1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "chrome/renderer/spellchecker/hunspell_engine.h"
6
7 #include <algorithm>
8 #include <iterator>
9
10 #include "base/files/memory_mapped_file.h"
11 #include "base/time/time.h"
12 #include "chrome/common/spellcheck_common.h"
13 #include "chrome/common/spellcheck_messages.h"
14 #include "content/public/renderer/render_thread.h"
15 #include "third_party/hunspell/src/hunspell/hunspell.hxx"
16
17 using content::RenderThread;
18
19 namespace {
20 // Maximum length of words we actually check.
21 // 64 is the observed limits for OSX system checker.
22 const size_t kMaxCheckedLen = 64;
23
24 // Maximum length of words we provide suggestions for.
25 // 24 is the observed limits for OSX system checker.
26 const size_t kMaxSuggestLen = 24;
27
28 COMPILE_ASSERT(kMaxCheckedLen <= size_t(MAXWORDLEN), MaxCheckedLen_too_long);
29 COMPILE_ASSERT(kMaxSuggestLen <= kMaxCheckedLen, MaxSuggestLen_too_long);
30 } // namespace
31
32 #if !defined(OS_MACOSX)
CreateNativeSpellingEngine()33 SpellingEngine* CreateNativeSpellingEngine() {
34 return new HunspellEngine();
35 }
36 #endif
37
HunspellEngine()38 HunspellEngine::HunspellEngine()
39 : hunspell_enabled_(false),
40 initialized_(false),
41 dictionary_requested_(false) {
42 // Wait till we check the first word before doing any initializing.
43 }
44
~HunspellEngine()45 HunspellEngine::~HunspellEngine() {
46 }
47
Init(base::File file)48 void HunspellEngine::Init(base::File file) {
49 initialized_ = true;
50 hunspell_.reset();
51 bdict_file_.reset();
52 file_ = file.Pass();
53 hunspell_enabled_ = file_.IsValid();
54 // Delay the actual initialization of hunspell until it is needed.
55 }
56
InitializeHunspell()57 void HunspellEngine::InitializeHunspell() {
58 if (hunspell_.get())
59 return;
60
61 bdict_file_.reset(new base::MemoryMappedFile);
62
63 if (bdict_file_->Initialize(file_.Pass())) {
64 hunspell_.reset(new Hunspell(bdict_file_->data(), bdict_file_->length()));
65 } else {
66 NOTREACHED() << "Could not mmap spellchecker dictionary.";
67 }
68 }
69
CheckSpelling(const base::string16 & word_to_check,int tag)70 bool HunspellEngine::CheckSpelling(const base::string16& word_to_check,
71 int tag) {
72 // Assume all words that cannot be checked are valid. Since Chrome can't
73 // offer suggestions on them, either, there's no point in flagging them to
74 // the user.
75 bool word_correct = true;
76 std::string word_to_check_utf8(base::UTF16ToUTF8(word_to_check));
77
78 // Limit the size of checked words.
79 if (word_to_check_utf8.length() <= kMaxCheckedLen) {
80 // If |hunspell_| is NULL here, an error has occurred, but it's better
81 // to check rather than crash.
82 if (hunspell_.get()) {
83 // |hunspell_->spell| returns 0 if the word is misspelled.
84 word_correct = (hunspell_->spell(word_to_check_utf8.c_str()) != 0);
85 }
86 }
87
88 return word_correct;
89 }
90
FillSuggestionList(const base::string16 & wrong_word,std::vector<base::string16> * optional_suggestions)91 void HunspellEngine::FillSuggestionList(
92 const base::string16& wrong_word,
93 std::vector<base::string16>* optional_suggestions) {
94 std::string wrong_word_utf8(base::UTF16ToUTF8(wrong_word));
95 if (wrong_word_utf8.length() > kMaxSuggestLen)
96 return;
97
98 // If |hunspell_| is NULL here, an error has occurred, but it's better
99 // to check rather than crash.
100 // TODO(groby): Technically, it's not. We should track down the issue.
101 if (!hunspell_.get())
102 return;
103
104 char** suggestions = NULL;
105 int number_of_suggestions =
106 hunspell_->suggest(&suggestions, wrong_word_utf8.c_str());
107
108 // Populate the vector of WideStrings.
109 for (int i = 0; i < number_of_suggestions; ++i) {
110 if (i < chrome::spellcheck_common::kMaxSuggestions)
111 optional_suggestions->push_back(base::UTF8ToUTF16(suggestions[i]));
112 free(suggestions[i]);
113 }
114 if (suggestions != NULL)
115 free(suggestions);
116 }
117
InitializeIfNeeded()118 bool HunspellEngine::InitializeIfNeeded() {
119 if (!initialized_ && !dictionary_requested_) {
120 // RenderThread will not exist in test.
121 if (RenderThread::Get())
122 RenderThread::Get()->Send(new SpellCheckHostMsg_RequestDictionary);
123 dictionary_requested_ = true;
124 return true;
125 }
126
127 // Don't initialize if hunspell is disabled.
128 if (file_.IsValid())
129 InitializeHunspell();
130
131 return !initialized_;
132 }
133
IsEnabled()134 bool HunspellEngine::IsEnabled() {
135 return hunspell_enabled_;
136 }
137