courgette/bsdiff_memory_unittest.cc

   1 // Copyright (c) 2009 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 "courgette/third_party/bsdiff.h"
   6
   7 #include <string>
   8
   9 #include "base/file_util.h"
  10 #include "base/path_service.h"
  11 #include "base/string_util.h"
  12
  13 #include "courgette/courgette.h"
  14 #include "courgette/streams.h"
  15
  16 #include "testing/gtest/include/gtest/gtest.h"
  17
  18 class BSDiffMemoryTest : public testing::Test {
  19  public:
  20   std::string FileContents(const char* file_name) const;
  21   void GenerateAndTestPatch(const std::string& a, const std::string& b) const;
  22
  23   std::string GenerateSyntheticInput(size_t length, int seed) const;
  24
  25  private:
  26   void SetUp() {
  27     PathService::Get(base::DIR_SOURCE_ROOT, &test_dir_);
  28     test_dir_ = test_dir_.AppendASCII("courgette");
  29     test_dir_ = test_dir_.AppendASCII("testdata");
  30   }
  31
  32   FilePath test_dir_;
  33 };
  34
  35 //  Reads a test file into a string.
  36 std::string BSDiffMemoryTest::FileContents(const char* file_name) const {
  37   FilePath file_path = test_dir_;
  38   file_path = file_path.AppendASCII(file_name);
  39   std::string file_bytes;
  40   if (!file_util::ReadFileToString(file_path, &file_bytes)) {
  41     EXPECT_TRUE(!"Could not read test data");
  42   }
  43   return file_bytes;
  44 }
  45
  46 void BSDiffMemoryTest::GenerateAndTestPatch(const std::string& old_text,
  47                                             const std::string& new_text) const {
  48   courgette::SourceStream old1;
  49   courgette::SourceStream new1;
  50   old1.Init(old_text.c_str(), old_text.length());
  51   new1.Init(new_text.c_str(), new_text.length());
  52
  53   courgette::SinkStream patch1;
  54   courgette::BSDiffStatus status = CreateBinaryPatch(&old1, &new1, &patch1);
  55   EXPECT_EQ(courgette::OK, status);
  56
  57   courgette::SourceStream old2;
  58   courgette::SourceStream patch2;
  59   old2.Init(old_text.c_str(), old_text.length());
  60   patch2.Init(patch1);
  61
  62   courgette::SinkStream new2;
  63   status = ApplyBinaryPatch(&old2, &patch2, &new2);
  64   EXPECT_EQ(courgette::OK, status);
  65   EXPECT_EQ(new_text.length(), new2.Length());
  66   EXPECT_EQ(0, memcmp(new_text.c_str(), new2.Buffer(), new_text.length()));
  67 }
  68
  69 std::string BSDiffMemoryTest::GenerateSyntheticInput(size_t length, int seed)
  70   const {
  71   static const char* a[8] = {"O", "A", "x", "-", "y", ".", "|", ":"};
  72   std::string result;
  73   while (result.length() < length) {
  74     seed = (seed + 17) * 1049 + (seed >> 27);
  75     result.append(a[seed & 7]);
  76   }
  77   result.resize(length);
  78   return result;
  79 }
  80
  81 TEST_F(BSDiffMemoryTest, TestEmpty) {
  82   GenerateAndTestPatch("", "");
  83 }
  84
  85 TEST_F(BSDiffMemoryTest, TestEmptyVsNonempty) {
  86   GenerateAndTestPatch("", "xxx");
  87 }
  88
  89 TEST_F(BSDiffMemoryTest, TestNonemptyVsEmpty) {
  90   GenerateAndTestPatch("xxx", "");
  91 }
  92
  93 TEST_F(BSDiffMemoryTest, TestSmallInputsWithSmallChanges) {
  94   std::string file1 =
  95       "I would not, could not, in a box.\n"
  96       "I could not, would not, with a fox.\n"
  97       "I will not eat them with a mouse.\n"
  98       "I will not eat them in a house.\n"
  99       "I will not eat them here or there.\n"
 100       "I will not eat them anywhere.\n"
 101       "I do not eat green eggs and ham.\n"
 102       "I do not like them, Sam-I-am.\n";
 103   std::string file2 =
 104       "I would not, could not, in a BOX.\n"
 105       "I could not, would not, with a FOX.\n"
 106       "I will not eat them with a MOUSE.\n"
 107       "I will not eat them in a HOUSE.\n"
 108       "I will not eat them in a HOUSE.\n"     // Extra line.
 109       "I will not eat them here or THERE.\n"
 110       "I will not eat them ANYWHERE.\n"
 111       "I do not eat green eggs and HAM.\n"
 112       "I do not like them, Sam-I-am.\n";
 113   GenerateAndTestPatch(file1, file2);
 114 }
 115
 116 TEST_F(BSDiffMemoryTest, TestNearPageArrayPageSize) {
 117   // This magic number is the size of one block of the PageArray in
 118   // third_party/bsdiff_create.cc.
 119   size_t critical_size = 1 << 18;
 120
 121   // Test first-inputs with sizes that straddle the magic size to test this
 122   // PageArray's internal boundary condition.
 123
 124   std::string file1 = GenerateSyntheticInput(critical_size, 0);
 125   std::string file2 = GenerateSyntheticInput(critical_size, 1);
 126   GenerateAndTestPatch(file1, file2);
 127
 128   std::string file1a = file1.substr(0, critical_size - 1);
 129   GenerateAndTestPatch(file1a, file2);
 130
 131   std::string file1b = file1.substr(0, critical_size - 2);
 132   GenerateAndTestPatch(file1b, file2);
 133
 134   std::string file1c = file1 + file1.substr(0, 1);
 135   GenerateAndTestPatch(file1c, file2);
 136 }
 137
 138 TEST_F(BSDiffMemoryTest, TestIndenticalDlls) {
 139   std::string file1 = FileContents("en-US.dll");
 140   GenerateAndTestPatch(file1, file1);
 141 }
 142
 143 TEST_F(BSDiffMemoryTest, TestDifferentExes) {
 144   std::string file1 = FileContents("setup1.exe");
 145   std::string file2 = FileContents("setup2.exe");
 146   GenerateAndTestPatch(file1, file2);
 147 }