code review 6999045: go.net/publicsuffix: tighten the encoding from 8 bytes ...

publicsuffix/list.go

 // Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 // Package publicsuffix provides a public suffix list based on data from
 // http://publicsuffix.org/. A public suffix is one under which Internet users
 // can directly register names.
 package publicsuffix
 
 // TODO(nigeltao): do we need to distinguish between ICANN domains and private
@@ skipping 24 matching lines @@
                         suffix = 1 + dot
                 }
                 if lo == hi {
                         break
                 }
                 f := find(s[1+dot:], lo, hi)
                 if f == notFound {
                         break
                 }
 
-                u := nodes[f][0]
-                lo = u & 0xffff
-                u >>= 16
-                hi = u&0x1fff + lo
-                u >>= 13
-                wildcard = u&0x01 != 0
-                u >>= 1
-                switch u {
+                u := nodes[f] >> (nodesBitsTextOffset + nodesBitsTextLength)
+                switch u & (1<<nodesBitsNodeType - 1) {
                 case nodeTypeNormal:
                         suffix = 1 + dot
                 case nodeTypeException:
                         suffix = 1 + len(s)
                         break loop
                 }
+                u >>= nodesBitsNodeType
+
+                u = children[u&(1<<nodesBitsChildren-1)]
+                lo = u & (1<<childrenBitsLo - 1)
+                u >>= childrenBitsLo
+                hi = u & (1<<childrenBitsHi - 1)
+                u >>= childrenBitsHi
+                wildcard = u&(1<<childrenBitsWildcard-1) != 0
 
                 if dot == -1 {
                         break
                 }
                 s = s[:dot]
         }
         if suffix == len(domain) {
                 // If no rules match, the prevailing rule is "*".
                 return domain[1+strings.LastIndex(domain, "."):]
         }
@@ skipping 15 matching lines @@
                         return mid
                 } else {
                         hi = mid
                 }
         }
         return notFound
 }
 
 // nodeLabel returns the label for the i'th node.
 func nodeLabel(i uint32) string {
-        x := nodes[i][1]
-        offset, length := x>>8, x&0xff
+        x := nodes[i]
+        length := x & (1<<nodesBitsTextLength - 1)
+        x >>= nodesBitsTextLength
+        offset := x & (1<<nodesBitsTextOffset - 1)
         return text[offset : offset+length]
 }