Rework and document OS class

src/main/java/com/sheepit/client/os/OS.java

@@ -38,45 +38,90 @@ public abstract class OS {
 	
 	private static OS instance = null;
 	
+	/**
+	 * Operating system name
+	 * @return a string representing the OS name.
+	 */
 	public abstract String name();
 	
+	/**
+	 * Blender requires 64 bits
+	 * @return boolean if we are supported i.e. if we run on 64 bits
+	 */
 	public boolean isSupported() {  return "64bit".equals(getCPU().getArch()); }
 	
-	/** Get the full version of the os.
+	/** Get the full version of the operating system.
 	 * For example windows, should give "windows 8.1"
+	 * @return a lowercassed string with the os name and the version info
+	 * @see OperatingSystem#getVersionInfo()
 	 */
 	public String getVersion() {
 		return (name() + " " + operatingSystem.getVersionInfo()).toLowerCase();
 	}
 	
+	/**
+	 * @see oshi.hardware.GlobalMemory#getTotal()
+	 * @return long of getTotal() in kilobytes
+	 */
 	public long getTotalMemory() {
 		return hardwareAbstractionLayer.getMemory().getTotal() / 1024;
 	}
 	
+	/**
+	 * @see oshi.hardware.GlobalMemory#getAvailable()
+	 * @return long of getAvailable() in kilobytes
+	 */
 	public long getFreeMemory() {
 		return hardwareAbstractionLayer.getMemory().getAvailable() / 1024;
 	}
 	
+	/**
+	 * Get the path to the Blender executable
+	 * @return a string representing a path to Blender,
+	 * relative or absolute depends on the implementation
+	 */
 	public abstract String getRenderBinaryPath();
 	
+	/**
+	 * Get the path to the CUDA library
+	 * @return a string representing a path the CUDA library,
+	 * relative or absolute depends on the implementation
+	 */
 	public String getCUDALib() {
 		return null;
 	}
 	
-	//path to NVIDIA NVML lib
+	/**
+	 * Get the path to the NVIDIA NVML library
+	 * @return a string representing a path the NVIDIA NVML library,
+	 * relative or absolute depends on the implementation
+	 */
 	public String getNVMLLib() {
 		return null;
 	}
 	
-	public abstract boolean getSupportHighPriority();
-	
-	public abstract boolean checkNiceAvailability();
+	/**
+	 * Determines if the platform supports setting a higher priority
+	 * @return a boolean representing if the platform supports setting a higher priority
+	 */
+	public abstract boolean isHighPrioritySupported();
 	
 	/**
-	 * Shutdown the computer waiting delayInMinutes minutes to allow all SheepIt threads to close and exit the app
+	 * Determines if the platform supports being IO nice
+	 * @return a boolean representing if the platform supports being IO nice
+	 */
+	public abstract boolean isNiceAvailable();
+	
+	/**
+	 * Shuts the computer down waiting allow all SheepIt threads to close and exit
+	 * @param delayInMinutes integer repressing the amount minutes to wait before shutting down
 	 */
 	public abstract void shutdownComputer(int delayInMinutes);
 	
+	/**
+	 * Creates and populates a CPU object
+	 * @return a populated CPU object
+	 */
 	public CPU getCPU() {
 		CentralProcessor.ProcessorIdentifier cpuID = hardwareAbstractionLayer.getProcessor().getProcessorIdentifier();
 		CPU ret = new CPU();
@@ -86,15 +131,20 @@ public abstract class OS {
 		return ret;
 	}
 	
-	public Process exec(List<String> command, Map<String, String> env) throws IOException {
-		ProcessBuilder builder = new ProcessBuilder(command);
-		builder.redirectErrorStream(true);
-		if (env != null) {
-			builder.environment().putAll(env);
-		}
-		return builder.start();
-	}
+	/**
+	 * Executes a Process
+	 * @param command List of strings of the command and the respective command line arguments
+	 * @param env Map of strings of environment variables and their values for the execution
+	 * @return a Process object reflecting the execution of the command
+	 * @throws IOException if an I/O error occurs
+	 */
+	public abstract Process exec(List<String> command, Map<String, String> env) throws IOException;
 	
+	/**
+	 * Terminates a process
+	 * @param proc Process to kill
+	 * @return true if proc wasn't null and was destroyed
+	 */
 	public boolean kill(Process proc) {
 		if (proc != null) {
 			proc.destroy();
@@ -103,6 +153,10 @@ public abstract class OS {
 		return false;
 	}
 	
+	/**
+	 * Get the operating system currently in use
+	 * @return object instance of OS specific to the used operating system.
+	 */
 	public static OS getOS() {
 		if (instance == null) {
 			switch (operatingSystem.getManufacturer()){
@@ -110,7 +164,7 @@ public abstract class OS {
 					instance = new Windows();
 					break;
 				case "Apple":
-					if ("aarch64".equalsIgnoreCase(System.getProperty("os.arch"))) { // ARM arch ?
+					if ("aarch64".equalsIgnoreCase(System.getProperty("os.arch"))) { // Set as M1 Mac if we are on ARM64
 						instance = new MacM1();
 					}
 					else {
@@ -124,7 +178,13 @@ public abstract class OS {
 		}
 		return instance;
 	}
-
+	
+	/**
+	 * Returns the default path that SheepIt would place the config file
+	 * This respects the XDG specification for Linux and macOS
+	 * @see <a href="https://www.freedesktop.org/wiki/Software/xdg-user-dirs/">XDG specification</a>
+	 * @return string representing the default path to the sheepit.conf
+	 */
 	public String getDefaultConfigFilePath() {
 		String xdgConfigHome = System.getenv("XDG_CONFIG_HOME");
 		String userHome = System.getProperty("user.home");