org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/trace/Metadata.java

   1 /*******************************************************************************
   2  * Copyright (c) 2011-2012 Ericsson, Ecole Polytechnique de Montreal and others
   3  *
   4  * All rights reserved. This program and the accompanying materials are made
   5  * available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors: Matthew Khouzam - Initial API and implementation
  10  * Contributors: Simon Marchi - Initial API and implementation
  11  *******************************************************************************/
  12
  13 package org.eclipse.linuxtools.ctf.core.trace;
  14
  15 import java.io.File;
  16 import java.io.FileInputStream;
  17 import java.io.FileNotFoundException;
  18 import java.io.FileReader;
  19 import java.io.IOException;
  20 import java.io.Reader;
  21 import java.io.StringReader;
  22 import java.nio.ByteBuffer;
  23 import java.nio.ByteOrder;
  24 import java.nio.channels.FileChannel;
  25 import java.util.Arrays;
  26 import java.util.UUID;
  27
  28 import org.antlr.runtime.ANTLRReaderStream;
  29 import org.antlr.runtime.CommonTokenStream;
  30 import org.antlr.runtime.RecognitionException;
  31 import org.antlr.runtime.tree.CommonTree;
  32 import org.eclipse.linuxtools.ctf.core.event.metadata.exceptions.ParseException;
  33 import org.eclipse.linuxtools.ctf.parser.CTFLexer;
  34 import org.eclipse.linuxtools.ctf.parser.CTFParser;
  35 import org.eclipse.linuxtools.ctf.parser.CTFParser.parse_return;
  36 import org.eclipse.linuxtools.internal.ctf.core.event.metadata.IOStructGen;
  37
  38 /**
  39  * <b><u>Metadata</u></b>
  40  * <p>
  41  * Represents a metadata file
  42  */
  43 public class Metadata {
  44
  45     // ------------------------------------------------------------------------
  46     // Constants
  47     // ------------------------------------------------------------------------
  48
  49     /**
  50      * Name of the metadata file in the trace directory
  51      */
  52     final String METADATA_FILENAME = "metadata"; //$NON-NLS-1$
  53
  54     /**
  55      * Size of the metadata packet header, in bytes, computed by hand.
  56      */
  57     final int METADATA_PACKET_HEADER_SIZE = 37;
  58
  59     // ------------------------------------------------------------------------
  60     // Attributes
  61     // ------------------------------------------------------------------------
  62
  63     /**
  64      * Reference to the metadata file
  65      */
  66     private File metadataFile = null;
  67
  68     /**
  69      * Byte order as detected when reading the TSDL magic number.
  70      */
  71     private ByteOrder detectedByteOrder = null;
  72
  73     /**
  74      * The trace file to which belongs this metadata file.
  75      */
  76     private CTFTrace trace = null;
  77
  78     // ------------------------------------------------------------------------
  79     // Constructors
  80     // ------------------------------------------------------------------------
  81
  82     /**
  83      * Constructs a Metadata object.
  84      *
  85      * @param trace
  86      *            The trace to which belongs this metadata file.
  87      */
  88     public Metadata(CTFTrace trace) {
  89         this.trace = trace;
  90
  91         /* Path of metadata file = trace directory path + metadata filename */
  92         String metadataPath = trace.getTraceDirectory().getPath()
  93                 + Utils.SEPARATOR + METADATA_FILENAME;
  94
  95         /* Create a file reference to the metadata file */
  96         metadataFile = new File(metadataPath);
  97     }
  98
  99     // ------------------------------------------------------------------------
 100     // Getters/Setters/Predicates
 101     // ------------------------------------------------------------------------
 102
 103     /**
 104      * Returns the ByteOrder that was detected while parsing the metadata.
 105      *
 106      * @return The byte order.
 107      */
 108     public ByteOrder getDetectedByteOrder() {
 109         return detectedByteOrder;
 110     }
 111
 112     // ------------------------------------------------------------------------
 113     // Operations
 114     // ------------------------------------------------------------------------
 115
 116     /**
 117      * Parse the metadata file.
 118      *
 119      * @throws CTFReaderException
 120      */
 121     public void parse() throws CTFReaderException {
 122         /* Open the file and get the FileChannel */
 123         FileChannel metadataFileChannel;
 124         try {
 125             metadataFileChannel = new FileInputStream(metadataFile).getChannel();
 126         } catch (FileNotFoundException e) {
 127             throw new CTFReaderException("Cannot find metadata file!"); //$NON-NLS-1$
 128         }
 129
 130         /*
 131          * Reader. It will contain a StringReader if we are using packet-based
 132          * metadata and it will contain a FileReader if we have text-based
 133          * metadata.
 134          */
 135         Reader metadataTextInput = null;
 136
 137         /* Check if metadata is packet-based */
 138         if (isPacketBased(metadataFileChannel)) {
 139             /* Create StringBuffer to receive metadata text */
 140             StringBuffer metadataText = new StringBuffer();
 141
 142             /*
 143              * Read metadata packet one by one, appending the text to the
 144              * StringBuffer
 145              */
 146             MetadataPacketHeader packetHeader = readMetadataPacket(
 147                     metadataFileChannel, metadataText);
 148             while (packetHeader != null) {
 149                 packetHeader = readMetadataPacket(metadataFileChannel,
 150                         metadataText);
 151             }
 152
 153             /* Wrap the metadata string with a StringReader */
 154             metadataTextInput = new StringReader(metadataText.toString());
 155         } else {
 156             /* Wrap the metadata file with a FileReader */
 157             try {
 158                 metadataTextInput = new FileReader(metadataFile);
 159             } catch (FileNotFoundException e) {
 160                 /*
 161                  * We've already checked for this earlier. Why does StringReader
 162                  * not throw this too??
 163                  */
 164                 throw new CTFReaderException(e);
 165             }
 166         }
 167
 168         /* Create an ANTLR reader */
 169         ANTLRReaderStream antlrStream;
 170         try {
 171             antlrStream = new ANTLRReaderStream(metadataTextInput);
 172         } catch (IOException e) {
 173             /* This would indicate a problem with the ANTLR library... */
 174             throw new CTFReaderException(e);
 175         }
 176
 177         /* Parse the metadata text and get the AST */
 178         CTFLexer ctfLexer = new CTFLexer(antlrStream);
 179         CommonTokenStream tokens = new CommonTokenStream(ctfLexer);
 180         CTFParser ctfParser = new CTFParser(tokens, false);
 181         parse_return ret;
 182         try {
 183             ret = ctfParser.parse();
 184         } catch (RecognitionException e) {
 185             /*
 186              * We don't want to expose this ANTLR-specific exception type to the
 187              * outside..
 188              */
 189             throw new CTFReaderException(e);
 190         }
 191         CommonTree tree = (CommonTree) ret.getTree();
 192
 193         /* Generate IO structures (declarations) */
 194         IOStructGen gen = new IOStructGen(tree, trace);
 195         try {
 196             gen.generate();
 197         } catch (ParseException e) {
 198             throw new CTFReaderException(e);
 199         }
 200     }
 201
 202     /**
 203      * Determines whether the metadata file is packet-based by looking at the
 204      * TSDL magic number. If it is packet-based, it also gives information about
 205      * the endianness of the trace using the detectedByteOrder attribute.
 206      *
 207      * @param metadataFileChannel
 208      *            FileChannel of the metadata file.
 209      * @return True if the metadata is packet-based.
 210      * @throws CTFReaderException
 211      */
 212     private boolean isPacketBased(FileChannel metadataFileChannel)
 213             throws CTFReaderException {
 214         /*
 215          * Create a ByteBuffer to read the TSDL magic number (default is big
 216          * endian)
 217          */
 218         ByteBuffer magicByteBuffer = ByteBuffer.allocate(Utils.TSDL_MAGIC_LEN);
 219
 220         /* Read without changing file position */
 221         try {
 222             metadataFileChannel.read(magicByteBuffer, 0);
 223         } catch (IOException e) {
 224             throw new CTFReaderException(
 225                     "Unable to read metadata file channel."); //$NON-NLS-1$
 226         }
 227
 228         /* Get the first int from the file */
 229         int magic = magicByteBuffer.getInt(0);
 230
 231         /* Check if it matches */
 232         if (Utils.TSDL_MAGIC == magic) {
 233             detectedByteOrder = ByteOrder.BIG_ENDIAN;
 234             return true;
 235         }
 236
 237         /* Try the same thing, but with little endian */
 238         magicByteBuffer.order(ByteOrder.LITTLE_ENDIAN);
 239         magic = magicByteBuffer.getInt(0);
 240
 241         if (Utils.TSDL_MAGIC == magic) {
 242             detectedByteOrder = ByteOrder.LITTLE_ENDIAN;
 243             return true;
 244         }
 245
 246         return false;
 247     }
 248
 249     /**
 250      * Reads a metadata packet from the given metadata FileChannel, do some
 251      * basic validation and append the text to the StringBuffer.
 252      *
 253      * @param metadataFileChannel
 254      *            Metadata FileChannel
 255      * @param metadataText
 256      *            StringBuffer to which the metadata text will be appended.
 257      * @return A structure describing the header of the metadata packet, or null
 258      *         if the end of the file is reached.
 259      * @throws CTFReaderException
 260      */
 261     private MetadataPacketHeader readMetadataPacket(
 262             FileChannel metadataFileChannel, StringBuffer metadataText)
 263             throws CTFReaderException {
 264         /* Allocate a ByteBuffer for the header */
 265         ByteBuffer headerByteBuffer = ByteBuffer.allocate(METADATA_PACKET_HEADER_SIZE);
 266
 267         /* Read the header */
 268         int nbBytesRead;
 269         try {
 270             nbBytesRead = metadataFileChannel.read(headerByteBuffer);
 271         } catch (IOException e) {
 272             throw new CTFReaderException("Error reading the metadata header."); //$NON-NLS-1$
 273         }
 274
 275         /* Return null if EOF */
 276         if (nbBytesRead < 0) {
 277             return null;
 278         }
 279
 280         /* Set ByteBuffer's position to 0 */
 281         headerByteBuffer.position(0);
 282
 283         /* Use byte order that was detected with the magic number */
 284         headerByteBuffer.order(detectedByteOrder);
 285
 286         assert (nbBytesRead == METADATA_PACKET_HEADER_SIZE);
 287
 288         MetadataPacketHeader header = new MetadataPacketHeader();
 289
 290         /* Read from the ByteBuffer */
 291         header.magic = headerByteBuffer.getInt();
 292         headerByteBuffer.get(header.uuid);
 293         header.checksum = headerByteBuffer.getInt();
 294         header.contentSize = headerByteBuffer.getInt();
 295         header.packetSize = headerByteBuffer.getInt();
 296         header.compressionScheme = headerByteBuffer.get();
 297         header.encryptionScheme = headerByteBuffer.get();
 298         header.checksumScheme = headerByteBuffer.get();
 299         header.ctfMajorVersion = headerByteBuffer.get();
 300         header.ctfMinorVersion = headerByteBuffer.get();
 301
 302         /* Check TSDL magic number */
 303         if (header.magic != Utils.TSDL_MAGIC) {
 304             throw new CTFReaderException("TSDL magic number does not match"); //$NON-NLS-1$
 305         }
 306
 307         /* Check UUID */
 308         UUID uuid = Utils.makeUUID(header.uuid);
 309         if (!trace.UUIDIsSet()) {
 310             trace.setUUID(uuid);
 311         } else {
 312             if (!trace.getUUID().equals(uuid)) {
 313                 throw new CTFReaderException("UUID mismatch"); //$NON-NLS-1$
 314             }
 315         }
 316
 317         /* Extract the text from the packet */
 318         int payloadSize = ((header.contentSize / 8) - METADATA_PACKET_HEADER_SIZE);
 319         int skipSize = (header.packetSize - header.contentSize) / 8;
 320
 321         /* Read the payload + the padding in a ByteBuffer */
 322         ByteBuffer payloadByteBuffer = ByteBuffer.allocateDirect(payloadSize
 323                 + skipSize);
 324         try {
 325             metadataFileChannel.read(payloadByteBuffer);
 326         } catch (IOException e) {
 327             throw new CTFReaderException(
 328                     "Error reading metadata packet payload."); //$NON-NLS-1$
 329         }
 330         payloadByteBuffer.rewind();
 331
 332         /* Read only the payload from the ByteBuffer into a byte array */
 333         byte payloadByteArray[] = new byte[payloadByteBuffer.remaining()];
 334         payloadByteBuffer.get(payloadByteArray, 0, payloadSize);
 335
 336         /* Convert the byte array to a String */
 337         String str = new String(payloadByteArray, 0, payloadSize);
 338
 339         /* Append it to the existing metadata */
 340         metadataText.append(str);
 341
 342         return header;
 343     }
 344
 345     static class MetadataPacketHeader {
 346
 347         public int magic;
 348         public byte uuid[] = new byte[16];
 349         public int checksum;
 350         public int contentSize;
 351         public int packetSize;
 352         public byte compressionScheme;
 353         public byte encryptionScheme;
 354         public byte checksumScheme;
 355         public byte ctfMajorVersion;
 356         public byte ctfMinorVersion;
 357
 358         @Override
 359         public String toString() {
 360             /* Only for debugging, shouldn't be externalized */
 361             /* Therefore it cannot be covered by test cases */
 362             return "MetadataPacketHeader [magic=0x" //$NON-NLS-1$
 363                     + Integer.toHexString(magic) + ", uuid=" //$NON-NLS-1$
 364                     + Arrays.toString(uuid) + ", checksum=" + checksum //$NON-NLS-1$
 365                     + ", contentSize=" + contentSize + ", packetSize=" //$NON-NLS-1$ //$NON-NLS-2$
 366                     + packetSize + ", compressionScheme=" + compressionScheme //$NON-NLS-1$
 367                     + ", encryptionScheme=" + encryptionScheme //$NON-NLS-1$
 368                     + ", checksumScheme=" + checksumScheme //$NON-NLS-1$
 369                     + ", ctfMajorVersion=" + ctfMajorVersion //$NON-NLS-1$
 370                     + ", ctfMinorVersion=" + ctfMinorVersion + ']'; //$NON-NLS-1$
 371         }
 372
 373     }
 374 }