diff options
| -rw-r--r-- | background_scripts/completion.coffee | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/background_scripts/completion.coffee b/background_scripts/completion.coffee index f1016ebb..8b18ce90 100644 --- a/background_scripts/completion.coffee +++ b/background_scripts/completion.coffee @@ -101,15 +101,8 @@ class HistoryCompleter onComplete(suggestions) computeRelevancy: (queryTerms, suggestion) -> - @oneMonthAgo ||= 1000 * 60 * 60 * 24 * 30 historyEntry = suggestion.extraRelevancyData - recency = Date.now() - historyEntry.lastVisitTime - recencyDifference = Math.max(0, @oneMonthAgo - recency) / @oneMonthAgo - - # recencyScore is between [0, 1]. It is 1 when recenyDifference is 0. This qudratic equation will - # incresingly discount older history entries. - recencyScore = recencyDifference * recencyDifference * recencyDifference - + recencyScore = RankingUtils.recencyScore(historyEntry.lastVisitTime) wordRelevancy = RankingUtils.wordRelevancy(queryTerms, suggestion.url, suggestion.title) # Average out the word score and the recency. Recency has the ability to pull the score up, but not down. score = (wordRelevancy + Math.max(recencyScore, wordRelevancy)) / 2 @@ -165,6 +158,20 @@ RankingUtils = titleScore = titleScore * RankingUtils.normalizeDifference(queryLength, title.length) (urlScore + titleScore) / 2 + # Returns a score between [0, 1] which indicates how recent the given timestamp is. Items which are over + # a month old are counted as 0. This range is quadratic, so an item from one day ago has a much stronger + # score than an item from two days ago. + recencyScore: (lastAccessedTime) -> + @oneMonthAgo ||= 1000 * 60 * 60 * 24 * 30 + recency = Date.now() - lastAccessedTime + recencyDifference = Math.max(0, @oneMonthAgo - recency) / @oneMonthAgo + + # recencyScore is between [0, 1]. It is 1 when recenyDifference is 0. This quadratic equation will + # incresingly discount older history entries. + recencyScore = recencyDifference * recencyDifference * recencyDifference + + + # Takes the difference of two numbers and returns a number between [0, 1] (the percentage difference). normalizeDifference: (a, b) -> max = Math.max(a, b) |