From fbfca0d10f3cc5ad57c16f304bf8b3e6b3396db5 Mon Sep 17 00:00:00 2001
From: Ori Livneh <ori@wikimedia.org>
Date: Thu, 31 Oct 2013 09:26:40 -0700
Subject: [PATCH] mw.inspect: add report for mw.loader.store

Adds a 'store' report to mw.inspect, which outputs:
* Whether localStorage module caching is enabled.
* Cache hit / miss counts.
* Number of items purged from the cache.
* Total size of the cache blob in localStorage.

Rather than duplicate the logic that converted a numeric byte count to a
human-readable format, I moved it to new helper function: humanSize.

Change-Id: I5b98322ba843f32e6a99829b4cf3d8fb0bc61514
---
 resources/mediawiki/mediawiki.inspect.js | 28 +++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/resources/mediawiki/mediawiki.inspect.js b/resources/mediawiki/mediawiki.inspect.js
index 668aa2af7d..d93254b03a 100644
--- a/resources/mediawiki/mediawiki.inspect.js
+++ b/resources/mediawiki/mediawiki.inspect.js
@@ -14,6 +14,13 @@
 		} );
 	}
 
+	function humanSize( bytes ) {
+		if ( !$.isNumeric( bytes ) || bytes === 0 ) { return bytes; }
+		var i = 0, units = [ '', ' kB', ' MB', ' GB', ' TB', ' PB' ];
+		for ( ; bytes >= 1024; bytes /= 1024 ) { i++; }
+		return bytes.toFixed( 1 ) + units[i];
+	}
+
 	/**
 	 * @class mw.inspect
 	 * @singleton
@@ -181,9 +188,7 @@
 
 				// Convert size to human-readable string.
 				$.each( modules, function ( i, module ) {
-					module.size = module.size > 1024 ?
-						( module.size / 1024 ).toFixed( 2 ) + ' KB' :
-						( module.size !== null ? module.size + ' B' : null );
+					module.size = humanSize( module.size );
 				} );
 
 				return modules;
@@ -214,6 +219,23 @@
 				} );
 				sortByProperty( modules, 'allSelectors', true );
 				return modules;
+			},
+
+			/**
+			 * Report stats on mw.loader.store: the number of localStorage
+			 * cache hits and misses, the number of items purged from the
+			 * cache, and the total size of the module blob in localStorage.
+			 */
+			store: function () {
+				var raw, stats = { enabled: mw.loader.store.enabled };
+				if ( stats.enabled ) {
+					$.extend( stats, mw.loader.store.stats );
+					try {
+						raw = localStorage.getItem( mw.loader.store.getStoreKey() );
+						stats.totalSize = humanSize( $.byteLength( raw ) );
+					} catch (e) {}
+				}
+				return [stats];
 			}
 		}
 	};
-- 
2.20.1