src/jdk.jshell/share/classes/jdk/internal/jshell/tool/Startup.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 package jdk.internal.jshell.tool;

 import java.nio.file.AccessDeniedException;
 import java.nio.file.Files;
 import java.nio.file.NoSuchFileException;
 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
 import java.time.format.FormatStyle;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 import static java.util.stream.Collectors.joining;
 import static java.util.stream.Collectors.toList;
 import static jdk.internal.jshell.tool.JShellTool.RECORD_SEPARATOR;
 import static jdk.internal.jshell.tool.JShellTool.getResource;
 import static jdk.internal.jshell.tool.JShellTool.readResource;
 import static jdk.internal.jshell.tool.JShellTool.toPathResolvingUserHome;

 /**
  * Processing start-up "script" information.  The startup may consist of several
  * entries, each of which may have been read from a user file or be a built-in
  * resource.  The startup may also be empty ("-none"); Which is stored as the
  * empty string different from unset (null).  Built-in resources come from
  * resource files.  Startup is stored as named elements rather than concatenated
  * text, for display purposes but also importantly so that when resources update
  * with new releases the built-in will update.
  * @author Robert Field
  */
 class Startup {

     // Store one entry in the start-up list
     private static class StartupEntry {

         // is this a JShell built-in?
         private final boolean isBuiltIn;

         // the file or resource name
         private final String name;

         // the commands/snippets as text
         private final String content;

         // for files, the date/time read in -- makes clear it is a snapshot
         private final String timeStamp;

         StartupEntry(boolean isBuiltIn, String name, String content) {
             this(isBuiltIn, name, content, "");
         }

         StartupEntry(boolean isBuiltIn, String name, String content, String timeStamp) {
             this.isBuiltIn = isBuiltIn;
             this.name = name;
             this.content = content;
             this.timeStamp = timeStamp;
         }

         // string form to store in storage (e.g. Preferences)
         String storedForm() {
             return (isBuiltIn ? "*" : "-") + RECORD_SEPARATOR +
                     name + RECORD_SEPARATOR +
                     timeStamp + RECORD_SEPARATOR +
                     content + RECORD_SEPARATOR;
         }

         // the content
         @Override
         public String toString() {
             return content;
         }

         @Override
         public int hashCode() {
             int hash = 7;
             hash = 41 * hash + (this.isBuiltIn ? 1 : 0);
             hash = 41 * hash + Objects.hashCode(this.name);
             if (!isBuiltIn) {
                 hash = 41 * hash + Objects.hashCode(this.content);
             }
             return hash;
         }

         // built-ins match on name only.  Time stamp isn't considered
         @Override
         public boolean equals(Object o) {
             if (!(o instanceof StartupEntry)) {
                 return false;
             }
             StartupEntry sue = (StartupEntry) o;
             return isBuiltIn == sue.isBuiltIn &&
                      name.equals(sue.name) &&
                      (isBuiltIn || content.equals(sue.content));
         }
     }

     private static final String DEFAULT_STARTUP_NAME = "DEFAULT";

     // cached DEFAULT start-up
     private static Startup defaultStartup = null;

     // the list of entries
     private List<StartupEntry> entries;

     // the concatenated content of the list of entries
     private String content;

     // created only with factory methods (below)
     private Startup(List<StartupEntry> entries) {
         this.entries = entries;
         this.content = entries.stream()
                 .map(sue -> sue.toString())
                 .collect(joining());
     }

     private Startup(StartupEntry entry) {
         this(Collections.singletonList(entry));
     }

     // retrieve the content
     @Override
     public String toString() {
         return content;
     }

     @Override
     public int hashCode() {
         return 9  + Objects.hashCode(this.entries);
     }

     @Override
     public boolean equals(Object o) {
         return (o instanceof Startup)
                 && entries.equals(((Startup) o).entries);
     }

     // are there no entries ("-none")?
     boolean isEmpty() {
         return entries.isEmpty();
     }

     // is this the "-default" setting -- one entry which is DEFAULT
     boolean isDefault() {
         if (entries.size() == 1) {
             StartupEntry sue = entries.get(0);
             if (sue.isBuiltIn && sue.name.equals(DEFAULT_STARTUP_NAME)) {
                 return true;
             }
         }
         return false;
     }

     // string form to store in storage (e.g. Preferences)
     String storedForm() {
         return entries.stream()
                 .map(sue -> sue.storedForm())
                 .collect(joining());
     }

     // show commands to re-create
     String show(boolean isRetained) {
         String cmd = "/set start " + (isRetained ? "-retain " : "");
         if (isDefault()) {
             return cmd + "-default\n";
         } else if (isEmpty()) {
             return cmd + "-none\n";
         } else {
             return entries.stream()
                     .map(sue -> sue.name)
                     .collect(joining(" ", cmd, "\n"));
         }
     }

     // show corresponding contents for show()
     String showDetail() {
         if (isDefault() || isEmpty()) {
             return "";
         } else {
             return entries.stream()
                     .map(sue -> "---- " + sue.name
                             + (sue.timeStamp.isEmpty()
                                     ? ""
                                     : " @ " + sue.timeStamp)
                             + " ----\n" + sue.content)
                     .collect(joining());
         }
     }

     /**
      * Factory method: Unpack from stored form.
      *
      * @param storedForm the Startup in the form as stored on persistent
      * storage (e.g. Preferences)
      * @param mh handler for error messages
      * @return Startup, or default startup when error (message has been printed)
      */
     static Startup unpack(String storedForm, MessageHandler mh) {
         if (storedForm != null) {
             if (storedForm.isEmpty()) {
                 return noStartup();
             }
             try {
                 String[] all = storedForm.split(RECORD_SEPARATOR);
                 if (all.length == 1) {
                     // legacy (content only)
                     return new Startup(new StartupEntry(false, "user.jsh", storedForm));
                 } else if (all.length % 4 == 0) {
                     List<StartupEntry> e = new ArrayList<>(all.length / 4);
                     for (int i = 0; i < all.length; i += 4) {
                         final boolean isBuiltIn;
                         switch (all[i]) {
                             case "*":
                                 isBuiltIn = true;
                                 break;
                             case "-":
                                 isBuiltIn = false;
                                 break;
                             default:
                                 throw new IllegalArgumentException("Unexpected StartupEntry kind: " + all[i]);
                         }
                         String name = all[i + 1];
                         String timeStamp = all[i + 2];
                         String content = all[i + 3];
                         if (isBuiltIn) {
                             // update to current definition, use stored if removed/error
                             String resource = getResource(name);
                             if (resource != null) {
                                 content = resource;
                             }
                         }
                         e.add(new StartupEntry(isBuiltIn, name, content, timeStamp));
                     }
                     return new Startup(e);
                 } else {
                     throw new IllegalArgumentException("Unexpected StartupEntry entry count: " + all.length);
                 }
             } catch (Exception ex) {
                 mh.errormsg("jshell.err.corrupted.stored.startup", ex.getMessage());
             }
         }
         return defaultStartup(mh);
     }

     /**
      * Factory method: Read Startup from a list of external files or resources.
      *
      * @param fns list of file/resource names to access
      * @param context printable non-natural language context for errors
      * @param mh handler for error messages
      * @return files as Startup, or null when error (message has been printed)
      */
     static Startup fromFileList(List<String> fns, String context, MessageHandler mh) {
         List<StartupEntry> entries = fns.stream()
                 .map(fn -> readFile(fn, context, mh))
                 .collect(toList());
         if (entries.stream().anyMatch(sue -> sue == null)) {
             return null;
         }
         return new Startup(entries);
     }

     /**
      * Read a external file or a resource.
      *
      * @param filename file/resource to access
      * @param context printable non-natural language context for errors
      * @param mh handler for error messages
      * @return file as startup entry, or null when error (message has been printed)
      */
     private static StartupEntry readFile(String filename, String context, MessageHandler mh) {
         if (filename != null) {
             try {
                 byte[] encoded = Files.readAllBytes(toPathResolvingUserHome(filename));
                 return new StartupEntry(false, filename, new String(encoded),
                         LocalDateTime.now().format(DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM)));
             } catch (AccessDeniedException e) {
                 mh.errormsg("jshell.err.file.not.accessible", context, filename, e.getMessage());
             } catch (NoSuchFileException e) {
                 String resource = getResource(filename);
                 if (resource != null) {
                     // Not found as file, but found as resource
                     return new StartupEntry(true, filename, resource);
                 }
                 mh.errormsg("jshell.err.file.not.found", context, filename);
             } catch (Exception e) {
                 mh.errormsg("jshell.err.file.exception", context, filename, e);
             }
         } else {
             mh.errormsg("jshell.err.file.filename", context);
         }
         return null;

     }

     /**
      * Factory method: The empty Startup ("-none").
      *
      * @return the empty Startup
      */
     static Startup noStartup() {
         return new Startup(Collections.emptyList());
     }

     /**
      * Factory method: The default Startup ("-default.").
      *
      * @param mh handler for error messages
      * @return The default Startup, or empty startup when error (message has been printed)
      */
     static Startup defaultStartup(MessageHandler mh) {
         if (defaultStartup != null) {
             return defaultStartup;
         }
         try {
             String content = readResource(DEFAULT_STARTUP_NAME);
             return defaultStartup = new Startup(
                     new StartupEntry(true, DEFAULT_STARTUP_NAME, content));
         } catch (AccessDeniedException e) {
             mh.errormsg("jshell.err.file.not.accessible", "jshell", DEFAULT_STARTUP_NAME, e.getMessage());
         } catch (NoSuchFileException e) {
             mh.errormsg("jshell.err.file.not.found", "jshell", DEFAULT_STARTUP_NAME);
         } catch (Exception e) {
             mh.errormsg("jshell.err.file.exception", "jshell", DEFAULT_STARTUP_NAME, e);
         }
         return defaultStartup = noStartup();
     }

 }
	/*
	* Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package jdk.internal.jshell.tool;

	import java.nio.file.AccessDeniedException;
	import java.nio.file.Files;
	import java.nio.file.NoSuchFileException;
	import java.time.LocalDateTime;
	import java.time.format.DateTimeFormatter;
	import java.time.format.FormatStyle;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.List;
	import java.util.Objects;
	import static java.util.stream.Collectors.joining;
	import static java.util.stream.Collectors.toList;
	import static jdk.internal.jshell.tool.JShellTool.RECORD_SEPARATOR;
	import static jdk.internal.jshell.tool.JShellTool.getResource;
	import static jdk.internal.jshell.tool.JShellTool.readResource;
	import static jdk.internal.jshell.tool.JShellTool.toPathResolvingUserHome;

	/**
	* Processing start-up "script" information. The startup may consist of several
	* entries, each of which may have been read from a user file or be a built-in
	* resource. The startup may also be empty ("-none"); Which is stored as the
	* empty string different from unset (null). Built-in resources come from
	* resource files. Startup is stored as named elements rather than concatenated
	* text, for display purposes but also importantly so that when resources update
	* with new releases the built-in will update.
	* @author Robert Field
	*/
	class Startup {

	// Store one entry in the start-up list
	private static class StartupEntry {

	// is this a JShell built-in?
	private final boolean isBuiltIn;

	// the file or resource name
	private final String name;

	// the commands/snippets as text
	private final String content;

	// for files, the date/time read in -- makes clear it is a snapshot
	private final String timeStamp;

	StartupEntry(boolean isBuiltIn, String name, String content) {
	this(isBuiltIn, name, content, "");
	}

	StartupEntry(boolean isBuiltIn, String name, String content, String timeStamp) {
	this.isBuiltIn = isBuiltIn;
	this.name = name;
	this.content = content;
	this.timeStamp = timeStamp;
	}

	// string form to store in storage (e.g. Preferences)
	String storedForm() {
	return (isBuiltIn ? "*" : "-") + RECORD_SEPARATOR +
	name + RECORD_SEPARATOR +
	timeStamp + RECORD_SEPARATOR +
	content + RECORD_SEPARATOR;
	}

	// the content
	@Override
	public String toString() {
	return content;
	}

	@Override
	public int hashCode() {
	int hash = 7;
	hash = 41 * hash + (this.isBuiltIn ? 1 : 0);
	hash = 41 * hash + Objects.hashCode(this.name);
	if (!isBuiltIn) {
	hash = 41 * hash + Objects.hashCode(this.content);
	}
	return hash;
	}

	// built-ins match on name only. Time stamp isn't considered
	@Override
	public boolean equals(Object o) {
	if (!(o instanceof StartupEntry)) {
	return false;
	}
	StartupEntry sue = (StartupEntry) o;
	return isBuiltIn == sue.isBuiltIn &&
	name.equals(sue.name) &&
	(isBuiltIn \|\| content.equals(sue.content));
	}
	}

	private static final String DEFAULT_STARTUP_NAME = "DEFAULT";

	// cached DEFAULT start-up
	private static Startup defaultStartup = null;

	// the list of entries
	private List<StartupEntry> entries;

	// the concatenated content of the list of entries
	private String content;

	// created only with factory methods (below)
	private Startup(List<StartupEntry> entries) {
	this.entries = entries;
	this.content = entries.stream()
	.map(sue -> sue.toString())
	.collect(joining());
	}

	private Startup(StartupEntry entry) {
	this(Collections.singletonList(entry));
	}

	// retrieve the content
	@Override
	public String toString() {
	return content;
	}

	@Override
	public int hashCode() {
	return 9 + Objects.hashCode(this.entries);
	}

	@Override
	public boolean equals(Object o) {
	return (o instanceof Startup)
	&& entries.equals(((Startup) o).entries);
	}

	// are there no entries ("-none")?
	boolean isEmpty() {
	return entries.isEmpty();
	}

	// is this the "-default" setting -- one entry which is DEFAULT
	boolean isDefault() {
	if (entries.size() == 1) {
	StartupEntry sue = entries.get(0);
	if (sue.isBuiltIn && sue.name.equals(DEFAULT_STARTUP_NAME)) {
	return true;
	}
	}
	return false;
	}

	// string form to store in storage (e.g. Preferences)
	String storedForm() {
	return entries.stream()
	.map(sue -> sue.storedForm())
	.collect(joining());
	}

	// show commands to re-create
	String show(boolean isRetained) {
	String cmd = "/set start " + (isRetained ? "-retain " : "");
	if (isDefault()) {
	return cmd + "-default\n";
	} else if (isEmpty()) {
	return cmd + "-none\n";
	} else {
	return entries.stream()
	.map(sue -> sue.name)
	.collect(joining(" ", cmd, "\n"));
	}
	}

	// show corresponding contents for show()
	String showDetail() {
	if (isDefault() \|\| isEmpty()) {
	return "";
	} else {
	return entries.stream()
	.map(sue -> "---- " + sue.name
	+ (sue.timeStamp.isEmpty()
	? ""
	: " @ " + sue.timeStamp)
	+ " ----\n" + sue.content)
	.collect(joining());
	}
	}

	/**
	* Factory method: Unpack from stored form.
	*
	* @param storedForm the Startup in the form as stored on persistent
	* storage (e.g. Preferences)
	* @param mh handler for error messages
	* @return Startup, or default startup when error (message has been printed)
	*/
	static Startup unpack(String storedForm, MessageHandler mh) {
	if (storedForm != null) {
	if (storedForm.isEmpty()) {
	return noStartup();
	}
	try {
	String[] all = storedForm.split(RECORD_SEPARATOR);
	if (all.length == 1) {
	// legacy (content only)
	return new Startup(new StartupEntry(false, "user.jsh", storedForm));
	} else if (all.length % 4 == 0) {
	List<StartupEntry> e = new ArrayList<>(all.length / 4);
	for (int i = 0; i < all.length; i += 4) {
	final boolean isBuiltIn;
	switch (all[i]) {
	case "*":
	isBuiltIn = true;
	break;
	case "-":
	isBuiltIn = false;
	break;
	default:
	throw new IllegalArgumentException("Unexpected StartupEntry kind: " + all[i]);
	}
	String name = all[i + 1];
	String timeStamp = all[i + 2];
	String content = all[i + 3];
	if (isBuiltIn) {
	// update to current definition, use stored if removed/error
	String resource = getResource(name);
	if (resource != null) {
	content = resource;
	}
	}
	e.add(new StartupEntry(isBuiltIn, name, content, timeStamp));
	}
	return new Startup(e);
	} else {
	throw new IllegalArgumentException("Unexpected StartupEntry entry count: " + all.length);
	}
	} catch (Exception ex) {
	mh.errormsg("jshell.err.corrupted.stored.startup", ex.getMessage());
	}
	}
	return defaultStartup(mh);
	}

	/**
	* Factory method: Read Startup from a list of external files or resources.
	*
	* @param fns list of file/resource names to access
	* @param context printable non-natural language context for errors
	* @param mh handler for error messages
	* @return files as Startup, or null when error (message has been printed)
	*/
	static Startup fromFileList(List<String> fns, String context, MessageHandler mh) {
	List<StartupEntry> entries = fns.stream()
	.map(fn -> readFile(fn, context, mh))
	.collect(toList());
	if (entries.stream().anyMatch(sue -> sue == null)) {
	return null;
	}
	return new Startup(entries);
	}

	/**
	* Read a external file or a resource.
	*
	* @param filename file/resource to access
	* @param context printable non-natural language context for errors
	* @param mh handler for error messages
	* @return file as startup entry, or null when error (message has been printed)
	*/
	private static StartupEntry readFile(String filename, String context, MessageHandler mh) {
	if (filename != null) {
	try {
	byte[] encoded = Files.readAllBytes(toPathResolvingUserHome(filename));
	return new StartupEntry(false, filename, new String(encoded),
	LocalDateTime.now().format(DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM)));
	} catch (AccessDeniedException e) {
	mh.errormsg("jshell.err.file.not.accessible", context, filename, e.getMessage());
	} catch (NoSuchFileException e) {
	String resource = getResource(filename);
	if (resource != null) {
	// Not found as file, but found as resource
	return new StartupEntry(true, filename, resource);
	}
	mh.errormsg("jshell.err.file.not.found", context, filename);
	} catch (Exception e) {
	mh.errormsg("jshell.err.file.exception", context, filename, e);
	}
	} else {
	mh.errormsg("jshell.err.file.filename", context);
	}
	return null;

	}

	/**
	* Factory method: The empty Startup ("-none").
	*
	* @return the empty Startup
	*/
	static Startup noStartup() {
	return new Startup(Collections.emptyList());
	}

	/**
	* Factory method: The default Startup ("-default.").
	*
	* @param mh handler for error messages
	* @return The default Startup, or empty startup when error (message has been printed)
	*/
	static Startup defaultStartup(MessageHandler mh) {
	if (defaultStartup != null) {
	return defaultStartup;
	}
	try {
	String content = readResource(DEFAULT_STARTUP_NAME);
	return defaultStartup = new Startup(
	new StartupEntry(true, DEFAULT_STARTUP_NAME, content));
	} catch (AccessDeniedException e) {
	mh.errormsg("jshell.err.file.not.accessible", "jshell", DEFAULT_STARTUP_NAME, e.getMessage());
	} catch (NoSuchFileException e) {
	mh.errormsg("jshell.err.file.not.found", "jshell", DEFAULT_STARTUP_NAME);
	} catch (Exception e) {
	mh.errormsg("jshell.err.file.exception", "jshell", DEFAULT_STARTUP_NAME, e);
	}
	return defaultStartup = noStartup();
	}

	}