1/*
2 * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package com.sun.tools.javac.comp;
27
28import java.util.AbstractQueue;
29import java.util.Collection;
30import java.util.HashMap;
31import java.util.Iterator;
32import java.util.LinkedList;
33import java.util.Map;
34import java.util.Queue;
35import javax.tools.JavaFileObject;
36
37import com.sun.tools.javac.util.Context;
38
39/** A queue of all as yet unattributed classes.
40 *
41 *  <p><b>This is NOT part of any supported API.
42 *  If you write code that depends on this, you do so at your own risk.
43 *  This code and its internal interfaces are subject to change or
44 *  deletion without notice.</b>
45 */
46public class Todo extends AbstractQueue<Env<AttrContext>> {
47    /** The context key for the todo list. */
48    protected static final Context.Key<Todo> todoKey = new Context.Key<>();
49
50    /** Get the Todo instance for this context. */
51    public static Todo instance(Context context) {
52        Todo instance = context.get(todoKey);
53        if (instance == null)
54            instance = new Todo(context);
55        return instance;
56    }
57
58    /** Create a new todo list. */
59    protected Todo(Context context) {
60        context.put(todoKey, this);
61    }
62
63    public void append(Env<AttrContext> env) {
64        add(env);
65    }
66
67    @Override
68    public Iterator<Env<AttrContext>> iterator() {
69        return contents.iterator();
70    }
71
72    @Override
73    public int size() {
74        return contents.size();
75    }
76
77    public boolean offer(Env<AttrContext> e) {
78        if (contents.add(e)) {
79            if (contentsByFile != null)
80                addByFile(e);
81            return true;
82        } else {
83            return false;
84        }
85    }
86
87    /**
88     * Removes all unattributed classes except those belonging to the given
89     * collection of files.
90     *
91     * @param sourceFiles The source files of the classes to keep.
92     */
93    public void retainFiles(Collection<? extends JavaFileObject> sourceFiles) {
94        for (Iterator<Env<AttrContext>> it = contents.iterator(); it.hasNext(); ) {
95            Env<AttrContext> env = it.next();
96            if (!sourceFiles.contains(env.toplevel.sourcefile)) {
97                if (contentsByFile != null) removeByFile(env);
98                it.remove();
99            }
100        }
101    }
102
103    public Env<AttrContext> poll() {
104        if (size() == 0)
105            return null;
106        Env<AttrContext> env = contents.remove(0);
107        if (contentsByFile != null)
108            removeByFile(env);
109        return env;
110    }
111
112    public Env<AttrContext> peek() {
113        return (size() == 0 ? null : contents.get(0));
114    }
115
116    public Queue<Queue<Env<AttrContext>>> groupByFile() {
117        if (contentsByFile == null) {
118            contentsByFile = new LinkedList<>();
119            for (Env<AttrContext> env: contents) {
120                addByFile(env);
121            }
122        }
123        return contentsByFile;
124    }
125
126    private void addByFile(Env<AttrContext> env) {
127        JavaFileObject file = env.toplevel.sourcefile;
128        if (fileMap == null)
129            fileMap = new HashMap<>();
130        FileQueue fq = fileMap.get(file);
131        if (fq == null) {
132            fq = new FileQueue();
133            fileMap.put(file, fq);
134            contentsByFile.add(fq);
135        }
136        fq.fileContents.add(env);
137    }
138
139    private void removeByFile(Env<AttrContext> env) {
140        JavaFileObject file = env.toplevel.sourcefile;
141        FileQueue fq = fileMap.get(file);
142        if (fq == null)
143            return;
144        if (fq.fileContents.remove(env)) {
145            if (fq.isEmpty()) {
146                fileMap.remove(file);
147                contentsByFile.remove(fq);
148            }
149        }
150    }
151
152    LinkedList<Env<AttrContext>> contents = new LinkedList<>();
153    LinkedList<Queue<Env<AttrContext>>> contentsByFile;
154    Map<JavaFileObject, FileQueue> fileMap;
155
156    class FileQueue extends AbstractQueue<Env<AttrContext>> {
157        @Override
158        public Iterator<Env<AttrContext>> iterator() {
159            return fileContents.iterator();
160        }
161
162        @Override
163        public int size() {
164            return fileContents.size();
165        }
166
167        public boolean offer(Env<AttrContext> e) {
168            if (fileContents.offer(e)) {
169                contents.add(e);
170                return true;
171            }
172            return false;
173        }
174
175        public Env<AttrContext> poll() {
176            if (fileContents.size() == 0)
177                return null;
178            Env<AttrContext> env = fileContents.remove(0);
179            contents.remove(env);
180            return env;
181        }
182
183        public Env<AttrContext> peek() {
184            return (fileContents.size() == 0 ? null : fileContents.get(0));
185        }
186
187        LinkedList<Env<AttrContext>> fileContents = new LinkedList<>();
188    }
189}
190