Rewrite all root method with own su library

app/src/main/java/com/topjohnwu/magisk/utils/StreamGobbler.java

@@ -0,0 +1,52 @@
+package com.topjohnwu.magisk.utils;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.List;
+
+/**
+ * Modified by topjohnwu, based on Chainfire's libsuperuser
+ */
+
+public class StreamGobbler extends Thread {
+
+    private BufferedReader reader = null;
+    private List<String> writer = null;
+
+    /**
+     * <p>StreamGobbler constructor</p>
+     *
+     * <p>We use this class because shell STDOUT and STDERR should be read as quickly as
+     * possible to prevent a deadlock from occurring, or Process.waitFor() never
+     * returning (as the buffer is full, pausing the native process)</p>
+     *
+     * @param inputStream InputStream to read from
+     * @param outputList  {@literal List<String>} to write to, or null
+     */
+    public StreamGobbler(InputStream inputStream, List<String> outputList) {
+        reader = new BufferedReader(new InputStreamReader(inputStream));
+        writer = outputList;
+    }
+
+    @Override
+    public void run() {
+        // keep reading the InputStream until it ends (or an error occurs)
+        try {
+            String line;
+            while ((line = reader.readLine()) != null) {
+                writer.add(line);
+            }
+        } catch (IOException e) {
+            // reader probably closed, expected exit condition
+        }
+
+        // make sure our stream is closed and resources will be freed
+        try {
+            reader.close();
+        } catch (IOException e) {
+            // read already closed
+        }
+    }
+}