Prepare ntcore for merge into allwpilib.

ntcore/src/main/native/cpp/LoggerImpl.cpp

@@ -0,0 +1,77 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015-2018. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "LoggerImpl.h"
+
+#include <llvm/Path.h>
+#include <llvm/SmallString.h>
+#include <llvm/StringRef.h>
+#include <llvm/raw_ostream.h>
+
+using namespace nt;
+
+static void DefaultLogger(unsigned int level, const char* file,
+                          unsigned int line, const char* msg) {
+  llvm::SmallString<128> buf;
+  llvm::raw_svector_ostream oss(buf);
+  if (level == 20) {
+    oss << "NT: " << msg << '\n';
+    llvm::errs() << oss.str();
+    return;
+  }
+
+  llvm::StringRef levelmsg;
+  if (level >= 50)
+    levelmsg = "CRITICAL: ";
+  else if (level >= 40)
+    levelmsg = "ERROR: ";
+  else if (level >= 30)
+    levelmsg = "WARNING: ";
+  else
+    return;
+  oss << "NT: " << levelmsg << msg << " (" << file << ':' << line << ")\n";
+  llvm::errs() << oss.str();
+}
+
+LoggerImpl::LoggerImpl(int inst) : m_inst(inst) {}
+
+void LoggerImpl::Start() { DoStart(m_inst); }
+
+unsigned int LoggerImpl::Add(
+    std::function<void(const LogMessage& msg)> callback, unsigned int min_level,
+    unsigned int max_level) {
+  return DoAdd(callback, min_level, max_level);
+}
+
+unsigned int LoggerImpl::AddPolled(unsigned int poller_uid,
+                                   unsigned int min_level,
+                                   unsigned int max_level) {
+  return DoAdd(poller_uid, min_level, max_level);
+}
+
+unsigned int LoggerImpl::GetMinLevel() {
+  auto thr = GetThread();
+  if (!thr) return NT_LOG_INFO;
+  unsigned int level = NT_LOG_INFO;
+  for (size_t i = 0; i < thr->m_listeners.size(); ++i) {
+    const auto& listener = thr->m_listeners[i];
+    if (listener && listener.min_level < level) level = listener.min_level;
+  }
+  return level;
+}
+
+void LoggerImpl::Log(unsigned int level, const char* file, unsigned int line,
+                     const char* msg) {
+  // this is safe because it's null terminated and always the end
+  const char* filename = llvm::sys::path::filename(file).data();
+  {
+    auto thr = GetThread();
+    if (!thr || thr->m_listeners.empty())
+      DefaultLogger(level, filename, line, msg);
+  }
+  Send(UINT_MAX, 0, level, filename, line, msg);
+}