src/graphics/GraphicsCacheItem.cpp

   1 /**
   2  * \file GraphicsCacheItem.cpp
   3  * This file is part of LyX, the document processor.
   4  * Licence details can be found in the file COPYING.
   5  *
   6  * \author Baruch Even
   7  * \author Herbert Voß
   8  * \author Angus Leeming
   9  *
  10  * Full author contact details are available in file CREDITS.
  11  */
  12
  13 #include <config.h>
  14
  15 #include "GraphicsCacheItem.h"
  16
  17 #include "GraphicsCache.h"
  18 #include "GraphicsConverter.h"
  19 #include "GraphicsImage.h"
  20
  21 #include "ConverterCache.h"
  22 #include "Format.h"
  23
  24 #include "support/debug.h"
  25 #include "support/FileName.h"
  26 #include "support/filetools.h"
  27 #include "support/FileMonitor.h"
  28
  29 #include <boost/bind.hpp>
  30
  31 using namespace std;
  32 using namespace lyx::support;
  33
  34 namespace lyx {
  35
  36 namespace graphics {
  37
  38 class CacheItem::Impl : public boost::signals::trackable {
  39 public:
  40
  41         ///
  42         Impl(FileName const & file);
  43
  44         /**
  45          *  If no file conversion is needed, then tryDisplayFormat() calls
  46          *  loadImage() directly.
  47          * \return true if a conversion is necessary and no error occurred.
  48          */
  49         bool tryDisplayFormat(FileName & filename, string & from);
  50
  51         /** Start the image conversion process, checking first that it is
  52          *  necessary. If it is necessary, then a conversion task is started.
  53          *  CacheItem asumes that the conversion is asynchronous and so
  54          *  passes a Signal to the converting routine. When the conversion
  55          *  is finished, this Signal is emitted, returning the converted
  56          *  file to this->imageConverted.
  57          *
  58          *  convertToDisplayFormat() will set the loading status flag as
  59          *  approriate through calls to setStatus().
  60          */
  61         void convertToDisplayFormat();
  62
  63         /** Load the image into memory. This is called either from
  64          *  convertToDisplayFormat() direct or from imageConverted().
  65          */
  66         bool loadImage();
  67
  68         /** Get a notification when the image conversion is done.
  69          *  Connected to a signal on_finish_ which is passed to
  70          *  Converter::convert.
  71          */
  72         void imageConverted(bool);
  73
  74         /** Sets the status of the loading process. Also notifies
  75          *  listeners that the status has changed.
  76          */
  77         void setStatus(ImageStatus new_status);
  78
  79         /** Can be invoked directly by the user, but is also connected to the
  80          *  FileMonitor and so is invoked when the file is changed
  81          *  (if monitoring is taking place).
  82          */
  83         void startLoading();
  84
  85         /** If we are asked to load the file for a second or further time,
  86          *  (because the file has changed), then we'll have to first reset
  87          *  many of the variables below.
  88          */
  89         void reset();
  90
  91         /// The filename we refer too.
  92         FileName const filename_;
  93         ///
  94         FileMonitor const monitor_;
  95
  96         /// Is the file compressed?
  97         bool zipped_;
  98         /// If so, store the uncompressed file in this temporary file.
  99         FileName unzipped_filename_;
 100         /// The target format
 101         string to_;
 102         /// What file are we trying to load?
 103         FileName file_to_load_;
 104         /** Should we delete the file after loading? True if the file is
 105          *  the result of a conversion process.
 106          */
 107         bool remove_loaded_file_;
 108
 109         /// The image and its loading status.
 110         boost::shared_ptr<Image> image_;
 111         ///
 112         ImageStatus status_;
 113
 114         /// This signal is emitted when the image loading status changes.
 115         boost::signal<void()> statusChanged;
 116
 117         /// The connection of the signal ConvProcess::finishedConversion,
 118         boost::signals::connection cc_;
 119
 120         ///
 121         boost::scoped_ptr<Converter> converter_;
 122 };
 123
 124
 125 CacheItem::CacheItem(FileName const & file)
 126         : pimpl_(new Impl(file))
 127 {}
 128
 129
 130 CacheItem::~CacheItem()
 131 {
 132         delete pimpl_;
 133 }
 134
 135
 136 FileName const & CacheItem::filename() const
 137 {
 138         return pimpl_->filename_;
 139 }
 140
 141
 142 bool CacheItem::tryDisplayFormat() const
 143 {
 144         if (pimpl_->status_ != WaitingToLoad)
 145                 pimpl_->reset();
 146         FileName filename;
 147         string from;
 148         bool const conversion_needed = pimpl_->tryDisplayFormat(filename, from);
 149         bool const success = status() == Loaded && !conversion_needed;
 150         if (!success)
 151                 pimpl_->reset();
 152         return success;
 153 }
 154
 155
 156 void CacheItem::startLoading() const
 157 {
 158         pimpl_->startLoading();
 159 }
 160
 161
 162 void CacheItem::startMonitoring() const
 163 {
 164         if (!pimpl_->monitor_.monitoring())
 165                 pimpl_->monitor_.start();
 166 }
 167
 168
 169 bool CacheItem::monitoring() const
 170 {
 171         return pimpl_->monitor_.monitoring();
 172 }
 173
 174
 175 unsigned long CacheItem::checksum() const
 176 {
 177         return pimpl_->monitor_.checksum();
 178 }
 179
 180
 181 Image const * CacheItem::image() const
 182 {
 183         return pimpl_->image_.get();
 184 }
 185
 186
 187 ImageStatus CacheItem::status() const
 188 {
 189         return pimpl_->status_;
 190 }
 191
 192
 193 boost::signals::connection CacheItem::connect(slot_type const & slot) const
 194 {
 195         return pimpl_->statusChanged.connect(slot);
 196 }
 197
 198
 199 //------------------------------
 200 // Implementation details follow
 201 //------------------------------
 202
 203
 204 CacheItem::Impl::Impl(FileName const & file)
 205         : filename_(file),
 206           monitor_(file, 2000),
 207           zipped_(false),
 208           remove_loaded_file_(false),
 209           status_(WaitingToLoad)
 210 {
 211         monitor_.connect(boost::bind(&Impl::startLoading, this));
 212 }
 213
 214
 215 void CacheItem::Impl::startLoading()
 216 {
 217         if (status_ != WaitingToLoad)
 218                 reset();
 219
 220         convertToDisplayFormat();
 221 }
 222
 223
 224 void CacheItem::Impl::reset()
 225 {
 226         zipped_ = false;
 227         if (!unzipped_filename_.empty())
 228                 unzipped_filename_.removeFile();
 229         unzipped_filename_.erase();
 230
 231         if (remove_loaded_file_ && !file_to_load_.empty())
 232                 file_to_load_.removeFile();
 233         remove_loaded_file_ = false;
 234         file_to_load_.erase();
 235         to_.erase();
 236
 237         if (image_.get())
 238                 image_.reset();
 239
 240         status_ = WaitingToLoad;
 241
 242         if (cc_.connected())
 243                 cc_.disconnect();
 244
 245         if (converter_.get())
 246                 converter_.reset();
 247 }
 248
 249
 250 void CacheItem::Impl::setStatus(ImageStatus new_status)
 251 {
 252         if (status_ == new_status)
 253                 return;
 254
 255         status_ = new_status;
 256         statusChanged();
 257 }
 258
 259
 260 void CacheItem::Impl::imageConverted(bool success)
 261 {
 262         string const text = success ? "succeeded" : "failed";
 263         LYXERR(Debug::GRAPHICS, "Image conversion " << text << '.');
 264
 265         file_to_load_ = converter_.get() ?
 266                 FileName(converter_->convertedFile()) : FileName();
 267         converter_.reset();
 268         cc_.disconnect();
 269
 270         success = !file_to_load_.empty() && file_to_load_.isReadableFile();
 271
 272         if (!success) {
 273                 LYXERR(Debug::GRAPHICS, "Unable to find converted file!");
 274                 setStatus(ErrorConverting);
 275
 276                 if (zipped_)
 277                         unzipped_filename_.removeFile();
 278
 279                 return;
 280         }
 281
 282         // Add the converted file to the file cache
 283         ConverterCache::get().add(filename_, to_, file_to_load_);
 284
 285         setStatus(loadImage() ? Loaded : ErrorLoading);
 286 }
 287
 288
 289 // This function gets called from the callback after the image has been
 290 // converted successfully.
 291 bool CacheItem::Impl::loadImage()
 292 {
 293         LYXERR(Debug::GRAPHICS, "Loading image.");
 294
 295         image_.reset(newImage());
 296
 297         bool success = image_->load(file_to_load_);
 298         string const text = success ? "succeeded" : "failed";
 299         LYXERR(Debug::GRAPHICS, "Image loading " << text << '.');
 300
 301         // Clean up after loading.
 302         if (zipped_)
 303                 unzipped_filename_.removeFile();
 304
 305         if (remove_loaded_file_ && unzipped_filename_ != file_to_load_)
 306                 file_to_load_.removeFile();
 307
 308         return success;
 309 }
 310
 311
 312 static string const findTargetFormat(string const & from)
 313 {
 314         typedef vector<string> FormatList;
 315         FormatList const & formats = Cache::get().loadableFormats();
 316
 317          // There must be a format to load from.
 318         LASSERT(!formats.empty(), /**/);
 319
 320         // Use the standard converter if we don't know the format to load
 321         // from.
 322         if (from.empty())
 323                 return string("ppm");
 324
 325         // First ascertain if we can load directly with no conversion
 326         FormatList::const_iterator it  = formats.begin();
 327         FormatList::const_iterator end = formats.end();
 328         for (; it != end; ++it) {
 329                 if (from == *it)
 330                         return *it;
 331         }
 332
 333         // So, we have to convert to a loadable format. Can we?
 334         it = formats.begin();
 335         for (; it != end; ++it) {
 336                 if (lyx::graphics::Converter::isReachable(from, *it))
 337                         return *it;
 338                 else
 339                         LYXERR(Debug::GRAPHICS, "Unable to convert from " << from
 340                                 << " to " << *it);
 341         }
 342
 343         // Failed! so we have to try to convert it to PPM format
 344         // with the standard converter
 345         return string("ppm");
 346 }
 347
 348
 349 bool CacheItem::Impl::tryDisplayFormat(FileName & filename, string & from)
 350 {
 351         // First, check that the file exists!
 352         // force a refresh.
 353         filename_.lastModified();
 354         if (!filename_.isReadableFile()) {
 355                 if (status_ != ErrorNoFile) {
 356                         status_ = ErrorNoFile;
 357                         LYXERR(Debug::GRAPHICS, "\tThe file is not readable");
 358                 }
 359                 return false;
 360         }
 361
 362         zipped_ = filename_.isZippedFile();
 363         if (zipped_) {
 364                 unzipped_filename_ = FileName::tempName(
 365                         filename_.toFilesystemEncoding());
 366                 if (unzipped_filename_.empty()) {
 367                         status_ = ErrorConverting;
 368                         LYXERR(Debug::GRAPHICS, "\tCould not create temporary file.");
 369                         return false;
 370                 }
 371                 filename = unzipFile(filename_, unzipped_filename_.toFilesystemEncoding());
 372         } else {
 373                 filename = filename_;
 374         }
 375
 376         docstring const displayed_filename = makeDisplayPath(filename_.absFilename());
 377         LYXERR(Debug::GRAPHICS, "[CacheItem::Impl::convertToDisplayFormat]\n"
 378                 << "\tAttempting to convert image file: " << filename
 379                 << "\n\twith displayed filename: " << to_utf8(displayed_filename));
 380
 381         from = formats.getFormatFromFile(filename);
 382         if (from.empty()) {
 383                 status_ = ErrorConverting;
 384                 LYXERR(Debug::GRAPHICS, "\tCould not determine file format.");
 385         }
 386         LYXERR(Debug::GRAPHICS, "\n\tThe file contains " << from << " format data.");
 387         to_ = findTargetFormat(from);
 388
 389         if (from == to_) {
 390                 // No conversion needed!
 391                 LYXERR(Debug::GRAPHICS, "\tNo conversion needed (from == to)!");
 392                 file_to_load_ = filename;
 393                 status_ = loadImage() ? Loaded : ErrorLoading;
 394                 return false;
 395         }
 396
 397         if (ConverterCache::get().inCache(filename, to_)) {
 398                 LYXERR(Debug::GRAPHICS, "\tNo conversion needed (file in file cache)!");
 399                 file_to_load_ = ConverterCache::get().cacheName(filename, to_);
 400                 status_ = loadImage() ? Loaded : ErrorLoading;
 401                 return false;
 402         }
 403         return true;
 404 }
 405
 406
 407 void CacheItem::Impl::convertToDisplayFormat()
 408 {
 409         LYXERR(Debug::GRAPHICS, "\tConverting it to " << to_ << " format.");
 410
 411         // Make a local copy in case we unzip it
 412         FileName filename;
 413         string from;
 414         if (!tryDisplayFormat(filename, from)) {
 415                 // The image status has changed, tell it to the outside world.
 416                 statusChanged();
 417                 return;
 418         }
 419
 420         // We will need a conversion, tell it to the outside world.
 421         setStatus(Converting);
 422
 423         // Add some stuff to create a uniquely named temporary file.
 424         // This file is deleted in loadImage after it is loaded into memory.
 425         FileName const to_file_base = FileName::tempName("CacheItem");
 426         remove_loaded_file_ = true;
 427
 428         // Connect a signal to this->imageConverted and pass this signal to
 429         // the graphics converter so that we can load the modified file
 430         // on completion of the conversion process.
 431         converter_.reset(new Converter(filename, to_file_base.absFilename(), from, to_));
 432         converter_->connect(boost::bind(&Impl::imageConverted, this, _1));
 433         converter_->startConversion();
 434 }
 435
 436 } // namespace graphics
 437 } // namespace lyx