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// Copyright 2019 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_PARSING_LITERAL_BUFFER_H_
#define V8_PARSING_LITERAL_BUFFER_H_
#include "src/strings/unicode-decoder.h"
#include "src/utils/vector.h"
namespace v8 {
namespace internal {
// LiteralBuffer - Collector of chars of literals.
class LiteralBuffer final {
public:
LiteralBuffer() : backing_store_(), position_(0), is_one_byte_(true) {}
~LiteralBuffer() { backing_store_.Dispose(); }
V8_INLINE void AddChar(char code_unit) {
DCHECK(IsValidAscii(code_unit));
AddOneByteChar(static_cast<byte>(code_unit));
}
V8_INLINE void AddChar(uc32 code_unit) {
if (is_one_byte()) {
if (code_unit <= static_cast<uc32>(unibrow::Latin1::kMaxChar)) {
AddOneByteChar(static_cast<byte>(code_unit));
return;
}
ConvertToTwoByte();
}
AddTwoByteChar(code_unit);
}
bool is_one_byte() const { return is_one_byte_; }
bool Equals(Vector<const char> keyword) const {
return is_one_byte() && keyword.length() == position_ &&
(memcmp(keyword.begin(), backing_store_.begin(), position_) == 0);
}
Vector<const uint16_t> two_byte_literal() const {
return literal<uint16_t>();
}
Vector<const uint8_t> one_byte_literal() const { return literal<uint8_t>(); }
template <typename Char>
Vector<const Char> literal() const {
DCHECK_EQ(is_one_byte_, sizeof(Char) == 1);
DCHECK_EQ(position_ & (sizeof(Char) - 1), 0);
return Vector<const Char>(
reinterpret_cast<const Char*>(backing_store_.begin()),
position_ >> (sizeof(Char) - 1));
}
int length() const { return is_one_byte() ? position_ : (position_ >> 1); }
void Start() {
position_ = 0;
is_one_byte_ = true;
}
template <typename LocalIsolate>
Handle<String> Internalize(LocalIsolate* isolate) const;
private:
static const int kInitialCapacity = 16;
static const int kGrowthFactor = 4;
static const int kMaxGrowth = 1 * MB;
inline bool IsValidAscii(char code_unit) {
// Control characters and printable characters span the range of
// valid ASCII characters (0-127). Chars are unsigned on some
// platforms which causes compiler warnings if the validity check
// tests the lower bound >= 0 as it's always true.
return iscntrl(code_unit) || isprint(code_unit);
}
V8_INLINE void AddOneByteChar(byte one_byte_char) {
DCHECK(is_one_byte());
if (position_ >= backing_store_.length()) ExpandBuffer();
backing_store_[position_] = one_byte_char;
position_ += kOneByteSize;
}
void AddTwoByteChar(uc32 code_unit);
int NewCapacity(int min_capacity);
void ExpandBuffer();
void ConvertToTwoByte();
Vector<byte> backing_store_;
int position_;
bool is_one_byte_;
DISALLOW_COPY_AND_ASSIGN(LiteralBuffer);
};
} // namespace internal
} // namespace v8
#endif // V8_PARSING_LITERAL_BUFFER_H_