[wpiutil] Rename Java package to edu.wpi.first.util (#3431)

This is more consistent with wpimath being edu.wpi.first.math.

wpiutil/src/main/java/edu/wpi/first/util/CombinedRuntimeLoader.java

@@ -0,0 +1,182 @@
+// 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.
+
+package edu.wpi.first.util;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+public final class CombinedRuntimeLoader {
+  private CombinedRuntimeLoader() {}
+
+  private static String extractionDirectory;
+
+  public static synchronized String getExtractionDirectory() {
+    return extractionDirectory;
+  }
+
+  private static synchronized void setExtractionDirectory(String directory) {
+    extractionDirectory = directory;
+  }
+
+  public static native String setDllDirectory(String directory);
+
+  private static String getLoadErrorMessage(String libraryName, UnsatisfiedLinkError ule) {
+    StringBuilder msg = new StringBuilder(512);
+    msg.append(libraryName)
+        .append(" could not be loaded from path\n" + "\tattempted to load for platform ")
+        .append(RuntimeDetector.getPlatformPath())
+        .append("\nLast Load Error: \n")
+        .append(ule.getMessage())
+        .append('\n');
+    if (RuntimeDetector.isWindows()) {
+      msg.append(
+          "A common cause of this error is missing the C++ runtime.\n"
+              + "Download the latest at https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads\n");
+    }
+    return msg.toString();
+  }
+
+  /**
+   * Extract a list of native libraries.
+   *
+   * @param <T> The class where the resources would be located
+   * @param clazz The actual class object
+   * @param resourceName The resource name on the classpath to use for file lookup
+   * @return List of all libraries that were extracted
+   * @throws IOException Thrown if resource not found or file could not be extracted
+   */
+  @SuppressWarnings({"PMD.UnnecessaryCastRule", "unchecked"})
+  public static <T> List<String> extractLibraries(Class<T> clazz, String resourceName)
+      throws IOException {
+    TypeReference<HashMap<String, Object>> typeRef =
+        new TypeReference<HashMap<String, Object>>() {};
+    ObjectMapper mapper = new ObjectMapper();
+    Map<String, Object> map;
+    try (var stream = clazz.getResourceAsStream(resourceName)) {
+      map = mapper.readValue(stream, typeRef);
+    }
+
+    var platformPath = Paths.get(RuntimeDetector.getPlatformPath());
+    var platform = platformPath.getName(0).toString();
+    var arch = platformPath.getName(1).toString();
+
+    var platformMap = (Map<String, List<String>>) map.get(platform);
+
+    var fileList = platformMap.get(arch);
+
+    var extractionPathString = getExtractionDirectory();
+
+    if (extractionPathString == null) {
+      String hash = (String) map.get("hash");
+
+      var defaultExtractionRoot = RuntimeLoader.getDefaultExtractionRoot();
+      var extractionPath = Paths.get(defaultExtractionRoot, platform, arch, hash);
+      extractionPathString = extractionPath.toString();
+
+      setExtractionDirectory(extractionPathString);
+    }
+
+    List<String> extractedFiles = new ArrayList<>();
+
+    byte[] buffer = new byte[0x10000]; // 64K copy buffer
+
+    for (var file : fileList) {
+      try (var stream = clazz.getResourceAsStream(file)) {
+        Objects.requireNonNull(stream);
+
+        var outputFile = Paths.get(extractionPathString, new File(file).getName());
+        extractedFiles.add(outputFile.toString());
+        if (outputFile.toFile().exists()) {
+          continue;
+        }
+        outputFile.getParent().toFile().mkdirs();
+
+        try (var os = Files.newOutputStream(outputFile)) {
+          int readBytes;
+          while ((readBytes = stream.read(buffer)) != -1) { // NOPMD
+            os.write(buffer, 0, readBytes);
+          }
+        }
+      }
+    }
+
+    return extractedFiles;
+  }
+
+  /**
+   * Load a single library from a list of extracted files.
+   *
+   * @param libraryName The library name to load
+   * @param extractedFiles The extracted files to search
+   * @throws IOException If library was not found
+   */
+  public static void loadLibrary(String libraryName, List<String> extractedFiles)
+      throws IOException {
+    String currentPath = null;
+    String oldDllDirectory = null;
+    try {
+      if (RuntimeDetector.isWindows()) {
+        var extractionPathString = getExtractionDirectory();
+        oldDllDirectory = setDllDirectory(extractionPathString);
+      }
+      for (var extractedFile : extractedFiles) {
+        if (extractedFile.contains(libraryName)) {
+          // Load it
+          currentPath = extractedFile;
+          System.load(extractedFile);
+          return;
+        }
+      }
+      throw new IOException("Could not find library " + libraryName);
+    } catch (UnsatisfiedLinkError ule) {
+      throw new IOException(getLoadErrorMessage(currentPath, ule));
+    } finally {
+      if (oldDllDirectory != null) {
+        setDllDirectory(oldDllDirectory);
+      }
+    }
+  }
+
+  /**
+   * Load a list of native libraries out of a single directory.
+   *
+   * @param <T> The class where the resources would be located
+   * @param clazz The actual class object
+   * @param librariesToLoad List of libraries to load
+   * @throws IOException Throws an IOException if not found
+   */
+  public static <T> void loadLibraries(Class<T> clazz, String... librariesToLoad)
+      throws IOException {
+    // Extract everything
+
+    var extractedFiles = extractLibraries(clazz, "/ResourceInformation.json");
+
+    String currentPath = "";
+
+    try {
+      if (RuntimeDetector.isWindows()) {
+        var extractionPathString = getExtractionDirectory();
+        // Load windows, set dll directory
+        currentPath = Paths.get(extractionPathString, "WindowsLoaderHelper.dll").toString();
+        System.load(currentPath);
+      }
+    } catch (UnsatisfiedLinkError ule) {
+      throw new IOException(getLoadErrorMessage(currentPath, ule));
+    }
+
+    for (var library : librariesToLoad) {
+      loadLibrary(library, extractedFiles);
+    }
+  }
+}