chrome/common/partial_circular_buffer_unittest.cc

   1 // Copyright 2013 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 // The test buffer data is 52 bytes, wrap position is set to 20 (this is
   6 // arbitrarily chosen). The total buffer size is allocated dynamically based on
   7 // the actual header size. This gives:
   8 // Header of some size, non-wrapping part 20 bytes, wrapping part 32 bytes.
   9 // As input data, a 14 byte array is used and repeatedly written. It's chosen
  10 // not to be an integer factor smaller than the wrapping part. This ensures that
  11 // the wrapped data isn't repeated at the same position.
  12 // Note that desipte the number of wraps (if one or more), the reference output
  13 // data is the same since the offset at each wrap is always the same.
  14
  15 #include "base/memory/scoped_ptr.h"
  16 #include "chrome/common/partial_circular_buffer.h"
  17 #include "testing/gtest/include/gtest/gtest.h"
  18
  19 const uint32 kWrapPosition = 20;
  20 const uint8 kInputData[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14};
  21 const uint8 kOutputRefDataWrap[] =
  22     // The 20 bytes in the non-wrapping part.
  23     {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 1, 2, 3, 4, 5, 6,
  24      // The 32 bytes in wrapping part.
  25      11, 12, 13, 14,
  26      1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
  27      1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14};
  28
  29 class PartialCircularBufferTest : public testing::Test {
  30  public:
  31   PartialCircularBufferTest() {
  32     PartialCircularBuffer::BufferData test_struct;
  33     buffer_header_size_ =
  34         &test_struct.data[0] - reinterpret_cast<uint8*>(&test_struct);
  35
  36     buffer_.reset(new uint8[buffer_header_size_ + sizeof(kOutputRefDataWrap)]);
  37   }
  38
  39   void InitWriteBuffer(bool append) {
  40     pcb_write_.reset(new PartialCircularBuffer(
  41         buffer_.get(),
  42         buffer_header_size_ + sizeof(kOutputRefDataWrap),
  43         kWrapPosition,
  44         append));
  45   }
  46
  47   void WriteToBuffer(int num) {
  48     for (int i = 0; i < num; ++i)
  49       pcb_write_->Write(kInputData, sizeof(kInputData));
  50   }
  51
  52   void InitReadBuffer() {
  53     pcb_read_.reset(new PartialCircularBuffer(
  54         buffer_.get(), buffer_header_size_ + sizeof(kOutputRefDataWrap)));
  55   }
  56
  57  protected:
  58   scoped_ptr<PartialCircularBuffer> pcb_write_;
  59   scoped_ptr<PartialCircularBuffer> pcb_read_;
  60   scoped_ptr<uint8[]> buffer_;
  61   uint32 buffer_header_size_;
  62
  63   DISALLOW_COPY_AND_ASSIGN(PartialCircularBufferTest);
  64 };
  65
  66 TEST_F(PartialCircularBufferTest, NoWrapBeginningPartOnly) {
  67   InitWriteBuffer(false);
  68   WriteToBuffer(1);
  69   InitReadBuffer();
  70
  71   uint8 output_data[sizeof(kInputData)] = {0};
  72   EXPECT_EQ(sizeof(output_data),
  73             pcb_read_->Read(output_data, sizeof(output_data)));
  74
  75   EXPECT_EQ(0, memcmp(kInputData, output_data, sizeof(kInputData)));
  76
  77   EXPECT_EQ(0u, pcb_read_->Read(output_data, sizeof(output_data)));
  78 }
  79
  80 TEST_F(PartialCircularBufferTest, NoWrapBeginningAndEndParts) {
  81   InitWriteBuffer(false);
  82   WriteToBuffer(2);
  83   InitReadBuffer();
  84
  85   uint8 output_data[2 * sizeof(kInputData)] = {0};
  86   EXPECT_EQ(sizeof(output_data),
  87             pcb_read_->Read(output_data, sizeof(output_data)));
  88
  89   const uint8 output_ref_data[2 * sizeof(kInputData)] =
  90       {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
  91        1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14};
  92   EXPECT_EQ(0, memcmp(output_ref_data, output_data, sizeof(output_data)));
  93
  94   EXPECT_EQ(0u, pcb_read_->Read(output_data, sizeof(output_data)));
  95 }
  96
  97 TEST_F(PartialCircularBufferTest, WrapOnce) {
  98   InitWriteBuffer(false);
  99   WriteToBuffer(4);
 100   InitReadBuffer();
 101
 102   uint8 output_data[sizeof(kOutputRefDataWrap)] = {0};
 103   EXPECT_EQ(sizeof(output_data),
 104             pcb_read_->Read(output_data, sizeof(output_data)));
 105
 106   EXPECT_EQ(0, memcmp(kOutputRefDataWrap, output_data, sizeof(output_data)));
 107
 108   EXPECT_EQ(0u, pcb_read_->Read(output_data, sizeof(output_data)));
 109 }
 110
 111 TEST_F(PartialCircularBufferTest, WrapTwice) {
 112   InitWriteBuffer(false);
 113   WriteToBuffer(7);
 114   InitReadBuffer();
 115
 116   uint8 output_data[sizeof(kOutputRefDataWrap)] = {0};
 117   EXPECT_EQ(sizeof(output_data),
 118             pcb_read_->Read(output_data, sizeof(output_data)));
 119
 120   EXPECT_EQ(0, memcmp(kOutputRefDataWrap, output_data, sizeof(output_data)));
 121
 122   EXPECT_EQ(0u, pcb_read_->Read(output_data, sizeof(output_data)));
 123 }
 124
 125 TEST_F(PartialCircularBufferTest, WrapOnceSmallerOutputBuffer) {
 126   InitWriteBuffer(false);
 127   WriteToBuffer(4);
 128   InitReadBuffer();
 129
 130   uint8 output_data[sizeof(kOutputRefDataWrap)] = {0};
 131   const uint32 size_per_read = 16;
 132   uint32 read = 0;
 133   for (; read + size_per_read <= sizeof(output_data); read += size_per_read) {
 134     EXPECT_EQ(size_per_read,
 135               pcb_read_->Read(output_data + read, size_per_read));
 136   }
 137   EXPECT_EQ(sizeof(output_data) - read,
 138             pcb_read_->Read(output_data + read, size_per_read));
 139
 140   EXPECT_EQ(0, memcmp(kOutputRefDataWrap, output_data, sizeof(output_data)));
 141
 142   EXPECT_EQ(0u, pcb_read_->Read(output_data, sizeof(output_data)));
 143 }
 144
 145 TEST_F(PartialCircularBufferTest, WrapOnceWithAppend) {
 146   InitWriteBuffer(false);
 147   WriteToBuffer(2);
 148   InitWriteBuffer(true);
 149   WriteToBuffer(2);
 150   InitReadBuffer();
 151
 152   uint8 output_data[sizeof(kOutputRefDataWrap)] = {0};
 153   EXPECT_EQ(sizeof(output_data),
 154             pcb_read_->Read(output_data, sizeof(output_data)));
 155
 156   EXPECT_EQ(0, memcmp(kOutputRefDataWrap, output_data, sizeof(output_data)));
 157
 158   EXPECT_EQ(0u, pcb_read_->Read(output_data, sizeof(output_data)));
 159 }
 160
 161 TEST_F(PartialCircularBufferTest, WrapTwiceWithAppend) {
 162   InitWriteBuffer(false);
 163   WriteToBuffer(4);
 164   InitWriteBuffer(true);
 165   WriteToBuffer(3);
 166   InitReadBuffer();
 167
 168   uint8 output_data[sizeof(kOutputRefDataWrap)] = {0};
 169   EXPECT_EQ(sizeof(output_data),
 170             pcb_read_->Read(output_data, sizeof(output_data)));
 171
 172   EXPECT_EQ(0, memcmp(kOutputRefDataWrap, output_data, sizeof(output_data)));
 173
 174   EXPECT_EQ(0u, pcb_read_->Read(output_data, sizeof(output_data)));
 175 }
 176
 177 TEST_F(PartialCircularBufferTest, WrapOnceThenOverwriteWithNoWrap) {
 178   InitWriteBuffer(false);
 179   WriteToBuffer(4);
 180   InitWriteBuffer(false);
 181   WriteToBuffer(1);
 182   InitReadBuffer();
 183
 184   uint8 output_data[sizeof(kInputData)] = {0};
 185   EXPECT_EQ(sizeof(output_data),
 186             pcb_read_->Read(output_data, sizeof(output_data)));
 187
 188   EXPECT_EQ(0, memcmp(kInputData, output_data, sizeof(kInputData)));
 189
 190   EXPECT_EQ(0u, pcb_read_->Read(output_data, sizeof(output_data)));
 191 }
 192
 193 TEST_F(PartialCircularBufferTest, WrapTwiceWithSingleWrite) {
 194   const size_t kInputSize = sizeof(kInputData);
 195   const size_t kLargeSize = kInputSize * 7;
 196   uint8 large_input[kLargeSize] = {0};
 197   for (size_t offset = 0; offset < kLargeSize; offset += kInputSize)
 198     memcpy(large_input + offset, kInputData, kInputSize);
 199
 200   InitWriteBuffer(false);
 201   pcb_write_->Write(large_input, kLargeSize);
 202   InitReadBuffer();
 203
 204   uint8 output_data[sizeof(kOutputRefDataWrap)] = {0};
 205   EXPECT_EQ(sizeof(output_data),
 206             pcb_read_->Read(output_data, sizeof(output_data)));
 207
 208   EXPECT_EQ(0, memcmp(kOutputRefDataWrap, output_data, sizeof(output_data)));
 209
 210   EXPECT_EQ(0u, pcb_read_->Read(output_data, sizeof(output_data)));
 211 }
 212