[datalogtool] Add datalogtool

This is a support tool for datalog file conversion (and eventually
download/remote datalog file management).

datalogtool/src/main/native/cpp/DataLogThread.cpp

@@ -0,0 +1,72 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include "DataLogThread.h"
+
+#include <fmt/format.h>
+
+DataLogThread::~DataLogThread() {
+  if (m_thread.joinable()) {
+    m_active = false;
+    m_thread.join();
+  }
+}
+
+void DataLogThread::ReadMain() {
+  for (auto record : m_reader) {
+    if (!m_active) {
+      break;
+    }
+    ++m_numRecords;
+    if (record.IsStart()) {
+      wpi::log::StartRecordData data;
+      if (record.GetStartData(&data)) {
+        std::scoped_lock lock{m_mutex};
+        if (m_entries.find(data.entry) != m_entries.end()) {
+          fmt::print("...DUPLICATE entry ID, overriding\n");
+        }
+        m_entries[data.entry] = data;
+        m_entryNames.emplace(data.name, data);
+        sigEntryAdded(data);
+      } else {
+        fmt::print("Start(INVALID)\n");
+      }
+    } else if (record.IsFinish()) {
+      int entry;
+      if (record.GetFinishEntry(&entry)) {
+        std::scoped_lock lock{m_mutex};
+        auto it = m_entries.find(entry);
+        if (it == m_entries.end()) {
+          fmt::print("...ID not found\n");
+        } else {
+          m_entries.erase(it);
+        }
+      } else {
+        fmt::print("Finish(INVALID)\n");
+      }
+    } else if (record.IsSetMetadata()) {
+      wpi::log::MetadataRecordData data;
+      if (record.GetSetMetadataData(&data)) {
+        std::scoped_lock lock{m_mutex};
+        auto it = m_entries.find(data.entry);
+        if (it == m_entries.end()) {
+          fmt::print("...ID not found\n");
+        } else {
+          it->second.metadata = data.metadata;
+          auto nameIt = m_entryNames.find(it->second.name);
+          if (nameIt != m_entryNames.end()) {
+            nameIt->second.metadata = data.metadata;
+          }
+        }
+      } else {
+        fmt::print("SetMetadata(INVALID)\n");
+      }
+    } else if (record.IsControl()) {
+      fmt::print("Unrecognized control record\n");
+    }
+  }
+
+  sigDone();
+  m_done = true;
+}