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

   1 /*******************************************************************************
   2  * Copyright (c) 2012, 2014 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.statesystem.core;
  14
  15 import java.util.List;
  16
  17 import org.eclipse.core.runtime.IProgressMonitor;
  18 import org.eclipse.linuxtools.statesystem.core.exceptions.AttributeNotFoundException;
  19 import org.eclipse.linuxtools.statesystem.core.exceptions.StateSystemDisposedException;
  20 import org.eclipse.linuxtools.statesystem.core.exceptions.StateValueTypeException;
  21 import org.eclipse.linuxtools.statesystem.core.exceptions.TimeRangeException;
  22 import org.eclipse.linuxtools.statesystem.core.interval.ITmfStateInterval;
  23 import org.eclipse.linuxtools.statesystem.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  * @since 3.0
  31  */
  32 public interface ITmfStateSystem {
  33
  34     /**
  35      * Get the ID of this state system.
  36      *
  37      * @return The state system's ID
  38      */
  39     String getSSID();
  40
  41     /**
  42      * Return the start time of this history. It usually matches the start time
  43      * of the original trace.
  44      *
  45      * @return The history's registered start time
  46      */
  47     long getStartTime();
  48
  49     /**
  50      * Return the current end time of the history.
  51      *
  52      * @return The current end time of this state history
  53      */
  54     long getCurrentEndTime();
  55
  56     /**
  57      * Check if the construction of this state system was cancelled or not. If
  58      * false is returned, it can mean that the building was finished
  59      * successfully, or that it is still ongoing. You can check independently
  60      * with {@link #waitUntilBuilt()} if it is finished or not.
  61      *
  62      * @return If the construction was cancelled or not. In true is returned, no
  63      *         queries should be run afterwards.
  64      */
  65     boolean isCancelled();
  66
  67     /**
  68      * While it's possible to query a state history that is being built,
  69      * sometimes we might want to wait until the construction is finished before
  70      * we start doing queries.
  71      *
  72      * This method blocks the calling thread until the history back-end is done
  73      * building. If it's already built (ie, opening a pre-existing file) this
  74      * should return immediately.
  75      *
  76      * You should always check with {@link #isCancelled()} if it is safe to
  77      * query this state system before doing queries.
  78      */
  79     void waitUntilBuilt();
  80
  81     /**
  82      * Wait until the state system construction is finished. Similar to
  83      * {@link #waitUntilBuilt()}, but we also specify a timeout. If the timeout
  84      * elapses before the construction is finished, the method will return.
  85      *
  86      * The return value determines if the return was due to the construction
  87      * finishing (true), or the timeout elapsing (false).
  88      *
  89      * This can be useful, for example, for a component doing queries
  90      * periodically to the system while it is being built.
  91      *
  92      * @param timeout
  93      *            Timeout value in milliseconds
  94      * @return True if the return was due to the construction finishing, false
  95      *         if it was because the timeout elapsed. Same logic as
  96      *         {@link java.util.concurrent.CountDownLatch#await(long, java.util.concurrent.TimeUnit)}
  97      */
  98     boolean waitUntilBuilt(long timeout);
  99
 100     /**
 101      * Notify the state system that the trace is being closed, so it should
 102      * clean up, close its files, etc.
 103      */
 104     void dispose();
 105
 106     /**
 107      * Return the current total amount of attributes in the system. This is also
 108      * equal to the quark that will be assigned to the next attribute that's
 109      * created.
 110      *
 111      * @return The current number of attributes in the system
 112      */
 113     int getNbAttributes();
 114
 115     /**
 116      * @name Read-only quark-getting methods
 117      */
 118
 119     /**
 120      * Basic quark-retrieving method. Pass an attribute in parameter as an array
 121      * of strings, the matching quark will be returned.
 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 attribute
 127      *            Attribute given as its full path in the Attribute Tree
 128      * @return The quark of the requested attribute, if it existed.
 129      * @throws AttributeNotFoundException
 130      *             This exception is thrown if the requested attribute simply
 131      *             did not exist in the system.
 132      */
 133     int getQuarkAbsolute(String... attribute)
 134             throws AttributeNotFoundException;
 135
 136     /**
 137      * "Relative path" quark-getting method. Instead of specifying a full path,
 138      * if you know the path is relative to another attribute for which you
 139      * already have the quark, use this for better performance.
 140      *
 141      * This is useful for cases where a lot of modifications or queries will
 142      * originate from the same branch of the attribute tree : the common part of
 143      * the path won't have to be re-hashed for every access.
 144      *
 145      * This version will NOT create any new attributes. If an invalid attribute
 146      * is requested, an exception will be thrown.
 147      *
 148      * @param startingNodeQuark
 149      *            The quark of the attribute from which 'subPath' originates.
 150      * @param subPath
 151      *            "Rest" of the path to get to the final attribute
 152      * @return The matching quark, if it existed
 153      * @throws AttributeNotFoundException
 154      *             If the quark is invalid
 155      */
 156     int getQuarkRelative(int startingNodeQuark, String... subPath)
 157             throws AttributeNotFoundException;
 158
 159     /**
 160      * Return the sub-attributes of the target attribute, as a List of quarks.
 161      *
 162      * @param quark
 163      *            The attribute of which you want to sub-attributes. You can use
 164      *            "-1" here to specify the root node.
 165      * @param recursive
 166      *            True if you want all recursive sub-attributes, false if you
 167      *            only want the first level.
 168      * @return A List of integers, matching the quarks of the sub-attributes.
 169      * @throws AttributeNotFoundException
 170      *             If the quark was not existing or invalid.
 171      */
 172     List<Integer> getSubAttributes(int quark, boolean recursive)
 173             throws AttributeNotFoundException;
 174
 175     /**
 176      * Return the sub-attributes of the target attribute, as a List of quarks,
 177      * similarly to {@link #getSubAttributes(int, boolean)}, but with an added
 178      * regex pattern to filter on the return attributes.
 179      *
 180      * @param quark
 181      *            The attribute of which you want to sub-attributes. You can use
 182      *            "-1" here to specify the root node.
 183      * @param recursive
 184      *            True if you want all recursive sub-attributes, false if you
 185      *            only want the first level. Note that the returned value will
 186      *            be flattened.
 187      * @param pattern
 188      *            The regular expression to match the attribute base name.
 189      * @return A List of integers, matching the quarks of the sub-attributes
 190      *         that match the regex. An empty list is returned if there is no
 191      *         matching attribute.
 192      * @throws AttributeNotFoundException
 193      *             If the 'quark' was not existing or invalid.
 194      */
 195     List<Integer> getSubAttributes(int quark, boolean recursive, String pattern)
 196             throws AttributeNotFoundException;
 197
 198     /**
 199      * Batch quark-retrieving method. This method allows you to specify a path
 200      * pattern which includes a wildcard "*" somewhere. It will check all the
 201      * existing attributes in the attribute tree and return those who match the
 202      * pattern.
 203      *
 204      * For example, passing ("Threads", "*", "Exec_mode") will return the list
 205      * of quarks for attributes "Threads/1000/Exec_mode",
 206      * "Threads/1500/Exec_mode", and so on, depending on what exists at this
 207      * time in the attribute tree.
 208      *
 209      * If no wildcard is specified, the behavior is the same as
 210      * getQuarkAbsolute() (except it will return a List with one entry). This
 211      * method will never create new attributes.
 212      *
 213      * Only one wildcard "*" is supported at this time.
 214      *
 215      * @param pattern
 216      *            The array of strings representing the pattern to look for. It
 217      *            should ideally contain one entry that is only a "*".
 218      * @return A List of attribute quarks, representing attributes that matched
 219      *         the pattern. If no attribute matched, the list will be empty (but
 220      *         not null).
 221      */
 222     List<Integer> getQuarks(String... pattern);
 223
 224     /**
 225      * Return the name assigned to this quark. This returns only the "basename",
 226      * not the complete path to this attribute.
 227      *
 228      * @param attributeQuark
 229      *            The quark for which we want the name
 230      * @return The name of the quark
 231      */
 232     String getAttributeName(int attributeQuark);
 233
 234     /**
 235      * This returns the slash-separated path of an attribute by providing its
 236      * quark
 237      *
 238      * @param attributeQuark
 239      *            The quark of the attribute we want
 240      * @return One single string separated with '/', like a filesystem path
 241      */
 242     String getFullAttributePath(int attributeQuark);
 243
 244     /**
 245      * Returns the parent quark of the attribute.
 246      *
 247      * @param attributeQuark
 248      *            The quark of the attribute
 249      * @return Quark of the parent attribute or <code>-1</code> if root quark or
 250      *         no parent.
 251      */
 252     int getParentAttributeQuark(int attributeQuark);
 253
 254     /**
 255      * @name Query methods
 256      */
 257
 258     /**
 259      * Returns the current state value we have (in the Transient State) for the
 260      * given attribute.
 261      *
 262      * This is useful even for a StateHistorySystem, as we are guaranteed it
 263      * will only do a memory access and not go look on disk (and we don't even
 264      * have to provide a timestamp!)
 265      *
 266      * @param attributeQuark
 267      *            For which attribute we want the current state
 268      * @return The State value that's "current" for this attribute
 269      * @throws AttributeNotFoundException
 270      *             If the requested attribute is invalid
 271      */
 272     ITmfStateValue queryOngoingState(int attributeQuark)
 273             throws AttributeNotFoundException;
 274
 275     /**
 276      * Get the start time of the current ongoing state, for the specified
 277      * attribute.
 278      *
 279      * @param attribute
 280      *            Quark of the attribute
 281      * @return The current start time of the ongoing state
 282      * @throws AttributeNotFoundException
 283      *             If the attribute is invalid
 284      */
 285     long getOngoingStartTime(int attribute)
 286             throws AttributeNotFoundException;
 287
 288     /**
 289      * Load the complete state information at time 't' into the returned List.
 290      * You can then get the intervals for single attributes by using
 291      * List.get(n), where 'n' is the quark of the attribute.
 292      *
 293      * On average if you need around 10 or more queries for the same timestamps,
 294      * use this method. If you need less than 10 (for example, running many
 295      * queries for the same attributes but at different timestamps), you might
 296      * be better using the querySingleState() methods instead.
 297      *
 298      * @param t
 299      *            We will recreate the state information to what it was at time
 300      *            t.
 301      * @return The List of intervals, where the offset = the quark
 302      * @throws TimeRangeException
 303      *             If the 't' parameter is outside of the range of the state
 304      *             history.
 305      * @throws StateSystemDisposedException
 306      *             If the query is sent after the state system has been disposed
 307      */
 308     List<ITmfStateInterval> queryFullState(long t)
 309             throws StateSystemDisposedException;
 310
 311     /**
 312      * Singular query method. This one does not update the whole stateInfo
 313      * vector, like queryFullState() does. It only searches for one specific
 314      * entry in the state history.
 315      *
 316      * It should be used when you only want very few entries, instead of the
 317      * whole state (or many entries, but all at different timestamps). If you do
 318      * request many entries all at the same time, you should use the
 319      * conventional queryFullState() + List.get() method.
 320      *
 321      * @param t
 322      *            The timestamp at which we want the state
 323      * @param attributeQuark
 324      *            Which attribute we want to get the state of
 325      * @return The StateInterval representing the state
 326      * @throws TimeRangeException
 327      *             If 't' is invalid
 328      * @throws AttributeNotFoundException
 329      *             If the requested quark does not exist in the model
 330      * @throws StateSystemDisposedException
 331      *             If the query is sent after the state system has been disposed
 332      */
 333     ITmfStateInterval querySingleState(long t, int attributeQuark)
 334             throws AttributeNotFoundException, StateSystemDisposedException;
 335
 336     /**
 337      * Convenience method to query attribute stacks (created with
 338      * pushAttribute()/popAttribute()). This will return the interval that is
 339      * currently at the top of the stack, or 'null' if that stack is currently
 340      * empty. It works similarly to querySingleState().
 341      *
 342      * To retrieve the other values in a stack, you can query the sub-attributes
 343      * manually.
 344      *
 345      * @param t
 346      *            The timestamp of the query
 347      * @param stackAttributeQuark
 348      *            The top-level stack-attribute (that was the target of
 349      *            pushAttribute() at creation time)
 350      * @return The interval that was at the top of the stack, or 'null' if the
 351      *         stack was empty.
 352      * @throws StateValueTypeException
 353      *             If the target attribute is not a valid stack attribute (if it
 354      *             has a string value for example)
 355      * @throws AttributeNotFoundException
 356      *             If the attribute was simply not found
 357      * @throws TimeRangeException
 358      *             If the given timestamp is invalid
 359      * @throws StateSystemDisposedException
 360      *             If the query is sent after the state system has been disposed
 361      */
 362     ITmfStateInterval querySingleStackTop(long t, int stackAttributeQuark)
 363             throws  AttributeNotFoundException, StateSystemDisposedException;
 364
 365     /**
 366      * Return a list of state intervals, containing the "history" of a given
 367      * attribute between timestamps t1 and t2. The list will be ordered by
 368      * ascending time.
 369      *
 370      * Note that contrary to queryFullState(), the returned list here is in the
 371      * "direction" of time (and not in the direction of attributes, as is the
 372      * case with queryFullState()).
 373      *
 374      * @param attributeQuark
 375      *            Which attribute this query is interested in
 376      * @param t1
 377      *            Start time of the range query
 378      * @param t2
 379      *            Target end time of the query. If t2 is greater than the end of
 380      *            the trace, we will return what we have up to the end of the
 381      *            history.
 382      * @return The List of state intervals that happened between t1 and t2
 383      * @throws TimeRangeException
 384      *             If t1 is invalid, or if t2 <= t1
 385      * @throws AttributeNotFoundException
 386      *             If the requested quark does not exist in the model.
 387      * @throws StateSystemDisposedException
 388      *             If the query is sent after the state system has been disposed
 389      */
 390     List<ITmfStateInterval> queryHistoryRange(int attributeQuark, long t1, long t2)
 391             throws AttributeNotFoundException, StateSystemDisposedException;
 392
 393     /**
 394      * Return the state history of a given attribute, but with at most one
 395      * update per "resolution". This can be useful for populating views (where
 396      * it's useless to have more than one query per pixel, for example). A
 397      * progress monitor can be used to cancel the query before completion.
 398      *
 399      * @param attributeQuark
 400      *            Which attribute this query is interested in
 401      * @param t1
 402      *            Start time of the range query
 403      * @param t2
 404      *            Target end time of the query. If t2 is greater than the end of
 405      *            the trace, we will return what we have up to the end of the
 406      *            history.
 407      * @param resolution
 408      *            The "step" of this query
 409      * @param monitor
 410      *            A progress monitor. If the monitor is canceled during a query,
 411      *            we will return what has been found up to that point. You can
 412      *            use "null" if you do not want to use one.
 413      * @return The List of states that happened between t1 and t2
 414      * @throws TimeRangeException
 415      *             If t1 is invalid, if t2 <= t1, or if the resolution isn't
 416      *             greater than zero.
 417      * @throws AttributeNotFoundException
 418      *             If the attribute doesn't exist
 419      * @throws StateSystemDisposedException
 420      *             If the query is sent after the state system has been disposed
 421      */
 422     List<ITmfStateInterval> queryHistoryRange(int attributeQuark,
 423             long t1, long t2, long resolution, IProgressMonitor monitor)
 424             throws AttributeNotFoundException, StateSystemDisposedException;
 425 }