move VirtualFileSystem into test.*

src/build_test.cc

@@ -188,42 +188,6 @@ TEST_F(PlanTest, DependencyCycle) {
   ASSERT_EQ("dependency cycle: out -> mid -> in -> pre -> out", err);
 }
 
-struct VirtualFileSystem : public DiskInterface {
-  struct Entry {
-    int mtime;
-    string contents;
-  };
-
-  void Create(const string& path, int time, const string& contents) {
-    files_[path].mtime = time;
-    files_[path].contents = contents;
-  }
-
-  // DiskInterface
-  virtual int Stat(const string& path) {
-    FileMap::iterator i = files_.find(path);
-    if (i != files_.end())
-      return i->second.mtime;
-    return 0;
-  }
-  virtual bool MakeDir(const string& path) {
-    directories_made_.push_back(path);
-    return true;  // success
-  }
-  virtual string ReadFile(const string& path, string* err) {
-    files_read_.push_back(path);
-    FileMap::iterator i = files_.find(path);
-    if (i != files_.end())
-      return i->second.contents;
-    return "";
-  }
-
-  vector<string> directories_made_;
-  vector<string> files_read_;
-  typedef map<string, Entry> FileMap;
-  FileMap files_;
-};
-
 struct BuildTest : public StateTestWithBuiltinRules,
                    public CommandRunner {
   BuildTest() : config_(MakeConfig()), builder_(&state_, config_), now_(1),

src/test.cc

@@ -32,3 +32,29 @@ void AssertParse(State* state, const char* input) {
   ASSERT_TRUE(parser.Parse(input, &err)) << err;
   ASSERT_EQ("", err);
 }
+
+void VirtualFileSystem::Create(const string& path, int time,
+                               const string& contents) {
+  files_[path].mtime = time;
+  files_[path].contents = contents;
+}
+
+int VirtualFileSystem::Stat(const string& path) {
+  FileMap::iterator i = files_.find(path);
+  if (i != files_.end())
+    return i->second.mtime;
+  return 0;
+}
+
+bool VirtualFileSystem::MakeDir(const string& path) {
+  directories_made_.push_back(path);
+  return true;  // success
+}
+
+string VirtualFileSystem::ReadFile(const string& path, string* err) {
+  files_read_.push_back(path);
+  FileMap::iterator i = files_.find(path);
+  if (i != files_.end())
+    return i->second.contents;
+  return "";
+}

src/test.h

@@ -28,3 +28,26 @@ struct StateTestWithBuiltinRules : public testing::Test {
 };
 
 void AssertParse(State* state, const char* input);
+
+// An implementation of DiskInterface that uses an in-memory representation
+// of disk state.  It also logs file accesses and directory creations
+// so it can be used by tests to verify disk access patterns.
+struct VirtualFileSystem : public DiskInterface {
+  // "Create" a file with a given mtime and contents.
+  void Create(const string& path, int time, const string& contents);
+
+  // DiskInterface
+  virtual int Stat(const string& path);
+  virtual bool MakeDir(const string& path);
+  virtual string ReadFile(const string& path, string* err);
+
+  struct Entry {
+    int mtime;
+    string contents;
+  };
+
+  vector<string> directories_made_;
+  vector<string> files_read_;
+  typedef map<string, Entry> FileMap;
+  FileMap files_;
+};