org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/trace/StreamInputPacketReader.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 package org.eclipse.linuxtools.ctf.core.trace;
  13
  14 import java.io.IOException;
  15 import java.nio.MappedByteBuffer;
  16 import java.nio.channels.FileChannel.MapMode;
  17 import java.util.Collection;
  18 import java.util.HashMap;
  19
  20 import org.eclipse.linuxtools.ctf.core.event.EventDeclaration;
  21 import org.eclipse.linuxtools.ctf.core.event.EventDefinition;
  22 import org.eclipse.linuxtools.ctf.core.event.types.Definition;
  23 import org.eclipse.linuxtools.ctf.core.event.types.IDefinitionScope;
  24 import org.eclipse.linuxtools.ctf.core.event.types.IntegerDefinition;
  25 import org.eclipse.linuxtools.ctf.core.event.types.SimpleDatatypeDefinition;
  26 import org.eclipse.linuxtools.ctf.core.event.types.StructDeclaration;
  27 import org.eclipse.linuxtools.ctf.core.event.types.StructDefinition;
  28 import org.eclipse.linuxtools.ctf.core.event.types.VariantDefinition;
  29 import org.eclipse.linuxtools.internal.ctf.core.event.io.BitBuffer;
  30 import org.eclipse.linuxtools.internal.ctf.core.trace.Stream;
  31 import org.eclipse.linuxtools.internal.ctf.core.trace.StreamInputPacketIndexEntry;
  32
  33 /**
  34  * CTF trace packet reader. Reads the events of a packet of a trace file.
  35  *
  36  * @version 1.0
  37  * @author Matthew Khouzam
  38  * @author Simon Marchi
  39  */
  40 public class StreamInputPacketReader implements IDefinitionScope {
  41
  42     // ------------------------------------------------------------------------
  43     // Attributes
  44     // ------------------------------------------------------------------------
  45
  46     /** BitBuffer used to read the trace file. */
  47     private final BitBuffer bitBuffer;
  48
  49     /** StreamInputReader that uses this StreamInputPacketReader. */
  50     private final StreamInputReader streamInputReader;
  51
  52     /** Trace packet header. */
  53     private final StructDefinition tracePacketHeaderDef;
  54
  55     /** Stream packet context definition. */
  56     private final StructDefinition streamPacketContextDef;
  57
  58     /** Stream event header definition. */
  59     private final StructDefinition streamEventHeaderDef;
  60
  61     /** Stream event context definition.*/
  62     private final StructDefinition streamEventContextDef;
  63
  64     /** Maps event ID to event definitions. */
  65     private final HashMap<Long, EventDefinition> events;
  66
  67     /** Reference to the index entry of the current packet. */
  68     private StreamInputPacketIndexEntry currentPacket = null;
  69
  70     /**
  71      * Last timestamp recorded.
  72      *
  73      * Needed to calculate the complete timestamp values for the events with
  74      * compact headers.
  75      */
  76     private long lastTimestamp = 0;
  77
  78     /** CPU id of current packet. */
  79     private int currentCpu = 0;
  80
  81     /** number of lost events in this packet */
  82     private int lostSoFar;
  83
  84     private int lostEventsInThisPacket;
  85
  86     // ------------------------------------------------------------------------
  87     // Constructors
  88     // ------------------------------------------------------------------------
  89
  90     /**
  91      * Constructs a StreamInputPacketReader.
  92      *
  93      * @param streamInputReader
  94      *            The StreamInputReader to which this packet reader belongs to.
  95      */
  96     public StreamInputPacketReader(StreamInputReader streamInputReader) {
  97         this.streamInputReader = streamInputReader;
  98
  99         /* Set the BitBuffer's byte order. */
 100         bitBuffer = new BitBuffer();
 101         bitBuffer.setByteOrder(streamInputReader.getByteOrder());
 102
 103         events = streamInputReader.getStreamInput().getStream().getTrace().getEventDefs(streamInputReader.getStreamInput());
 104         lostSoFar = 0;
 105
 106         /* Create trace packet header definition. */
 107         final Stream currentStream = streamInputReader.getStreamInput().getStream();
 108         StructDeclaration tracePacketHeaderDecl = currentStream.getTrace().getPacketHeader();
 109         if (tracePacketHeaderDecl != null) {
 110             tracePacketHeaderDef = tracePacketHeaderDecl.createDefinition(this, "trace.packet.header"); //$NON-NLS-1$
 111         } else {
 112             tracePacketHeaderDef = null;
 113         }
 114
 115         /* Create stream packet context definition. */
 116         StructDeclaration streamPacketContextDecl = currentStream.getPacketContextDecl();
 117         if (streamPacketContextDecl != null) {
 118             streamPacketContextDef = streamPacketContextDecl.createDefinition(this, "stream.packet.context"); //$NON-NLS-1$
 119         } else {
 120             streamPacketContextDef = null;
 121         }
 122
 123         /* Create stream event header definition. */
 124         StructDeclaration streamEventHeaderDecl = currentStream.getEventHeaderDecl();
 125         if (streamEventHeaderDecl != null) {
 126             streamEventHeaderDef = streamEventHeaderDecl.createDefinition(this, "stream.event.header"); //$NON-NLS-1$
 127         } else {
 128             streamEventHeaderDef = null;
 129         }
 130
 131         /* Create stream event context definition. */
 132         StructDeclaration streamEventContextDecl = currentStream.getEventContextDecl();
 133         if (streamEventContextDecl != null) {
 134             streamEventContextDef = streamEventContextDecl.createDefinition(this, "stream.event.context"); //$NON-NLS-1$
 135         } else {
 136             streamEventContextDef = null;
 137         }
 138
 139         /* Create event definitions */
 140         Collection<EventDeclaration> eventDecls = streamInputReader.getStreamInput().getStream().getEvents().values();
 141
 142         for (EventDeclaration event : eventDecls) {
 143             if (!events.containsKey(event.getId())) {
 144                 EventDefinition eventDef = event.createDefinition(streamInputReader);
 145                 events.put(event.getId(), eventDef);
 146             }
 147         }
 148     }
 149
 150     // ------------------------------------------------------------------------
 151     // Getters/Setters/Predicates
 152     // ------------------------------------------------------------------------
 153
 154     /**
 155      * Gets the current packet
 156      *
 157      * @return the current packet
 158      */
 159     public StreamInputPacketIndexEntry getCurrentPacket() {
 160         return this.currentPacket;
 161     }
 162
 163     /**
 164      * Gets the steamPacketContext Definition
 165      *
 166      * @return steamPacketContext Definition
 167      */
 168     public StructDefinition getStreamPacketContextDef() {
 169         return this.streamPacketContextDef;
 170     }
 171
 172     /**
 173      * Gets the stream's event context definition.
 174      *
 175      * @return The streamEventContext definition
 176      */
 177     public StructDefinition getStreamEventContextDef() {
 178         return streamEventContextDef;
 179     }
 180
 181     /**
 182      * Gets the CPU (core) number
 183      *
 184      * @return the CPU (core) number
 185      */
 186     public int getCPU() {
 187         return this.currentCpu;
 188     }
 189
 190     @Override
 191     public String getPath() {
 192         return ""; //$NON-NLS-1$
 193     }
 194
 195     // ------------------------------------------------------------------------
 196     // Operations
 197     // ------------------------------------------------------------------------
 198
 199     /**
 200      * Changes the current packet to the given one.
 201      *
 202      * @param currentPacket
 203      *            The index entry of the packet to switch to.
 204      */
 205     public void setCurrentPacket(StreamInputPacketIndexEntry currentPacket) {
 206         this.currentPacket = currentPacket;
 207
 208         if (this.currentPacket != null) {
 209             /*
 210              * Change the map of the BitBuffer.
 211              */
 212             MappedByteBuffer bb = null;
 213             try {
 214                 bb = streamInputReader.getStreamInput().getFileChannel()
 215                         .map(MapMode.READ_ONLY,
 216                                 this.currentPacket.getOffsetBytes(),
 217                                 (this.currentPacket.getPacketSizeBits() + 7) / 8);
 218             } catch (IOException e) {
 219                 /*
 220                  * The streamInputReader object is already allocated, so this
 221                  * shouldn't fail bar some very bad kernel or RAM errors...
 222                  */
 223                 e.printStackTrace();
 224             }
 225
 226             bitBuffer.setByteBuffer(bb);
 227
 228             /*
 229              * Read trace packet header.
 230              */
 231             if (tracePacketHeaderDef != null) {
 232                 tracePacketHeaderDef.read(bitBuffer);
 233             }
 234
 235             /*
 236              * Read stream packet context.
 237              */
 238             if (getStreamPacketContextDef() != null) {
 239                 getStreamPacketContextDef().read(bitBuffer);
 240
 241                 /* Read CPU ID */
 242                 if (this.getCurrentPacket().getTarget() != null) {
 243                     this.currentCpu = (int) this.getCurrentPacket().getTargetId();
 244                 }
 245
 246                 /* Read number of lost events */
 247                 lostEventsInThisPacket = (int) this.getCurrentPacket().getLostEvents();
 248                 lostSoFar = 0;
 249
 250             }
 251
 252             /*
 253              * Use the timestamp begin of the packet as the reference for the
 254              * timestamp reconstitution.
 255              */
 256             lastTimestamp = currentPacket.getTimestampBegin();
 257         } else {
 258             bitBuffer.setByteBuffer(null);
 259
 260             lastTimestamp = 0;
 261         }
 262     }
 263
 264     /**
 265      * Returns whether it is possible to read any more events from this packet.
 266      *
 267      * @return True if it is possible to read any more events from this packet.
 268      */
 269     public boolean hasMoreEvents() {
 270         if (currentPacket != null) {
 271             return bitBuffer.position() < currentPacket.getContentSizeBits();
 272         }
 273         return false;
 274     }
 275
 276     /**
 277      * Reads the next event of the packet into the right event definition.
 278      *
 279      * @return The event definition containing the event data that was just
 280      *         read.
 281      * @throws CTFReaderException
 282      *             If there was a problem reading the trace
 283      */
 284     public EventDefinition readNextEvent() throws CTFReaderException {
 285         /* Default values for those fields */
 286         long eventID = 0;
 287         long timestamp = 0;
 288
 289         if (lostEventsInThisPacket > lostSoFar) {
 290             EventDefinition eventDef = EventDeclaration.getLostEventDeclaration().createDefinition(streamInputReader);
 291             eventDef.setTimestamp(this.lastTimestamp);
 292             ++lostSoFar;
 293             return eventDef;
 294         }
 295
 296         final StructDefinition sehd = streamEventHeaderDef;
 297         final BitBuffer currentBitBuffer = bitBuffer;
 298
 299         /* Read the stream event header. */
 300         if (sehd != null) {
 301             sehd.read(currentBitBuffer);
 302
 303             /* Check for the event id. */
 304             Definition idDef = sehd.lookupDefinition("id"); //$NON-NLS-1$
 305             if (idDef instanceof SimpleDatatypeDefinition) {
 306                 eventID = ((SimpleDatatypeDefinition) idDef).getIntegerValue();
 307             } // else, eventID remains 0
 308
 309             /* Get the timestamp from the event header (may be overridden later on) */
 310             Definition timestampDef = sehd.lookupInteger("timestamp"); //$NON-NLS-1$
 311             if (timestampDef instanceof IntegerDefinition) {
 312                 timestamp = calculateTimestamp((IntegerDefinition) timestampDef);
 313             } // else timestamp remains 0
 314
 315             /* Check for the variant v. */
 316             Definition variantDef = sehd.lookupDefinition("v"); //$NON-NLS-1$
 317             if (variantDef instanceof VariantDefinition) {
 318
 319                 /* Get the variant current field */
 320                 StructDefinition variantCurrentField = (StructDefinition) ((VariantDefinition) variantDef).getCurrentField();
 321
 322                 /*
 323                  * Try to get the id field in the current field of the variant.
 324                  * If it is present, it overrides the previously read event id.
 325                  */
 326                 Definition idIntegerDef = variantCurrentField.lookupDefinition("id"); //$NON-NLS-1$
 327                 if (idIntegerDef instanceof IntegerDefinition) {
 328                     eventID = ((IntegerDefinition) idIntegerDef).getValue();
 329                 }
 330
 331                 /* Get the timestamp. This would overwrite any previous timestamp definition */
 332                 timestampDef = variantCurrentField.lookupDefinition("timestamp"); //$NON-NLS-1$
 333                 if (timestampDef instanceof IntegerDefinition) {
 334                     timestamp = calculateTimestamp((IntegerDefinition) timestampDef);
 335                 }
 336             }
 337         }
 338
 339         /* Read the stream event context. */
 340         if (streamEventContextDef != null) {
 341             streamEventContextDef.read(currentBitBuffer);
 342         }
 343
 344         /* Get the right event definition using the event id. */
 345         EventDefinition eventDef = events.get(eventID);
 346         if (eventDef == null) {
 347             throw new CTFReaderException("Incorrect event id : " + eventID); //$NON-NLS-1$
 348         }
 349
 350         /* Read the event context. */
 351         if (eventDef.getContext() != null) {
 352             eventDef.getContext().read(currentBitBuffer);
 353         }
 354
 355         /* Read the event fields. */
 356         if (eventDef.getFields() != null) {
 357             eventDef.getFields().read(currentBitBuffer);
 358         }
 359
 360         /*
 361          * Set the event timestamp using the timestamp calculated by
 362          * updateTimestamp.
 363          */
 364         eventDef.setTimestamp(timestamp);
 365
 366         return eventDef;
 367     }
 368
 369     /**
 370      * Calculates the timestamp value of the event, possibly using the timestamp
 371      * from the last event.
 372      *
 373      * @param timestampDef
 374      *            Integer definition of the timestamp.
 375      * @return The calculated timestamp value.
 376      */
 377     private long calculateTimestamp(IntegerDefinition timestampDef) {
 378         long newval;
 379         long majorasbitmask;
 380         int len = timestampDef.getDeclaration().getLength();
 381
 382         /*
 383          * If the timestamp length is 64 bits, it is a full timestamp.
 384          */
 385         if (timestampDef.getDeclaration().getLength() == 64) {
 386             lastTimestamp = timestampDef.getValue();
 387             return lastTimestamp;
 388         }
 389
 390         /*
 391          * Bit mask to keep / remove all old / new bits.
 392          */
 393         majorasbitmask = (1L << len) - 1;
 394
 395         /*
 396          * If the new value is smaller than the corresponding bits of the last
 397          * timestamp, we assume an overflow of the compact representation.
 398          */
 399         newval = timestampDef.getValue();
 400         if (newval < (lastTimestamp & majorasbitmask)) {
 401             newval = newval + (1L << len);
 402         }
 403
 404         /* Keep only the high bits of the old value */
 405         lastTimestamp = lastTimestamp & ~majorasbitmask;
 406
 407         /* Then add the low bits of the new value */
 408         lastTimestamp = lastTimestamp + newval;
 409
 410         return lastTimestamp;
 411     }
 412
 413     @Override
 414     public Definition lookupDefinition(String lookupPath) {
 415         // TODO Auto-generated method stub
 416         return null;
 417     }
 418 }