zachbray / hashbang Goto Github PK

Hi Zack,

95% of the compilation time is spent in YuiCompressor.Net. The YuiCompressor.Net implementation uses ArrayLists in way which makes it extremely inefficient when the JavaScript to be compressed contains a large number of short identifiers.

Compilation times on my system and resulting file sizes (the entire HashBang file - HTML + CSS + JavaScript) (release build, 023f8a4):

1. Funscript( compression: on) ~2s, 0.92 MB
2. Funscript( compression: off) ~2 s, 1.27 MB
3. Funscript( compression: on) + YuiCompressor.Net: ~38s, 0.72 MB
4. Funscript( compression: off) + YuiCompressor.Net: ~7s, 1.0 MB

While it is true that option3 (the one currently in use in release mode) achieves the best compression, I am thinking the performance cost is unacceptable - especially in the current scenario, in which the compilation is performed at site start-up.

As an aside, note that utilizing the YuiCompressor to compress uncompressed FunScript-generated JavaScript is both slower and less efficient than using FunScript compression exclusively.

I think that modifying the code to only use the compression achieved by Funscript alone is acceptable at this stage (I vote for modifying HashBang to use option 1, until the performance of 3 can be addressed).

Moving forward, I see two long-term solutions:

1. Optimize YuiCompressor.Net - speaking of which: YuiCompressor.Net fails as of 5385839 (works for 023f8a4 - and I have yet to check at which point it broke).
2. Improve Funscript's native JavaScript compression

Let me know how you'd like to proceed.

Catalin

Line 84 of src/TypeInferred.HashBang.Core/Website.fs reads:

use compressor = new GZipStream(memoryStream, level, false)

In Mono this .NET 4.5 constructor signature throws a NotImplementedException. It has a MonoTODO attribute in the Mono source code at:

https://github.com/mono/mono/blob/master/mcs/class/System/System.IO.Compression/GZipStream.cs

My current work around is to change this line to the following implemented constructor signature:

use compressor = new GZipStream(memoryStream, CompressionMode.Compress, false)

This allows the demo to run however at this time, I am uncertain about the implications of the workaround.

Made a naive attempt just to start playing and got

Unhandled Exception: System.MissingMethodException: Method not found: 'Microsoft.FSharp.Core.FSharpOption`1<System.Tuple`2<ContentType,TypeInferred.HashBang.TypeMetadata>> TypeInferred.HashBang.HandlerMetadata.get_RequestType()'.
   at TypeInferred.HashBang.DynamicWebsite.Start(DynamicWebsite site)
   at StartupCode$CrawlerFriendlyDynamicWebsite>.$CrawlerFriendlyDynamicWebsite.main@() in C:\data3\mw\HashBang\src\Samples\CrawlerFriendlyDynamicWebsite\CrawlerFriendlyDynamicWebsite\Program.fs:line 141
Press any key to continue . . .

Line 140 of src/TypeInferred.HashBang.Core/Website.fs reads:

if metadata.CanCacheResponse then Some CompressionLevel.Optimal

Although this line is correct. Any Mono version below 3.2.4 has a System.IO.Compression.CompressionLevel enum of CompressionLevel.Optional instead of CompressionLevel.Optimal. This is fixed in Mono 3.2.4. The workaround for lower Mono versions is to change line 140 to:

if metadata.CanCacheResponse then Some CompressionLevel.Optional