| /* |
| * Copyright (C) 2015, Google Inc. and others |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Distribution License v. 1.0 which is available at |
| * https://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| package org.eclipse.jgit.transport; |
| |
| import static java.nio.charset.StandardCharsets.UTF_8; |
| |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.util.concurrent.TimeUnit; |
| |
| /** |
| * A simple spinner connected to an {@code OutputStream}. |
| * <p> |
| * This is class is not thread-safe. The update method may only be used from a |
| * single thread. Updates are sent only as frequently as {@link #update()} is |
| * invoked by the caller, and are capped at no more than 2 times per second by |
| * requiring at least 500 milliseconds between updates. |
| * |
| * @since 4.2 |
| */ |
| public class ProgressSpinner { |
| private static final long MIN_REFRESH_MILLIS = 500; |
| private static final char[] STATES = new char[] { '-', '\\', '|', '/' }; |
| |
| private final OutputStream out; |
| private String msg; |
| private int state; |
| private boolean write; |
| private boolean shown; |
| private long nextUpdateMillis; |
| |
| /** |
| * Initialize a new spinner. |
| * |
| * @param out |
| * where to send output to. |
| */ |
| public ProgressSpinner(OutputStream out) { |
| this.out = out; |
| this.write = true; |
| } |
| |
| /** |
| * Begin a time consuming task. |
| * |
| * @param title |
| * description of the task, suitable for human viewing. |
| * @param delay |
| * delay to wait before displaying anything at all. |
| * @param delayUnits |
| * unit for {@code delay}. |
| */ |
| public void beginTask(String title, long delay, TimeUnit delayUnits) { |
| msg = title; |
| state = 0; |
| shown = false; |
| |
| long now = System.currentTimeMillis(); |
| if (delay > 0) { |
| nextUpdateMillis = now + delayUnits.toMillis(delay); |
| } else { |
| send(now); |
| } |
| } |
| |
| /** |
| * Update the spinner if it is showing. |
| */ |
| public void update() { |
| long now = System.currentTimeMillis(); |
| if (now >= nextUpdateMillis) { |
| send(now); |
| state = (state + 1) % STATES.length; |
| } |
| } |
| |
| private void send(long now) { |
| StringBuilder buf = new StringBuilder(msg.length() + 16); |
| buf.append('\r').append(msg).append("... ("); //$NON-NLS-1$ |
| buf.append(STATES[state]); |
| buf.append(") "); //$NON-NLS-1$ |
| shown = true; |
| write(buf.toString()); |
| nextUpdateMillis = now + MIN_REFRESH_MILLIS; |
| } |
| |
| /** |
| * Denote the current task completed. |
| * |
| * @param result |
| * text to print after the task's title |
| * {@code "$title ... $result"}. |
| */ |
| public void endTask(String result) { |
| if (shown) { |
| write('\r' + msg + "... " + result + "\n"); //$NON-NLS-1$ //$NON-NLS-2$ |
| } |
| } |
| |
| private void write(String s) { |
| if (write) { |
| try { |
| out.write(s.getBytes(UTF_8)); |
| out.flush(); |
| } catch (IOException e) { |
| write = false; |
| } |
| } |
| } |
| } |