Implemented some more Linux equivalents

internal/platform/implementation/linux/log_message.cc

@@ -0,0 +1,71 @@
+// Copyright 2020 Google LLC
+//
+// 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
+//
+//     https://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 "internal/platform/implementation/linux/log_message.h"
+
+#include <algorithm>
+
+#include "strings/strappendv.h"
+
+namespace nearby {
+namespace linux {
+
+api::LogMessage::Severity min_log_severity_ = api::LogMessage::Severity::kInfo;
+
+inline absl::LogSeverity ConvertSeverity(api::LogMessage::Severity severity) {
+  switch (severity) {
+    // api::LogMessage::Severity kVerbose and kInfo is mapped to
+    // absl::LogSeverity kInfo since absl::LogSeverity doesn't have kVerbose
+    // level.
+    case api::LogMessage::Severity::kVerbose:
+    case api::LogMessage::Severity::kInfo:
+      return absl::LogSeverity::kInfo;
+    case api::LogMessage::Severity::kWarning:
+      return absl::LogSeverity::kWarning;
+    case api::LogMessage::Severity::kError:
+      return absl::LogSeverity::kError;
+    case api::LogMessage::Severity::kFatal:
+      return absl::LogSeverity::kFatal;
+  }
+}
+
+LogMessage::LogMessage(const char* file, int line, Severity severity)
+    : log_streamer_(ConvertSeverity(severity), file, line) {}
+
+LogMessage::~LogMessage() = default;
+
+void LogMessage::Print(const char* format, ...) {
+  va_list ap;
+  va_start(ap, format);
+  std::string result;
+  strings::StrAppendV(&result, format, ap);
+  log_streamer_.stream() << result;
+  va_end(ap);
+}
+
+std::ostream& LogMessage::Stream() { return log_streamer_.stream(); }
+
+}  // namespace linux
+
+namespace api {
+
+void LogMessage::SetMinLogSeverity(Severity severity) {
+  windows::min_log_severity_ = severity;
+}
+
+bool LogMessage::ShouldCreateLogMessage(Severity severity) {
+  return severity >= windows::min_log_severity_;
+}
+}  // namespace api
+}  // namespace nearby