRenderFactory()222 PdfRenderFactory::~PdfRenderFactory() {
223 RenderUtils::notifyShutdown();
224 }
225