Land Recent QUIC changes.

net/quic/quic_protocol.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_QUIC_QUIC_PROTOCOL_H_
 #define NET_QUIC_QUIC_PROTOCOL_H_
 
 #include <stddef.h>
 #include <limits>
 #include <map>
@@ skipping 65 matching lines @@
 // Reserved ID for the crypto stream.
 // TODO(rch): ensure that this is not usable by any other streams.
 const QuicStreamId kCryptoStreamId = 1;
 
 // This is the default network timeout a for connection till the crypto
 // handshake succeeds and the negotiated timeout from the handshake is received.
 const int64 kDefaultInitialTimeoutSecs = 120;  // 2 mins.
 const int64 kDefaultTimeoutSecs = 60 * 10;  // 10 minutes.
 const int64 kDefaultMaxTimeForCryptoHandshakeSecs = 5;  // 5 secs.
 
+// We define an unsigned 16-bit floating point value, inspired by IEEE floats
+// (http://en.wikipedia.org/wiki/Half_precision_floating-point_format),
+// with 5-bit exponent (bias 1), 11-bit mantissa (effective 12 with hidden
+// bit) and denormals, but without signs, transfinites or fractions. Wire format
+// 16 bits (little-endian byte order) are split into exponent (high 5) and
+// mantissa (low 11) and decoded as:
+//   uint64 value;
+//   if (exponent == 0) value = mantissa;
+//   else value = (mantissa | 1 << 11) << (exponent - 1)
+const int kUFloat16ExponentBits = 5;
+const int kUFloat16MaxExponent = (1 << kUFloat16ExponentBits) - 2;  // 30
+const int kUFloat16MantissaBits = 16 - kUFloat16ExponentBits;  // 11
+const int kUFloat16MantissaEffectiveBits = kUFloat16MantissaBits + 1;  // 12
+const uint64 kUFloat16MaxValue =  // 0x3FFC0000000
+    ((GG_UINT64_C(1) << kUFloat16MantissaEffectiveBits) - 1) <<
+    kUFloat16MaxExponent;
+
 enum TransmissionType {
   NOT_RETRANSMISSION,
   NACK_RETRANSMISSION,
   RTO_RETRANSMISSION,
 };
 
 enum HasRetransmittableData {
   NO_RETRANSMITTABLE_DATA,
   HAS_RETRANSMITTABLE_DATA,
 };
@@ skipping 100 matching lines @@
 
 // This vector contains QUIC versions which we currently support.
 // This should be ordered such that the highest supported version is the first
 // element, with subsequent elements in descending order (versions can be
 // skipped as necessary).
 static const QuicVersion kSupportedQuicVersions[] =
     {QUIC_VERSION_10};
 
 typedef std::vector<QuicVersion> QuicVersionVector;
 
-// Upper limit on versions we support.
-NET_EXPORT_PRIVATE QuicVersion QuicVersionMax();
-
-// Lower limit on versions we support.
-NET_EXPORT_PRIVATE QuicVersion QuicVersionMin();
+// Returns a vector of QUIC versions in kSupportedQuicVersions.
+NET_EXPORT_PRIVATE QuicVersionVector QuicSupportedVersions();
 
 // QuicTag is written to and read from the wire, but we prefer to use
 // the more readable QuicVersion at other levels.
 // Helper function which translates from a QuicVersion to a QuicTag. Returns 0
 // if QuicVersion is unsupported.
 NET_EXPORT_PRIVATE QuicTag QuicVersionToQuicTag(const QuicVersion version);
 
 // Returns appropriate QuicVersion from a QuicTag.
 // Returns QUIC_VERSION_UNSUPPORTED if version_tag cannot be understood.
 NET_EXPORT_PRIVATE QuicVersion QuicTagToQuicVersion(const QuicTag version_tag);
 
 // Helper function which translates from a QuicVersion to a string.
 // Returns strings corresponding to enum names (e.g. QUIC_VERSION_6).
 NET_EXPORT_PRIVATE std::string QuicVersionToString(const QuicVersion version);
 
 // Returns comma separated list of string representations of QuicVersion enum
-// values in the supplied QuicVersionArray.
-NET_EXPORT_PRIVATE std::string QuicVersionArrayToString(
-    const QuicVersion versions[], int num_versions);
+// values in the supplied |versions| vector.
+NET_EXPORT_PRIVATE std::string QuicVersionVectorToString(
+    const QuicVersionVector& versions);
 
 // Version and Crypto tags are written to the wire with a big-endian
 // representation of the name of the tag.  For example
 // the client hello tag (CHLO) will be written as the
 // following 4 bytes: 'C' 'H' 'L' 'O'.  Since it is
 // stored in memory as a little endian uint32, we need
 // to reverse the order of the bytes.
 
 // MakeQuicTag returns a value given the four bytes. For example:
 //   MakeQuicTag('C', 'H', 'L', 'O');
@@ skipping 646 matching lines @@
   WriteStatus status;
   union {
     int bytes_written;  // only valid when status is OK
     int error_code;  // only valid when status is ERROR
   };
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_PROTOCOL_H_