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JSimpleDB classes supporting command line interfaces.
/*
* Copyright (C) 2015 Archie L. Cobbs. All rights reserved.
*/
package org.jsimpledb.cli;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import org.jsimpledb.JSimpleDB;
import org.jsimpledb.core.Database;
import org.jsimpledb.kv.KVDatabase;
import org.jsimpledb.parse.ParseException;
import org.jsimpledb.parse.util.AddPrefixFunction;
import org.jsimpledb.util.ParseContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import jline.Terminal;
import jline.console.ConsoleReader;
import jline.console.UserInterruptException;
import jline.console.completer.Completer;
import jline.console.history.FileHistory;
/**
* CLI console.
*/
public class Console {
protected final Logger log = LoggerFactory.getLogger(this.getClass());
protected final ConsoleReader console;
protected final CliSession session;
private final CommandParser commandParser = new CommandParser();
private final CommandListParser commandListParser = new CommandListParser(this.commandParser);
private FileHistory history;
/**
* Simplified constructor for {@link org.jsimpledb.SessionMode#KEY_VALUE} mode.
*
* @param kvdb key/value {@link KVDatabase}
* @param input console input
* @param output console output
* @throws IOException if an I/O error occurs
*/
public Console(KVDatabase kvdb, InputStream input, OutputStream output) throws IOException {
this(kvdb, null, null, input, output, null, null, null);
}
/**
* Simplified constructor for {@link org.jsimpledb.SessionMode#CORE_API} mode.
*
* @param db core API {@link Database}
* @param input console input
* @param output console output
* @throws IOException if an I/O error occurs
*/
public Console(Database db, InputStream input, OutputStream output) throws IOException {
this(null, db, null, input, output, null, null, null);
}
/**
* Simplified constructor for {@link org.jsimpledb.SessionMode#JSIMPLEDB} mode.
*
* @param jdb {@link JSimpleDB} database
* @param input console input
* @param output console output
* @throws IOException if an I/O error occurs
*/
public Console(JSimpleDB jdb, InputStream input, OutputStream output) throws IOException {
this(null, null, jdb, input, output, null, null, null);
}
/**
* Generic constructor.
*
* @param kvdb {@link KVDatabase} for {@link org.jsimpledb.SessionMode#KEY_VALUE} (otherwise must be null)
* @param db {@link Database} for {@link org.jsimpledb.SessionMode#CORE_API} (otherwise must be null)
* @param jdb {@link JSimpleDB} for {@link org.jsimpledb.SessionMode#JSIMPLEDB} (otherwise must be null)
* @param input console input
* @param output console output
* @param terminal JLine terminal interface, or null for default
* @param encoding character encoding for {@code terminal}, or null for default
* @param appName JLine application name, or null for none
* @throws IOException if an I/O error occurs
* @throws IllegalArgumentException if not exactly one of {@code kvdb}, {@code db} or {@code jdb} is not null
*/
public Console(KVDatabase kvdb, Database db, JSimpleDB jdb, InputStream input, OutputStream output,
Terminal terminal, String encoding, String appName) throws IOException {
Preconditions.checkArgument((kvdb != null ? 1 : 0) + (db != null ? 1 : 0) + (jdb != null ? 1 : 0) == 1,
"exactly one of kvdb, db or jdb must be not null");
Preconditions.checkArgument(input != null, "null input");
Preconditions.checkArgument(output != null, "null output");
this.console = new ConsoleReader(appName, input, output, terminal, encoding);
this.console.setBellEnabled(true);
this.console.setHistoryEnabled(true);
this.console.setHandleUserInterrupt(true);
final PrintWriter writer = new PrintWriter(console.getOutput(), true);
this.session = jdb != null ? new CliSession(jdb, writer, this) :
db != null ? new CliSession(db, writer, this) : new CliSession(kvdb, writer, this);
}
/**
* Get the associated JLine {@link ConsoleReader}.
*
* @return associated console reader
*/
public ConsoleReader getConsoleReader() {
return this.console;
}
/**
* Get the associated {@link CliSession}.
*
* @return associated CLI session
*/
public CliSession getSession() {
return this.session;
}
/**
* Configure the command history file.
*
* @param historyFile file for storing command history
*/
public void setHistoryFile(File historyFile) {
Preconditions.checkState(this.history == null, "history file already configured");
try {
this.history = new FileHistory(historyFile);
} catch (IOException e) {
// ignore
}
this.console.setHistory(this.history);
}
/**
* Run this instance. This method blocks until the connected user exits the console.
*
* @throws IOException if an I/O error occurs
*/
public void run() throws IOException {
// Input buffer
final StringBuilder lineBuffer = new StringBuilder();
// Set up tab completion
console.addCompleter(new ConsoleCompleter(lineBuffer));
// Get prompt
final String prompt;
switch (this.session.getMode()) {
case KEY_VALUE:
prompt = "KeyValue> ";
break;
case CORE_API:
prompt = "CoreAPI> ";
break;
case JSIMPLEDB:
prompt = "JSimpleDB> ";
break;
default:
throw new RuntimeException("internal error");
}
// Main command loop
try {
this.console.println("Welcome to JSimpleDB. You are in " + this.session.getMode() + " mode. Type `help' for help.");
this.console.println();
while (!session.isDone()) {
// Read command line
String line;
try {
line = this.console.readLine(lineBuffer.length() == 0 ?
prompt : String.format("%" + (prompt.length() - 3) + "s-> ", ""));
} catch (UserInterruptException e) {
this.console.print("^C");
line = null;
}
if (line == null) {
this.console.println();
break;
}
// Detect backslash continuations
boolean continuation = false;
if (line.length() > 0 && line.charAt(line.length() - 1) == '\\') {
line = line.substring(0, line.length() - 1) + "\n";
continuation = true;
}
// Append line to buffer
lineBuffer.append(line);
// Handle backslash continuations
if (continuation)
continue;
final ParseContext ctx = new ParseContext(lineBuffer.toString());
// Skip initial whitespace
ctx.skipWhitespace();
// Ignore blank input
if (ctx.getInput().length() == 0)
continue;
// Parse command(s)
final ArrayList actions = new ArrayList<>();
final boolean[] needMoreInput = new boolean[1];
final boolean ok = this.session.performCliSessionAction(new CliSession.Action() {
@Override
public void run(CliSession session) {
try {
actions.addAll(Console.this.commandListParser.parse(session, ctx, false));
} catch (ParseException e) {
if (ctx.getInput().length() == 0)
needMoreInput[0] = true;
else
throw e;
}
}
});
if (needMoreInput[0]) {
lineBuffer.append('\n');
continue;
}
lineBuffer.setLength(0);
if (!ok)
continue;
// Execute commands
for (CliSession.Action action : actions) {
if (!this.session.performCliSessionAction(action))
break;
}
// Proceed
this.console.flush();
}
} finally {
if (this.history != null)
this.history.flush();
this.console.flush();
this.console.shutdown();
}
}
/**
* Parse the given command(s).
*
* @param text command input
* @return command actions, or null if there was an error during parsing
* @throws ParseException if {@code text} cannot be parsed
* @throws IllegalArgumentException if {@code text} is null
*/
public List parseCommand(String text) {
Preconditions.checkArgument(text != null, "null text");
final ParseContext ctx = new ParseContext(text);
final ArrayList actions = new ArrayList<>();
return this.session.performCliSessionAction(new CliSession.Action() {
@Override
public void run(CliSession session) {
actions.addAll(commandListParser.parse(session, ctx, false));
}
}) ? actions : null;
}
// ConsoleCompleter
private class ConsoleCompleter implements Completer {
private final StringBuilder lineBuffer;
ConsoleCompleter(StringBuilder lineBuffer) {
this.lineBuffer = lineBuffer;
}
@Override
public int complete(final String buffer, final int cursor, final List candidates) {
final ParseContext ctx = new ParseContext(this.lineBuffer + buffer.substring(0, cursor));
try {
Console.this.commandListParser.parse(Console.this.session, ctx, true);
} catch (ParseException e) {
String prefix = "";
int index = ctx.getIndex();
while (index > 0 && Character.isJavaIdentifierPart(ctx.getOriginalInput().charAt(index - 1)))
prefix = ctx.getOriginalInput().charAt(--index) + prefix;
candidates.addAll(Lists.transform(e.getCompletions(), new AddPrefixFunction(prefix)));
return index;
} catch (Exception e) {
try {
Console.this.console.println();
Console.this.console.println("Error: got exception calculating command line completions");
e.printStackTrace(Console.this.session.getWriter());
} catch (IOException e2) {
// ignore
}
}
return cursor;
}
}
}
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