1 /*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "string-inl.h"
18
19 #include "arch/memcmp16.h"
20 #include "array.h"
21 #include "class-inl.h"
22 #include "gc/accounting/card_table-inl.h"
23 #include "handle_scope-inl.h"
24 #include "intern_table.h"
25 #include "object-inl.h"
26 #include "runtime.h"
27 #include "string-inl.h"
28 #include "thread.h"
29 #include "utf-inl.h"
30
31 namespace art {
32 namespace mirror {
33
34 // TODO: get global references for these
35 GcRoot<Class> String::java_lang_String_;
36
FastIndexOf(int32_t ch,int32_t start)37 int32_t String::FastIndexOf(int32_t ch, int32_t start) {
38 int32_t count = GetLength();
39 if (start < 0) {
40 start = 0;
41 } else if (start > count) {
42 start = count;
43 }
44 const uint16_t* chars = GetValue();
45 const uint16_t* p = chars + start;
46 const uint16_t* end = chars + count;
47 while (p < end) {
48 if (*p++ == ch) {
49 return (p - 1) - chars;
50 }
51 }
52 return -1;
53 }
54
SetClass(Class * java_lang_String)55 void String::SetClass(Class* java_lang_String) {
56 CHECK(java_lang_String_.IsNull());
57 CHECK(java_lang_String != nullptr);
58 java_lang_String_ = GcRoot<Class>(java_lang_String);
59 }
60
ResetClass()61 void String::ResetClass() {
62 CHECK(!java_lang_String_.IsNull());
63 java_lang_String_ = GcRoot<Class>(nullptr);
64 }
65
ComputeHashCode()66 int String::ComputeHashCode() {
67 const int32_t hash_code = ComputeUtf16Hash(GetValue(), GetLength());
68 SetHashCode(hash_code);
69 return hash_code;
70 }
71
GetUtfLength()72 int32_t String::GetUtfLength() {
73 return CountUtf8Bytes(GetValue(), GetLength());
74 }
75
SetCharAt(int32_t index,uint16_t c)76 void String::SetCharAt(int32_t index, uint16_t c) {
77 DCHECK((index >= 0) && (index < count_));
78 GetValue()[index] = c;
79 }
80
AllocFromStrings(Thread * self,Handle<String> string,Handle<String> string2)81 String* String::AllocFromStrings(Thread* self, Handle<String> string, Handle<String> string2) {
82 int32_t length = string->GetLength();
83 int32_t length2 = string2->GetLength();
84 gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator();
85 SetStringCountVisitor visitor(length + length2);
86 String* new_string = Alloc<true>(self, length + length2, allocator_type, visitor);
87 if (UNLIKELY(new_string == nullptr)) {
88 return nullptr;
89 }
90 uint16_t* new_value = new_string->GetValue();
91 memcpy(new_value, string->GetValue(), length * sizeof(uint16_t));
92 memcpy(new_value + length, string2->GetValue(), length2 * sizeof(uint16_t));
93 return new_string;
94 }
95
AllocFromUtf16(Thread * self,int32_t utf16_length,const uint16_t * utf16_data_in)96 String* String::AllocFromUtf16(Thread* self, int32_t utf16_length, const uint16_t* utf16_data_in) {
97 CHECK(utf16_data_in != nullptr || utf16_length == 0);
98 gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator();
99 SetStringCountVisitor visitor(utf16_length);
100 String* string = Alloc<true>(self, utf16_length, allocator_type, visitor);
101 if (UNLIKELY(string == nullptr)) {
102 return nullptr;
103 }
104 uint16_t* array = string->GetValue();
105 memcpy(array, utf16_data_in, utf16_length * sizeof(uint16_t));
106 return string;
107 }
108
AllocFromModifiedUtf8(Thread * self,const char * utf)109 String* String::AllocFromModifiedUtf8(Thread* self, const char* utf) {
110 DCHECK(utf != nullptr);
111 size_t char_count = CountModifiedUtf8Chars(utf);
112 return AllocFromModifiedUtf8(self, char_count, utf);
113 }
114
AllocFromModifiedUtf8(Thread * self,int32_t utf16_length,const char * utf8_data_in)115 String* String::AllocFromModifiedUtf8(Thread* self, int32_t utf16_length,
116 const char* utf8_data_in) {
117 gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator();
118 SetStringCountVisitor visitor(utf16_length);
119 String* string = Alloc<true>(self, utf16_length, allocator_type, visitor);
120 if (UNLIKELY(string == nullptr)) {
121 return nullptr;
122 }
123 uint16_t* utf16_data_out = string->GetValue();
124 ConvertModifiedUtf8ToUtf16(utf16_data_out, utf8_data_in);
125 return string;
126 }
127
Equals(String * that)128 bool String::Equals(String* that) {
129 if (this == that) {
130 // Quick reference equality test
131 return true;
132 } else if (that == nullptr) {
133 // Null isn't an instanceof anything
134 return false;
135 } else if (this->GetLength() != that->GetLength()) {
136 // Quick length inequality test
137 return false;
138 } else {
139 // Note: don't short circuit on hash code as we're presumably here as the
140 // hash code was already equal
141 for (int32_t i = 0; i < that->GetLength(); ++i) {
142 if (this->CharAt(i) != that->CharAt(i)) {
143 return false;
144 }
145 }
146 return true;
147 }
148 }
149
Equals(const uint16_t * that_chars,int32_t that_offset,int32_t that_length)150 bool String::Equals(const uint16_t* that_chars, int32_t that_offset, int32_t that_length) {
151 if (this->GetLength() != that_length) {
152 return false;
153 } else {
154 for (int32_t i = 0; i < that_length; ++i) {
155 if (this->CharAt(i) != that_chars[that_offset + i]) {
156 return false;
157 }
158 }
159 return true;
160 }
161 }
162
Equals(const char * modified_utf8)163 bool String::Equals(const char* modified_utf8) {
164 const int32_t length = GetLength();
165 int32_t i = 0;
166 while (i < length) {
167 const uint32_t ch = GetUtf16FromUtf8(&modified_utf8);
168 if (ch == '\0') {
169 return false;
170 }
171
172 if (GetLeadingUtf16Char(ch) != CharAt(i++)) {
173 return false;
174 }
175
176 const uint16_t trailing = GetTrailingUtf16Char(ch);
177 if (trailing != 0) {
178 if (i == length) {
179 return false;
180 }
181
182 if (CharAt(i++) != trailing) {
183 return false;
184 }
185 }
186 }
187 return *modified_utf8 == '\0';
188 }
189
Equals(const StringPiece & modified_utf8)190 bool String::Equals(const StringPiece& modified_utf8) {
191 const int32_t length = GetLength();
192 const char* p = modified_utf8.data();
193 for (int32_t i = 0; i < length; ++i) {
194 uint32_t ch = GetUtf16FromUtf8(&p);
195
196 if (GetLeadingUtf16Char(ch) != CharAt(i)) {
197 return false;
198 }
199
200 const uint16_t trailing = GetTrailingUtf16Char(ch);
201 if (trailing != 0) {
202 if (i == (length - 1)) {
203 return false;
204 }
205
206 if (CharAt(++i) != trailing) {
207 return false;
208 }
209 }
210 }
211 return true;
212 }
213
214 // Create a modified UTF-8 encoded std::string from a java/lang/String object.
ToModifiedUtf8()215 std::string String::ToModifiedUtf8() {
216 const uint16_t* chars = GetValue();
217 size_t byte_count = GetUtfLength();
218 std::string result(byte_count, static_cast<char>(0));
219 ConvertUtf16ToModifiedUtf8(&result[0], chars, GetLength());
220 return result;
221 }
222
CompareTo(String * rhs)223 int32_t String::CompareTo(String* rhs) {
224 // Quick test for comparison of a string with itself.
225 String* lhs = this;
226 if (lhs == rhs) {
227 return 0;
228 }
229 // TODO: is this still true?
230 // The annoying part here is that 0x00e9 - 0xffff != 0x00ea,
231 // because the interpreter converts the characters to 32-bit integers
232 // *without* sign extension before it subtracts them (which makes some
233 // sense since "char" is unsigned). So what we get is the result of
234 // 0x000000e9 - 0x0000ffff, which is 0xffff00ea.
235 int32_t lhsCount = lhs->GetLength();
236 int32_t rhsCount = rhs->GetLength();
237 int32_t countDiff = lhsCount - rhsCount;
238 int32_t minCount = (countDiff < 0) ? lhsCount : rhsCount;
239 const uint16_t* lhsChars = lhs->GetValue();
240 const uint16_t* rhsChars = rhs->GetValue();
241 int32_t otherRes = MemCmp16(lhsChars, rhsChars, minCount);
242 if (otherRes != 0) {
243 return otherRes;
244 }
245 return countDiff;
246 }
247
VisitRoots(RootVisitor * visitor)248 void String::VisitRoots(RootVisitor* visitor) {
249 java_lang_String_.VisitRootIfNonNull(visitor, RootInfo(kRootStickyClass));
250 }
251
ToCharArray(Thread * self)252 CharArray* String::ToCharArray(Thread* self) {
253 StackHandleScope<1> hs(self);
254 Handle<String> string(hs.NewHandle(this));
255 CharArray* result = CharArray::Alloc(self, GetLength());
256 memcpy(result->GetData(), string->GetValue(), string->GetLength() * sizeof(uint16_t));
257 return result;
258 }
259
GetChars(int32_t start,int32_t end,Handle<CharArray> array,int32_t index)260 void String::GetChars(int32_t start, int32_t end, Handle<CharArray> array, int32_t index) {
261 uint16_t* data = array->GetData() + index;
262 uint16_t* value = GetValue() + start;
263 memcpy(data, value, (end - start) * sizeof(uint16_t));
264 }
265
266 } // namespace mirror
267 } // namespace art
268