SERVER-41686 Add unittest to prototype structured logging using boost::log.

* JSON and Text formatting, including with custom types
* Google benchmark to compare against current log system
* Ramlog, Console and File logging prototyped
* Two ways to implement multiple log domains

1 files changed, 93 insertions, 0 deletions

diff --git a/src/mongo/logv2/text_formatter.h b/src/mongo/logv2/text_formatter.h
new file mode 100644
index 00000000000..de267352ca0
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+++ b/src/mongo/logv2/text_formatter.h
@@ -0,0 +1,93 @@
+/**
+ *    Copyright (C) 2019-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#pragma once
+
+#include <boost/log/attributes/value_extraction.hpp>
+#include <boost/log/core/record_view.hpp>
+#include <boost/log/expressions/message.hpp>
+#include <boost/log/utility/formatting_ostream.hpp>
+
+#include "mongo/logv2/attribute_argument_set.h"
+#include "mongo/logv2/attributes.h"
+#include "mongo/logv2/log_component.h"
+#include "mongo/logv2/log_severity.h"
+#include "mongo/logv2/log_tag.h"
+#include "mongo/util/time_support.h"
+
+#include <fmt/format.h>
+
+namespace mongo {
+namespace logv2 {
+
+class TextFormatter {
+public:
+    TextFormatter() = default;
+
+    // Boost log synchronizes calls to a formatter within a backend sink. If this is copied for some
+    // reason (to another backend sink), no need to copy the buffer. This is just storage so we
+    // don't need to allocate this memory every time. A final solution should format directly into
+    // the formatting_ostream.
+    TextFormatter(TextFormatter const&) {}
+
+    static bool binary() {
+        return false;
+    };
+
+    void operator()(boost::log::record_view const& rec, boost::log::formatting_ostream& strm) {
+        using namespace boost::log;
+
+        StringData message = extract<StringData>(attributes::message(), rec).get();
+        const auto& attrs = extract<AttributeArgumentSet>(attributes::attributes(), rec).get();
+
+        _buffer.clear();
+        fmt::format_to(
+            _buffer,
+            "{} {:<2} {:<8} [{}] ",
+            extract<Date_t>(attributes::timeStamp(), rec).get().toString(),
+            extract<LogSeverity>(attributes::severity(), rec).get().toStringDataCompact(),
+            extract<LogComponent>(attributes::component(), rec).get().getNameForLog(),
+            extract<StringData>(attributes::threadName(), rec).get());
+        strm.write(_buffer.data(), _buffer.size());
+
+        if (extract<LogTag>(attributes::tags(), rec).get().has(LogTag::kStartupWarnings)) {
+            strm << "** WARNING: ";
+        }
+
+        _buffer.clear();
+        fmt::internal::vformat_to(_buffer, to_string_view(message), attrs._values);
+        strm.write(_buffer.data(), _buffer.size());
+    }
+
+private:
+    fmt::memory_buffer _buffer;
+};
+
+}  // namespace logv2
+}  // namespace mongo