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      * Notify the state system that the trace is being closed, so it should
  80      * clean up, close its files, etc.
  81      */
  82     void dispose();
  83
  84     /**
  85      * Return the current total amount of attributes in the system. This is also
  86      * equal to the quark that will be assigned to the next attribute that's
  87      * created.
  88      *
  89      * @return The current number of attributes in the system
  90      */
  91     int getNbAttributes();
  92
  93     /**
  94      * @name Read-only quark-getting methods
  95      */
  96
  97     /**
  98      * Basic quark-retrieving method. Pass an attribute in parameter as an array
  99      * of strings, the matching quark will be returned.
 100      *
 101      * This version will NOT create any new attributes. If an invalid attribute
 102      * is requested, an exception will be thrown.
 103      *
 104      * @param attribute
 105      *            Attribute given as its full path in the Attribute Tree
 106      * @return The quark of the requested attribute, if it existed.
 107      * @throws AttributeNotFoundException
 108      *             This exception is thrown if the requested attribute simply
 109      *             did not exist in the system.
 110      */
 111     int getQuarkAbsolute(String... attribute)
 112             throws AttributeNotFoundException;
 113
 114     /**
 115      * "Relative path" quark-getting method. Instead of specifying a full path,
 116      * if you know the path is relative to another attribute for which you
 117      * already have the quark, use this for better performance.
 118      *
 119      * This is useful for cases where a lot of modifications or queries will
 120      * originate from the same branch of the attribute tree : the common part of
 121      * the path won't have to be re-hashed for every access.
 122      *
 123      * This version will NOT create any new attributes. If an invalid attribute
 124      * is requested, an exception will be thrown.
 125      *
 126      * @param startingNodeQuark
 127      *            The quark of the attribute from which 'subPath' originates.
 128      * @param subPath
 129      *            "Rest" of the path to get to the final attribute
 130      * @return The matching quark, if it existed
 131      * @throws AttributeNotFoundException
 132      *             If the quark is invalid
 133      */
 134     int getQuarkRelative(int startingNodeQuark, String... subPath)
 135             throws AttributeNotFoundException;
 136
 137     /**
 138      * Return the sub-attributes of the target attribute, as a List of quarks.
 139      *
 140      * @param quark
 141      *            The attribute of which you want to sub-attributes. You can use
 142      *            "-1" here to specify the root node.
 143      * @param recursive
 144      *            True if you want all recursive sub-attributes, false if you
 145      *            only want the first level.
 146      * @return A List of integers, matching the quarks of the sub-attributes.
 147      * @throws AttributeNotFoundException
 148      *             If the quark was not existing or invalid.
 149      */
 150     List<Integer> getSubAttributes(int quark, boolean recursive)
 151             throws AttributeNotFoundException;
 152
 153     /**
 154      * Batch quark-retrieving method. This method allows you to specify a path
 155      * pattern which includes a wildcard "*" somewhere. It will check all the
 156      * existing attributes in the attribute tree and return those who match the
 157      * pattern.
 158      *
 159      * For example, passing ("Threads", "*", "Exec_mode") will return the list
 160      * of quarks for attributes "Threads/1000/Exec_mode",
 161      * "Threads/1500/Exec_mode", and so on, depending on what exists at this
 162      * time in the attribute tree.
 163      *
 164      * If no wildcard is specified, the behavior is the same as
 165      * getQuarkAbsolute() (except it will return a List with one entry). This
 166      * method will never create new attributes.
 167      *
 168      * Only one wildcard "*" is supported at this time.
 169      *
 170      * @param pattern
 171      *            The array of strings representing the pattern to look for. It
 172      *            should ideally contain one entry that is only a "*".
 173      * @return A List of attribute quarks, representing attributes that matched
 174      *         the pattern. If no attribute matched, the list will be empty (but
 175      *         not null).
 176      */
 177     List<Integer> getQuarks(String... pattern);
 178
 179     /**
 180      * Return the name assigned to this quark. This returns only the "basename",
 181      * not the complete path to this attribute.
 182      *
 183      * @param attributeQuark
 184      *            The quark for which we want the name
 185      * @return The name of the quark
 186      */
 187     String getAttributeName(int attributeQuark);
 188
 189     /**
 190      * This returns the slash-separated path of an attribute by providing its
 191      * quark
 192      *
 193      * @param attributeQuark
 194      *            The quark of the attribute we want
 195      * @return One single string separated with '/', like a filesystem path
 196      */
 197     String getFullAttributePath(int attributeQuark);
 198
 199     /**
 200      * @name Query methods
 201      */
 202
 203     /**
 204      * Returns the current state value we have (in the Transient State) for the
 205      * given attribute.
 206      *
 207      * This is useful even for a StateHistorySystem, as we are guaranteed it
 208      * will only do a memory access and not go look on disk (and we don't even
 209      * have to provide a timestamp!)
 210      *
 211      * @param attributeQuark
 212      *            For which attribute we want the current state
 213      * @return The State value that's "current" for this attribute
 214      * @throws AttributeNotFoundException
 215      *             If the requested attribute is invalid
 216      */
 217     ITmfStateValue queryOngoingState(int attributeQuark)
 218             throws AttributeNotFoundException;
 219
 220     /**
 221      * Get the start time of the current ongoing state, for the specified
 222      * attribute.
 223      *
 224      * @param attribute
 225      *            Quark of the attribute
 226      * @return The current start time of the ongoing state
 227      * @throws AttributeNotFoundException
 228      *             If the attribute is invalid
 229      */
 230     long getOngoingStartTime(int attribute)
 231             throws AttributeNotFoundException;
 232
 233     /**
 234      * Load the complete state information at time 't' into the returned List.
 235      * You can then get the intervals for single attributes by using
 236      * List.get(n), where 'n' is the quark of the attribute.
 237      *
 238      * On average if you need around 10 or more queries for the same timestamps,
 239      * use this method. If you need less than 10 (for example, running many
 240      * queries for the same attributes but at different timestamps), you might
 241      * be better using the querySingleState() methods instead.
 242      *
 243      * @param t
 244      *            We will recreate the state information to what it was at time
 245      *            t.
 246      * @return The List of intervals, where the offset = the quark
 247      * @throws TimeRangeException
 248      *             If the 't' parameter is outside of the range of the state
 249      *             history.
 250      * @throws StateSystemDisposedException
 251      *             If the query is sent after the state system has been disposed
 252      */
 253     List<ITmfStateInterval> queryFullState(long t)
 254             throws TimeRangeException, StateSystemDisposedException;
 255
 256     /**
 257      * Singular query method. This one does not update the whole stateInfo
 258      * vector, like queryFullState() does. It only searches for one specific
 259      * entry in the state history.
 260      *
 261      * It should be used when you only want very few entries, instead of the
 262      * whole state (or many entries, but all at different timestamps). If you do
 263      * request many entries all at the same time, you should use the
 264      * conventional queryFullState() + List.get() method.
 265      *
 266      * @param t
 267      *            The timestamp at which we want the state
 268      * @param attributeQuark
 269      *            Which attribute we want to get the state of
 270      * @return The StateInterval representing the state
 271      * @throws TimeRangeException
 272      *             If 't' is invalid
 273      * @throws AttributeNotFoundException
 274      *             If the requested quark does not exist in the model
 275      * @throws StateSystemDisposedException
 276      *             If the query is sent after the state system has been disposed
 277      */
 278     ITmfStateInterval querySingleState(long t, int attributeQuark)
 279             throws AttributeNotFoundException, TimeRangeException,
 280             StateSystemDisposedException;
 281
 282     /**
 283      * Convenience method to query attribute stacks (created with
 284      * pushAttribute()/popAttribute()). This will return the interval that is
 285      * currently at the top of the stack, or 'null' if that stack is currently
 286      * empty. It works similarly to querySingleState().
 287      *
 288      * To retrieve the other values in a stack, you can query the sub-attributes
 289      * manually.
 290      *
 291      * @param t
 292      *            The timestamp of the query
 293      * @param stackAttributeQuark
 294      *            The top-level stack-attribute (that was the target of
 295      *            pushAttribute() at creation time)
 296      * @return The interval that was at the top of the stack, or 'null' if the
 297      *         stack was empty.
 298      * @throws StateValueTypeException
 299      *             If the target attribute is not a valid stack attribute (if it
 300      *             has a string value for example)
 301      * @throws AttributeNotFoundException
 302      *             If the attribute was simply not found
 303      * @throws TimeRangeException
 304      *             If the given timestamp is invalid
 305      * @throws StateSystemDisposedException
 306      *             If the query is sent after the state system has been disposed
 307      * @since 2.0
 308      */
 309     ITmfStateInterval querySingleStackTop(long t, int stackAttributeQuark)
 310             throws StateValueTypeException, AttributeNotFoundException,
 311             TimeRangeException, StateSystemDisposedException;
 312
 313     /**
 314      * Return a list of state intervals, containing the "history" of a given
 315      * attribute between timestamps t1 and t2. The list will be ordered by
 316      * ascending time.
 317      *
 318      * Note that contrary to queryFullState(), the returned list here is in the
 319      * "direction" of time (and not in the direction of attributes, as is the
 320      * case with queryFullState()).
 321      *
 322      * @param attributeQuark
 323      *            Which attribute this query is interested in
 324      * @param t1
 325      *            Start time of the range query
 326      * @param t2
 327      *            Target end time of the query. If t2 is greater than the end of
 328      *            the trace, we will return what we have up to the end of the
 329      *            history.
 330      * @return The List of state intervals that happened between t1 and t2
 331      * @throws TimeRangeException
 332      *             If t1 is invalid, or if t2 <= t1
 333      * @throws AttributeNotFoundException
 334      *             If the requested quark does not exist in the model.
 335      * @throws StateSystemDisposedException
 336      *             If the query is sent after the state system has been disposed
 337      */
 338     List<ITmfStateInterval> queryHistoryRange(int attributeQuark,
 339             long t1, long t2) throws TimeRangeException,
 340             AttributeNotFoundException, StateSystemDisposedException;
 341
 342     /**
 343      * Return the state history of a given attribute, but with at most one
 344      * update per "resolution". This can be useful for populating views (where
 345      * it's useless to have more than one query per pixel, for example). A
 346      * progress monitor can be used to cancel the query before completion.
 347      *
 348      * @param attributeQuark
 349      *            Which attribute this query is interested in
 350      * @param t1
 351      *            Start time of the range query
 352      * @param t2
 353      *            Target end time of the query. If t2 is greater than the end of
 354      *            the trace, we will return what we have up to the end of the
 355      *            history.
 356      * @param resolution
 357      *            The "step" of this query
 358      * @param monitor
 359      *            A progress monitor. If the monitor is canceled during a query,
 360      *            we will return what has been found up to that point. You can
 361      *            use "null" if you do not want to use one.
 362      * @return The List of states that happened between t1 and t2
 363      * @throws TimeRangeException
 364      *             If t1 is invalid, if t2 <= t1, or if the resolution isn't
 365      *             greater than zero.
 366      * @throws AttributeNotFoundException
 367      *             If the attribute doesn't exist
 368      * @throws StateSystemDisposedException
 369      *             If the query is sent after the state system has been disposed
 370      * @since 2.0
 371      */
 372     List<ITmfStateInterval> queryHistoryRange(int attributeQuark,
 373             long t1, long t2, long resolution, IProgressMonitor monitor)
 374             throws TimeRangeException, AttributeNotFoundException,
 375             StateSystemDisposedException;
 376 }