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  * @version 1.0
  27  * @author Alexandre Montplaisir
  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 The current end time of this state history
  43      */
  44     public long getCurrentEndTime();
  45
  46     /**
  47      * Return the current total amount of attributes in the system.
  48      *
  49      * @return The current number of attributes in the system
  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      *             If the quark is invalid
  93      */
  94     public int getQuarkRelative(int startingNodeQuark, String... subPath)
  95             throws AttributeNotFoundException;
  96
  97     /**
  98      * Return the sub-attributes of the target attribute, as a List of quarks.
  99      *
 100      * @param quark
 101      *            The attribute of which you want to sub-attributes. You can use
 102      *            "-1" here to specify the root node.
 103      * @param recursive
 104      *            True if you want all recursive sub-attributes, false if you
 105      *            only want the first level.
 106      * @return A List of integers, matching the quarks of the sub-attributes.
 107      * @throws AttributeNotFoundException
 108      *             If the quark was not existing or invalid.
 109      */
 110     public List<Integer> getSubAttributes(int quark, boolean recursive)
 111             throws AttributeNotFoundException;
 112
 113     /**
 114      * Batch quark-retrieving method. This method allows you to specify a path
 115      * pattern which includes a wildcard "*" somewhere. It will check all the
 116      * existing attributes in the attribute tree and return those who match the
 117      * pattern.
 118      *
 119      * For example, passing ("Threads", "*", "Exec_mode") will return the list
 120      * of quarks for attributes "Threads/1000/Exec_mode",
 121      * "Threads/1500/Exec_mode", and so on, depending on what exists at this
 122      * time in the attribute tree.
 123      *
 124      * If no wildcard is specified, the behavior is the same as
 125      * getQuarkAbsolute() (except it will return a List with one entry). This
 126      * method will never create new attributes.
 127      *
 128      * Only one wildcard "*" is supported at this time.
 129      *
 130      * @param pattern
 131      *            The array of strings representing the pattern to look for. It
 132      *            should ideally contain one entry that is only a "*".
 133      * @return A List of attribute quarks, representing attributes that matched
 134      *         the pattern. If no attribute matched, the list will be empty (but
 135      *         not null).
 136      */
 137     public List<Integer> getQuarks(String... pattern);
 138
 139     /**
 140      * Return the name assigned to this quark. This returns only the "basename",
 141      * not the complete path to this attribute.
 142      *
 143      * @param attributeQuark
 144      *            The quark for which we want the name
 145      * @return The name of the quark
 146      */
 147     public String getAttributeName(int attributeQuark);
 148
 149     /**
 150      * This returns the slash-separated path of an attribute by providing its
 151      * quark
 152      *
 153      * @param attributeQuark
 154      *            The quark of the attribute we want
 155      * @return One single string separated with '/', like a filesystem path
 156      */
 157     public String getFullAttributePath(int attributeQuark);
 158
 159     /**
 160      * @name Query methods
 161      */
 162
 163     /**
 164      * Returns the current state value we have (in the Transient State) for the
 165      * given attribute.
 166      *
 167      * This is useful even for a StateHistorySystem, as we are guaranteed it
 168      * will only do a memory access and not go look on disk (and we don't even
 169      * have to provide a timestamp!)
 170      *
 171      * @param attributeQuark
 172      *            For which attribute we want the current state
 173      * @return The State value that's "current" for this attribute
 174      * @throws AttributeNotFoundException
 175      *             If the requested attribute is invalid
 176      */
 177     public ITmfStateValue queryOngoingState(int attributeQuark)
 178             throws AttributeNotFoundException;
 179
 180     /**
 181      * Load the complete state information at time 't' into the returned List.
 182      * You can then get the intervals for single attributes by using
 183      * List.get(n), where 'n' is the quark of the attribute.
 184      *
 185      * On average if you need around 10 or more queries for the same timestamps,
 186      * use this method. If you need less than 10 (for example, running many
 187      * queries for the same attributes but at different timestamps), you might
 188      * be better using the querySingleState() methods instead.
 189      *
 190      * @param t
 191      *            We will recreate the state information to what it was at time
 192      *            t.
 193      * @return The List of intervals, where the offset = the quark
 194      * @throws TimeRangeException
 195      *             If the 't' parameter is outside of the range of the state
 196      *             history.
 197      */
 198     public List<ITmfStateInterval> queryFullState(long t)
 199             throws TimeRangeException;
 200
 201     /**
 202      * Singular query method. This one does not update the whole stateInfo
 203      * vector, like queryFullState() does. It only searches for one specific
 204      * entry in the state history.
 205      *
 206      * It should be used when you only want very few entries, instead of the
 207      * whole state (or many entries, but all at different timestamps). If you do
 208      * request many entries all at the same time, you should use the
 209      * conventional queryFullState() + List.get() method.
 210      *
 211      * @param t
 212      *            The timestamp at which we want the state
 213      * @param attributeQuark
 214      *            Which attribute we want to get the state of
 215      * @return The StateInterval representing the state
 216      * @throws TimeRangeException
 217      *             If 't' is invalid
 218      * @throws AttributeNotFoundException
 219      *             If the requested quark does not exist in the model
 220      */
 221     public ITmfStateInterval querySingleState(long t, int attributeQuark)
 222             throws AttributeNotFoundException, TimeRangeException;
 223
 224     /**
 225      * Return a list of state intervals, containing the "history" of a given
 226      * attribute between timestamps t1 and t2. The list will be ordered by
 227      * ascending time.
 228      *
 229      * Note that contrary to queryFullState(), the returned list here is in the
 230      * "direction" of time (and not in the direction of attributes, as is the
 231      * case with queryFullState()).
 232      *
 233      * @param attributeQuark
 234      *            Which attribute this query is interested in
 235      * @param t1
 236      *            Start time of the range query
 237      * @param t2
 238      *            Target end time of the query. If t2 is greater than the end of
 239      *            the trace, we will return what we have up to the end of the
 240      *            history.
 241      * @return The List of state intervals that happened between t1 and t2
 242      * @throws TimeRangeException
 243      *             If t1 is invalid, or if t2 <= t1
 244      * @throws AttributeNotFoundException
 245      *             If the requested quark does not exist in the model.
 246      */
 247     public List<ITmfStateInterval> queryHistoryRange(int attributeQuark,
 248             long t1, long t2) throws TimeRangeException,
 249             AttributeNotFoundException;
 250
 251     /**
 252      * Return the state history of a given attribute, but with at most one
 253      * update per "resolution". This can be useful for populating views (where
 254      * it's useless to have more than one query per pixel, for example).
 255      *
 256      * @param attributeQuark
 257      *            Which attribute this query is interested in
 258      * @param t1
 259      *            Start time of the range query
 260      * @param t2
 261      *            Target end time of the query. If t2 is greater than the end of
 262      *            the trace, we will return what we have up to the end of the
 263      *            history.
 264      * @param resolution
 265      *            The "step" of this query
 266      * @return The List of states that happened between t1 and t2
 267      * @throws TimeRangeException
 268      *             If t1 is invalid, if t2 <= t1, or if the resolution isn't
 269      *             greater than zero.
 270      * @throws AttributeNotFoundException
 271      *             If the attribute doesn't exist
 272      */
 273     public List<ITmfStateInterval> queryHistoryRange(int attributeQuark,
 274             long t1, long t2, long resolution) throws TimeRangeException,
 275             AttributeNotFoundException;
 276 }