i::Handle<i::String> obj = Utils::OpenHandle(this);
i::Isolate* isolate = obj->GetIsolate();
if (IsDeadCheck(isolate, "v8::String::CanMakeExternal()")) return false;
- if (isolate->string_tracker()->IsFreshUnusedString(obj)) {
- return false;
- }
+ if (isolate->string_tracker()->IsFreshUnusedString(obj)) return false;
int size = obj->Size(); // Byte size of the original string.
- if (size < i::ExternalString::kSize)
- return false;
+ if (size < i::ExternalString::kShortSize) return false;
i::StringShape shape(*obj);
return !shape.IsExternal();
}
ExternalString::kResourceOffset -
kHeapObjectTag);
- // Clear pointer cache.
- ExternalString::cast(string)->clear_data_cache();
-
// Dispose of the C++ object if it has not already been disposed.
if (*resource_addr != NULL) {
(*resource_addr)->Dispose();
+ *resource_addr = NULL;
}
-
- // Clear the resource pointer in the string.
- *resource_addr = NULL;
}
if (map == external_string_with_ascii_data_map()) {
return external_symbol_with_ascii_data_map();
}
+ if (map == short_external_string_map()) {
+ return short_external_symbol_map();
+ }
+ if (map == short_external_ascii_string_map()) {
+ return short_external_ascii_symbol_map();
+ }
+ if (map == short_external_string_with_ascii_data_map()) {
+ return short_external_symbol_with_ascii_data_map();
+ }
// No match found.
return NULL;
V(Map, external_string_map, ExternalStringMap) \
V(Map, external_string_with_ascii_data_map, ExternalStringWithAsciiDataMap) \
V(Map, external_ascii_string_map, ExternalAsciiStringMap) \
+ V(Map, short_external_symbol_map, ShortExternalSymbolMap) \
+ V(Map, \
+ short_external_symbol_with_ascii_data_map, \
+ ShortExternalSymbolWithAsciiDataMap) \
+ V(Map, short_external_ascii_symbol_map, ShortExternalAsciiSymbolMap) \
+ V(Map, short_external_string_map, ShortExternalStringMap) \
+ V(Map, \
+ short_external_string_with_ascii_data_map, \
+ ShortExternalStringWithAsciiDataMap) \
+ V(Map, short_external_ascii_string_map, ShortExternalAsciiStringMap) \
V(Map, undetectable_string_map, UndetectableStringMap) \
V(Map, undetectable_ascii_string_map, UndetectableAsciiStringMap) \
V(Map, external_pixel_array_map, ExternalPixelArrayMap) \
__ test(result, Immediate(kIsIndirectStringMask));
__ Assert(zero, "external string expected, but not found");
}
+ // Rule out short external strings.
+ STATIC_CHECK(kShortExternalStringTag != 0);
+ __ test_b(result, kShortExternalStringMask);
+ __ j(not_zero, call_runtime);
+ // Check encoding.
+ STATIC_ASSERT(kTwoByteStringTag == 0);
+ __ test_b(result, kStringEncodingMask);
__ mov(result, FieldOperand(string, ExternalString::kResourceDataOffset));
- // Assert that the external string has not been finalized yet.
- __ test(result, result);
- __ j(zero, call_runtime);
- Register scratch = string;
- __ mov(scratch, FieldOperand(string, HeapObject::kMapOffset));
- __ cmp(scratch, Immediate(factory->external_ascii_string_map()));
- __ j(equal, &ascii_external, Label::kNear);
- __ cmp(scratch, Immediate(factory->external_ascii_symbol_map()));
- __ j(equal, &ascii_external, Label::kNear);
+ __ j(not_equal, &ascii_external, Label::kNear);
// Two-byte string.
__ movzx_w(result, Operand(result, index, times_2, 0));
__ jmp(&done);
}
-void ExternalString::clear_data_cache() {
- WRITE_INTPTR_FIELD(this, kResourceDataOffset, 0);
+bool ExternalString::is_short() {
+ InstanceType type = map()->instance_type();
+ return (type & kShortExternalStringMask) == kShortExternalStringTag;
}
}
+void ExternalAsciiString::update_data_cache() {
+ if (is_short()) return;
+ const char** data_field =
+ reinterpret_cast<const char**>(FIELD_ADDR(this, kResourceDataOffset));
+ *data_field = resource()->data();
+}
+
+
void ExternalAsciiString::set_resource(
const ExternalAsciiString::Resource* resource) {
*reinterpret_cast<const Resource**>(
FIELD_ADDR(this, kResourceOffset)) = resource;
- clear_data_cache();
+ if (resource != NULL) update_data_cache();
}
const char* ExternalAsciiString::GetChars() {
- const char** data_field =
- reinterpret_cast<const char**>(FIELD_ADDR(this, kResourceDataOffset));
- if (*data_field == NULL) *data_field = resource()->data();
- return *data_field;
+ return resource()->data();
}
}
+void ExternalTwoByteString::update_data_cache() {
+ if (is_short()) return;
+ const uint16_t** data_field =
+ reinterpret_cast<const uint16_t**>(FIELD_ADDR(this, kResourceDataOffset));
+ *data_field = resource()->data();
+}
+
+
void ExternalTwoByteString::set_resource(
const ExternalTwoByteString::Resource* resource) {
*reinterpret_cast<const Resource**>(
FIELD_ADDR(this, kResourceOffset)) = resource;
- clear_data_cache();
+ if (resource != NULL) update_data_cache();
}
const uint16_t* ExternalTwoByteString::GetChars() {
- const uint16_t** data_field =
- reinterpret_cast<const uint16_t**>(FIELD_ADDR(this, kResourceDataOffset));
- if (*data_field == NULL) *data_field = resource()->data();
- return *data_field;
+ return resource()->data();
}
case EXTERNAL_ASCII_SYMBOL_TYPE:
case EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE:
case EXTERNAL_SYMBOL_TYPE: return "EXTERNAL_SYMBOL";
+ case SHORT_EXTERNAL_ASCII_SYMBOL_TYPE:
+ case SHORT_EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE:
+ case SHORT_EXTERNAL_SYMBOL_TYPE: return "SHORT_EXTERNAL_SYMBOL";
case ASCII_STRING_TYPE: return "ASCII_STRING";
case STRING_TYPE: return "TWO_BYTE_STRING";
case CONS_STRING_TYPE:
case EXTERNAL_ASCII_STRING_TYPE:
case EXTERNAL_STRING_WITH_ASCII_DATA_TYPE:
case EXTERNAL_STRING_TYPE: return "EXTERNAL_STRING";
+ case SHORT_EXTERNAL_ASCII_STRING_TYPE:
+ case SHORT_EXTERNAL_STRING_WITH_ASCII_DATA_TYPE:
+ case SHORT_EXTERNAL_STRING_TYPE: return "SHORT_EXTERNAL_STRING";
case FIXED_ARRAY_TYPE: return "FIXED_ARRAY";
case BYTE_ARRAY_TYPE: return "BYTE_ARRAY";
case FREE_SPACE_TYPE: return "FREE_SPACE";
case kExternalStringTag:
return GetVisitorIdForSize(kVisitDataObject,
kVisitDataObjectGeneric,
- ExternalString::kSize);
+ instance_size);
}
UNREACHABLE();
}
#endif // DEBUG
Heap* heap = GetHeap();
int size = this->Size(); // Byte size of the original string.
- if (size < ExternalString::kSize) {
+ if (size < ExternalString::kShortSize) {
return false;
}
- ASSERT(size >= ExternalString::kSize);
bool is_ascii = this->IsAsciiRepresentation();
bool is_symbol = this->IsSymbol();
- int length = this->length();
- int hash_field = this->hash_field();
// Morph the object to an external string by adjusting the map and
// reinitializing the fields.
- this->set_map(is_ascii ?
- heap->external_string_with_ascii_data_map() :
- heap->external_string_map());
+ if (size >= ExternalString::kSize) {
+ this->set_map(
+ is_symbol
+ ? (is_ascii ? heap->external_symbol_with_ascii_data_map()
+ : heap->external_symbol_map())
+ : (is_ascii ? heap->external_string_with_ascii_data_map()
+ : heap->external_string_map()));
+ } else {
+ this->set_map(
+ is_symbol
+ ? (is_ascii ? heap->short_external_symbol_with_ascii_data_map()
+ : heap->short_external_symbol_map())
+ : (is_ascii ? heap->short_external_string_with_ascii_data_map()
+ : heap->short_external_string_map()));
+ }
ExternalTwoByteString* self = ExternalTwoByteString::cast(this);
- self->set_length(length);
- self->set_hash_field(hash_field);
self->set_resource(resource);
- // Additionally make the object into an external symbol if the original string
- // was a symbol to start with.
- if (is_symbol) {
- self->Hash(); // Force regeneration of the hash value.
- // Now morph this external string into a external symbol.
- this->set_map(is_ascii ?
- heap->external_symbol_with_ascii_data_map() :
- heap->external_symbol_map());
- }
+ if (is_symbol) self->Hash(); // Force regeneration of the hash value.
// Fill the remainder of the string with dead wood.
int new_size = this->Size(); // Byte size of the external String object.
#endif // DEBUG
Heap* heap = GetHeap();
int size = this->Size(); // Byte size of the original string.
- if (size < ExternalString::kSize) {
+ if (size < ExternalString::kShortSize) {
return false;
}
- ASSERT(size >= ExternalString::kSize);
bool is_symbol = this->IsSymbol();
- int length = this->length();
- int hash_field = this->hash_field();
// Morph the object to an external string by adjusting the map and
- // reinitializing the fields.
- this->set_map(heap->external_ascii_string_map());
+ // reinitializing the fields. Use short version if space is limited.
+ if (size >= ExternalString::kSize) {
+ this->set_map(is_symbol ? heap->external_ascii_symbol_map()
+ : heap->external_ascii_string_map());
+ } else {
+ this->set_map(is_symbol ? heap->short_external_ascii_symbol_map()
+ : heap->short_external_ascii_string_map());
+ }
ExternalAsciiString* self = ExternalAsciiString::cast(this);
- self->set_length(length);
- self->set_hash_field(hash_field);
self->set_resource(resource);
- // Additionally make the object into an external symbol if the original string
- // was a symbol to start with.
- if (is_symbol) {
- self->Hash(); // Force regeneration of the hash value.
- // Now morph this external string into a external symbol.
- this->set_map(heap->external_ascii_symbol_map());
- }
+ if (is_symbol) self->Hash(); // Force regeneration of the hash value.
// Fill the remainder of the string with dead wood.
int new_size = this->Size(); // Byte size of the external String object.
if (Marking::IsBlack(Marking::MarkBitFrom(this))) {
MemoryChunk::IncrementLiveBytes(this->address(), new_size - size);
}
-
return true;
}
V(EXTERNAL_SYMBOL_TYPE) \
V(EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE) \
V(EXTERNAL_ASCII_SYMBOL_TYPE) \
+ V(SHORT_EXTERNAL_SYMBOL_TYPE) \
+ V(SHORT_EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE) \
+ V(SHORT_EXTERNAL_ASCII_SYMBOL_TYPE) \
V(STRING_TYPE) \
V(ASCII_STRING_TYPE) \
V(CONS_STRING_TYPE) \
V(EXTERNAL_STRING_TYPE) \
V(EXTERNAL_STRING_WITH_ASCII_DATA_TYPE) \
V(EXTERNAL_ASCII_STRING_TYPE) \
+ V(SHORT_EXTERNAL_STRING_TYPE) \
+ V(SHORT_EXTERNAL_STRING_WITH_ASCII_DATA_TYPE) \
+ V(SHORT_EXTERNAL_ASCII_STRING_TYPE) \
V(PRIVATE_EXTERNAL_ASCII_STRING_TYPE) \
\
V(MAP_TYPE) \
ExternalAsciiString::kSize, \
external_ascii_symbol, \
ExternalAsciiSymbol) \
+ V(SHORT_EXTERNAL_SYMBOL_TYPE, \
+ ExternalTwoByteString::kShortSize, \
+ short_external_symbol, \
+ ShortExternalSymbol) \
+ V(SHORT_EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE, \
+ ExternalTwoByteString::kShortSize, \
+ short_external_symbol_with_ascii_data, \
+ ShortExternalSymbolWithAsciiData) \
+ V(SHORT_EXTERNAL_ASCII_SYMBOL_TYPE, \
+ ExternalAsciiString::kShortSize, \
+ short_external_ascii_symbol, \
+ ShortExternalAsciiSymbol) \
V(STRING_TYPE, \
kVariableSizeSentinel, \
string, \
V(EXTERNAL_ASCII_STRING_TYPE, \
ExternalAsciiString::kSize, \
external_ascii_string, \
- ExternalAsciiString)
+ ExternalAsciiString) \
+ V(SHORT_EXTERNAL_STRING_TYPE, \
+ ExternalTwoByteString::kShortSize, \
+ short_external_string, \
+ ShortExternalString) \
+ V(SHORT_EXTERNAL_STRING_WITH_ASCII_DATA_TYPE, \
+ ExternalTwoByteString::kShortSize, \
+ short_external_string_with_ascii_data, \
+ ShortExternalStringWithAsciiData) \
+ V(SHORT_EXTERNAL_ASCII_STRING_TYPE, \
+ ExternalAsciiString::kShortSize, \
+ short_external_ascii_string, \
+ ShortExternalAsciiString)
// A struct is a simple object a set of object-valued fields. Including an
// object type in this causes the compiler to generate most of the boilerplate
const uint32_t kAsciiDataHintMask = 0x08;
const uint32_t kAsciiDataHintTag = 0x08;
+// If bit 7 is clear and string representation indicates an external string,
+// then bit 4 indicates whether the data pointer is cached.
+const uint32_t kShortExternalStringMask = 0x10;
+const uint32_t kShortExternalStringTag = 0x10;
+
// A ConsString with an empty string as the right side is a candidate
// for being shortcut by the garbage collector unless it is a
ASCII_SYMBOL_TYPE = kAsciiStringTag | kSymbolTag | kSeqStringTag,
CONS_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kConsStringTag,
CONS_ASCII_SYMBOL_TYPE = kAsciiStringTag | kSymbolTag | kConsStringTag,
+ SHORT_EXTERNAL_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag |
+ kExternalStringTag | kShortExternalStringTag,
+ SHORT_EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE =
+ kTwoByteStringTag | kSymbolTag | kExternalStringTag |
+ kAsciiDataHintTag | kShortExternalStringTag,
+ SHORT_EXTERNAL_ASCII_SYMBOL_TYPE = kAsciiStringTag | kExternalStringTag |
+ kSymbolTag | kShortExternalStringTag,
EXTERNAL_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kExternalStringTag,
EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE =
kTwoByteStringTag | kSymbolTag | kExternalStringTag | kAsciiDataHintTag,
CONS_ASCII_STRING_TYPE = kAsciiStringTag | kConsStringTag,
SLICED_STRING_TYPE = kTwoByteStringTag | kSlicedStringTag,
SLICED_ASCII_STRING_TYPE = kAsciiStringTag | kSlicedStringTag,
+ SHORT_EXTERNAL_STRING_TYPE =
+ kTwoByteStringTag | kExternalStringTag | kShortExternalStringTag,
+ SHORT_EXTERNAL_STRING_WITH_ASCII_DATA_TYPE =
+ kTwoByteStringTag | kExternalStringTag |
+ kAsciiDataHintTag | kShortExternalStringTag,
+ SHORT_EXTERNAL_ASCII_STRING_TYPE =
+ kAsciiStringTag | kExternalStringTag | kShortExternalStringTag,
EXTERNAL_STRING_TYPE = kTwoByteStringTag | kExternalStringTag,
EXTERNAL_STRING_WITH_ASCII_DATA_TYPE =
kTwoByteStringTag | kExternalStringTag | kAsciiDataHintTag,
// Layout description.
static const int kResourceOffset = POINTER_SIZE_ALIGN(String::kSize);
+ static const int kShortSize = kResourceOffset + kPointerSize;
static const int kResourceDataOffset = kResourceOffset + kPointerSize;
static const int kSize = kResourceDataOffset + kPointerSize;
- // Clear the cached pointer to the character array provided by the resource.
- // This cache is updated the first time the character array is accessed.
- inline void clear_data_cache();
+ // Return whether external string is short (data pointer is not cached).
+ inline bool is_short();
STATIC_CHECK(kResourceOffset == Internals::kStringResourceOffset);
inline const Resource* resource();
inline void set_resource(const Resource* buffer);
+ // Update the pointer cache to the external character array.
+ // The cached pointer is always valid, as the external character array does =
+ // not move during lifetime. Deserialization is the only exception, after
+ // which the pointer cache has to be refreshed.
+ inline void update_data_cache();
+
inline const char* GetChars();
// Dispatched behavior.
inline const Resource* resource();
inline void set_resource(const Resource* buffer);
+ // Update the pointer cache to the external character array.
+ // The cached pointer is always valid, as the external character array does =
+ // not move during lifetime. Deserialization is the only exception, after
+ // which the pointer cache has to be refreshed.
+ inline void update_data_cache();
+
inline const uint16_t* GetChars();
// Dispatched behavior.
isolate_->heap()->set_global_contexts_list(
isolate_->heap()->undefined_value());
+
+ // Update data pointers to the external strings containing natives sources.
+ for (int i = 0; i < Natives::GetBuiltinsCount(); i++) {
+ Object* source = isolate_->heap()->natives_source_cache()->get(i);
+ if (!source->IsUndefined()) {
+ ExternalAsciiString::cast(source)->update_data_cache();
+ }
+ }
}
sink_->Put(kNativesStringResource, "NativesStringResource");
sink_->PutSection(i, "NativesStringResourceEnd");
bytes_processed_so_far_ += sizeof(resource);
- string->clear_data_cache();
return;
}
}
HEAP->CollectGarbage(i::NEW_SPACE);
HEAP->CollectGarbage(i::NEW_SPACE);
- uint16_t* two_byte_string = AsciiToTwoByteString("abcdefghi");
+ uint16_t* two_byte_string = AsciiToTwoByteString("s1");
Local<String> small_string = String::New(two_byte_string);
i::DeleteArray(two_byte_string);
// Old space strings should be accepted.
CHECK(small_string->CanMakeExternal());
- two_byte_string = AsciiToTwoByteString("abcdefghi");
+ two_byte_string = AsciiToTwoByteString("small string 2");
small_string = String::New(two_byte_string);
i::DeleteArray(two_byte_string);
HEAP->CollectGarbage(i::NEW_SPACE);
HEAP->CollectGarbage(i::NEW_SPACE);
- Local<String> small_string = String::New("abcdefghi");
+ Local<String> small_string = String::New("s1");
// We should refuse to externalize newly created small string.
CHECK(!small_string->CanMakeExternal());
// Trigger GCs so that the newly allocated string moves to old gen.
// Old space strings should be accepted.
CHECK(small_string->CanMakeExternal());
- small_string = String::New("abcdefghi");
+ small_string = String::New("small string 2");
// We should refuse externalizing newly created small string.
CHECK(!small_string->CanMakeExternal());
for (int i = 0; i < 100; i++) {
assertTrue(isAsciiString(str));
var twoByteExternalWithAsciiData =
- "AAAAAAAA" + (function() { return "A"; })();
+ "AA" + (function() { return "A"; })();
externalizeString(twoByteExternalWithAsciiData, true /* force two-byte */);
assertFalse(isAsciiString(twoByteExternalWithAsciiData));
assertEquals('A', charat_str[i].charAt(3*16 + 10));
assertEquals('B', charat_str[i].charAt(3*16 + 11));
}
+
+ charat_short = "012";
+ try { // String can only be externalized once
+ externalizeString(charat_short, true);
+ } catch (ex) { }
+ assertEquals("1", charat_short.charAt(1));
}
// Run the test many times to ensure IC-s don't break things.
projects / platform / upstream / v8.git / commitdiff