Land Recent QUIC changes.

net/quic/quic_data_writer_test.cc

Index: net/quic/quic_data_writer_test.cc
diff --git a/net/quic/quic_data_writer_test.cc b/net/quic/quic_data_writer_test.cc
index 4fbd7e4efdfefacb1424554f3ab6722417408b84..9106947b52e7ccabd533b10f1d9acbc58612f505 100644
--- a/net/quic/quic_data_writer_test.cc
+++ b/net/quic/quic_data_writer_test.cc
@@ -4,13 +4,15 @@
 
 #include "net/quic/quic_data_writer.h"
 
+#include "base/memory/scoped_ptr.h"
+#include "net/quic/quic_data_reader.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace net {
 namespace test {
 namespace {
 
-TEST(QuicDataWriterTest, WriteUint8ToOffset) {
+TEST(QuicDataWriterTest, WriteUInt8ToOffset) {
   QuicDataWriter writer(4);
 
   writer.WriteUInt32(0xfefdfcfb);
@@ -19,17 +21,15 @@ TEST(QuicDataWriterTest, WriteUint8ToOffset) {
   EXPECT_TRUE(writer.WriteUInt8ToOffset(3, 2));
   EXPECT_TRUE(writer.WriteUInt8ToOffset(4, 3));
 
-  char* data = writer.take();
+  scoped_ptr<char[]> data(writer.take());
 
   EXPECT_EQ(1, data[0]);
   EXPECT_EQ(2, data[1]);
   EXPECT_EQ(3, data[2]);
   EXPECT_EQ(4, data[3]);
-
-  delete[] data;
 }
 
-TEST(QuicDataWriterDeathTest, WriteUint8ToOffset) {
+TEST(QuicDataWriterDeathTest, WriteUInt8ToOffset) {
   QuicDataWriter writer(4);
 
 #if !defined(WIN32) && defined(GTEST_HAS_DEATH_TEST)
@@ -41,6 +41,127 @@ TEST(QuicDataWriterDeathTest, WriteUint8ToOffset) {
 #endif
 }
 
+TEST(QuicDataWriterTest, SanityCheckUFloat16Consts) {
+  // Check the arithmetic on the constants - otherwise the values below make
+  // no sense.
+  EXPECT_EQ(30, kUFloat16MaxExponent);
+  EXPECT_EQ(11, kUFloat16MantissaBits);
+  EXPECT_EQ(12, kUFloat16MantissaEffectiveBits);
+  EXPECT_EQ(GG_UINT64_C(0x3FFC0000000), kUFloat16MaxValue);
+}
+
+TEST(QuicDataWriterTest, WriteUFloat16) {
+  struct TestCase {
+    uint64 decoded;
+    uint16 encoded;
+  };
+  TestCase test_cases[] = {
+    // Small numbers represent themselves.
+    { 0, 0 }, { 1, 1 }, { 2, 2 }, { 3, 3 }, { 4, 4 }, { 5, 5 }, { 6, 6 },
+    { 7, 7 }, { 15, 15 }, { 31, 31 }, { 42, 42 }, { 123, 123 }, { 1234, 1234 },
+    // Check transition through 2^11.
+    { 2046, 2046 }, { 2047, 2047 }, { 2048, 2048 }, { 2049, 2049 },
+    // Running out of mantissa at 2^12.
+    { 4094, 4094 }, { 4095, 4095 }, { 4096, 4096 }, { 4097, 4096 },
+    { 4098, 4097 }, { 4099, 4097 }, { 4100, 4098 }, { 4101, 4098 },
+    // Check transition through 2^13.
+    { 8190, 6143 }, { 8191, 6143 }, { 8192, 6144 }, { 8193, 6144 },
+    { 8194, 6144 }, { 8195, 6144 }, { 8196, 6145 }, { 8197, 6145 },
+    // Half-way through the exponents.
+    { 0x7FF8000, 0x87FF }, { 0x7FFFFFF, 0x87FF }, { 0x8000000, 0x8800 },
+    { 0xFFF0000, 0x8FFF }, { 0xFFFFFFF, 0x8FFF }, { 0x10000000, 0x9000 },
+    // Transition into the largest exponent.
+    { 0x1FFFFFFFFFE, 0xF7FF}, { 0x1FFFFFFFFFF, 0xF7FF},
+    { 0x20000000000, 0xF800}, { 0x20000000001, 0xF800},
+    { 0x2003FFFFFFE, 0xF800}, { 0x2003FFFFFFF, 0xF800},
+    { 0x20040000000, 0xF801}, { 0x20040000001, 0xF801},
+    // Transition into the max value and clamping.
+    { 0x3FF80000000, 0xFFFE}, { 0x3FFBFFFFFFF, 0xFFFE},
+    { 0x3FFC0000000, 0xFFFF}, { 0x3FFC0000001, 0xFFFF},
+    { 0x3FFFFFFFFFF, 0xFFFF}, { 0x40000000000, 0xFFFF},
+    { 0xFFFFFFFFFFFFFFFF, 0xFFFF},
+  };
+  int num_test_cases = sizeof(test_cases) / sizeof(test_cases[0]);
+
+  for (int i = 0; i < num_test_cases; ++i) {
+    QuicDataWriter writer(2);
+    EXPECT_TRUE(writer.WriteUFloat16(test_cases[i].decoded));
+    scoped_ptr<char[]> data(writer.take());
+    EXPECT_EQ(test_cases[i].encoded, *reinterpret_cast<uint16*>(data.get()));
+  }
+}
+
+TEST(QuicDataWriterTest, ReadUFloat16) {
+  struct TestCase {
+    uint64 decoded;
+    uint16 encoded;
+  };
+  TestCase test_cases[] = {
+    // There are fewer decoding test cases because encoding truncates, and
+    // decoding returns the smallest expansion.
+    // Small numbers represent themselves.
+    { 0, 0 }, { 1, 1 }, { 2, 2 }, { 3, 3 }, { 4, 4 }, { 5, 5 }, { 6, 6 },
+    { 7, 7 }, { 15, 15 }, { 31, 31 }, { 42, 42 }, { 123, 123 }, { 1234, 1234 },
+    // Check transition through 2^11.
+    { 2046, 2046 }, { 2047, 2047 }, { 2048, 2048 }, { 2049, 2049 },
+    // Running out of mantissa at 2^12.
+    { 4094, 4094 }, { 4095, 4095 }, { 4096, 4096 },
+    { 4098, 4097 }, { 4100, 4098 },
+    // Check transition through 2^13.
+    { 8190, 6143 }, { 8192, 6144 }, { 8196, 6145 },
+    // Half-way through the exponents.
+    { 0x7FF8000, 0x87FF }, { 0x8000000, 0x8800 },
+    { 0xFFF0000, 0x8FFF }, { 0x10000000, 0x9000 },
+    // Transition into the largest exponent.
+    { 0x1FFE0000000, 0xF7FF}, { 0x20000000000, 0xF800},
+    { 0x20040000000, 0xF801},
+    // Transition into the max value.
+    { 0x3FF80000000, 0xFFFE}, { 0x3FFC0000000, 0xFFFF},
+  };
+  int num_test_cases = sizeof(test_cases) / sizeof(test_cases[0]);
+
+  for (int i = 0; i < num_test_cases; ++i) {
+    QuicDataReader reader(reinterpret_cast<char*>(&test_cases[i].encoded), 2);
+    uint64 value;
+    EXPECT_TRUE(reader.ReadUFloat16(&value));
+    EXPECT_EQ(test_cases[i].decoded, value);
+  }
+}
+
+TEST(QuicDataWriterTest, RoundTripUFloat16) {
+  // Just test all 16-bit encoded values. 0 and max already tested above.
+  uint64 previous_value = 0;
+  for (uint16 i = 1; i < 0xFFFF; ++i) {
+    // Read the two bytes.
+    QuicDataReader reader(reinterpret_cast<char*>(&i), 2);
+    uint64 value;
+    // All values must be decodable.
+    EXPECT_TRUE(reader.ReadUFloat16(&value));
+    // Check that small numbers represent themselves
+    if (i < 4097)
+      EXPECT_EQ(i, value);
+    // Check there's monotonic growth.
+    EXPECT_LT(previous_value, value);
+    // Check that precision is within 0.5% away from the denormals.
+    if (i > 2000)
+      EXPECT_GT(previous_value * 1005, value * 1000);
+    // Check we're always within the promised range.
+    EXPECT_LT(value, GG_UINT64_C(0x3FFC0000000));
+    previous_value = value;
+    QuicDataWriter writer(6);
+    EXPECT_TRUE(writer.WriteUFloat16(value - 1));
+    EXPECT_TRUE(writer.WriteUFloat16(value));
+    EXPECT_TRUE(writer.WriteUFloat16(value + 1));
+    scoped_ptr<char[]> data(writer.take());
+    // Check minimal decoding (previous decoding has previous encoding).
+    EXPECT_EQ(i-1, *reinterpret_cast<uint16*>(data.get()));
+    // Check roundtrip.
+    EXPECT_EQ(i, *reinterpret_cast<uint16*>(data.get() + 2));
+    // Check next decoding.
+    EXPECT_EQ(i < 4096? i+1 : i, *reinterpret_cast<uint16*>(data.get() + 4));
+  }
+}
+
 }  // namespace
 }  // namespace test
 }  // namespace net