From 5cc923de33a126a8b37a9177d844501ffb0aee80 Mon Sep 17 00:00:00 2001
From: Peter Johnson <johnson.peter@gmail.com>
Date: Thu, 30 Nov 2023 23:13:51 -0800
Subject: [PATCH] [wpilib] DataLogManager: Use logs subdirectory on USB drives
 (#5975)

---
 ntcoreffi/src/main/native/cpp/DataLogManager.cpp            | 6 +++---
 wpilibc/src/main/native/cpp/DataLogManager.cpp              | 6 +++---
 .../src/main/java/edu/wpi/first/wpilibj/DataLogManager.java | 5 ++++-
 3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/ntcoreffi/src/main/native/cpp/DataLogManager.cpp b/ntcoreffi/src/main/native/cpp/DataLogManager.cpp
index d007f4f064..bd200aea17 100644
--- a/ntcoreffi/src/main/native/cpp/DataLogManager.cpp
+++ b/ntcoreffi/src/main/native/cpp/DataLogManager.cpp
@@ -217,12 +217,12 @@ static std::string MakeLogDir(std::string_view dir) {
   }
 #ifdef __FRC_ROBORIO__
   // prefer a mounted USB drive if one is accessible
-  constexpr std::string_view usbDir{"/u"};
   std::error_code ec;
-  auto s = fs::status(usbDir, ec);
+  auto s = fs::status("/u", ec);
   if (!ec && fs::is_directory(s) &&
       (s.permissions() & fs::perms::others_write) != fs::perms::none) {
-    return std::string{usbDir};
+    fs::create_directory("/u/logs", ec);
+    return "/u/logs";
   }
   if (RobotBase::GetRuntimeType() == kRoboRIO) {
     FRC_ReportError(warn::Warning,
diff --git a/wpilibc/src/main/native/cpp/DataLogManager.cpp b/wpilibc/src/main/native/cpp/DataLogManager.cpp
index 156b4054cc..d0e627359b 100644
--- a/wpilibc/src/main/native/cpp/DataLogManager.cpp
+++ b/wpilibc/src/main/native/cpp/DataLogManager.cpp
@@ -64,12 +64,12 @@ static std::string MakeLogDir(std::string_view dir) {
   }
 #ifdef __FRC_ROBORIO__
   // prefer a mounted USB drive if one is accessible
-  constexpr std::string_view usbDir{"/u"};
   std::error_code ec;
-  auto s = fs::status(usbDir, ec);
+  auto s = fs::status("/u", ec);
   if (!ec && fs::is_directory(s) &&
       (s.permissions() & fs::perms::others_write) != fs::perms::none) {
-    return std::string{usbDir};
+    fs::create_directory("/u/logs", ec);
+    return "/u/logs";
   }
   if (RobotBase::GetRuntimeType() == kRoboRIO) {
     FRC_ReportError(warn::Warning,
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/DataLogManager.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/DataLogManager.java
index d588d4049a..4d56d994cc 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/DataLogManager.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/DataLogManager.java
@@ -214,7 +214,10 @@ public final class DataLogManager {
         // prefer a mounted USB drive if one is accessible
         Path usbDir = Paths.get("/u").toRealPath();
         if (Files.isWritable(usbDir)) {
-          return usbDir.toString();
+          if (!new File("/u/logs").mkdir()) {
+            // ignored
+          }
+          return "/u/logs";
         }
       } catch (IOException ex) {
         // ignored