Add tests for ConsumeDecimalNumber.

ConsumeDecimalNumber has fairly non-trivial logic, and a previous
version has crashed inexplicably on Android. Having some test coverage
will make it easier to tweak / simplify the function later on.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=192821751

CMakeLists.txt

@@ -326,6 +326,7 @@ if(LEVELDB_BUILD_TESTS)
     leveldb_test("${PROJECT_SOURCE_DIR}/util/coding_test.cc")
     leveldb_test("${PROJECT_SOURCE_DIR}/util/crc32c_test.cc")
     leveldb_test("${PROJECT_SOURCE_DIR}/util/hash_test.cc")
+    leveldb_test("${PROJECT_SOURCE_DIR}/util/logging_test.cc")
 
     # TODO(costan): This test also uses
     #               "${PROJECT_SOURCE_DIR}/util/env_posix_test_helper.h"

util/logging_test.cc

@@ -0,0 +1,145 @@
+// Copyright (c) 2018 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#include <limits>
+#include <string>
+
+#include "leveldb/slice.h"
+#include "util/logging.h"
+#include "util/testharness.h"
+
+namespace leveldb {
+
+class Logging { };
+
+TEST(Logging, NumberToString) {
+  ASSERT_EQ("0", NumberToString(0));
+  ASSERT_EQ("1", NumberToString(1));
+  ASSERT_EQ("9", NumberToString(9));
+
+  ASSERT_EQ("10", NumberToString(10));
+  ASSERT_EQ("11", NumberToString(11));
+  ASSERT_EQ("19", NumberToString(19));
+  ASSERT_EQ("99", NumberToString(99));
+
+  ASSERT_EQ("100", NumberToString(100));
+  ASSERT_EQ("109", NumberToString(109));
+  ASSERT_EQ("190", NumberToString(190));
+  ASSERT_EQ("123", NumberToString(123));
+  ASSERT_EQ("12345678", NumberToString(12345678));
+
+  static_assert(std::numeric_limits<uint64_t>::max() == 18446744073709551615U,
+                "Test consistency check");
+  ASSERT_EQ("18446744073709551000", NumberToString(18446744073709551000U));
+  ASSERT_EQ("18446744073709551600", NumberToString(18446744073709551600U));
+  ASSERT_EQ("18446744073709551610", NumberToString(18446744073709551610U));
+  ASSERT_EQ("18446744073709551614", NumberToString(18446744073709551614U));
+  ASSERT_EQ("18446744073709551615", NumberToString(18446744073709551615U));
+}
+
+void ConsumeDecimalNumberRoundtripTest(uint64_t number,
+                                       const std::string& padding = "") {
+  std::string decimal_number = NumberToString(number);
+  std::string input_string = decimal_number + padding;
+  Slice input(input_string);
+  Slice output = input;
+  uint64_t result;
+  ASSERT_TRUE(ConsumeDecimalNumber(&output, &result));
+  ASSERT_EQ(number, result);
+  ASSERT_EQ(decimal_number.size(), output.data() - input.data());
+  ASSERT_EQ(padding.size(), output.size());
+}
+
+TEST(Logging, ConsumeDecimalNumberRoundtrip) {
+  ConsumeDecimalNumberRoundtripTest(0);
+  ConsumeDecimalNumberRoundtripTest(1);
+  ConsumeDecimalNumberRoundtripTest(9);
+
+  ConsumeDecimalNumberRoundtripTest(10);
+  ConsumeDecimalNumberRoundtripTest(11);
+  ConsumeDecimalNumberRoundtripTest(19);
+  ConsumeDecimalNumberRoundtripTest(99);
+
+  ConsumeDecimalNumberRoundtripTest(100);
+  ConsumeDecimalNumberRoundtripTest(109);
+  ConsumeDecimalNumberRoundtripTest(190);
+  ConsumeDecimalNumberRoundtripTest(123);
+  ASSERT_EQ("12345678", NumberToString(12345678));
+
+  for (uint64_t i = 0; i < 100; ++i) {
+    uint64_t large_number = std::numeric_limits<uint64_t>::max() - i;
+    ConsumeDecimalNumberRoundtripTest(large_number);
+  }
+}
+
+TEST(Logging, ConsumeDecimalNumberRoundtripWithPadding) {
+  ConsumeDecimalNumberRoundtripTest(0, " ");
+  ConsumeDecimalNumberRoundtripTest(1, "abc");
+  ConsumeDecimalNumberRoundtripTest(9, "x");
+
+  ConsumeDecimalNumberRoundtripTest(10, "_");
+  ConsumeDecimalNumberRoundtripTest(11, std::string("\0\0\0", 3));
+  ConsumeDecimalNumberRoundtripTest(19, "abc");
+  ConsumeDecimalNumberRoundtripTest(99, "padding");
+
+  ConsumeDecimalNumberRoundtripTest(100, " ");
+
+  for (uint64_t i = 0; i < 100; ++i) {
+    uint64_t large_number = std::numeric_limits<uint64_t>::max() - i;
+    ConsumeDecimalNumberRoundtripTest(large_number, "pad");
+  }
+}
+
+void ConsumeDecimalNumberOverflowTest(const std::string& input_string) {
+  Slice input(input_string);
+  Slice output = input;
+  uint64_t result;
+  ASSERT_EQ(false, ConsumeDecimalNumber(&output, &result));
+}
+
+TEST(Logging, ConsumeDecimalNumberOverflow) {
+  static_assert(std::numeric_limits<uint64_t>::max() == 18446744073709551615U,
+                "Test consistency check");
+  ConsumeDecimalNumberOverflowTest("18446744073709551616");
+  ConsumeDecimalNumberOverflowTest("18446744073709551617");
+  ConsumeDecimalNumberOverflowTest("18446744073709551618");
+  ConsumeDecimalNumberOverflowTest("18446744073709551619");
+  ConsumeDecimalNumberOverflowTest("18446744073709551620");
+  ConsumeDecimalNumberOverflowTest("18446744073709551621");
+  ConsumeDecimalNumberOverflowTest("18446744073709551622");
+  ConsumeDecimalNumberOverflowTest("18446744073709551623");
+  ConsumeDecimalNumberOverflowTest("18446744073709551624");
+  ConsumeDecimalNumberOverflowTest("18446744073709551625");
+  ConsumeDecimalNumberOverflowTest("18446744073709551626");
+
+  ConsumeDecimalNumberOverflowTest("18446744073709551700");
+
+  ConsumeDecimalNumberOverflowTest("99999999999999999999");
+}
+
+void ConsumeDecimalNumberNoDigitsTest(const std::string& input_string) {
+  Slice input(input_string);
+  Slice output = input;
+  uint64_t result;
+  ASSERT_EQ(false, ConsumeDecimalNumber(&output, &result));
+  ASSERT_EQ(input.data(), output.data());
+  ASSERT_EQ(input.size(), output.size());
+}
+
+TEST(Logging, ConsumeDecimalNumberNoDigits) {
+  ConsumeDecimalNumberNoDigitsTest("");
+  ConsumeDecimalNumberNoDigitsTest(" ");
+  ConsumeDecimalNumberNoDigitsTest("a");
+  ConsumeDecimalNumberNoDigitsTest(" 123");
+  ConsumeDecimalNumberNoDigitsTest("a123");
+  ConsumeDecimalNumberNoDigitsTest(std::string("\000123", 4));
+  ConsumeDecimalNumberNoDigitsTest(std::string("\177123", 4));
+  ConsumeDecimalNumberNoDigitsTest(std::string("\377123", 4));
+}
+
+}  // namespace leveldb
+
+int main(int argc, char** argv) {
+  return leveldb::test::RunAllTests();
+}