Compute masks in IPAddressV6

Summary:
[Folly] Compute masks in `IPAddressV6`.

At runtime, instead of storing a 2Kb masks array in the binary.

Reviewed By: WillerZ, ot

Differential Revision: D5369901

fbshipit-source-id: 031a4eeda1670021236d8ab97f6e85e753675ae5

diff --git a/folly/IPAddressV6.cpp b/folly/IPAddressV6.cpp
index 1cb2ce6e5e6f9c008904436e48d6d9adab16cbf4..29450f4b08ac6c35c5a7ee398343ac1195a75381 100644 (file)
--- a/folly/IPAddressV6.cpp
+++ b/folly/IPAddressV6.cpp
@@ -469,8 +469,18 @@ const ByteArray16 IPAddressV6::fetchMask(size_t numBits) {
   if (numBits > bits) {
     throw IPAddressFormatException("IPv6 addresses are 128 bits.");
   }
-  // masks_ is backed by an array so is zero indexed
-  return masks_[numBits];
+  if (numBits == 0) {
+    return {{0}};
+  }
+  constexpr auto _0s = uint64_t(0);
+  constexpr auto _1s = ~_0s;
+  auto const fragment = Endian::big(_1s << ((128 - numBits) % 64));
+  auto const hi = numBits <= 64 ? fragment : _1s;
+  auto const lo = numBits <= 64 ? _0s : fragment;
+  uint64_t const parts[] = {hi, lo};
+  ByteArray16 arr;
+  std::memcpy(arr.data(), parts, sizeof(parts));
+  return arr;
 }
 
 // public static
@@ -488,525 +498,4 @@ bool IPAddressV6::inBinarySubnet(const std::array<uint8_t, 2> addr,
   auto masked = mask(numBits);
   return (std::memcmp(addr.data(), masked.bytes(), 2) == 0);
 }
-
-// static private
-const std::array<ByteArray16, 129> IPAddressV6::masks_ = {{
-/* /0   */ {{ 0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /1   */ {{ 0x80,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /2   */ {{ 0xc0,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /3   */ {{ 0xe0,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /4   */ {{ 0xf0,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /5   */ {{ 0xf8,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /6   */ {{ 0xfc,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /7   */ {{ 0xfe,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /8   */ {{ 0xff,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /9   */ {{ 0xff,0x80,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /10  */ {{ 0xff,0xc0,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /11  */ {{ 0xff,0xe0,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /12  */ {{ 0xff,0xf0,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /13  */ {{ 0xff,0xf8,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /14  */ {{ 0xff,0xfc,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /15  */ {{ 0xff,0xfe,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /16  */ {{ 0xff,0xff,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /17  */ {{ 0xff,0xff,0x80,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /18  */ {{ 0xff,0xff,0xc0,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /19  */ {{ 0xff,0xff,0xe0,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /20  */ {{ 0xff,0xff,0xf0,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /21  */ {{ 0xff,0xff,0xf8,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /22  */ {{ 0xff,0xff,0xfc,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /23  */ {{ 0xff,0xff,0xfe,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /24  */ {{ 0xff,0xff,0xff,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /25  */ {{ 0xff,0xff,0xff,0x80,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /26  */ {{ 0xff,0xff,0xff,0xc0,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /27  */ {{ 0xff,0xff,0xff,0xe0,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /28  */ {{ 0xff,0xff,0xff,0xf0,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /29  */ {{ 0xff,0xff,0xff,0xf8,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /30  */ {{ 0xff,0xff,0xff,0xfc,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /31  */ {{ 0xff,0xff,0xff,0xfe,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /32  */ {{ 0xff,0xff,0xff,0xff,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /33  */ {{ 0xff,0xff,0xff,0xff,
-             0x80,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /34  */ {{ 0xff,0xff,0xff,0xff,
-             0xc0,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /35  */ {{ 0xff,0xff,0xff,0xff,
-             0xe0,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /36  */ {{ 0xff,0xff,0xff,0xff,
-             0xf0,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /37  */ {{ 0xff,0xff,0xff,0xff,
-             0xf8,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /38  */ {{ 0xff,0xff,0xff,0xff,
-             0xfc,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /39  */ {{ 0xff,0xff,0xff,0xff,
-             0xfe,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /40  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /41  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0x80,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /42  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xc0,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /43  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xe0,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /44  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xf0,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /45  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xf8,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /46  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xfc,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /47  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xfe,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /48  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0x00,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /49  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0x80,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /50  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xc0,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /51  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xe0,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /52  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xf0,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /53  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xf8,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /54  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xfc,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /55  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xfe,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /56  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0x00,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /57  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0x80,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /58  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xc0,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /59  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xe0,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /60  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xf0,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /61  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xf8,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /62  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xfc,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /63  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xfe,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /64  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0x00,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /65  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0x80,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /66  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xc0,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /67  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xe0,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /68  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xf0,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /69  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xf8,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /70  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xfc,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /71  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xfe,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /72  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0x00,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /73  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0x80,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /74  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xc0,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /75  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xe0,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /76  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xf0,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /77  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xf8,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /78  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xfc,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /79  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xfe,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /80  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0x00,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /81  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0x80,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /82  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xc0,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /83  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xe0,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /84  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xf0,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /85  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xf8,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /86  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xfc,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /87  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xfe,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /88  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0x00,
-             0x00,0x00,0x00,0x00 }},
-/* /89  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0x80,
-             0x00,0x00,0x00,0x00 }},
-/* /90  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xc0,
-             0x00,0x00,0x00,0x00 }},
-/* /91  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xe0,
-             0x00,0x00,0x00,0x00 }},
-/* /92  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xf0,
-             0x00,0x00,0x00,0x00 }},
-/* /93  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xf8,
-             0x00,0x00,0x00,0x00 }},
-/* /94  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xfc,
-             0x00,0x00,0x00,0x00 }},
-/* /95  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xfe,
-             0x00,0x00,0x00,0x00 }},
-/* /96  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0x00,0x00,0x00,0x00 }},
-/* /97  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0x80,0x00,0x00,0x00 }},
-/* /98  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xc0,0x00,0x00,0x00 }},
-/* /99  */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xe0,0x00,0x00,0x00 }},
-/* /100 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xf0,0x00,0x00,0x00 }},
-/* /101 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xf8,0x00,0x00,0x00 }},
-/* /102 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xfc,0x00,0x00,0x00 }},
-/* /103 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xfe,0x00,0x00,0x00 }},
-/* /104 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0x00,0x00,0x00 }},
-/* /105 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0x80,0x00,0x00 }},
-/* /106 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xc0,0x00,0x00 }},
-/* /107 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xe0,0x00,0x00 }},
-/* /108 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xf0,0x00,0x00 }},
-/* /109 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xf8,0x00,0x00 }},
-/* /110 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xfc,0x00,0x00 }},
-/* /111 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xfe,0x00,0x00 }},
-/* /112 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0x00,0x00 }},
-/* /113 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0x80,0x00 }},
-/* /114 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xc0,0x00 }},
-/* /115 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xe0,0x00 }},
-/* /116 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xf0,0x00 }},
-/* /117 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xf8,0x00 }},
-/* /118 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xfc,0x00 }},
-/* /119 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xfe,0x00 }},
-/* /120 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0x00 }},
-/* /121 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0x80 }},
-/* /122 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xc0 }},
-/* /123 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xe0 }},
-/* /124 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xf0 }},
-/* /125 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xf8 }},
-/* /126 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xfc }},
-/* /127 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xfe }},
-/* /128 */ {{ 0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff,
-             0xff,0xff,0xff,0xff }},
-}};
-
 } // folly

diff --git a/folly/IPAddressV6.h b/folly/IPAddressV6.h
index 2a3880bb17328a061ed9ceb173d043e9c422f62c..7de7dfbd5f8bdbd91505e48902a1c62739e91f79 100644 (file)
--- a/folly/IPAddressV6.h
+++ b/folly/IPAddressV6.h
@@ -354,8 +354,6 @@ class IPAddressV6 {
   // are *not* link-local.
   uint16_t scope_{0};
 
-  static const std::array<ByteArray16, 129> masks_;
-
   /**
    * Set the current IPAddressV6 object to have the address specified by bytes.
    * @throws IPAddressFormatException if bytes.size() is not 16.

diff --git a/folly/test/IPAddressTest.cpp b/folly/test/IPAddressTest.cpp
index 7f1f5a932ae6b0175e0ffe9d4bf8572923bfb814..f41bb8fd67e816f60645a59c3db495fabe17706c 100644 (file)
--- a/folly/test/IPAddressTest.cpp
+++ b/folly/test/IPAddressTest.cpp
@@ -21,6 +21,7 @@
 #include <folly/MacAddress.h>
 #include <folly/String.h>
 #include <folly/detail/IPAddressSource.h>
+#include <folly/portability/GMock.h>
 #include <folly/portability/GTest.h>
 
 using namespace folly;
@@ -1251,3 +1252,66 @@ INSTANTIATE_TEST_CASE_P(IPAddress,
 INSTANTIATE_TEST_CASE_P(IPAddress,
                         IPAddressBitAccessorTest,
                         ::testing::ValuesIn(validAddressProvider));
+
+TEST(IPAddressV6, fetchMask) {
+  using ByteArray8 = std::array<uint8_t, 8>;
+
+  struct X : private IPAddressV6 {
+    using IPAddressV6::fetchMask;
+  };
+
+  auto join = [](std::array<ByteArray8, 2> parts) {
+    ByteArray16 _return;
+    std::memcpy(_return.data(), parts.data(), _return.size());
+    return _return;
+  };
+
+  EXPECT_THAT(
+      X::fetchMask(0),
+      ::testing::ElementsAreArray(join({{
+          ByteArray8{{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}},
+          ByteArray8{{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}},
+      }})));
+
+  EXPECT_THAT(
+      X::fetchMask(1),
+      ::testing::ElementsAreArray(join({{
+          ByteArray8{{0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}},
+          ByteArray8{{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}},
+      }})));
+
+  EXPECT_THAT(
+      X::fetchMask(63),
+      ::testing::ElementsAreArray(join({{
+          ByteArray8{{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe}},
+          ByteArray8{{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}},
+      }})));
+
+  EXPECT_THAT(
+      X::fetchMask(64),
+      ::testing::ElementsAreArray(join({{
+          ByteArray8{{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}},
+          ByteArray8{{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}},
+      }})));
+
+  EXPECT_THAT(
+      X::fetchMask(65),
+      ::testing::ElementsAreArray(join({{
+          ByteArray8{{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}},
+          ByteArray8{{0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}},
+      }})));
+
+  EXPECT_THAT(
+      X::fetchMask(127),
+      ::testing::ElementsAreArray(join({{
+          ByteArray8{{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}},
+          ByteArray8{{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe}},
+      }})));
+
+  EXPECT_THAT(
+      X::fetchMask(128),
+      ::testing::ElementsAreArray(join({{
+          ByteArray8{{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}},
+          ByteArray8{{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}},
+      }})));
+}