SERVER-45985 Add truncation support to the text formatter

 create mode 100644 src/mongo/logv2/log_truncation.h

9 files changed, 80 insertions, 4 deletions

diff --git a/src/mongo/logger/logv2_appender.h b/src/mongo/logger/logv2_appender.h
index 75c7bb8f684..4e8735f677f 100644
--- a/src/mongo/logger/logv2_appender.h
+++ b/src/mongo/logger/logv2_appender.h
@@ -111,7 +111,9 @@ public:
                 _domain,
                 logv2::LogTag{static_cast<logv2::LogTag::Value>(
                     static_cast<std::underlying_type_t<logv2::LogTag::Value>>(logTagValue) |
-                    static_cast<std::underlying_type_t<logv2::LogTag::Value>>(_tag))}},
+                    static_cast<std::underlying_type_t<logv2::LogTag::Value>>(_tag))},
+                event.isTruncatable() ? logv2::LogTruncation::Enabled
+                                      : logv2::LogTruncation::Disabled},
 
             "{}",
             "message"_attr = message);
diff --git a/src/mongo/logv2/attributes.cpp b/src/mongo/logv2/attributes.cpp
index dc76a88fb8f..f767f3ae94c 100644
--- a/src/mongo/logv2/attributes.cpp
+++ b/src/mongo/logv2/attributes.cpp
@@ -78,6 +78,11 @@ const boost::log::attribute_name& attributes() {
     return attr;
 }
 
+const boost::log::attribute_name& truncation() {
+    static const boost::log::attribute_name attr("truncation");
+    return attr;
+}
+
 }  // namespace attributes
 }  // namespace logv2
 }  // namespace mongo
diff --git a/src/mongo/logv2/attributes.h b/src/mongo/logv2/attributes.h
index a69e097aaf6..f39f24a95cd 100644
--- a/src/mongo/logv2/attributes.h
+++ b/src/mongo/logv2/attributes.h
@@ -45,6 +45,7 @@ const boost::log::attribute_name& tags();
 const boost::log::attribute_name& id();
 const boost::log::attribute_name& message();
 const boost::log::attribute_name& attributes();
+const boost::log::attribute_name& truncation();
 
 }  // namespace attributes
 }  // namespace logv2
diff --git a/src/mongo/logv2/constants.h b/src/mongo/logv2/constants.h
index 5c702e723e8..6b16cccbc8a 100644
--- a/src/mongo/logv2/constants.h
+++ b/src/mongo/logv2/constants.h
@@ -29,6 +29,8 @@
 
 #pragma once
 
+#include "mongo/logv2/log_truncation.h"
+
 namespace mongo::logv2::constants {
 
 // Used in data structures to indicate number of attributes to store without having to allocate
@@ -48,4 +50,7 @@ constexpr StringData kTagsFieldName = "tags"_sd;
 // String to be used when logging empty boost::optional with the text formatter
 constexpr StringData kNullOptionalString = "(nothing)"_sd;
 
+constexpr LogTruncation kDefaultTruncation = LogTruncation::Enabled;
+constexpr size_t kDefaultMaxAttributeOutputSize = 10 * 1024;
+
 }  // namespace mongo::logv2::constants
diff --git a/src/mongo/logv2/log_detail.cpp b/src/mongo/logv2/log_detail.cpp
index 048fa423d7f..4668ff2339f 100644
--- a/src/mongo/logv2/log_detail.cpp
+++ b/src/mongo/logv2/log_detail.cpp
@@ -49,7 +49,8 @@ void doLogImpl(int32_t id,
                TypeErasedAttributeStorage const& attrs) {
     dassert(options.component() != LogComponent::kNumLogComponents);
     auto& source = options.domain().internal().source();
-    auto record = source.open_record(id, severity, options.component(), options.tags());
+    auto record =
+        source.open_record(id, severity, options.component(), options.tags(), options.truncation());
     if (record) {
         record.attribute_values().insert(
             attributes::message(),
diff --git a/src/mongo/logv2/log_options.h b/src/mongo/logv2/log_options.h
index baf3faafd5c..cc7601baddb 100644
--- a/src/mongo/logv2/log_options.h
+++ b/src/mongo/logv2/log_options.h
@@ -32,6 +32,7 @@
 #include "mongo/logv2/log_component.h"
 #include "mongo/logv2/log_manager.h"
 #include "mongo/logv2/log_tag.h"
+#include "mongo/logv2/log_truncation.h"
 
 namespace mongo {
 namespace logv2 {
@@ -51,9 +52,14 @@ public:
 
     LogOptions(LogTag tags) : _tags(tags) {}
 
+    LogOptions(LogTruncation truncation) : _truncation(truncation) {}
+
     LogOptions(LogComponent component, LogDomain* domain, LogTag tags)
         : _domain(domain), _tags(tags), _component(component) {}
 
+    LogOptions(LogComponent component, LogDomain* domain, LogTag tags, LogTruncation truncation)
+        : _domain(domain), _tags(tags), _component(component), _truncation(truncation) {}
+
     LogComponent component() const {
         return _component;
     }
@@ -66,10 +72,15 @@ public:
         return _tags;
     }
 
+    LogTruncation truncation() const {
+        return _truncation;
+    }
+
 private:
     LogDomain* _domain = &LogManager::global().getGlobalDomain();
     LogTag _tags;
     LogComponent _component = LogComponent::kAutomaticDetermination;
+    LogTruncation _truncation = constants::kDefaultTruncation;
 };
 
 }  // namespace logv2
diff --git a/src/mongo/logv2/log_source.h b/src/mongo/logv2/log_source.h
index 108f623ad99..25eea5c36b4 100644
--- a/src/mongo/logv2/log_source.h
+++ b/src/mongo/logv2/log_source.h
@@ -38,10 +38,12 @@
 #include <boost/log/sources/threading_models.hpp>
 
 #include "mongo/logv2/attributes.h"
+#include "mongo/logv2/constants.h"
 #include "mongo/logv2/log_component.h"
 #include "mongo/logv2/log_domain.h"
 #include "mongo/logv2/log_severity.h"
 #include "mongo/logv2/log_tag.h"
+#include "mongo/logv2/log_truncation.h"
 #include "mongo/util/time_support.h"
 
 namespace mongo {
@@ -60,11 +62,13 @@ public:
           _severity(LogSeverity::Log()),
           _component(LogComponent::kDefault),
           _tags(LogTag::kNone),
+          _truncation(constants::kDefaultTruncation),
           _id(-1) {
         add_attribute_unlocked(attributes::domain(), _domain);
         add_attribute_unlocked(attributes::severity(), _severity);
         add_attribute_unlocked(attributes::component(), _component);
         add_attribute_unlocked(attributes::tags(), _tags);
+        add_attribute_unlocked(attributes::truncation(), _truncation);
         add_attribute_unlocked(attributes::id(), _id);
         add_attribute_unlocked(attributes::timeStamp(), boost::log::attributes::make_function([]() {
                                    return Date_t::now();
@@ -77,12 +81,14 @@ public:
     boost::log::record open_record(int32_t id,
                                    LogSeverity severity,
                                    LogComponent component,
-                                   LogTag tags) {
+                                   LogTag tags,
+                                   LogTruncation truncation) {
         // Perform a quick check first
         if (this->core()->get_logging_enabled()) {
             _severity.set(severity);
             _component.set(component);
             _tags.set(tags);
+            _truncation.set(truncation);
             _id.set(id);
             return Base::open_record_unlocked();
         } else
@@ -94,6 +100,7 @@ public:
         _severity.set(LogSeverity::Log());
         _component.set(LogComponent::kDefault);
         _tags.set(LogTag::kNone);
+        _truncation.set(constants::kDefaultTruncation);
         _id.set(-1);
     }
 
@@ -102,6 +109,7 @@ private:
     boost::log::attributes::mutable_constant<LogSeverity> _severity;
     boost::log::attributes::mutable_constant<LogComponent> _component;
     boost::log::attributes::mutable_constant<LogTag> _tags;
+    boost::log::attributes::mutable_constant<LogTruncation> _truncation;
     boost::log::attributes::mutable_constant<int32_t> _id;
 };
 
diff --git a/src/mongo/logv2/log_truncation.h b/src/mongo/logv2/log_truncation.h
new file mode 100644
index 00000000000..5336a2ff0c0
--- /dev/null
+++ b/src/mongo/logv2/log_truncation.h
@@ -0,0 +1,38 @@
+/**
+ *    Copyright (C) 2020-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
+
+namespace mongo {
+namespace logv2 {
+
+enum class LogTruncation { Enabled, Disabled };
+
+}  // namespace logv2
+}  // namespace mongo
diff --git a/src/mongo/logv2/plain_formatter.cpp b/src/mongo/logv2/plain_formatter.cpp
index d6d11ffb523..e156a1148ac 100644
--- a/src/mongo/logv2/plain_formatter.cpp
+++ b/src/mongo/logv2/plain_formatter.cpp
@@ -149,7 +149,12 @@ void PlainFormatter::operator()(boost::log::record_view const& rec,
         buffer,
         to_string_view(message),
         fmt::basic_format_args<fmt::format_context>(extractor.args.data(), extractor.args.size()));
-    strm.write(buffer.data(), buffer.size());
+
+    LogTruncation truncation = extract<LogTruncation>(attributes::truncation(), rec).get();
+    strm.write(buffer.data(),
+               truncation == LogTruncation::Enabled
+                   ? std::min(constants::kDefaultMaxAttributeOutputSize, buffer.size())
+                   : buffer.size());
 }
 
 }  // namespace mongo::logv2