regulators: Create ErrorHistory class
Create a class to track error history, such as error count and whether
the error has been logged.
Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: Iead88963110a699eee1d6cd8750303f05d6ecef1
diff --git a/phosphor-regulators/src/error_history.hpp b/phosphor-regulators/src/error_history.hpp
new file mode 100644
index 0000000..834cd79
--- /dev/null
+++ b/phosphor-regulators/src/error_history.hpp
@@ -0,0 +1,79 @@
+/**
+ * Copyright © 2020 IBM Corporation
+ *
+ * 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.
+ */
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+
+namespace phosphor::power::regulators
+{
+
+/**
+ * @class ErrorHistory
+ *
+ * This class represents the history of an error.
+ *
+ * ErrorHistory tracks the error count and whether the error has been logged.
+ *
+ * This class is often used to limit the number of journal messages and error
+ * logs created by code that runs repeatedly, such as sensor monitoring.
+ */
+class ErrorHistory
+{
+ public:
+ // Specify which compiler-generated methods we want
+ ErrorHistory() = default;
+ ErrorHistory(const ErrorHistory&) = default;
+ ErrorHistory(ErrorHistory&&) = default;
+ ErrorHistory& operator=(const ErrorHistory&) = default;
+ ErrorHistory& operator=(ErrorHistory&&) = default;
+ ~ErrorHistory() = default;
+
+ /**
+ * Clears the error history.
+ */
+ void clear()
+ {
+ count = 0;
+ wasLogged = false;
+ }
+
+ /**
+ * Increments the error count.
+ *
+ * Does nothing if the error count is already at the maximum. This avoids
+ * wrapping back to 0 again.
+ */
+ void incrementCount()
+ {
+ if (count < SIZE_MAX)
+ {
+ ++count;
+ }
+ }
+
+ /**
+ * Error count.
+ */
+ std::size_t count{0};
+
+ /**
+ * Indicates whether this error was logged, resulting in an error log entry.
+ */
+ bool wasLogged{false};
+};
+
+} // namespace phosphor::power::regulators
diff --git a/phosphor-regulators/test/error_history_tests.cpp b/phosphor-regulators/test/error_history_tests.cpp
new file mode 100644
index 0000000..3e3cba8
--- /dev/null
+++ b/phosphor-regulators/test/error_history_tests.cpp
@@ -0,0 +1,60 @@
+/**
+ * Copyright © 2020 IBM Corporation
+ *
+ * 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 "error_history.hpp"
+
+#include <cstdint>
+
+#include <gtest/gtest.h>
+
+using namespace phosphor::power::regulators;
+
+TEST(ErrorHistoryTests, Constructor)
+{
+ ErrorHistory history{};
+ EXPECT_EQ(history.count, 0);
+ EXPECT_EQ(history.wasLogged, false);
+}
+
+TEST(ErrorHistoryTests, Clear)
+{
+ ErrorHistory history{};
+ history.count = 23;
+ history.wasLogged = true;
+ history.clear();
+ EXPECT_EQ(history.count, 0);
+ EXPECT_EQ(history.wasLogged, false);
+}
+
+TEST(ErrorHistoryTests, IncrementCount)
+{
+ ErrorHistory history{};
+
+ // Test where count is not near the max
+ EXPECT_EQ(history.count, 0);
+ history.incrementCount();
+ EXPECT_EQ(history.count, 1);
+ history.incrementCount();
+ EXPECT_EQ(history.count, 2);
+
+ // Test where count is near the max. Verify it does not wrap/overflow.
+ history.count = SIZE_MAX - 2;
+ history.incrementCount();
+ EXPECT_EQ(history.count, SIZE_MAX - 1);
+ history.incrementCount();
+ EXPECT_EQ(history.count, SIZE_MAX);
+ history.incrementCount();
+ EXPECT_EQ(history.count, SIZE_MAX);
+}
diff --git a/phosphor-regulators/test/meson.build b/phosphor-regulators/test/meson.build
index b73c3a0..8a1d059 100644
--- a/phosphor-regulators/test/meson.build
+++ b/phosphor-regulators/test/meson.build
@@ -9,6 +9,7 @@
'config_file_parser_tests.cpp',
'configuration_tests.cpp',
'device_tests.cpp',
+ 'error_history_tests.cpp',
'exception_utils_tests.cpp',
'id_map_tests.cpp',
'mock_journal.cpp',