org.eclipse.linuxtools.tmf.core/src/org/eclipse/linuxtools/tmf/core/statesystem/ITmfStateSystem.java

   1 /*******************************************************************************
   2  * Copyright (c) 2012, 2013 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made 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:
  10  *   Alexandre Montplaisir - Initial API
  11  ******************************************************************************/
  12
  13 package org.eclipse.linuxtools.tmf.core.statesystem;
  14
  15 import java.util.List;
  16
  17 import org.eclipse.core.runtime.IProgressMonitor;
  18 import org.eclipse.linuxtools.tmf.core.exceptions.AttributeNotFoundException;
  19 import org.eclipse.linuxtools.tmf.core.exceptions.StateSystemDisposedException;
  20 import org.eclipse.linuxtools.tmf.core.exceptions.StateValueTypeException;
  21 import org.eclipse.linuxtools.tmf.core.exceptions.TimeRangeException;
  22 import org.eclipse.linuxtools.tmf.core.interval.ITmfStateInterval;
  23 import org.eclipse.linuxtools.tmf.core.statevalue.ITmfStateValue;
  24
  25 /**
  26  * This is the read-only interface to the generic state system. It contains all
  27  * the read-only quark-getting methods, as well as the history-querying ones.
  28  *
  29  * @author Alexandre Montplaisir
  30  * @version 2.0
  31  * @since 2.0
  32  */
  33 public interface ITmfStateSystem {
  34
  35     /**
  36      * Return the start time of this history. It usually matches the start time
  37      * of the original trace.
  38      *
  39      * @return The history's registered start time
  40      */
  41     long getStartTime();
  42
  43     /**
  44      * Return the current end time of the history.
  45      *
  46      * @return The current end time of this state history
  47      */
  48     long getCurrentEndTime();
  49
  50     /**
  51      * Check if the construction of this state system was cancelled or not. If
  52      * false is returned, it can mean that the building was finished
  53      * successfully, or that it is still ongoing. You can check independently
  54      * with {@link #waitUntilBuilt()} if it is finished or not.
  55      *
  56      * @return If the construction was cancelled or not. In true is returned, no
  57      *         queries should be run afterwards.
  58      * @since 3.0
  59      */
  60     boolean isCancelled();
  61
  62     /**
  63      * While it's possible to query a state history that is being built,
  64      * sometimes we might want to wait until the construction is finished before
  65      * we start doing queries.
  66      *
  67      * This method blocks the calling thread until the history back-end is done
  68      * building. If it's already built (ie, opening a pre-existing file) this
  69      * should return immediately.
  70      *
  71      * You should always check with {@link #isCancelled()} if it is safe to
  72      * query this state system before doing queries.
  73      *
  74      * @since 3.0
  75      */
  76     void waitUntilBuilt();
  77
  78     /**
  79      * Wait until the state system construction is finished. Similar to
  80      * {@link #waitUntilBuilt()}, but we also specify a timeout. If the timeout
  81      * elapses before the construction is finished, the method will return.
  82      *
  83      * The return value determines if the return was due to the construction
  84      * finishing (true), or the timeout elapsing (false).
  85      *
  86      * This can be useful, for example, for a component doing queries
  87      * periodically to the system while it is being built.
  88      *
  89      * @param timeout
  90      *            Timeout value in milliseconds
  91      * @return True if the return was due to the construction finishing, false
  92      *         if it was because the timeout elapsed. Same logic as
  93      *         {@link java.util.concurrent.CountDownLatch#await(long, java.util.concurrent.TimeUnit)}
  94      * @since 3.0
  95      */
  96     boolean waitUntilBuilt(long timeout);
  97
  98     /**
  99      * Notify the state system that the trace is being closed, so it should
 100      * clean up, close its files, etc.
 101      */
 102     void dispose();
 103
 104     /**
 105      * Return the current total amount of attributes in the system. This is also
 106      * equal to the quark that will be assigned to the next attribute that's
 107      * created.
 108      *
 109      * @return The current number of attributes in the system
 110      */
 111     int getNbAttributes();
 112
 113     /**
 114      * @name Read-only quark-getting methods
 115      */
 116
 117     /**
 118      * Basic quark-retrieving method. Pass an attribute in parameter as an array
 119      * of strings, the matching quark will be returned.
 120      *
 121      * This version will NOT create any new attributes. If an invalid attribute
 122      * is requested, an exception will be thrown.
 123      *
 124      * @param attribute
 125      *            Attribute given as its full path in the Attribute Tree
 126      * @return The quark of the requested attribute, if it existed.
 127      * @throws AttributeNotFoundException
 128      *             This exception is thrown if the requested attribute simply
 129      *             did not exist in the system.
 130      */
 131     int getQuarkAbsolute(String... attribute)
 132             throws AttributeNotFoundException;
 133
 134     /**
 135      * "Relative path" quark-getting method. Instead of specifying a full path,
 136      * if you know the path is relative to another attribute for which you
 137      * already have the quark, use this for better performance.
 138      *
 139      * This is useful for cases where a lot of modifications or queries will
 140      * originate from the same branch of the attribute tree : the common part of
 141      * the path won't have to be re-hashed for every access.
 142      *
 143      * This version will NOT create any new attributes. If an invalid attribute
 144      * is requested, an exception will be thrown.
 145      *
 146      * @param startingNodeQuark
 147      *            The quark of the attribute from which 'subPath' originates.
 148      * @param subPath
 149      *            "Rest" of the path to get to the final attribute
 150      * @return The matching quark, if it existed
 151      * @throws AttributeNotFoundException
 152      *             If the quark is invalid
 153      */
 154     int getQuarkRelative(int startingNodeQuark, String... subPath)
 155             throws AttributeNotFoundException;
 156
 157     /**
 158      * Return the sub-attributes of the target attribute, as a List of quarks.
 159      *
 160      * @param quark
 161      *            The attribute of which you want to sub-attributes. You can use
 162      *            "-1" here to specify the root node.
 163      * @param recursive
 164      *            True if you want all recursive sub-attributes, false if you
 165      *            only want the first level.
 166      * @return A List of integers, matching the quarks of the sub-attributes.
 167      * @throws AttributeNotFoundException
 168      *             If the quark was not existing or invalid.
 169      */
 170     List<Integer> getSubAttributes(int quark, boolean recursive)
 171             throws AttributeNotFoundException;
 172
 173     /**
 174      * Batch quark-retrieving method. This method allows you to specify a path
 175      * pattern which includes a wildcard "*" somewhere. It will check all the
 176      * existing attributes in the attribute tree and return those who match the
 177      * pattern.
 178      *
 179      * For example, passing ("Threads", "*", "Exec_mode") will return the list
 180      * of quarks for attributes "Threads/1000/Exec_mode",
 181      * "Threads/1500/Exec_mode", and so on, depending on what exists at this
 182      * time in the attribute tree.
 183      *
 184      * If no wildcard is specified, the behavior is the same as
 185      * getQuarkAbsolute() (except it will return a List with one entry). This
 186      * method will never create new attributes.
 187      *
 188      * Only one wildcard "*" is supported at this time.
 189      *
 190      * @param pattern
 191      *            The array of strings representing the pattern to look for. It
 192      *            should ideally contain one entry that is only a "*".
 193      * @return A List of attribute quarks, representing attributes that matched
 194      *         the pattern. If no attribute matched, the list will be empty (but
 195      *         not null).
 196      */
 197     List<Integer> getQuarks(String... pattern);
 198
 199     /**
 200      * Return the name assigned to this quark. This returns only the "basename",
 201      * not the complete path to this attribute.
 202      *
 203      * @param attributeQuark
 204      *            The quark for which we want the name
 205      * @return The name of the quark
 206      */
 207     String getAttributeName(int attributeQuark);
 208
 209     /**
 210      * This returns the slash-separated path of an attribute by providing its
 211      * quark
 212      *
 213      * @param attributeQuark
 214      *            The quark of the attribute we want
 215      * @return One single string separated with '/', like a filesystem path
 216      */
 217     String getFullAttributePath(int attributeQuark);
 218
 219     /**
 220      * @name Query methods
 221      */
 222
 223     /**
 224      * Returns the current state value we have (in the Transient State) for the
 225      * given attribute.
 226      *
 227      * This is useful even for a StateHistorySystem, as we are guaranteed it
 228      * will only do a memory access and not go look on disk (and we don't even
 229      * have to provide a timestamp!)
 230      *
 231      * @param attributeQuark
 232      *            For which attribute we want the current state
 233      * @return The State value that's "current" for this attribute
 234      * @throws AttributeNotFoundException
 235      *             If the requested attribute is invalid
 236      */
 237     ITmfStateValue queryOngoingState(int attributeQuark)
 238             throws AttributeNotFoundException;
 239
 240     /**
 241      * Get the start time of the current ongoing state, for the specified
 242      * attribute.
 243      *
 244      * @param attribute
 245      *            Quark of the attribute
 246      * @return The current start time of the ongoing state
 247      * @throws AttributeNotFoundException
 248      *             If the attribute is invalid
 249      */
 250     long getOngoingStartTime(int attribute)
 251             throws AttributeNotFoundException;
 252
 253     /**
 254      * Load the complete state information at time 't' into the returned List.
 255      * You can then get the intervals for single attributes by using
 256      * List.get(n), where 'n' is the quark of the attribute.
 257      *
 258      * On average if you need around 10 or more queries for the same timestamps,
 259      * use this method. If you need less than 10 (for example, running many
 260      * queries for the same attributes but at different timestamps), you might
 261      * be better using the querySingleState() methods instead.
 262      *
 263      * @param t
 264      *            We will recreate the state information to what it was at time
 265      *            t.
 266      * @return The List of intervals, where the offset = the quark
 267      * @throws TimeRangeException
 268      *             If the 't' parameter is outside of the range of the state
 269      *             history.
 270      * @throws StateSystemDisposedException
 271      *             If the query is sent after the state system has been disposed
 272      */
 273     List<ITmfStateInterval> queryFullState(long t)
 274             throws TimeRangeException, StateSystemDisposedException;
 275
 276     /**
 277      * Singular query method. This one does not update the whole stateInfo
 278      * vector, like queryFullState() does. It only searches for one specific
 279      * entry in the state history.
 280      *
 281      * It should be used when you only want very few entries, instead of the
 282      * whole state (or many entries, but all at different timestamps). If you do
 283      * request many entries all at the same time, you should use the
 284      * conventional queryFullState() + List.get() method.
 285      *
 286      * @param t
 287      *            The timestamp at which we want the state
 288      * @param attributeQuark
 289      *            Which attribute we want to get the state of
 290      * @return The StateInterval representing the state
 291      * @throws TimeRangeException
 292      *             If 't' is invalid
 293      * @throws AttributeNotFoundException
 294      *             If the requested quark does not exist in the model
 295      * @throws StateSystemDisposedException
 296      *             If the query is sent after the state system has been disposed
 297      */
 298     ITmfStateInterval querySingleState(long t, int attributeQuark)
 299             throws AttributeNotFoundException, TimeRangeException,
 300             StateSystemDisposedException;
 301
 302     /**
 303      * Convenience method to query attribute stacks (created with
 304      * pushAttribute()/popAttribute()). This will return the interval that is
 305      * currently at the top of the stack, or 'null' if that stack is currently
 306      * empty. It works similarly to querySingleState().
 307      *
 308      * To retrieve the other values in a stack, you can query the sub-attributes
 309      * manually.
 310      *
 311      * @param t
 312      *            The timestamp of the query
 313      * @param stackAttributeQuark
 314      *            The top-level stack-attribute (that was the target of
 315      *            pushAttribute() at creation time)
 316      * @return The interval that was at the top of the stack, or 'null' if the
 317      *         stack was empty.
 318      * @throws StateValueTypeException
 319      *             If the target attribute is not a valid stack attribute (if it
 320      *             has a string value for example)
 321      * @throws AttributeNotFoundException
 322      *             If the attribute was simply not found
 323      * @throws TimeRangeException
 324      *             If the given timestamp is invalid
 325      * @throws StateSystemDisposedException
 326      *             If the query is sent after the state system has been disposed
 327      * @since 2.0
 328      */
 329     ITmfStateInterval querySingleStackTop(long t, int stackAttributeQuark)
 330             throws StateValueTypeException, AttributeNotFoundException,
 331             TimeRangeException, StateSystemDisposedException;
 332
 333     /**
 334      * Return a list of state intervals, containing the "history" of a given
 335      * attribute between timestamps t1 and t2. The list will be ordered by
 336      * ascending time.
 337      *
 338      * Note that contrary to queryFullState(), the returned list here is in the
 339      * "direction" of time (and not in the direction of attributes, as is the
 340      * case with queryFullState()).
 341      *
 342      * @param attributeQuark
 343      *            Which attribute this query is interested in
 344      * @param t1
 345      *            Start time of the range query
 346      * @param t2
 347      *            Target end time of the query. If t2 is greater than the end of
 348      *            the trace, we will return what we have up to the end of the
 349      *            history.
 350      * @return The List of state intervals that happened between t1 and t2
 351      * @throws TimeRangeException
 352      *             If t1 is invalid, or if t2 <= t1
 353      * @throws AttributeNotFoundException
 354      *             If the requested quark does not exist in the model.
 355      * @throws StateSystemDisposedException
 356      *             If the query is sent after the state system has been disposed
 357      */
 358     List<ITmfStateInterval> queryHistoryRange(int attributeQuark,
 359             long t1, long t2) throws TimeRangeException,
 360             AttributeNotFoundException, StateSystemDisposedException;
 361
 362     /**
 363      * Return the state history of a given attribute, but with at most one
 364      * update per "resolution". This can be useful for populating views (where
 365      * it's useless to have more than one query per pixel, for example). A
 366      * progress monitor can be used to cancel the query before completion.
 367      *
 368      * @param attributeQuark
 369      *            Which attribute this query is interested in
 370      * @param t1
 371      *            Start time of the range query
 372      * @param t2
 373      *            Target end time of the query. If t2 is greater than the end of
 374      *            the trace, we will return what we have up to the end of the
 375      *            history.
 376      * @param resolution
 377      *            The "step" of this query
 378      * @param monitor
 379      *            A progress monitor. If the monitor is canceled during a query,
 380      *            we will return what has been found up to that point. You can
 381      *            use "null" if you do not want to use one.
 382      * @return The List of states that happened between t1 and t2
 383      * @throws TimeRangeException
 384      *             If t1 is invalid, if t2 <= t1, or if the resolution isn't
 385      *             greater than zero.
 386      * @throws AttributeNotFoundException
 387      *             If the attribute doesn't exist
 388      * @throws StateSystemDisposedException
 389      *             If the query is sent after the state system has been disposed
 390      * @since 2.0
 391      */
 392     List<ITmfStateInterval> queryHistoryRange(int attributeQuark,
 393             long t1, long t2, long resolution, IProgressMonitor monitor)
 394             throws TimeRangeException, AttributeNotFoundException,
 395             StateSystemDisposedException;
 396 }