aosp12/art/runtime/mirror/string.cc

377 lines
14 KiB
C++

/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "string-alloc-inl.h"
#include "arch/memcmp16.h"
#include "array-alloc-inl.h"
#include "base/array_ref.h"
#include "base/stl_util.h"
#include "class-inl.h"
#include "dex/descriptors_names.h"
#include "dex/utf-inl.h"
#include "gc/accounting/card_table-inl.h"
#include "handle_scope-inl.h"
#include "intern_table.h"
#include "object-inl.h"
#include "runtime.h"
#include "string-inl.h"
#include "thread.h"
namespace art {
namespace mirror {
int32_t String::FastIndexOf(int32_t ch, int32_t start) {
int32_t count = GetLength();
if (start < 0) {
start = 0;
} else if (start > count) {
start = count;
}
if (IsCompressed()) {
return FastIndexOf<uint8_t>(GetValueCompressed(), ch, start);
} else {
return FastIndexOf<uint16_t>(GetValue(), ch, start);
}
}
int String::ComputeHashCode() {
int32_t hash_code = 0;
if (IsCompressed()) {
hash_code = ComputeUtf16Hash(GetValueCompressed(), GetLength());
} else {
hash_code = ComputeUtf16Hash(GetValue(), GetLength());
}
SetHashCode(hash_code);
return hash_code;
}
inline bool String::AllASCIIExcept(const uint16_t* chars, int32_t length, uint16_t non_ascii) {
DCHECK(!IsASCII(non_ascii));
for (int32_t i = 0; i < length; ++i) {
if (!IsASCII(chars[i]) && chars[i] != non_ascii) {
return false;
}
}
return true;
}
ObjPtr<String> String::DoReplace(Thread* self, Handle<String> src, uint16_t old_c, uint16_t new_c) {
int32_t length = src->GetLength();
DCHECK(src->IsCompressed()
? ContainsElement(ArrayRef<uint8_t>(src->value_compressed_, length), old_c)
: ContainsElement(ArrayRef<uint16_t>(src->value_, length), old_c));
bool compressible =
kUseStringCompression &&
IsASCII(new_c) &&
(src->IsCompressed() || (!IsASCII(old_c) && AllASCIIExcept(src->value_, length, old_c)));
gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator();
const int32_t length_with_flag = String::GetFlaggedCount(length, compressible);
auto visitor = [=](ObjPtr<Object> obj, size_t usable_size) REQUIRES_SHARED(Locks::mutator_lock_) {
SetStringCountVisitor set_string_count_visitor(length_with_flag);
set_string_count_visitor(obj, usable_size);
ObjPtr<String> new_string = obj->AsString();
if (compressible) {
auto replace = [old_c, new_c](uint16_t c) {
return dchecked_integral_cast<uint8_t>((old_c != c) ? c : new_c);
};
uint8_t* out = new_string->value_compressed_;
if (LIKELY(src->IsCompressed())) { // LIKELY(compressible == src->IsCompressed())
std::transform(src->value_compressed_, src->value_compressed_ + length, out, replace);
} else {
std::transform(src->value_, src->value_ + length, out, replace);
}
DCHECK(kUseStringCompression && AllASCII(out, length));
} else {
auto replace = [old_c, new_c](uint16_t c) {
return (old_c != c) ? c : new_c;
};
uint16_t* out = new_string->value_;
if (UNLIKELY(src->IsCompressed())) { // LIKELY(compressible == src->IsCompressed())
std::transform(src->value_compressed_, src->value_compressed_ + length, out, replace);
} else {
std::transform(src->value_, src->value_ + length, out, replace);
}
DCHECK(!kUseStringCompression || !AllASCII(out, length));
}
};
return Alloc(self, length_with_flag, allocator_type, visitor);
}
ObjPtr<String> String::DoConcat(Thread* self, Handle<String> h_this, Handle<String> h_arg) {
int32_t length_this = h_this->GetLength();
int32_t length_arg = h_arg->GetLength();
gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator();
const bool compressible =
kUseStringCompression && (h_this->IsCompressed() && h_arg->IsCompressed());
const int32_t length_with_flag = String::GetFlaggedCount(length_this + length_arg, compressible);
auto visitor = [=](ObjPtr<Object> obj, size_t usable_size) REQUIRES_SHARED(Locks::mutator_lock_) {
SetStringCountVisitor set_string_count_visitor(length_with_flag);
set_string_count_visitor(obj, usable_size);
ObjPtr<String> new_string = obj->AsString();
if (compressible) {
uint8_t* new_value = new_string->GetValueCompressed();
memcpy(new_value, h_this->GetValueCompressed(), length_this * sizeof(uint8_t));
memcpy(new_value + length_this, h_arg->GetValueCompressed(), length_arg * sizeof(uint8_t));
} else {
uint16_t* new_value = new_string->GetValue();
if (h_this->IsCompressed()) {
const uint8_t* value_this = h_this->GetValueCompressed();
for (int i = 0; i < length_this; ++i) {
new_value[i] = value_this[i];
}
} else {
memcpy(new_value, h_this->GetValue(), length_this * sizeof(uint16_t));
}
if (h_arg->IsCompressed()) {
const uint8_t* value_arg = h_arg->GetValueCompressed();
for (int i = 0; i < length_arg; ++i) {
new_value[i + length_this] = value_arg[i];
}
} else {
memcpy(new_value + length_this, h_arg->GetValue(), length_arg * sizeof(uint16_t));
}
}
};
return Alloc(self, length_with_flag, allocator_type, visitor);
}
ObjPtr<String> String::AllocFromUtf16(Thread* self,
int32_t utf16_length,
const uint16_t* utf16_data_in) {
CHECK(utf16_data_in != nullptr || utf16_length == 0);
gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator();
const bool compressible = kUseStringCompression &&
String::AllASCII<uint16_t>(utf16_data_in, utf16_length);
int32_t length_with_flag = String::GetFlaggedCount(utf16_length, compressible);
auto visitor = [=](ObjPtr<Object> obj, size_t usable_size) REQUIRES_SHARED(Locks::mutator_lock_) {
SetStringCountVisitor set_string_count_visitor(length_with_flag);
set_string_count_visitor(obj, usable_size);
ObjPtr<String> new_string = obj->AsString();
if (compressible) {
uint8_t* value = new_string->GetValueCompressed();
for (int i = 0; i < utf16_length; ++i) {
value[i] = static_cast<uint8_t>(utf16_data_in[i]);
}
} else {
memcpy(new_string->GetValue(), utf16_data_in, utf16_length * sizeof(uint16_t));
}
};
return Alloc(self, length_with_flag, allocator_type, visitor);
}
ObjPtr<String> String::AllocFromModifiedUtf8(Thread* self, const char* utf) {
DCHECK(utf != nullptr);
size_t byte_count = strlen(utf);
size_t char_count = CountModifiedUtf8Chars(utf, byte_count);
return AllocFromModifiedUtf8(self, char_count, utf, byte_count);
}
ObjPtr<String> String::AllocFromModifiedUtf8(Thread* self,
int32_t utf16_length,
const char* utf8_data_in) {
return AllocFromModifiedUtf8(self, utf16_length, utf8_data_in, strlen(utf8_data_in));
}
ObjPtr<String> String::AllocFromModifiedUtf8(Thread* self,
int32_t utf16_length,
const char* utf8_data_in,
int32_t utf8_length) {
gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator();
const bool compressible = kUseStringCompression && (utf16_length == utf8_length);
const int32_t length_with_flag = String::GetFlaggedCount(utf16_length, compressible);
auto visitor = [=](ObjPtr<Object> obj, size_t usable_size) REQUIRES_SHARED(Locks::mutator_lock_) {
SetStringCountVisitor set_string_count_visitor(length_with_flag);
set_string_count_visitor(obj, usable_size);
ObjPtr<String> new_string = obj->AsString();
if (compressible) {
memcpy(new_string->GetValueCompressed(), utf8_data_in, utf16_length * sizeof(uint8_t));
} else {
uint16_t* utf16_data_out = new_string->GetValue();
ConvertModifiedUtf8ToUtf16(utf16_data_out, utf16_length, utf8_data_in, utf8_length);
}
};
return Alloc(self, length_with_flag, allocator_type, visitor);
}
bool String::Equals(ObjPtr<String> that) {
if (this == that) {
// Quick reference equality test
return true;
} else if (that == nullptr) {
// Null isn't an instanceof anything
return false;
} else if (this->GetCount() != that->GetCount()) {
// Quick length and compression inequality test
return false;
} else {
// Note: don't short circuit on hash code as we're presumably here as the
// hash code was already equal
if (this->IsCompressed()) {
return memcmp(this->GetValueCompressed(), that->GetValueCompressed(), this->GetLength()) == 0;
} else {
return memcmp(this->GetValue(), that->GetValue(), sizeof(uint16_t) * this->GetLength()) == 0;
}
}
}
bool String::Equals(const char* modified_utf8) {
const int32_t length = GetLength();
if (IsCompressed()) {
return strlen(modified_utf8) == dchecked_integral_cast<uint32_t>(length) &&
memcmp(modified_utf8, GetValueCompressed(), length) == 0;
}
const uint16_t* value = GetValue();
int32_t i = 0;
while (i < length) {
const uint32_t ch = GetUtf16FromUtf8(&modified_utf8);
if (ch == '\0') {
return false;
}
if (GetLeadingUtf16Char(ch) != value[i++]) {
return false;
}
const uint16_t trailing = GetTrailingUtf16Char(ch);
if (trailing != 0) {
if (i == length) {
return false;
}
if (value[i++] != trailing) {
return false;
}
}
}
return *modified_utf8 == '\0';
}
// Create a modified UTF-8 encoded std::string from a java/lang/String object.
std::string String::ToModifiedUtf8() {
if (IsCompressed()) {
return std::string(reinterpret_cast<const char*>(GetValueCompressed()), GetLength());
} else {
size_t byte_count = GetUtfLength();
std::string result(byte_count, static_cast<char>(0));
ConvertUtf16ToModifiedUtf8(&result[0], byte_count, GetValue(), GetLength());
return result;
}
}
int32_t String::CompareTo(ObjPtr<String> rhs) {
// Quick test for comparison of a string with itself.
ObjPtr<String> lhs = this;
if (lhs == rhs) {
return 0;
}
int32_t lhs_count = lhs->GetLength();
int32_t rhs_count = rhs->GetLength();
int32_t count_diff = lhs_count - rhs_count;
int32_t min_count = (count_diff < 0) ? lhs_count : rhs_count;
if (lhs->IsCompressed() && rhs->IsCompressed()) {
const uint8_t* lhs_chars = lhs->GetValueCompressed();
const uint8_t* rhs_chars = rhs->GetValueCompressed();
for (int32_t i = 0; i < min_count; ++i) {
int32_t char_diff = static_cast<int32_t>(lhs_chars[i]) - static_cast<int32_t>(rhs_chars[i]);
if (char_diff != 0) {
return char_diff;
}
}
} else if (lhs->IsCompressed() || rhs->IsCompressed()) {
const uint8_t* compressed_chars =
lhs->IsCompressed() ? lhs->GetValueCompressed() : rhs->GetValueCompressed();
const uint16_t* uncompressed_chars = lhs->IsCompressed() ? rhs->GetValue() : lhs->GetValue();
for (int32_t i = 0; i < min_count; ++i) {
int32_t char_diff =
static_cast<int32_t>(compressed_chars[i]) - static_cast<int32_t>(uncompressed_chars[i]);
if (char_diff != 0) {
return lhs->IsCompressed() ? char_diff : -char_diff;
}
}
} else {
const uint16_t* lhs_chars = lhs->GetValue();
const uint16_t* rhs_chars = rhs->GetValue();
// FIXME: The MemCmp16() name is misleading. It returns the char difference on mismatch
// where memcmp() only guarantees that the returned value has the same sign.
int32_t char_diff = MemCmp16(lhs_chars, rhs_chars, min_count);
if (char_diff != 0) {
return char_diff;
}
}
return count_diff;
}
ObjPtr<CharArray> String::ToCharArray(Handle<String> h_this, Thread* self) {
ObjPtr<CharArray> result = CharArray::Alloc(self, h_this->GetLength());
if (result != nullptr) {
if (h_this->IsCompressed()) {
int32_t length = h_this->GetLength();
const uint8_t* src = h_this->GetValueCompressed();
uint16_t* dest = result->GetData();
for (int i = 0; i < length; ++i) {
dest[i] = src[i];
}
} else {
memcpy(result->GetData(), h_this->GetValue(), h_this->GetLength() * sizeof(uint16_t));
}
} else {
self->AssertPendingOOMException();
}
return result;
}
void String::GetChars(int32_t start, int32_t end, Handle<CharArray> array, int32_t index) {
uint16_t* data = array->GetData() + index;
DCHECK_LE(start, end);
int32_t length = end - start;
if (IsCompressed()) {
const uint8_t* value = GetValueCompressed() + start;
for (int i = 0; i < length; ++i) {
data[i] = value[i];
}
} else {
uint16_t* value = GetValue() + start;
memcpy(data, value, length * sizeof(uint16_t));
}
}
bool String::IsValueNull() {
return (IsCompressed()) ? (GetValueCompressed() == nullptr) : (GetValue() == nullptr);
}
std::string String::PrettyStringDescriptor(ObjPtr<mirror::String> java_descriptor) {
if (java_descriptor == nullptr) {
return "null";
}
return java_descriptor->PrettyStringDescriptor();
}
std::string String::PrettyStringDescriptor() {
return PrettyDescriptor(ToModifiedUtf8().c_str());
}
ObjPtr<String> String::Intern() {
return Runtime::Current()->GetInternTable()->InternWeak(this);
}
} // namespace mirror
} // namespace art