Add string_piece_util

Following functions are implemented for further performance
optimization.

* JoinStringPiece
* SplitStringPiece
* EqualsCaseInsensitiveASCII
* ToLowerASCII

To improve performance of CLParser, I will introduce above functions
into include_normalize-win32.cc.

1 files changed, 129 insertions, 0 deletions

diff --git a/src/string_piece_util_test.cc b/src/string_piece_util_test.cc
new file mode 100644
index 0000000..648c647
--- /dev/null
+++ b/src/string_piece_util_test.cc
@@ -0,0 +1,129 @@
+// Copyright 2017 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "string_piece_util.h"
+
+#include "test.h"
+
+TEST(StringPieceUtilTest, SplitStringPiece) {
+  {
+    string input("a:b:c");
+    vector<StringPiece> list = SplitStringPiece(input, ':');
+
+    EXPECT_EQ(list.size(), 3);
+
+    EXPECT_EQ(list[0], "a");
+    EXPECT_EQ(list[1], "b");
+    EXPECT_EQ(list[2], "c");
+  }
+
+  {
+    string empty("");
+    vector<StringPiece> list = SplitStringPiece(empty, ':');
+
+    EXPECT_EQ(list.size(), 1);
+
+    EXPECT_EQ(list[0], "");
+  }
+
+  {
+    string one("a");
+    vector<StringPiece> list = SplitStringPiece(one, ':');
+
+    EXPECT_EQ(list.size(), 1);
+
+    EXPECT_EQ(list[0], "a");
+  }
+
+  {
+    string sep_only(":");
+    vector<StringPiece> list = SplitStringPiece(sep_only, ':');
+
+    EXPECT_EQ(list.size(), 2);
+
+    EXPECT_EQ(list[0], "");
+    EXPECT_EQ(list[1], "");
+  }
+
+  {
+    string sep(":a:b:c:");
+    vector<StringPiece> list = SplitStringPiece(sep, ':');
+
+    EXPECT_EQ(list.size(), 5);
+
+    EXPECT_EQ(list[0], "");
+    EXPECT_EQ(list[1], "a");
+    EXPECT_EQ(list[2], "b");
+    EXPECT_EQ(list[3], "c");
+    EXPECT_EQ(list[4], "");
+  }
+}
+
+TEST(StringPieceUtilTest, JoinStringPiece) {
+  {
+    string input("a:b:c");
+    vector<StringPiece> list = SplitStringPiece(input, ':');
+
+    EXPECT_EQ("a:b:c", JoinStringPiece(list, ':'));
+    EXPECT_EQ("a/b/c", JoinStringPiece(list, '/'));
+  }
+
+  {
+    string empty("");
+    vector<StringPiece> list = SplitStringPiece(empty, ':');
+
+    EXPECT_EQ("", JoinStringPiece(list, ':'));
+  }
+
+  {
+    vector<StringPiece> empty_list;
+
+    EXPECT_EQ("", JoinStringPiece(empty_list, ':'));
+  }
+
+  {
+    string one("a");
+    vector<StringPiece> single_list = SplitStringPiece(one, ':');
+
+    EXPECT_EQ("a", JoinStringPiece(single_list, ':'));
+  }
+
+  {
+    string sep(":a:b:c:");
+    vector<StringPiece> list = SplitStringPiece(sep, ':');
+
+    EXPECT_EQ(":a:b:c:", JoinStringPiece(list, ':'));
+  }
+}
+
+TEST(StringPieceUtilTest, ToLowerASCII) {
+  EXPECT_EQ('a', ToLowerASCII('A'));
+  EXPECT_EQ('z', ToLowerASCII('Z'));
+  EXPECT_EQ('a', ToLowerASCII('a'));
+  EXPECT_EQ('z', ToLowerASCII('z'));
+  EXPECT_EQ('/', ToLowerASCII('/'));
+  EXPECT_EQ('1', ToLowerASCII('1'));
+}
+
+TEST(StringPieceUtilTest, EqualsCaseInsensitiveASCII) {
+  EXPECT_TRUE(EqualsCaseInsensitiveASCII("abc", "abc"));
+  EXPECT_TRUE(EqualsCaseInsensitiveASCII("abc", "ABC"));
+  EXPECT_TRUE(EqualsCaseInsensitiveASCII("abc", "aBc"));
+  EXPECT_TRUE(EqualsCaseInsensitiveASCII("AbC", "aBc"));
+  EXPECT_TRUE(EqualsCaseInsensitiveASCII("", ""));
+
+  EXPECT_FALSE(EqualsCaseInsensitiveASCII("a", "ac"));
+  EXPECT_FALSE(EqualsCaseInsensitiveASCII("/", "\\"));
+  EXPECT_FALSE(EqualsCaseInsensitiveASCII("1", "10"));
+}