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