org.eclipse.linuxtools.tmf.core/src/org/eclipse/linuxtools/tmf/core/statesystem/IStateSystemQuerier.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.linuxtools.tmf.core.exceptions.AttributeNotFoundException;
  18 import org.eclipse.linuxtools.tmf.core.exceptions.TimeRangeException;
  19 import org.eclipse.linuxtools.tmf.core.interval.ITmfStateInterval;
  20 import org.eclipse.linuxtools.tmf.core.statevalue.ITmfStateValue;
  21
  22 /**
  23  * This is the read-only interface to the generic state system. It contains all
  24  * the read-only quark-getting methods, as well as the history-querying ones.
  25  *
  26  * @author alexmont
  27  *
  28  */
  29 public interface IStateSystemQuerier {
  30
  31     /**
  32      * Return the start time of this history. It usually matches the start time
  33      * of the original trace.
  34      *
  35      * @return The history's registered start time
  36      */
  37     public long getStartTime();
  38
  39     /**
  40      * Return the current end time of the history.
  41      *
  42      * @return
  43      */
  44     public long getCurrentEndTime();
  45
  46     /**
  47      * Return the current total amount of attributes in the system.
  48      *
  49      * @return
  50      */
  51     public int getNbAttributes();
  52
  53     /**
  54      * @name Read-only quark-getting methods
  55      */
  56
  57     /**
  58      * Basic quark-retrieving method. Pass an attribute in parameter as an array
  59      * of strings, the matching quark will be returned.
  60      *
  61      * This version will NOT create any new attributes. If an invalid attribute
  62      * is requested, an exception will be thrown.
  63      *
  64      * @param attribute
  65      *            Attribute given as its full path in the Attribute Tree
  66      * @return The quark of the requested attribute, if it existed.
  67      * @throws AttributeNotFoundException
  68      *             This exception is thrown if the requested attribute simply
  69      *             did not exist in the system.
  70      */
  71     public int getQuarkAbsolute(String... attribute)
  72             throws AttributeNotFoundException;
  73
  74     /**
  75      * "Relative path" quark-getting method. Instead of specifying a full path,
  76      * if you know the path is relative to another attribute for which you
  77      * already have the quark, use this for better performance.
  78      *
  79      * This is useful for cases where a lot of modifications or queries will
  80      * originate from the same branch of the attribute tree : the common part of
  81      * the path won't have to be re-hashed for every access.
  82      *
  83      * This version will NOT create any new attributes. If an invalid attribute
  84      * is requested, an exception will be thrown.
  85      *
  86      * @param startingNodeQuark
  87      *            The quark of the attribute from which 'subPath' originates.
  88      * @param subPath
  89      *            "Rest" of the path to get to the final attribute
  90      * @return The matching quark, if it existed
  91      * @throws AttributeNotFoundException
  92      */
  93     public int getQuarkRelative(int startingNodeQuark, String... subPath)
  94             throws AttributeNotFoundException;
  95
  96     /**
  97      * Return the sub-attributes of the target attribute, as a List of quarks.
  98      *
  99      * @param quark
 100      *            The attribute of which you want to sub-attributes. You can use
 101      *            "-1" here to specify the root node.
 102      * @param recursive
 103      *            True if you want all recursive sub-attributes, false if you
 104      *            only want the first level.
 105      * @return A List of integers, matching the quarks of the sub-attributes.
 106      * @throws AttributeNotFoundException
 107      *             If the quark was not existing or invalid.
 108      */
 109     public List<Integer> getSubAttributes(int quark, boolean recursive)
 110             throws AttributeNotFoundException;
 111
 112     /**
 113      * Batch quark-retrieving method. This method allows you to specify a path
 114      * pattern which includes a wildcard "*" somewhere. It will check all the
 115      * existing attributes in the attribute tree and return those who match the
 116      * pattern.
 117      *
 118      * For example, passing ("Threads", "*", "Exec_mode") will return the list
 119      * of quarks for attributes "Threads/1000/Exec_mode",
 120      * "Threads/1500/Exec_mode", and so on, depending on what exists at this
 121      * time in the attribute tree.
 122      *
 123      * If no wildcard is specified, the behavior is the same as
 124      * getQuarkAbsolute() (except it will return a List with one entry). This
 125      * method will never create new attributes.
 126      *
 127      * Only one wildcard "*" is supported at this time.
 128      *
 129      * @param pattern
 130      *            The array of strings representing the pattern to look for. It
 131      *            should ideally contain one entry that is only a "*".
 132      * @return A List of attribute quarks, representing attributes that matched
 133      *         the pattern. If no attribute matched, the list will be empty (but
 134      *         not null).
 135      */
 136     public List<Integer> getQuarks(String... pattern);
 137
 138     /**
 139      * Return the name assigned to this quark. This returns only the "basename",
 140      * not the complete path to this attribute.
 141      *
 142      * @param attributeQuark
 143      *            The quark for which we want the name
 144      * @return The name of the quark
 145      */
 146     public String getAttributeName(int attributeQuark);
 147
 148     /**
 149      * This returns the slash-separated path of an attribute by providing its
 150      * quark
 151      *
 152      * @param attributeQuark
 153      *            The quark of the attribute we want
 154      * @return One single string separated with '/', like a filesystem path
 155      */
 156     public String getFullAttributePath(int attributeQuark);
 157
 158     /**
 159      * @name Query methods
 160      */
 161
 162     /**
 163      * Returns the current state value we have (in the Transient State) for the
 164      * given attribute.
 165      *
 166      * This is useful even for a StateHistorySystem, as we are guaranteed it
 167      * will only do a memory access and not go look on disk (and we don't even
 168      * have to provide a timestamp!)
 169      *
 170      * @param attributeQuark
 171      *            For which attribute we want the current state
 172      * @return The State value that's "current" for this attribute
 173      * @throws AttributeNotFoundException
 174      *             If the requested attribute is invalid
 175      */
 176     public ITmfStateValue queryOngoingState(int attributeQuark)
 177             throws AttributeNotFoundException;
 178
 179     /**
 180      * Load the complete state information at time 't' into the returned List.
 181      * You can then get the intervals for single attributes by using
 182      * List.get(n), where 'n' is the quark of the attribute.
 183      *
 184      * On average if you need around 10 or more queries for the same timestamps,
 185      * use this method. If you need less than 10 (for example, running many
 186      * queries for the same attributes but at different timestamps), you might
 187      * be better using the querySingleState() methods instead.
 188      *
 189      * @param t
 190      *            We will recreate the state information to what it was at time
 191      *            t.
 192      * @throws TimeRangeException
 193      *             If the 't' parameter is outside of the range of the state
 194      *             history.
 195      */
 196     public List<ITmfStateInterval> loadStateAtTime(long t)
 197             throws TimeRangeException;
 198
 199     /**
 200      * Singular query method. This one does not update the whole stateInfo
 201      * vector, like loadStateAtTimes() does. It only searches for one specific
 202      * entry in the state history.
 203      *
 204      * It should be used when you only want very few entries, instead of the
 205      * whole state (or many entries, but all at different timestamps). If you do
 206      * request many entries all at the same time, you should use the
 207      * conventional loadStateAtTime() + List.get() method.
 208      *
 209      * @param t
 210      *            The timestamp at which we want the state
 211      * @param attributeQuark
 212      *            Which attribute we want to get the state of
 213      * @return The StateInterval representing the state
 214      * @throws TimeRangeException
 215      *             If 't' is invalid
 216      * @throws AttributeNotFoundException
 217      *             If the requested quark does not exist in the model
 218      */
 219     public ITmfStateInterval querySingleState(long t, int attributeQuark)
 220             throws AttributeNotFoundException, TimeRangeException;
 221
 222     /**
 223      * Return a list of state intervals, containing the "history" of a given
 224      * attribute between timestamps t1 and t2. The list will be ordered by
 225      * ascending time.
 226      *
 227      * Note that contrary to loadStateAtTime(), the returned list here is in the
 228      * "direction" of time (and not in the direction of attributes, as is the
 229      * case with loadStateAtTime()).
 230      *
 231      * @param attributeQuark
 232      *            Which attribute this query is interested in
 233      * @param t1
 234      *            Start time of the range query
 235      * @param t2
 236      *            Target end time of the query. If t2 is greater than the end of
 237      *            the trace, we will return what we have up to the end of the
 238      *            history.
 239      * @return The List of state intervals that happened between t1 and t2
 240      * @throws TimeRangeException
 241      *             If t1 is invalid, or if t2 <= t1
 242      * @throws AttributeNotFoundException
 243      *             If the requested quark does not exist in the model.
 244      */
 245     public List<ITmfStateInterval> queryHistoryRange(int attributeQuark,
 246             long t1, long t2) throws TimeRangeException,
 247             AttributeNotFoundException;
 248
 249     /**
 250      * Return the state history of a given attribute, but with at most one
 251      * update per "resolution". This can be useful for populating views (where
 252      * it's useless to have more than one query per pixel, for example).
 253      *
 254      * @param attributeQuark
 255      *            Which attribute this query is interested in
 256      * @param t1
 257      *            Start time of the range query
 258      * @param t2
 259      *            Target end time of the query. If t2 is greater than the end of
 260      *            the trace, we will return what we have up to the end of the
 261      *            history.
 262      * @param resolution
 263      *            The "step" of this query
 264      * @return The List of states that happened between t1 and t2
 265      * @throws TimeRangeException
 266      *             If t1 is invalid, or if t2 <= t1
 267      * @throws AttributeNotFoundException
 268      *             If the attribute doesn't exist
 269      */
 270     public List<ITmfStateInterval> queryHistoryRange(int attributeQuark,
 271             long t1, long t2, long resolution) throws TimeRangeException,
 272             AttributeNotFoundException;
 273 }