MDict: User friendly error reporting for article request

mdx.cc

@@ -66,6 +66,8 @@ enum
   kCurrentFormatVersion = 7 + BtreeIndexing::FormatVersion
 };
 
+DEF_EX( exCorruptDictionary, "dictionary file was tampered or corrupted", std::exception )
+
 struct IdxHeader
 {
   uint32_t signature; // First comes the signature, MDIC
@@ -259,7 +261,7 @@ private:
   void loadArticle( uint32_t offset, string & articleText );
 
   /// Process resource links (images, audios, etc)
-  string filterResource( const char * articleId, const char * article );
+  QString & filterResource( QString const & articleId, QString & article );
 
   friend class MdxHeadwordsRequest;
   friend class MdxArticleRequest;
@@ -533,8 +535,32 @@ void MdxArticleRequest::run()
 
     // Grab that article
     string articleBody;
+    bool hasError = false;
+    QString errorMessage;
 
+    try
+    {
       dict.loadArticle( chain[ x ].articleOffset, articleBody );
+    }
+    catch ( exCorruptDictionary & )
+    {
+      errorMessage = "Dictionary file was tampered or corrupted";
+      hasError = true;
+    }
+    catch ( std::exception & e )
+    {
+      errorMessage = e.what();
+      hasError = true;
+    }
+
+    if ( hasError )
+    {
+      setErrorString( tr( "Failed loading article from %1, reason: %2" )
+                      .arg( QString::fromUtf8( dict.getDictionaryFilenames()[ 0 ].c_str() ) )
+                      .arg( errorMessage ) );
+      finish();
+      return;
+    }
 
     if ( articlesIncluded.find( chain[ x ].articleOffset ) != articlesIncluded.end() )
       continue; // We already have this article in the body.
@@ -762,8 +788,6 @@ void MdxDictionary::loadIcon() throw()
   dictionaryIconLoaded = true;
 }
 
-DEF_EX( exCorruptDictionary, "dictionary file tampered or corrupted", std::exception )
-
 void MdxDictionary::loadArticle( uint32_t offset, string & articleText )
 {
   vector< char > chunk;
@@ -774,14 +798,10 @@ void MdxDictionary::loadArticle( uint32_t offset, string & articleText )
   char * pRecordInfo = chunks.getBlock( offset, chunk );
   memcpy( &recordInfo, pRecordInfo, sizeof( recordInfo ) );
 
-  // Make an sub unique id for this article
+  // Make a sub unique id for this article
   QString articleId;
   articleId.setNum( ( quint64 )pRecordInfo, 16 );
 
-  articleText = string( QObject::tr( "Article loading error" ).toUtf8().constData() );
-
-  try
-  {
   ScopedMemMap compressed( dictFile, recordInfo.compressedBlockPos, recordInfo.compressedBlockSize );
   if ( !compressed.startAddress() )
     throw exCorruptDictionary();
@@ -789,35 +809,25 @@ void MdxDictionary::loadArticle( uint32_t offset, string & articleText )
   QByteArray decompressed;
   if ( !MdictParser::parseCompressedBlock( recordInfo.compressedBlockSize, ( char * )compressed.startAddress(),
                                            recordInfo.decompressedBlockSize, decompressed ) )
-      return;
+    throw exCorruptDictionary();
 
   QString article = MdictParser::toUtf16( encoding.c_str(),
                                           decompressed.constData() + recordInfo.recordOffset,
                                           recordInfo.recordSize );
 
   article = MdictParser::substituteStylesheet( article, styleSheets );
-    articleText = filterResource( articleId.toLatin1().constData(), article.toUtf8().constData() );
+  article = filterResource( articleId, article );
-  }
+  articleText = string( article.toUtf8().constData() );
-  catch ( std::exception & e )
-  {
-    FDPRINTF( stderr, "MDict: load article from %s failed, error: %s\n",
-              getDictionaryFilenames()[ 0 ].c_str(), e.what() );
-  }
-  catch ( ... )
-  {
-    FDPRINTF( stderr, "MDict: load article from %s failed, error: %s\n",
-              getDictionaryFilenames()[ 0 ].c_str(), "unknown error" );
-  }
 }
 
-string MdxDictionary::filterResource( const char * articleId, const char * article )
+QString & MdxDictionary::filterResource( QString const & articleId, QString & article )
 {
   QString id = QString::fromStdString( getId() );
-  QString uniquePrefix = QString::fromStdString( getId() + "_" + articleId + "_" );
+  QString uniquePrefix = id + "_" + articleId + "_";
   QRegExp anchorLinkRe( "(<\\s*a\\s+[^>]*\\b(?:name|id)\\b\\s*=\\s*[\"']*)(?=[^\"'])", Qt::CaseInsensitive );
   anchorLinkRe.setMinimal( true );
 
-  return string( QString::fromUtf8( article )
+  return article
          // anchors
          .replace( anchorLinkRe,
                    "\\1" + uniquePrefix )
@@ -843,8 +853,7 @@ string MdxDictionary::filterResource( const char * articleId, const char * artic
                    "\\1bres://" + id + "/\\2" )
          .replace( QRegExp( "(<\\s*img\\s+[^>]*\\bsrc\\b\\s*=\\s*)(?!['\"]+)(?!bres:|data:)(?:file://)?([^\\s>]+)",
                             Qt::CaseInsensitive, QRegExp::RegExp2 ),
-                           "\\1\"bres://" + id + "/\\2\"" )
+                   "\\1\"bres://" + id + "/\\2\"" );
-                 .toUtf8().constData() );
 }
 
 static void addEntryToIndex( QString const & word, uint32_t offset, IndexedWords & indexedWords )