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- /*
- * Copyright (c) 2006-2017 DMDirc Developers
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
- * documentation files (the "Software"), to deal in the Software without restriction, including without limitation the
- * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the
- * Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
- * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
- * OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
- * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-
- package com.dmdirc;
-
- import com.dmdirc.interfaces.Connection;
- import com.dmdirc.parser.interfaces.Parser;
- import com.dmdirc.util.collections.RollingList;
-
- import java.util.ArrayList;
- import java.util.List;
-
- /**
- * Describes the status of a server and manages transitions between different states.
- *
- * @since 0.6.3m1
- */
- public class ServerStatus {
-
- /** The connection to which this status belongs. */
- private final Connection connection;
- /** Object to notify when the state of the server changes. */
- private final Object notifier;
- /** The current state of the server. */
- private ServerState state = ServerState.DISCONNECTED;
- /** A history of transactions for debugging purposes. */
- private final RollingList<String> history = new RollingList<>(10);
- /** A list of known parser hashcodes. */
- private final List<Integer> parsers = new ArrayList<>();
-
- /**
- * Creates a new ServerStatus instance for the specified server.
- *
- * @param connection The connection to which this status belongs
- * @param notifier The object to notify when the state changes
- *
- * @since 0.6.3
- */
- public ServerStatus(final Connection connection, final Object notifier) {
- this.connection = connection;
- this.notifier = notifier;
- }
-
- /**
- * Transitions the status of this object to the specified state.
- *
- * @param newState The state to transition to
- *
- * @throws IllegalArgumentException If the specified transition is invalid
- */
- public synchronized void transition(final ServerState newState) {
- addHistoryEntry(state, newState);
-
- if (state.canTransitionTo(newState)) {
- state = newState;
-
- synchronized (notifier) {
- notifier.notifyAll();
- }
- } else {
- throw new IllegalArgumentException("Illegal server state "
- + "transition\n\n" + getTransitionHistory());
- }
- }
-
- /**
- * Retrieves the current state of this status object.
- *
- * @return This object's current state
- */
- public synchronized ServerState getState() {
- return state;
- }
-
- /**
- * Adds a history entry to this status object. The history entry contains the name of the states
- * being transitioned between, the details of the method (and class and line) which initiated
- * the transition, and the name of the thread in which the transition is occurring.
- *
- * @param fromState The state which is being transitioned from
- * @param toState The state which is being transitioned to
- */
- protected void addHistoryEntry(final ServerState fromState, final ServerState toState) {
- final StringBuilder builder = new StringBuilder();
- builder.append(fromState.name());
- builder.append('\u2192');
- builder.append(toState.name());
- builder.append(' ');
- builder.append(Thread.currentThread().getStackTrace()[3]);
- builder.append(" [");
- builder.append(Thread.currentThread().getName());
- builder.append("] (parser #");
- builder.append(getParserID(connection.getParser().orElse(null)));
- builder.append(')');
-
- history.add(builder.toString());
- }
-
- /**
- * Retrieves the transition history of this status object as a string.
- *
- * @see #addHistoryEntry(ServerState, ServerState)
- * @return A line feed ('\n') delimited string containing one entry for each of the entries in
- * this status's transition history.
- */
- public String getTransitionHistory() {
- final StringBuilder builder = new StringBuilder();
-
- for (String line : history.getList()) {
- if (builder.length() > 0) {
- builder.append('\n');
- }
-
- builder.append(line);
- }
-
- return builder.toString();
- }
-
- /**
- * Returns a unique, ID for the specified parser. Each parser that has been seen to be used by
- * this server is given a sequential id.
- *
- * @param parser The parser whose ID is being requested
- *
- * @return A unique ID for the specified parser, or 0 if the parser is null
- */
- public int getParserID(final Parser parser) {
- if (parser == null) {
- return 0;
- }
-
- final int hashcode = parser.hashCode();
- int offset;
-
- synchronized (parsers) {
- offset = parsers.indexOf(hashcode);
-
- if (offset == -1) {
- parsers.add(hashcode);
- offset = parsers.indexOf(hashcode);
- }
- }
-
- return 1 + offset;
- }
-
- }
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