unit_tests: Generate new db dir per test (#353)

Add a method that allows the test name to be part of the DB name.  This makes it easier to associate a given test run with a given test.  Otherwise, some of the tests will overwrite the old data from a previous test.

db/db_test_util.cc

@@ -86,7 +86,7 @@ DBTestBase::DBTestBase(const std::string path, bool env_do_fsync)
   env_->SetBackgroundThreads(1, Env::LOW);
   env_->SetBackgroundThreads(1, Env::HIGH);
   env_->skip_fsync_ = !env_do_fsync;
-  dbname_ = test::PerThreadDBPath(env_, path);
+  dbname_ = test::PerThreadDBPath(env_, test::GetTestNameForDB(path));
   alternative_wal_dir_ = dbname_ + "/wal";
   alternative_db_log_dir_ = dbname_ + "/db_log_dir";
   auto options = CurrentOptions();

test_util/testharness.cc

@@ -32,6 +32,30 @@ ::testing::AssertionResult AssertStatus(const char* s_expr, const Status& s) {
   }
 }
 
+// If suggested is empty, the name will be <test case>-<test name>
+// Replaces all of the "/" in the test case/name with "_", so that they will not
+// appear as directories
+std::string GetTestNameForDB(const std::string& suggested) {
+  const testing::TestInfo* const test_info =
+      testing::UnitTest::GetInstance()->current_test_info();
+  std::string test_name = test_info->name();
+  std::string test_case = test_info->test_case_name();
+  auto pos = test_case.find("/");
+  if (pos != test_case.npos && !suggested.empty()) {
+    test_case = suggested;
+  } else {
+    while (pos != test_case.npos) {
+      test_case[pos] = '_';
+      pos = test_case.find("/", pos);
+    }
+  }
+  for (pos = test_name.find("/"); pos != test_name.npos;
+       pos = test_name.find("/", pos)) {
+    test_name[pos] = '_';
+  }
+  return test_case + "-" + test_name;
+}
+
 std::string TmpDir(Env* env) {
   std::string dir;
   Status s = env->GetTestDirectory(&dir);

test_util/testharness.h

@@ -64,6 +64,9 @@
 namespace ROCKSDB_NAMESPACE {
 namespace test {
 
+// Return a name of the DB for this test, based on the test case/name
+std::string GetTestNameForDB(const std::string& suggested = "");
+
 // Return the directory to use for temporary storage.
 std::string TmpDir(Env* env = Env::Default());