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// 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 "base/hash.h"
#include <string>
#include <vector>
#include "testing/gtest/include/gtest/gtest.h"
namespace base {
TEST(HashTest, String) {
std::string str;
// Empty string (should hash to 0).
str = "";
EXPECT_EQ(0u, Hash(str));
// Simple test.
str = "hello world";
EXPECT_EQ(2794219650u, Hash(str));
// Change one bit.
str = "helmo world";
EXPECT_EQ(1006697176u, Hash(str));
// Insert a null byte.
str = "hello world";
str[5] = '\0';
EXPECT_EQ(2319902537u, Hash(str));
// Test that the bytes after the null contribute to the hash.
str = "hello worle";
str[5] = '\0';
EXPECT_EQ(553904462u, Hash(str));
// Extremely long string.
// Also tests strings with high bit set, and null byte.
std::vector<char> long_string_buffer;
for (int i = 0; i < 4096; ++i)
long_string_buffer.push_back((i % 256) - 128);
str.assign(&long_string_buffer.front(), long_string_buffer.size());
EXPECT_EQ(2797962408u, Hash(str));
// All possible lengths (mod 4). Tests separate code paths. Also test with
// final byte high bit set (regression test for http://crbug.com/90659).
// Note that the 1 and 3 cases have a weird bug where the final byte is
// treated as a signed char. It was decided on the above bug discussion to
// enshrine that behaviour as "correct" to avoid invalidating existing hashes.
// Length mod 4 == 0.
str = "hello w\xab";
EXPECT_EQ(615571198u, Hash(str));
// Length mod 4 == 1.
str = "hello wo\xab";
EXPECT_EQ(623474296u, Hash(str));
// Length mod 4 == 2.
str = "hello wor\xab";
EXPECT_EQ(4278562408u, Hash(str));
// Length mod 4 == 3.
str = "hello worl\xab";
EXPECT_EQ(3224633008u, Hash(str));
}
TEST(HashTest, CString) {
const char* str;
// Empty string (should hash to 0).
str = "";
EXPECT_EQ(0u, Hash(str, strlen(str)));
// Simple test.
str = "hello world";
EXPECT_EQ(2794219650u, Hash(str, strlen(str)));
// Ensure that it stops reading after the given length, and does not expect a
// null byte.
str = "hello world; don't read this part";
EXPECT_EQ(2794219650u, Hash(str, strlen("hello world")));
}
} // namespace base
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