improve DOM walking performances on the 'base' and 'noqsa' versions b…

…y using the native traversal API were available
dperini · Jul 24, 2017 · 413d17c · 413d17c
1 parent 0daa432
commit 413d17c
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Showing 2 changed files with 20 additions and 4 deletions.
diff --git a/src/nwmatcher-base.js b/src/nwmatcher-base.js
@@ -126,6 +126,10 @@
     'text': 1, 'type': 1, 'valign': 1, 'valuetype': 1, 'vlink': 1
   },
 
+  NATIVE_TRAVERSAL_API =
+    'nextElementSibling' in root &&
+    'previousElementSibling' in root,
+
   Selectors = { },
 
   Operators = {
@@ -512,11 +516,15 @@
         }
 
         else if ((match = selector.match(Patterns.adjacent))) {
-          source = 'var N' + k + '=e;while((e=e.previousSibling)){if(e.nodeType==1){' + source + 'break;}}e=N' + k + ';';
+          source = NATIVE_TRAVERSAL_API ?
+            'var N' + k + '=e;if((e=e.previousElementSibling)){' + source + '}e=N' + k + ';' :
+            'var N' + k + '=e;while((e=e.previousSibling)){if(e.nodeType==1){' + source + 'break;}}e=N' + k + ';';
         }
 
         else if ((match = selector.match(Patterns.relative))) {
-          source = 'var N' + k + '=e;while((e=e.previousSibling)){if(e.nodeType==1){' + source + '}}e=N' + k + ';';
+          source = NATIVE_TRAVERSAL_API ?
+            'var N' + k + '=e;while((e=e.previousElementSibling)){' + source + '}e=N' + k + ';' :
+            'var N' + k + '=e;while((e=e.previousSibling)){if(e.nodeType==1){' + source + '}}e=N' + k + ';';
         }
 
         else if ((match = selector.match(Patterns.children))) {

diff --git a/src/nwmatcher-noqsa.js b/src/nwmatcher-noqsa.js
@@ -129,6 +129,10 @@
     'text': 1, 'type': 1, 'valign': 1, 'valuetype': 1, 'vlink': 1
   },
 
+  NATIVE_TRAVERSAL_API =
+    'nextElementSibling' in root &&
+    'previousElementSibling' in root,
+
   Selectors = { },
 
   Operators = {
@@ -562,11 +566,15 @@
         }
 
         else if ((match = selector.match(Patterns.adjacent))) {
-          source = 'var N' + k + '=e;while((e=e.previousSibling)){if(e.nodeType==1){' + source + 'break;}}e=N' + k + ';';
+          source = NATIVE_TRAVERSAL_API ?
+            'var N' + k + '=e;if((e=e.previousElementSibling)){' + source + '}e=N' + k + ';' :
+            'var N' + k + '=e;while((e=e.previousSibling)){if(e.nodeType==1){' + source + 'break;}}e=N' + k + ';';
         }
 
         else if ((match = selector.match(Patterns.relative))) {
-          source = 'var N' + k + '=e;while((e=e.previousSibling)){if(e.nodeType==1){' + source + '}}e=N' + k + ';';
+          source = NATIVE_TRAVERSAL_API ?
+            'var N' + k + '=e;while((e=e.previousElementSibling)){' + source + '}e=N' + k + ';' :
+            'var N' + k + '=e;while((e=e.previousSibling)){if(e.nodeType==1){' + source + '}}e=N' + k + ';';
         }
 
         else if ((match = selector.match(Patterns.children))) {