net/quic/quic_data_writer_test.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/quic/quic_data_writer.h"
   6
   7 #include "base/memory/scoped_ptr.h"
   8 #include "net/quic/quic_data_reader.h"
   9 #include "net/test/gtest_util.h"
  10 #include "testing/gtest/include/gtest/gtest.h"
  11
  12 namespace net {
  13 namespace test {
  14 namespace {
  15
  16 TEST(QuicDataWriterTest, WriteUInt8ToOffset) {
  17   QuicDataWriter writer(4);
  18
  19   writer.WriteUInt32(0xfefdfcfb);
  20   EXPECT_TRUE(writer.WriteUInt8ToOffset(1, 0));
  21   EXPECT_TRUE(writer.WriteUInt8ToOffset(2, 1));
  22   EXPECT_TRUE(writer.WriteUInt8ToOffset(3, 2));
  23   EXPECT_TRUE(writer.WriteUInt8ToOffset(4, 3));
  24
  25   scoped_ptr<char[]> data(writer.take());
  26
  27   EXPECT_EQ(1, data[0]);
  28   EXPECT_EQ(2, data[1]);
  29   EXPECT_EQ(3, data[2]);
  30   EXPECT_EQ(4, data[3]);
  31 }
  32
  33 TEST(QuicDataWriterDeathTest, WriteUInt8ToOffset) {
  34   QuicDataWriter writer(4);
  35
  36   EXPECT_DFATAL(EXPECT_FALSE(writer.WriteUInt8ToOffset(5, 4)),
  37                 "offset: 4 >= capacity: 4");
  38 }
  39
  40 TEST(QuicDataWriterTest, SanityCheckUFloat16Consts) {
  41   // Check the arithmetic on the constants - otherwise the values below make
  42   // no sense.
  43   EXPECT_EQ(30, kUFloat16MaxExponent);
  44   EXPECT_EQ(11, kUFloat16MantissaBits);
  45   EXPECT_EQ(12, kUFloat16MantissaEffectiveBits);
  46   EXPECT_EQ(GG_UINT64_C(0x3FFC0000000), kUFloat16MaxValue);
  47 }
  48
  49 TEST(QuicDataWriterTest, WriteUFloat16) {
  50   struct TestCase {
  51     uint64 decoded;
  52     uint16 encoded;
  53   };
  54   TestCase test_cases[] = {
  55     // Small numbers represent themselves.
  56     { 0, 0 }, { 1, 1 }, { 2, 2 }, { 3, 3 }, { 4, 4 }, { 5, 5 }, { 6, 6 },
  57     { 7, 7 }, { 15, 15 }, { 31, 31 }, { 42, 42 }, { 123, 123 }, { 1234, 1234 },
  58     // Check transition through 2^11.
  59     { 2046, 2046 }, { 2047, 2047 }, { 2048, 2048 }, { 2049, 2049 },
  60     // Running out of mantissa at 2^12.
  61     { 4094, 4094 }, { 4095, 4095 }, { 4096, 4096 }, { 4097, 4096 },
  62     { 4098, 4097 }, { 4099, 4097 }, { 4100, 4098 }, { 4101, 4098 },
  63     // Check transition through 2^13.
  64     { 8190, 6143 }, { 8191, 6143 }, { 8192, 6144 }, { 8193, 6144 },
  65     { 8194, 6144 }, { 8195, 6144 }, { 8196, 6145 }, { 8197, 6145 },
  66     // Half-way through the exponents.
  67     { 0x7FF8000, 0x87FF }, { 0x7FFFFFF, 0x87FF }, { 0x8000000, 0x8800 },
  68     { 0xFFF0000, 0x8FFF }, { 0xFFFFFFF, 0x8FFF }, { 0x10000000, 0x9000 },
  69     // Transition into the largest exponent.
  70     { 0x1FFFFFFFFFE, 0xF7FF}, { 0x1FFFFFFFFFF, 0xF7FF},
  71     { 0x20000000000, 0xF800}, { 0x20000000001, 0xF800},
  72     { 0x2003FFFFFFE, 0xF800}, { 0x2003FFFFFFF, 0xF800},
  73     { 0x20040000000, 0xF801}, { 0x20040000001, 0xF801},
  74     // Transition into the max value and clamping.
  75     { 0x3FF80000000, 0xFFFE}, { 0x3FFBFFFFFFF, 0xFFFE},
  76     { 0x3FFC0000000, 0xFFFF}, { 0x3FFC0000001, 0xFFFF},
  77     { 0x3FFFFFFFFFF, 0xFFFF}, { 0x40000000000, 0xFFFF},
  78     { 0xFFFFFFFFFFFFFFFF, 0xFFFF},
  79   };
  80   int num_test_cases = sizeof(test_cases) / sizeof(test_cases[0]);
  81
  82   for (int i = 0; i < num_test_cases; ++i) {
  83     QuicDataWriter writer(2);
  84     EXPECT_TRUE(writer.WriteUFloat16(test_cases[i].decoded));
  85     scoped_ptr<char[]> data(writer.take());
  86     EXPECT_EQ(test_cases[i].encoded, *reinterpret_cast<uint16*>(data.get()));
  87   }
  88 }
  89
  90 TEST(QuicDataWriterTest, ReadUFloat16) {
  91   struct TestCase {
  92     uint64 decoded;
  93     uint16 encoded;
  94   };
  95   TestCase test_cases[] = {
  96     // There are fewer decoding test cases because encoding truncates, and
  97     // decoding returns the smallest expansion.
  98     // Small numbers represent themselves.
  99     { 0, 0 }, { 1, 1 }, { 2, 2 }, { 3, 3 }, { 4, 4 }, { 5, 5 }, { 6, 6 },
 100     { 7, 7 }, { 15, 15 }, { 31, 31 }, { 42, 42 }, { 123, 123 }, { 1234, 1234 },
 101     // Check transition through 2^11.
 102     { 2046, 2046 }, { 2047, 2047 }, { 2048, 2048 }, { 2049, 2049 },
 103     // Running out of mantissa at 2^12.
 104     { 4094, 4094 }, { 4095, 4095 }, { 4096, 4096 },
 105     { 4098, 4097 }, { 4100, 4098 },
 106     // Check transition through 2^13.
 107     { 8190, 6143 }, { 8192, 6144 }, { 8196, 6145 },
 108     // Half-way through the exponents.
 109     { 0x7FF8000, 0x87FF }, { 0x8000000, 0x8800 },
 110     { 0xFFF0000, 0x8FFF }, { 0x10000000, 0x9000 },
 111     // Transition into the largest exponent.
 112     { 0x1FFE0000000, 0xF7FF}, { 0x20000000000, 0xF800},
 113     { 0x20040000000, 0xF801},
 114     // Transition into the max value.
 115     { 0x3FF80000000, 0xFFFE}, { 0x3FFC0000000, 0xFFFF},
 116   };
 117   int num_test_cases = sizeof(test_cases) / sizeof(test_cases[0]);
 118
 119   for (int i = 0; i < num_test_cases; ++i) {
 120     QuicDataReader reader(reinterpret_cast<char*>(&test_cases[i].encoded), 2);
 121     uint64 value;
 122     EXPECT_TRUE(reader.ReadUFloat16(&value));
 123     EXPECT_EQ(test_cases[i].decoded, value);
 124   }
 125 }
 126
 127 TEST(QuicDataWriterTest, RoundTripUFloat16) {
 128   // Just test all 16-bit encoded values. 0 and max already tested above.
 129   uint64 previous_value = 0;
 130   for (uint16 i = 1; i < 0xFFFF; ++i) {
 131     // Read the two bytes.
 132     QuicDataReader reader(reinterpret_cast<char*>(&i), 2);
 133     uint64 value;
 134     // All values must be decodable.
 135     EXPECT_TRUE(reader.ReadUFloat16(&value));
 136     // Check that small numbers represent themselves
 137     if (i < 4097)
 138       EXPECT_EQ(i, value);
 139     // Check there's monotonic growth.
 140     EXPECT_LT(previous_value, value);
 141     // Check that precision is within 0.5% away from the denormals.
 142     if (i > 2000)
 143       EXPECT_GT(previous_value * 1005, value * 1000);
 144     // Check we're always within the promised range.
 145     EXPECT_LT(value, GG_UINT64_C(0x3FFC0000000));
 146     previous_value = value;
 147     QuicDataWriter writer(6);
 148     EXPECT_TRUE(writer.WriteUFloat16(value - 1));
 149     EXPECT_TRUE(writer.WriteUFloat16(value));
 150     EXPECT_TRUE(writer.WriteUFloat16(value + 1));
 151     scoped_ptr<char[]> data(writer.take());
 152     // Check minimal decoding (previous decoding has previous encoding).
 153     EXPECT_EQ(i-1, *reinterpret_cast<uint16*>(data.get()));
 154     // Check roundtrip.
 155     EXPECT_EQ(i, *reinterpret_cast<uint16*>(data.get() + 2));
 156     // Check next decoding.
 157     EXPECT_EQ(i < 4096? i+1 : i, *reinterpret_cast<uint16*>(data.get() + 4));
 158   }
 159 }
 160
 161 }  // namespace
 162 }  // namespace test
 163 }  // namespace net