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

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