1/*
2 * Copyright (C) 2011 Apple Inc. All Rights Reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef LineBreakIteratorPoolICU_h
27#define LineBreakIteratorPoolICU_h
28
29#include "TextBreakIteratorInternalICU.h"
30#include <unicode/ubrk.h>
31#include <wtf/Assertions.h>
32#include <wtf/HashMap.h>
33#include <wtf/PassOwnPtr.h>
34#include <wtf/ThreadSpecific.h>
35#include <wtf/text/AtomicString.h>
36#include <wtf/text/CString.h>
37
38namespace WebCore {
39
40class LineBreakIteratorPool {
41    WTF_MAKE_NONCOPYABLE(LineBreakIteratorPool);
42public:
43    static LineBreakIteratorPool& sharedPool()
44    {
45        static WTF::ThreadSpecific<LineBreakIteratorPool>* pool = new WTF::ThreadSpecific<LineBreakIteratorPool>;
46        return **pool;
47    }
48
49    static PassOwnPtr<LineBreakIteratorPool> create() { return adoptPtr(new LineBreakIteratorPool); }
50
51    UBreakIterator* take(const AtomicString& locale)
52    {
53        UBreakIterator* iterator = 0;
54        for (size_t i = 0; i < m_pool.size(); ++i) {
55            if (m_pool[i].first == locale) {
56                iterator = m_pool[i].second;
57                m_pool.remove(i);
58                break;
59            }
60        }
61
62        if (!iterator) {
63            UErrorCode openStatus = U_ZERO_ERROR;
64            bool localeIsEmpty = locale.isEmpty();
65            iterator = ubrk_open(UBRK_LINE, localeIsEmpty ? currentTextBreakLocaleID() : locale.string().utf8().data(), 0, 0, &openStatus);
66            // locale comes from a web page and it can be invalid, leading ICU
67            // to fail, in which case we fall back to the default locale.
68            if (!localeIsEmpty && U_FAILURE(openStatus)) {
69                openStatus = U_ZERO_ERROR;
70                iterator = ubrk_open(UBRK_LINE, currentTextBreakLocaleID(), 0, 0, &openStatus);
71            }
72
73            if (U_FAILURE(openStatus)) {
74                LOG_ERROR("ubrk_open failed with status %d", openStatus);
75                return 0;
76            }
77        }
78
79        ASSERT(!m_vendedIterators.contains(iterator));
80        m_vendedIterators.set(iterator, locale);
81        return iterator;
82    }
83
84    void put(UBreakIterator* iterator)
85    {
86        ASSERT_ARG(iterator, m_vendedIterators.contains(iterator));
87
88        if (m_pool.size() == capacity) {
89            ubrk_close(m_pool[0].second);
90            m_pool.remove(0);
91        }
92
93        m_pool.append(Entry(m_vendedIterators.take(iterator), iterator));
94    }
95
96private:
97    LineBreakIteratorPool() { }
98
99    static const size_t capacity = 4;
100
101    typedef pair<AtomicString, UBreakIterator*> Entry;
102    typedef Vector<Entry, capacity> Pool;
103    Pool m_pool;
104    HashMap<UBreakIterator*, AtomicString> m_vendedIterators;
105
106    friend WTF::ThreadSpecific<LineBreakIteratorPool>::operator LineBreakIteratorPool*();
107};
108
109}
110
111#endif
112