switch optimization

2011-08-14 16:34:19 -05:00 · 2011-08-14 16:34:19 -05:00 · 03c5fa3d19
commit 03c5fa3d19
parent 180747dbdc
1 changed files with 3 additions and 11 deletions
--- a/pdf.js
+++ b/pdf.js
@ -2081,17 +2081,9 @@ var LZWStream = (function() {
        dictionaryLengths[nextCode] = dictionaryLengths[prevCode] + 1;
        dictionaryValues[nextCode] = currentSequence[0];
        nextCode++;
-        switch (nextCode + earlyChange) {
-          case 512:
-            codeLength = 10;
-            break;
-          case 1024:
-            codeLength = 11;
-            break;
-          case 2048:
-            codeLength = 12;
-            break;
-        }
+        codeLength = (nextCode + earlyChange) & (nextCode + earlyChange - 1) ?
+          codeLength : Math.min(Math.log(nextCode + earlyChange) /
+          0.6931471805599453 + 1, 12) | 0;
      }
      prevCode = code;