| /******************************************************************************* |
| * Copyright (c) 2012, 2014 Ericsson |
| * Copyright (c) 2010, 2011 École Polytechnique de Montréal |
| * Copyright (c) 2010, 2011 Alexandre Montplaisir <alexandre.montplaisir@gmail.com> |
| * |
| * All rights reserved. This program and the accompanying materials are |
| * made available under the terms of the Eclipse Public License 2.0 which |
| * accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| *******************************************************************************/ |
| |
| package org.eclipse.tracecompass.statesystem.core.backend; |
| |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.util.List; |
| |
| import org.eclipse.jdt.annotation.NonNull; |
| import org.eclipse.jdt.annotation.Nullable; |
| import org.eclipse.tracecompass.internal.provisional.datastore.core.condition.IntegerRangeCondition; |
| import org.eclipse.tracecompass.internal.provisional.datastore.core.condition.TimeRangeCondition; |
| import org.eclipse.tracecompass.statesystem.core.exceptions.StateSystemDisposedException; |
| import org.eclipse.tracecompass.statesystem.core.exceptions.TimeRangeException; |
| import org.eclipse.tracecompass.statesystem.core.interval.ITmfStateInterval; |
| import org.eclipse.tracecompass.statesystem.core.statevalue.TmfStateValue; |
| |
| /** |
| * The main difference between StateSystem and StateHistorySystem is that SHS |
| * allows 'seeking' back in time to reload a Current State at a previous time. |
| * "How to go back in time" is defined by the implementation of the |
| * HistoryBackend. |
| * |
| * A StateHistorySystem contains one and only one HistoryBackend. If you want to |
| * use a paradigm with more than one provider (eg. more or less precision |
| * depending on what's asked by the user), implement one wrapper HistoryBackend |
| * which can then contain your 2-3 other backends underneath. |
| * |
| * @author Alexandre Montplaisir |
| */ |
| public interface IStateHistoryBackend { |
| |
| /** |
| * Get the ID of the state system that populates this backend. |
| * |
| * @return The state system's ID. |
| * @since 1.0 |
| */ |
| @NonNull String getSSID(); |
| |
| /** |
| * Get the start time of this state history. This is usually the same as the |
| * start time of the originating trace. |
| * |
| * @return The start time |
| */ |
| long getStartTime(); |
| |
| /** |
| * Get the current end time of the state history. It will change as the |
| * history is being built. |
| * |
| * @return The end time |
| */ |
| long getEndTime(); |
| |
| /** |
| * Main method to insert state intervals into the history. |
| * |
| * @param stateStartTime |
| * The start time of the interval |
| * @param stateEndTime |
| * The end time of the interval |
| * @param quark |
| * The quark of the attribute this interval refers to |
| * @param value |
| * The StateValue represented by this interval |
| * @throws TimeRangeException |
| * If the start or end time are invalid |
| * @since 3.1 |
| */ |
| default void insertPastState(long stateStartTime, long stateEndTime, |
| int quark, @Nullable Object value) throws TimeRangeException { |
| insertPastState(stateStartTime, stateEndTime, quark, TmfStateValue.newValue(value)); |
| } |
| |
| /** |
| * Indicate to the provider that we are done building the history (so it can |
| * close off, stop threads, etc.) |
| * |
| * @param endTime |
| * The end time to assign to this state history. It could be |
| * farther in time than the last state inserted, for example. |
| * @throws TimeRangeException |
| * If the requested time makes no sense. |
| */ |
| void finishedBuilding(long endTime) throws TimeRangeException; |
| |
| /** |
| * It is the responsibility of the backend to define where to save the |
| * Attribute Tree (since it's only useful to "reopen" an Attribute Tree if |
| * we have the matching History). |
| * |
| * This method defines where to read for the attribute tree when opening an |
| * already-existing history. Refer to the file format documentation. |
| * |
| * @return A FileInputStream object pointing to the correct file/location in |
| * the file where to read the attribute tree information. |
| */ |
| FileInputStream supplyAttributeTreeReader(); |
| |
| // FIXME change to FOS too? |
| /** |
| * Supply the File object to which we will write the attribute tree. The |
| * position in this file is supplied by -TreeWriterFilePosition. |
| * |
| * @return The target File |
| */ |
| File supplyAttributeTreeWriterFile(); |
| |
| /** |
| * Supply the position in the file where we should write the attribute tree |
| * when asked to. |
| * |
| * @return The file position (we will seek() to it) |
| */ |
| long supplyAttributeTreeWriterFilePosition(); |
| |
| /** |
| * Delete any generated files or anything that might have been created by |
| * the history backend (either temporary or save files). By calling this, we |
| * return to the state as it was before ever building the history. |
| * |
| * You might not want to call automatically if, for example, you want an |
| * index file to persist on disk. This could be limited to actions |
| * originating from the user. |
| */ |
| void removeFiles(); |
| |
| /** |
| * Notify the state history back-end that the trace is being closed, so it |
| * should release its file descriptors, close its connections, etc. |
| */ |
| void dispose(); |
| |
| // ------------------------------------------------------------------------ |
| // Query methods |
| // ------------------------------------------------------------------------ |
| |
| /** |
| * Complete "give me the state at a given time" method 'currentStateInfo' is |
| * an "out" parameter, that is, write to it the needed information and |
| * return. DO NOT 'new' currentStateInfo, it will be lost and nothing will |
| * be returned! |
| * |
| * @param currentStateInfo |
| * List of StateValues (index == quark) to fill up |
| * @param t |
| * Target timestamp of the query |
| * @throws TimeRangeException |
| * If the timestamp is outside of the history/trace |
| * @throws StateSystemDisposedException |
| * If the state system is disposed while a request is ongoing. |
| */ |
| void doQuery(@NonNull List<@Nullable ITmfStateInterval> currentStateInfo, long t) |
| throws TimeRangeException, StateSystemDisposedException; |
| |
| /** |
| * Some providers might want to specify a different way to obtain just a |
| * single StateValue instead of updating the whole list. If the method to |
| * use is the same, then feel free to just implement this as a wrapper using |
| * doQuery(). |
| * |
| * @param t |
| * The target timestamp of the query. |
| * @param attributeQuark |
| * The single attribute for which you want the state interval |
| * @return The state interval matching this timestamp/attribute pair, or |
| * null if it was not found |
| * @throws TimeRangeException |
| * If the timestamp was invalid |
| * @throws StateSystemDisposedException |
| * If the state system is disposed while a request is ongoing. |
| */ |
| ITmfStateInterval doSingularQuery(long t, int attributeQuark) |
| throws TimeRangeException, StateSystemDisposedException; |
| |
| /** |
| * Generalized 2D iterable query method. Iterates over intervals that match |
| * the conditions on quarks and times with no guaranteed order. |
| * |
| * @param quarkCondition |
| * Condition on the quarks for returned intervals. |
| * @param timeCondition |
| * Condition on the times for returned intervals |
| * @return An un-ordered iterable over the queried intervals |
| * @throws TimeRangeException |
| * if the time bounds are outside the range of the HistoryTree |
| * @since 3.0 |
| */ |
| default Iterable<@NonNull ITmfStateInterval> query2D(IntegerRangeCondition quarkCondition, TimeRangeCondition timeCondition) |
| throws TimeRangeException { |
| throw new UnsupportedOperationException("This backend does not support 2D queries"); //$NON-NLS-1$ |
| } |
| |
| /** |
| * Generalized 2D iterable query method. Iterates over intervals that match |
| * the conditions on quarks and times with no guaranteed order. |
| * |
| * @param quarkCondition |
| * Condition on the quarks for returned intervals. |
| * @param timeCondition |
| * Condition on the times for returned intervals |
| * @param reverse |
| * A hint to tell whether the backend should be queried backward |
| * or forward |
| * @return An un-ordered iterable over the queried intervals |
| * @throws TimeRangeException |
| * if the time bounds are outside the range of the HistoryTree |
| * @since 4.2 |
| */ |
| default Iterable<@NonNull ITmfStateInterval> query2D(IntegerRangeCondition quarkCondition, TimeRangeCondition timeCondition, boolean reverse) |
| throws TimeRangeException { |
| return query2D(quarkCondition, timeCondition); |
| } |
| } |