| /* |
| * Copyright (C) 2008-2010, Google Inc. |
| * Copyright (C) 2008-2009, Robin Rosenberg <robin.rosenberg@dewire.com> |
| * Copyright (C) 2008, 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 StringBuilder(0).toString(); /* 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 StringBuilder(0).toString(); /* must not string pool */ |
| |
| enum AckNackResult { |
| /** NAK */ |
| NAK, |
| /** ACK */ |
| ACK, |
| /** ACK + continue */ |
| ACK_CONTINUE, |
| /** ACK + common */ |
| ACK_COMMON, |
| /** ACK + ready */ |
| ACK_READY, |
| /** EOF (0000) recieved in protocol V2 when expecting an ACK/NAK */ |
| ACK_EOF; |
| } |
| |
| 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; |
| } |
| |
| |
| AckNackResult readACK(MutableObjectId returnedId) throws IOException { |
| AckNackResult result = readACKorEOF(returnedId); |
| if (result == AckNackResult.ACK_EOF) { |
| throw new PackProtocolException( |
| JGitText.get().expectedACKNAKFoundEOF); |
| } |
| return result; |
| } |
| |
| AckNackResult readACKorEOF(MutableObjectId returnedId) throws IOException { |
| final String line = readString(); |
| if (line.length() == 0) |
| return AckNackResult.ACK_EOF; |
| if ("NAK".equals(line)) //$NON-NLS-1$ |
| return AckNackResult.NAK; |
| if ("ready".equals(line)) { //$NON-NLS-1$ |
| // Protocol V2 |
| return AckNackResult.ACK_READY; |
| } |
| 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; |
| } |
| }; |
| } |
| |
| } |
| } |