| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "net/spdy/hpack_string_util.h" |
| |
| #include <cstddef> |
| #include <cstring> |
| |
| #include "base/basictypes.h" |
| #include "base/logging.h" |
| #include "base/strings/string_piece.h" |
| #include "testing/gtest/include/gtest/gtest.h" |
| |
| namespace net { |
| |
| namespace { |
| |
| using std::string; |
| |
| // Make sure StringPiecesEqualConstantTime() behaves like the regular |
| // string equality operator. |
| TEST(HpackStringUtilTest, StringPiecesEqualConstantTime) { |
| EXPECT_TRUE(StringPiecesEqualConstantTime("foo", "foo")); |
| EXPECT_FALSE(StringPiecesEqualConstantTime("foo", "foox")); |
| EXPECT_FALSE(StringPiecesEqualConstantTime("foo", "bar")); |
| } |
| |
| // TODO(jgraettinger): Support this benchmark. |
| /* |
| enum BM_StringPieceEqualityType { |
| STRCMP_EQUAL, |
| STRCMP_FIRST_CHAR_DIFFERS, |
| STRING_PIECES_EQUAL_CONSTANT_TIME_EQUAL, |
| STRING_PIECES_EQUAL_CONSTANT_TIME_FIRST_CHAR_DIFFERS, |
| }; |
| |
| void BM_StringPieceEquality(int iters, int size, int type_int) { |
| BM_StringPieceEqualityType type = |
| static_cast<BM_StringPieceEqualityType>(type_int); |
| string str_a(size, 'x'); |
| string str_b(size, 'x'); |
| int result = 0; |
| switch (type) { |
| case STRCMP_EQUAL: |
| for (int i = 0; i < iters; ++i) { |
| result |= std::strcmp(str_a.c_str(), str_b.c_str()); |
| } |
| CHECK_EQ(result, 0); |
| return; |
| |
| case STRCMP_FIRST_CHAR_DIFFERS: |
| str_b[0] = 'y'; |
| for (int i = 0; i < iters; ++i) { |
| result |= std::strcmp(str_a.c_str(), str_b.c_str()); |
| } |
| CHECK_LT(result, 0); |
| return; |
| |
| case STRING_PIECES_EQUAL_CONSTANT_TIME_EQUAL: |
| for (int i = 0; i < iters; ++i) { |
| result |= StringPiecesEqualConstantTime(str_a, str_b); |
| } |
| CHECK_EQ(result, 1); |
| return; |
| |
| case STRING_PIECES_EQUAL_CONSTANT_TIME_FIRST_CHAR_DIFFERS: |
| str_b[0] = 'y'; |
| for (int i = 0; i < iters; ++i) { |
| result |= StringPiecesEqualConstantTime(str_a, str_b); |
| } |
| CHECK_EQ(result, 0); |
| return; |
| } |
| |
| DCHECK(false); |
| } |
| |
| // Results should resemble the table below, where 0 and 1 are clearly |
| // different (STRCMP), but 2 and 3 are roughly the same |
| // (STRING_PIECES_EQUAL_CONSTANT_TIME). |
| // |
| // DEBUG: Benchmark Time(ns) CPU(ns) Iterations |
| // ------------------------------------------------------------------- |
| // DEBUG: BM_StringPieceEquality/1M/0 77796 77141 7778 |
| // DEBUG: BM_StringPieceEquality/1M/1 10 10 70000000 |
| // DEBUG: BM_StringPieceEquality/1M/2 7729735 7700000 100 |
| // DEBUG: BM_StringPieceEquality/1M/3 7803051 7800000 100 |
| BENCHMARK(BM_StringPieceEquality) |
| ->ArgPair(1<<20, STRCMP_EQUAL) |
| ->ArgPair(1<<20, STRCMP_FIRST_CHAR_DIFFERS) |
| ->ArgPair(1<<20, STRING_PIECES_EQUAL_CONSTANT_TIME_EQUAL) |
| ->ArgPair(1<<20, STRING_PIECES_EQUAL_CONSTANT_TIME_FIRST_CHAR_DIFFERS); |
| */ |
| |
| } // namespace |
| |
| } // namespace net |