Hi Charles Yes, NSAttributedString does unique attribute dictionaries.
Aki > On Mar 22, 2015, at 5:39 AM, Charles Jenkins <[email protected]> wrote: > > My app uses lots of attributed strings in “subdocuments” which get moved into > and out of a text edit window. > > I began to wonder if I needed to add a cache for paragraph styles and string > attributes, because when each subdocument gets loaded, I’m repetitively > deserializing identical attributes to apply to the strings. > > Today I wrote the first draft of a test to see what happens when you blindly > and repetitively instantiate the same attributes: > > func attributedStringsWithNoCache() { > var array = [NSAttributedString]() > let fm = NSFontManager.sharedFontManager() > for index in 1...30 { > var font = NSFont( name:"Times", size:12.0 ); > font = fm.convertFont( font!, toHaveTrait:NSFontTraitMask.BoldFontMask ) > if ( index % 3 == 0 ) { > font = fm.convertFont( font!, > toHaveTrait:NSFontTraitMask.ItalicFontMask ) > } > var para = NSMutableParagraphStyle(); > para.lineSpacing = 1.4 > para.alignment = NSTextAlignment.CenterTextAlignment; > let attributes = [ > "StyleName":"Bold", > NSFontAttributeName:font!, > NSParagraphStyleAttributeName:para > ]; > var attrStr = NSAttributedString( string:"Bold Para \(index)", > attributes:attributes ); > array.append( attrStr ); > } > for index in 1...30 { > var font = NSFont( name:"Times", size:10.0 ); > var para = NSMutableParagraphStyle(); > para.lineSpacing = 1.2 > para.alignment = NSTextAlignment.LeftTextAlignment; > let attributes = [ > "StyleName":"Roman", > NSFontAttributeName:font!, > NSParagraphStyleAttributeName:para > ]; > var attrStr = NSAttributedString( string:"Roman Para \(index)", > attributes:attributes ); > array.append( attrStr ); > } > var fontDict = [NSFont:Int]() > var attrDict = [NSDictionary:Int]() > var paraDict = [NSParagraphStyle:Int]() > for attrStr in array { > attrStr.enumerateAttributesInRange( > NSRange( location:0, length:attrStr.length ), > options:NSAttributedStringEnumerationOptions.allZeros, > usingBlock:{ ( attributes, Range, stop ) -> Void in > attrDict[ attributes ] = 1 > if let para = attributes[ NSParagraphStyleAttributeName ] as? > NSParagraphStyle { > paraDict[ para ] = 1 > } > if let font = attributes[ NSFontAttributeName ] as? NSFont { > fontDict[ font ] = 1 > } > }) > } > println( "NO CACHE:\nFound \(fontDict.count) fonts and \(paraDict.count) > paragraph styles in \(attrDict.count) attribute dictionaries" ) > } > > I expected the result to say it found 3 fonts and 60 paragraph styles in 60 > attribute dictionaries. (I know the system uniquifies fonts.) But when I run > the test, I get the best result possible—3 fonts and 2 paragraph styles in 3 > attribute dictionaries—as if NSAttributedString already uniquifies everything. > > Is my test bad somehow, or am I really seeing that the text system already > optimizes memory usage by uniquifying all attribute dictionaries, so I can > forget about doing any caching of my own? > > — > > Charles > _______________________________________________ > > Cocoa-dev mailing list ([email protected]) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/cocoa-dev/aki%40apple.com > > This email sent to [email protected] _______________________________________________ Cocoa-dev mailing list ([email protected]) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [email protected]
