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