1 files changed, 112 insertions, 0 deletions
diff --git a/extensions/openpower-pels/log_id.cpp b/extensions/openpower-pels/log_id.cpp
new file mode 100644
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--- /dev/null
+++ b/extensions/openpower-pels/log_id.cpp
@@ -0,0 +1,112 @@
+/**
+ * Copyright © 2019 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 "log_id.hpp"
+
+#include "paths.hpp"
+
+#include <chrono>
+#include <filesystem>
+#include <fstream>
+#include <phosphor-logging/log.hpp>
+
+namespace openpower
+{
+namespace pels
+{
+
+namespace fs = std::filesystem;
+using namespace phosphor::logging;
+
+constexpr uint32_t startingLogID = 1;
+constexpr uint32_t bmcLogIDPrefix = 0x50000000;
+
+namespace detail
+{
+
+uint32_t addLogIDPrefix(uint32_t id)
+{
+    // If redundant BMCs are ever a thing, may need a different prefix.
+    return (id & 0x00FFFFFF) | bmcLogIDPrefix;
+}
+
+uint32_t getTimeBasedLogID()
+{
+    using namespace std::chrono;
+
+    // Use 3 bytes of the nanosecond count since the epoch.
+    uint32_t id =
+        duration_cast<nanoseconds>(system_clock::now().time_since_epoch())
+            .count();
+
+    return addLogIDPrefix(id);
+}
+
+} // namespace detail
+
+uint32_t generatePELID()
+{
+    // Note: there isn't a need to be thread safe.
+
+    static std::string idFilename;
+    if (idFilename.empty())
+    {
+        idFilename = getPELIDFile();
+    }
+
+    uint32_t id = 0;
+
+    if (!fs::exists(idFilename))
+    {
+        auto path = fs::path(idFilename).parent_path();
+        if (!fs::exists(path))
+        {
+            fs::create_directories(path);
+        }
+
+        id = startingLogID;
+    }
+    else
+    {
+        std::ifstream idFile{idFilename};
+        idFile >> id;
+        if (idFile.fail())
+        {
+            // Just make up an ID
+            log<level::ERR>("Unable to read PEL ID File!");
+            return detail::getTimeBasedLogID();
+        }
+    }
+
+    // Wrapping shouldn't be a problem, but check anyway
+    if (id == 0x00FFFFFF)
+    {
+        id = startingLogID;
+    }
+
+    std::ofstream idFile{idFilename};
+    idFile << (id + 1);
+    if (idFile.fail())
+    {
+        // Just make up an ID so we don't reuse one next time
+        log<level::ERR>("Unable to write PEL ID File!");
+        return detail::getTimeBasedLogID();
+    }
+
+    return detail::addLogIDPrefix(id);
+}
+
+} // namespace pels
+} // namespace openpower