summaryrefslogtreecommitdiffstats
path: root/src/gvcore/cache.cpp
blob: f7508cbc918c466cdea1c9ce4bf079ac6fd49a1f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
// vim: set tabstop=4 shiftwidth=4 noexpandtab
/*
Gwenview - A simple image viewer for KDE
Copyright 2000-2004 Aur�lien G�teau
 
 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

*/

#include "cache.h"

// TQt

// KDE
#include <kconfig.h>
#include <kdebug.h>
#include <kdeversion.h>
#include <ksharedptr.h>
#include <kstaticdeleter.h>
#include <kio/global.h>

#include "cache.moc"

namespace Gwenview {

// Local

#undef ENABLE_LOG
#undef LOG
//#define ENABLE_LOG
#ifdef ENABLE_LOG
#define LOG(x) kdDebug() << k_funcinfo << x << endl
#else
#define LOG(x) ;
#endif

//#define DEBUG_CACHE

const char CONFIG_CACHE_MAXSIZE[]="maxSize";


struct ImageData : public KShared {
	ImageData( const KURL& url, const TQDateTime& _timestamp )
	: timestamp(_timestamp)
	, age(0)
	, fast_url( url.isLocalFile() && !KIO::probably_slow_mounted( url.path()))
	, priority( false ) {
	}

	void addFile( const TQByteArray& file );
	void addImage( const ImageFrames& frames, const TQCString& format );
	void addThumbnail( const TQPixmap& thumbnail, TQSize imagesize );
	long long cost() const;
	int size() const;
	TQByteArray file;
	ImageFrames frames;
	TQPixmap thumbnail;
	TQSize imagesize;
	TQCString format;
	TQDateTime timestamp;
	mutable int age;
	bool fast_url;
	bool priority;
	int fileSize() const;
	int imageSize() const;
	int thumbnailSize() const;
	bool reduceSize();
	bool isEmpty() const;

	typedef KSharedPtr<ImageData> Ptr;
};

typedef TQMap<KURL, ImageData::Ptr> ImageMap;

struct Cache::Private {
	ImageMap mImages;
	int mMaxSize;
	int mThumbnailSize;
	TQValueList< KURL > mPriorityURLs;


	/**
	 * This function tries to returns a valid ImageData for url and timestamp.
	 * If it can't find one, it will create a new one and return it.
	 */
	ImageData::Ptr getOrCreateImageData(const KURL& url, const TQDateTime& timestamp) {
		if (mImages.contains(url)) {
			ImageData::Ptr data = mImages[url];
			if (data->timestamp == timestamp) return data;
		}

		ImageData::Ptr data = new ImageData(url, timestamp);
		mImages[url] = data;
		if (mPriorityURLs.contains(url)) data->priority = true;
		return data;
	}
};


Cache::Cache()
{
	d = new Private;
	d->mMaxSize = DEFAULT_MAXSIZE;
	// don't remember size for every thumbnail, but have one global and dump all if needed
	d->mThumbnailSize = 0;
}


Cache::~Cache() {
	d->mImages.clear();
	delete d;
}


static Cache* sCache;
static KStaticDeleter<Cache> sCacheDeleter;


Cache* Cache::instance() {
	if (!sCache) {
		sCacheDeleter.setObject(sCache, new Cache());
	}
	return sCache;
}

// Priority URLs are used e.g. when prefetching for the slideshow - after an image is prefetched,
// the loader tries to put the image in the cache. When the slideshow advances, the next loader
// just gets the image from the cache. However, the prefetching may be useless if the image
// actually doesn't stay long enough in the cache, e.g. because of being too big for the cache.
// Marking an URL as a priority one will make sure it stays in the cache and that the cache
// will be even enlarged as necessary if needed.
void Cache::setPriorityURL( const KURL& url, bool set ) {
	if( set ) {
		d->mPriorityURLs.append( url );
		if( d->mImages.contains( url )) {
			d->mImages[ url ]->priority = true;
		}
	} else {
		d->mPriorityURLs.remove( url );
		if( d->mImages.contains( url )) {
			d->mImages[ url ]->priority = false;
		}
		checkMaxSize();
	}
}


void Cache::addFile( const KURL& url, const TQByteArray& file, const TQDateTime& timestamp ) {
	LOG(url.prettyURL());
	updateAge();
	d->getOrCreateImageData(url, timestamp)->addFile(file);
	checkMaxSize();
}

void Cache::addImage( const KURL& url, const ImageFrames& frames, const TQCString& format, const TQDateTime& timestamp ) {
	LOG(url.prettyURL());
	updateAge();
	d->getOrCreateImageData(url, timestamp)->addImage(frames, format);
	checkMaxSize();
}

void Cache::addThumbnail( const KURL& url, const TQPixmap& thumbnail, TQSize imagesize, const TQDateTime& timestamp ) {
// Thumbnails are many and often - things would age too quickly. Therefore
// when adding thumbnails updateAge() is called from the outside only once for all of them.
//	updateAge();
	d->getOrCreateImageData(url, timestamp)->addThumbnail(thumbnail, imagesize);
	checkMaxSize();
}

void Cache::tqinvalidate( const KURL& url ) {
	d->mImages.remove( url );
}

TQDateTime Cache::timestamp( const KURL& url ) const {
	LOG(url.prettyURL());
	if( d->mImages.contains( url )) return d->mImages[ url ]->timestamp;
	return TQDateTime();
}

TQByteArray Cache::file( const KURL& url ) const {
	LOG(url.prettyURL());
	if( d->mImages.contains( url )) {
		const ImageData::Ptr data = d->mImages[ url ];
		if( data->file.isNull()) return TQByteArray();
		data->age = 0;
		return data->file;
	}
	return TQByteArray();
}

void Cache::getFrames( const KURL& url, ImageFrames* frames, TQCString* format ) const {
	LOG(url.prettyURL());
	Q_ASSERT(frames);
	Q_ASSERT(format);
	frames->clear();
	*format = TQCString();
	if( d->mImages.contains( url )) {
		const ImageData::Ptr data = d->mImages[ url ];
		if( data->frames.isEmpty()) return;
		*frames = data->frames;
		*format = data->format;
		data->age = 0;
	}
}

TQPixmap Cache::thumbnail( const KURL& url, TQSize& imagesize ) const {
	if( d->mImages.contains( url )) {
		const ImageData::Ptr data = d->mImages[ url ];
		if( data->thumbnail.isNull()) return TQPixmap();
		imagesize = data->imagesize;
//		data.age = 0;
		return data->thumbnail;
	}
	return TQPixmap();
}

void Cache::updateAge() {
	for( ImageMap::Iterator it = d->mImages.begin();
		it != d->mImages.end();
		++it ) {
		(*it)->age++;
	}
}

void Cache::checkThumbnailSize( int size ) {
	if( size != d->mThumbnailSize ) {
		// simply remove all thumbnails, should happen rarely
		for( ImageMap::Iterator it = d->mImages.begin();
			it != d->mImages.end();
			) {
			if( !(*it)->thumbnail.isNull()) {
				ImageMap::Iterator it2 = it;
				++it;
				d->mImages.remove( it2 );
			} else {
				++it;
			}
		}
		d->mThumbnailSize = size;
	}
}

#ifdef DEBUG_CACHE
static KURL _cache_url; // hack only for debugging for item to show also its key
#endif

void Cache::checkMaxSize() {
	for(;;) {
		int size = 0;
		ImageMap::Iterator max;
		long long max_cost = -1;
#ifdef DEBUG_CACHE
		int with_file = 0;
		int with_thumb = 0;
		int with_image = 0;
#endif
		for( ImageMap::Iterator it = d->mImages.begin();
			it != d->mImages.end();
			++it ) {
			size += (*it)->size();
#ifdef DEBUG_CACHE
			if( !(*it).file.isNull()) ++with_file;
			if( !(*it).thumbnail.isNull()) ++with_thumb;
			if( !(*it).frames.isEmpty()) ++with_image;
#endif
			long long cost = (*it)->cost();
			if( cost > max_cost && ! (*it)->priority ) {
				max_cost = cost;
				max = it;
			}
		}
		if( size <= d->mMaxSize || max_cost == -1 ) {
#if 0
#ifdef DEBUG_CACHE
			kdDebug() << "Cache: Statistics (" << d->mImages.size() << "/" << with_file << "/"
				<< with_thumb << "/" << with_image << ")" << endl;
#endif
#endif
			break;
		}
#ifdef DEBUG_CACHE
		_cache_url = max.key();
#endif

		if( !(*max)->reduceSize() || (*max)->isEmpty()) d->mImages.remove( max );
	}
}

void Cache::readConfig(KConfig* config,const TQString& group) {
	KConfigGroupSaver saver( config, group );
	d->mMaxSize = config->readNumEntry( CONFIG_CACHE_MAXSIZE, d->mMaxSize );
	checkMaxSize();
}


void ImageData::addFile( const TQByteArray& f ) {
	file = f;
	file.detach(); // explicit sharing
	age = 0;
}

void ImageData::addImage( const ImageFrames& fs, const TQCString& f ) {
	frames = fs;
	format = f;
	age = 0;
}

void ImageData::addThumbnail( const TQPixmap& thumb, TQSize imgsize ) {
	thumbnail = thumb;
	imagesize = imgsize;
//	age = 0;
}

int ImageData::size() const {
	return TQMAX( fileSize() + imageSize() + thumbnailSize(), 100 ); // some minimal size per item
}

int ImageData::fileSize() const {
	return !file.isNull() ? file.size() : 0;
}

int ImageData::thumbnailSize() const {
	return !thumbnail.isNull() ? thumbnail.height() * thumbnail.width() * thumbnail.depth() / 8 : 0;
}

int ImageData::imageSize() const {
	int ret = 0;
	for( ImageFrames::ConstIterator it = frames.begin(); it != frames.end(); ++it ) {
		ret += (*it).image.height() * (*it).image.width() * (*it).image.depth() / 8;
	}
	return ret;
}

bool ImageData::reduceSize() {
	if( !file.isNull() && fast_url && !frames.isEmpty()) {
		file = TQByteArray();
#ifdef DEBUG_CACHE
		kdDebug() << "Cache: Dumping fast file: " << _cache_url.prettyURL() << ":" << cost() << endl;
#endif
		return true;
	}
	if( !thumbnail.isNull()) {
#ifdef DEBUG_CACHE
		kdDebug() << "Cache: Dumping thumbnail: " << _cache_url.prettyURL() << ":" << cost() << endl;
#endif
		thumbnail = TQPixmap();
		return true;
	}
	if( !file.isNull() && !frames.isEmpty()) {
	// possibly slow file to fetch - dump the image data unless the image
	// is JPEG (which needs raw data anyway) or the raw data much larger than the image
		if( format == "JPEG" || fileSize() < imageSize() / 10 ) {
			frames.clear();
#ifdef DEBUG_CACHE
			kdDebug() << "Cache: Dumping images: " << _cache_url.prettyURL() << ":" << cost() << endl;
#endif
		} else {
			file = TQByteArray();
#ifdef DEBUG_CACHE
			kdDebug() << "Cache: Dumping file: " << _cache_url.prettyURL() << ":" << cost() << endl;
#endif
		}
		return true;
	}
#ifdef DEBUG_CACHE
	kdDebug() << "Cache: Dumping completely: " << _cache_url.prettyURL() << ":" << cost() << endl;
#endif
	return false; // reducing here would mean clearing everything
}

bool ImageData::isEmpty() const {
	return file.isNull() && frames.isEmpty() && thumbnail.isNull();
}

long long ImageData::cost() const {
	long long s = size();
	if( fast_url && !file.isNull()) {
		s *= ( format == "JPEG" ? 10 : 100 ); // heavy penalty for storing local files
	} else if( !thumbnail.isNull()) {
		s *= 10 * 10; // thumbnails are small, and try to get rid of them soon
	}
	static const int mod[] = { 50, 30, 20, 16, 12, 10 };
	if( age <= 5 ) {
		return s * 10 / mod[ age ];
	} else {
		return s * ( age - 5 );
	}
}

} // namespace