org.eclipse.jgit/src/org/eclipse/jgit/transport/PacketLineIn.java - jgit - Git at Google

 /*
  * Copyright (C) 2008, 2010 Google Inc.
  * Copyright (C) 2008, 2009 Robin Rosenberg <robin.rosenberg@dewire.com>
  * Copyright (C) 2008, 2020 Shawn O. Pearce <spearce@spearce.org> 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.InputStream;
 import java.io.UncheckedIOException;
 import java.text.MessageFormat;
 import java.util.Iterator;

 import org.eclipse.jgit.errors.PackProtocolException;
 import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.lib.MutableObjectId;
 import org.eclipse.jgit.util.IO;
 import org.eclipse.jgit.util.RawParseUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 /**
  * Read Git style pkt-line formatting from an input stream.
  * <p>
  * This class is not thread safe and may issue multiple reads to the underlying
  * stream for each method call made.
  * <p>
  * This class performs no buffering on its own. This makes it suitable to
  * interleave reads performed by this class with reads performed directly
  * against the underlying InputStream.
  */
 public class PacketLineIn {
 	private static final Logger log = LoggerFactory.getLogger(PacketLineIn.class);

 	/**
 	 * Magic return from {@link #readString()} when a flush packet is found.
 	 *
 	 * @deprecated Callers should use {@link #isEnd(String)} to check if a
 	 *             string is the end marker, or
 	 *             {@link PacketLineIn#readStrings()} to iterate over all
 	 *             strings in the input stream until the marker is reached.
 	 */
 	@Deprecated
 	public static final String END = new String(); /* must not string pool */

 	/**
 	 * Magic return from {@link #readString()} when a delim packet is found.
 	 *
 	 * @since 5.0
 	 * @deprecated Callers should use {@link #isDelimiter(String)} to check if a
 	 *             string is the delimiter.
 	 */
 	@Deprecated
 	public static final String DELIM = new String(); /* must not string pool */

 	enum AckNackResult {
 		/** NAK */
 		NAK,
 		/** ACK */
 		ACK,
 		/** ACK + continue */
 		ACK_CONTINUE,
 		/** ACK + common */
 		ACK_COMMON,
 		/** ACK + ready */
 		ACK_READY;
 	}

 	private final byte[] lineBuffer = new byte[SideBandOutputStream.SMALL_BUF];
 	private final InputStream in;
 	private long limit;

 	/**
 	 * Create a new packet line reader.
 	 *
 	 * @param in
 	 *            the input stream to consume.
 	 */
 	public PacketLineIn(InputStream in) {
 		this(in, 0);
 	}

 	/**
 	 * Create a new packet line reader.
 	 *
 	 * @param in
 	 *            the input stream to consume.
 	 * @param limit
 	 *            bytes to read from the input; unlimited if set to 0.
 	 * @since 4.7
 	 */
 	public PacketLineIn(InputStream in, long limit) {
 		this.in = in;
 		this.limit = limit;
 	}

 	/**
 	 * Parses a ACK/NAK line in protocol V2.
 	 *
 	 * @param line
 	 *            to parse
 	 * @param returnedId
 	 *            in case of {@link AckNackResult#ACK_COMMON ACK_COMMON}
 	 * @return one of {@link AckNackResult#NAK NAK},
 	 *         {@link AckNackResult#ACK_COMMON ACK_COMMON}, or
 	 *         {@link AckNackResult#ACK_READY ACK_READY}
 	 * @throws IOException
 	 *             on protocol or transport errors
 	 */
 	static AckNackResult parseACKv2(String line, MutableObjectId returnedId)
 			throws IOException {
 		if ("NAK".equals(line)) { //$NON-NLS-1$
 			return AckNackResult.NAK;
 		}
 		if (line.startsWith("ACK ") && line.length() == 44) { //$NON-NLS-1$
 			returnedId.fromString(line.substring(4, 44));
 			return AckNackResult.ACK_COMMON;
 		}
 		if ("ready".equals(line)) { //$NON-NLS-1$
 			return AckNackResult.ACK_READY;
 		}
 		if (line.startsWith("ERR ")) { //$NON-NLS-1$
 			throw new PackProtocolException(line.substring(4));
 		}
 		throw new PackProtocolException(
 				MessageFormat.format(JGitText.get().expectedACKNAKGot, line));
 	}

 	AckNackResult readACK(MutableObjectId returnedId) throws IOException {
 		final String line = readString();
 		if (line.length() == 0)
 			throw new PackProtocolException(JGitText.get().expectedACKNAKFoundEOF);
 		if ("NAK".equals(line)) //$NON-NLS-1$
 			return AckNackResult.NAK;
 		if (line.startsWith("ACK ")) { //$NON-NLS-1$
 			returnedId.fromString(line.substring(4, 44));
 			if (line.length() == 44)
 				return AckNackResult.ACK;

 			final String arg = line.substring(44);
 			switch (arg) {
 			case " continue": //$NON-NLS-1$
 				return AckNackResult.ACK_CONTINUE;
 			case " common": //$NON-NLS-1$
 				return AckNackResult.ACK_COMMON;
 			case " ready": //$NON-NLS-1$
 				return AckNackResult.ACK_READY;
 			default:
 				break;
 			}
 		}
 		if (line.startsWith("ERR ")) //$NON-NLS-1$
 			throw new PackProtocolException(line.substring(4));
 		throw new PackProtocolException(MessageFormat.format(JGitText.get().expectedACKNAKGot, line));
 	}

 	/**
 	 * Read a single UTF-8 encoded string packet from the input stream.
 	 * <p>
 	 * If the string ends with an LF, it will be removed before returning the
 	 * value to the caller. If this automatic trimming behavior is not desired,
 	 * use {@link #readStringRaw()} instead.
 	 *
 	 * @return the string. {@link #END} if the string was the magic flush
 	 *         packet, {@link #DELIM} if the string was the magic DELIM
 	 *         packet.
 	 * @throws java.io.IOException
 	 *             the stream cannot be read.
 	 */
 	public String readString() throws IOException {
 		int len = readLength();
 		if (len == 0) {
 			log.debug("git< 0000"); //$NON-NLS-1$
 			return END;
 		}
 		if (len == 1) {
 			log.debug("git< 0001"); //$NON-NLS-1$
 			return DELIM;
 		}

 		len -= 4; // length header (4 bytes)
 		if (len == 0) {
 			log.debug("git< "); //$NON-NLS-1$
 			return ""; //$NON-NLS-1$
 		}

 		byte[] raw;
 		if (len <= lineBuffer.length)
 			raw = lineBuffer;
 		else
 			raw = new byte[len];

 		IO.readFully(in, raw, 0, len);
 		if (raw[len - 1] == '\n')
 			len--;

 		String s = RawParseUtils.decode(UTF_8, raw, 0, len);
 		log.debug("git< " + s); //$NON-NLS-1$
 		return s;
 	}

 	/**
 	 * Get an iterator to read strings from the input stream.
 	 *
 	 * @return an iterator that calls {@link #readString()} until {@link #END}
 	 *         is encountered.
 	 *
 	 * @throws IOException
 	 *             on failure to read the initial packet line.
 	 * @since 5.4
 	 */
 	public PacketLineInIterator readStrings() throws IOException {
 		return new PacketLineInIterator(this);
 	}

 	/**
 	 * Read a single UTF-8 encoded string packet from the input stream.
 	 * <p>
 	 * Unlike {@link #readString()} a trailing LF will be retained.
 	 *
 	 * @return the string. {@link #END} if the string was the magic flush
 	 *         packet.
 	 * @throws java.io.IOException
 	 *             the stream cannot be read.
 	 */
 	public String readStringRaw() throws IOException {
 		int len = readLength();
 		if (len == 0) {
 			log.debug("git< 0000"); //$NON-NLS-1$
 			return END;
 		}

 		len -= 4; // length header (4 bytes)

 		byte[] raw;
 		if (len <= lineBuffer.length)
 			raw = lineBuffer;
 		else
 			raw = new byte[len];

 		IO.readFully(in, raw, 0, len);

 		String s = RawParseUtils.decode(UTF_8, raw, 0, len);
 		log.debug("git< " + s); //$NON-NLS-1$
 		return s;
 	}

 	/**
 	 * Check if a string is the delimiter marker.
 	 *
 	 * @param s
 	 *            the string to check
 	 * @return true if the given string is {@link #DELIM}, otherwise false.
 	 * @since 5.4
 	 */
 	@SuppressWarnings({ "ReferenceEquality", "StringEquality" })
 	public static boolean isDelimiter(String s) {
 		return s == DELIM;
 	}

 	/**
 	 * Get the delimiter marker.
 	 * <p>
 	 * Intended for use only in tests.
 	 *
 	 * @return The delimiter marker.
 	 */
 	static String delimiter() {
 		return DELIM;
 	}

 	/**
 	 * Get the end marker.
 	 * <p>
 	 * Intended for use only in tests.
 	 *
 	 * @return The end marker.
 	 */
 	static String end() {
 		return END;
 	}

 	/**
 	 * Check if a string is the packet end marker.
 	 *
 	 * @param s
 	 *            the string to check
 	 * @return true if the given string is {@link #END}, otherwise false.
 	 * @since 5.4
 	 */
 	@SuppressWarnings({ "ReferenceEquality", "StringEquality" })
 	public static boolean isEnd(String s) {
 		return s == END;
 	}

 	void discardUntilEnd() throws IOException {
 		for (;;) {
 			int n = readLength();
 			if (n == 0) {
 				break;
 			}
 			IO.skipFully(in, n - 4);
 		}
 	}

 	int readLength() throws IOException {
 		IO.readFully(in, lineBuffer, 0, 4);
 		int len;
 		try {
 			len = RawParseUtils.parseHexInt16(lineBuffer, 0);
 		} catch (ArrayIndexOutOfBoundsException err) {
 			throw invalidHeader(err);
 		}

 		if (len == 0) {
 			return 0;
 		} else if (len == 1) {
 			return 1;
 		} else if (len < 4) {
 			throw invalidHeader();
 		}

 		if (limit != 0) {
 			int n = len - 4;
 			if (limit < n) {
 				limit = -1;
 				try {
 					IO.skipFully(in, n);
 				} catch (IOException e) {
 					// Ignore failure discarding packet over limit.
 				}
 				throw new InputOverLimitIOException();
 			}
 			// if set limit must not be 0 (means unlimited).
 			limit = n < limit ? limit - n : -1;
 		}
 		return len;
 	}

 	private IOException invalidHeader() {
 		return new IOException(MessageFormat.format(JGitText.get().invalidPacketLineHeader,
 				"" + (char) lineBuffer[0] + (char) lineBuffer[1] //$NON-NLS-1$
 				+ (char) lineBuffer[2] + (char) lineBuffer[3]));
 	}

 	private IOException invalidHeader(Throwable cause) {
 		IOException ioe = invalidHeader();
 		ioe.initCause(cause);
 		return ioe;
 	}

 	/**
 	 * IOException thrown by read when the configured input limit is exceeded.
 	 *
 	 * @since 4.7
 	 */
 	public static class InputOverLimitIOException extends IOException {
 		private static final long serialVersionUID = 1L;
 	}

 	/**
 	 * Iterator over packet lines.
 	 * <p>
 	 * Calls {@link #readString()} on the {@link PacketLineIn} until
 	 * {@link #END} is encountered.
 	 *
 	 * @since 5.4
 	 *
 	 */
 	public static class PacketLineInIterator implements Iterable<String> {
 		private PacketLineIn in;

 		private String current;

 		PacketLineInIterator(PacketLineIn in) throws IOException {
 			this.in = in;
 			current = in.readString();
 		}

 		@Override
 		public Iterator<String> iterator() {
 			return new Iterator<String>() {
 				@Override
 				public boolean hasNext() {
 					return !PacketLineIn.isEnd(current);
 				}

 				@Override
 				public String next() {
 					String next = current;
 					try {
 						current = in.readString();
 					} catch (IOException e) {
 						throw new UncheckedIOException(e);
 					}
 					return next;
 				}
 			};
 		}

 	}
 }
	/*
	* Copyright (C) 2008, 2010 Google Inc.
	* Copyright (C) 2008, 2009 Robin Rosenberg <robin.rosenberg@dewire.com>
	* Copyright (C) 2008, 2020 Shawn O. Pearce <spearce@spearce.org> 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.InputStream;
	import java.io.UncheckedIOException;
	import java.text.MessageFormat;
	import java.util.Iterator;

	import org.eclipse.jgit.errors.PackProtocolException;
	import org.eclipse.jgit.internal.JGitText;
	import org.eclipse.jgit.lib.MutableObjectId;
	import org.eclipse.jgit.util.IO;
	import org.eclipse.jgit.util.RawParseUtils;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	/**
	* Read Git style pkt-line formatting from an input stream.
	* <p>
	* This class is not thread safe and may issue multiple reads to the underlying
	* stream for each method call made.
	* <p>
	* This class performs no buffering on its own. This makes it suitable to
	* interleave reads performed by this class with reads performed directly
	* against the underlying InputStream.
	*/
	public class PacketLineIn {
	private static final Logger log = LoggerFactory.getLogger(PacketLineIn.class);

	/**
	* Magic return from {@link #readString()} when a flush packet is found.
	*
	* @deprecated Callers should use {@link #isEnd(String)} to check if a
	* string is the end marker, or
	* {@link PacketLineIn#readStrings()} to iterate over all
	* strings in the input stream until the marker is reached.
	*/
	@Deprecated
	public static final String END = new String(); /* must not string pool */

	/**
	* Magic return from {@link #readString()} when a delim packet is found.
	*
	* @since 5.0
	* @deprecated Callers should use {@link #isDelimiter(String)} to check if a
	* string is the delimiter.
	*/
	@Deprecated
	public static final String DELIM = new String(); /* must not string pool */

	enum AckNackResult {
	/** NAK */
	NAK,
	/** ACK */
	ACK,
	/** ACK + continue */
	ACK_CONTINUE,
	/** ACK + common */
	ACK_COMMON,
	/** ACK + ready */
	ACK_READY;
	}

	private final byte[] lineBuffer = new byte[SideBandOutputStream.SMALL_BUF];
	private final InputStream in;
	private long limit;

	/**
	* Create a new packet line reader.
	*
	* @param in
	* the input stream to consume.
	*/
	public PacketLineIn(InputStream in) {
	this(in, 0);
	}

	/**
	* Create a new packet line reader.
	*
	* @param in
	* the input stream to consume.
	* @param limit
	* bytes to read from the input; unlimited if set to 0.
	* @since 4.7
	*/
	public PacketLineIn(InputStream in, long limit) {
	this.in = in;
	this.limit = limit;
	}

	/**
	* Parses a ACK/NAK line in protocol V2.
	*
	* @param line
	* to parse
	* @param returnedId
	* in case of {@link AckNackResult#ACK_COMMON ACK_COMMON}
	* @return one of {@link AckNackResult#NAK NAK},
	* {@link AckNackResult#ACK_COMMON ACK_COMMON}, or
	* {@link AckNackResult#ACK_READY ACK_READY}
	* @throws IOException
	* on protocol or transport errors
	*/
	static AckNackResult parseACKv2(String line, MutableObjectId returnedId)
	throws IOException {
	if ("NAK".equals(line)) { //$NON-NLS-1$
	return AckNackResult.NAK;
	}
	if (line.startsWith("ACK ") && line.length() == 44) { //$NON-NLS-1$
	returnedId.fromString(line.substring(4, 44));
	return AckNackResult.ACK_COMMON;
	}
	if ("ready".equals(line)) { //$NON-NLS-1$
	return AckNackResult.ACK_READY;
	}
	if (line.startsWith("ERR ")) { //$NON-NLS-1$
	throw new PackProtocolException(line.substring(4));
	}
	throw new PackProtocolException(
	MessageFormat.format(JGitText.get().expectedACKNAKGot, line));
	}

	AckNackResult readACK(MutableObjectId returnedId) throws IOException {
	final String line = readString();
	if (line.length() == 0)
	throw new PackProtocolException(JGitText.get().expectedACKNAKFoundEOF);
	if ("NAK".equals(line)) //$NON-NLS-1$
	return AckNackResult.NAK;
	if (line.startsWith("ACK ")) { //$NON-NLS-1$
	returnedId.fromString(line.substring(4, 44));
	if (line.length() == 44)
	return AckNackResult.ACK;

	final String arg = line.substring(44);
	switch (arg) {
	case " continue": //$NON-NLS-1$
	return AckNackResult.ACK_CONTINUE;
	case " common": //$NON-NLS-1$
	return AckNackResult.ACK_COMMON;
	case " ready": //$NON-NLS-1$
	return AckNackResult.ACK_READY;
	default:
	break;
	}
	}
	if (line.startsWith("ERR ")) //$NON-NLS-1$
	throw new PackProtocolException(line.substring(4));
	throw new PackProtocolException(MessageFormat.format(JGitText.get().expectedACKNAKGot, line));
	}

	/**
	* Read a single UTF-8 encoded string packet from the input stream.
	* <p>
	* If the string ends with an LF, it will be removed before returning the
	* value to the caller. If this automatic trimming behavior is not desired,
	* use {@link #readStringRaw()} instead.
	*
	* @return the string. {@link #END} if the string was the magic flush
	* packet, {@link #DELIM} if the string was the magic DELIM
	* packet.
	* @throws java.io.IOException
	* the stream cannot be read.
	*/
	public String readString() throws IOException {
	int len = readLength();
	if (len == 0) {
	log.debug("git< 0000"); //$NON-NLS-1$
	return END;
	}
	if (len == 1) {
	log.debug("git< 0001"); //$NON-NLS-1$
	return DELIM;
	}

	len -= 4; // length header (4 bytes)
	if (len == 0) {
	log.debug("git< "); //$NON-NLS-1$
	return ""; //$NON-NLS-1$
	}

	byte[] raw;
	if (len <= lineBuffer.length)
	raw = lineBuffer;
	else
	raw = new byte[len];

	IO.readFully(in, raw, 0, len);
	if (raw[len - 1] == '\n')
	len--;

	String s = RawParseUtils.decode(UTF_8, raw, 0, len);
	log.debug("git< " + s); //$NON-NLS-1$
	return s;
	}

	/**
	* Get an iterator to read strings from the input stream.
	*
	* @return an iterator that calls {@link #readString()} until {@link #END}
	* is encountered.
	*
	* @throws IOException
	* on failure to read the initial packet line.
	* @since 5.4
	*/
	public PacketLineInIterator readStrings() throws IOException {
	return new PacketLineInIterator(this);
	}

	/**
	* Read a single UTF-8 encoded string packet from the input stream.
	* <p>
	* Unlike {@link #readString()} a trailing LF will be retained.
	*
	* @return the string. {@link #END} if the string was the magic flush
	* packet.
	* @throws java.io.IOException
	* the stream cannot be read.
	*/
	public String readStringRaw() throws IOException {
	int len = readLength();
	if (len == 0) {
	log.debug("git< 0000"); //$NON-NLS-1$
	return END;
	}

	len -= 4; // length header (4 bytes)

	byte[] raw;
	if (len <= lineBuffer.length)
	raw = lineBuffer;
	else
	raw = new byte[len];

	IO.readFully(in, raw, 0, len);

	String s = RawParseUtils.decode(UTF_8, raw, 0, len);
	log.debug("git< " + s); //$NON-NLS-1$
	return s;
	}

	/**
	* Check if a string is the delimiter marker.
	*
	* @param s
	* the string to check
	* @return true if the given string is {@link #DELIM}, otherwise false.
	* @since 5.4
	*/
	@SuppressWarnings({ "ReferenceEquality", "StringEquality" })
	public static boolean isDelimiter(String s) {
	return s == DELIM;
	}

	/**
	* Get the delimiter marker.
	* <p>
	* Intended for use only in tests.
	*
	* @return The delimiter marker.
	*/
	static String delimiter() {
	return DELIM;
	}

	/**
	* Get the end marker.
	* <p>
	* Intended for use only in tests.
	*
	* @return The end marker.
	*/
	static String end() {
	return END;
	}

	/**
	* Check if a string is the packet end marker.
	*
	* @param s
	* the string to check
	* @return true if the given string is {@link #END}, otherwise false.
	* @since 5.4
	*/
	@SuppressWarnings({ "ReferenceEquality", "StringEquality" })
	public static boolean isEnd(String s) {
	return s == END;
	}

	void discardUntilEnd() throws IOException {
	for (;;) {
	int n = readLength();
	if (n == 0) {
	break;
	}
	IO.skipFully(in, n - 4);
	}
	}

	int readLength() throws IOException {
	IO.readFully(in, lineBuffer, 0, 4);
	int len;
	try {
	len = RawParseUtils.parseHexInt16(lineBuffer, 0);
	} catch (ArrayIndexOutOfBoundsException err) {
	throw invalidHeader(err);
	}

	if (len == 0) {
	return 0;
	} else if (len == 1) {
	return 1;
	} else if (len < 4) {
	throw invalidHeader();
	}

	if (limit != 0) {
	int n = len - 4;
	if (limit < n) {
	limit = -1;
	try {
	IO.skipFully(in, n);
	} catch (IOException e) {
	// Ignore failure discarding packet over limit.
	}
	throw new InputOverLimitIOException();
	}
	// if set limit must not be 0 (means unlimited).
	limit = n < limit ? limit - n : -1;
	}
	return len;
	}

	private IOException invalidHeader() {
	return new IOException(MessageFormat.format(JGitText.get().invalidPacketLineHeader,
	"" + (char) lineBuffer[0] + (char) lineBuffer[1] //$NON-NLS-1$
	+ (char) lineBuffer[2] + (char) lineBuffer[3]));
	}

	private IOException invalidHeader(Throwable cause) {
	IOException ioe = invalidHeader();
	ioe.initCause(cause);
	return ioe;
	}

	/**
	* IOException thrown by read when the configured input limit is exceeded.
	*
	* @since 4.7
	*/
	public static class InputOverLimitIOException extends IOException {
	private static final long serialVersionUID = 1L;
	}

	/**
	* Iterator over packet lines.
	* <p>
	* Calls {@link #readString()} on the {@link PacketLineIn} until
	* {@link #END} is encountered.
	*
	* @since 5.4
	*
	*/
	public static class PacketLineInIterator implements Iterable<String> {
	private PacketLineIn in;

	private String current;

	PacketLineInIterator(PacketLineIn in) throws IOException {
	this.in = in;
	current = in.readString();
	}

	@Override
	public Iterator<String> iterator() {
	return new Iterator<String>() {
	@Override
	public boolean hasNext() {
	return !PacketLineIn.isEnd(current);
	}

	@Override
	public String next() {
	String next = current;
	try {
	current = in.readString();
	} catch (IOException e) {
	throw new UncheckedIOException(e);
	}
	return next;
	}
	};
	}

	}
	}