/*

* Copyright (c) Facebook, Inc. and its affiliates.

*

* This source code is licensed under the MIT license found in the

* LICENSE file in the root directory of this source tree.

*/

#ifndef HERMES_SUPPORT_STRINGTABLEENTRY_H

#define HERMES_SUPPORT_STRINGTABLEENTRY_H

#include "llvh/ADT/ArrayRef.h"

#include <cstdint>

namespace hermes {

/// An entry in the string table inside the ConsecutiveStringStorage.

class StringTableEntry {

static constexpr uint32_t UTF16_MASK = 1 << 31;

/// The offset of this string in the string storage.

uint32_t offset_;

/// The length of this string. We use the most significant bit to represent

/// whether it's a UTF16 string.

uint32_t length_;

public:

using StringTableRefTy = llvh::ArrayRef<StringTableEntry>;

using MutStringTableRefTy = llvh::MutableArrayRef<StringTableEntry>;

using StringStorageRefTy = llvh::ArrayRef<unsigned char>;

StringTableEntry(uint32_t offset, uint32_t length, bool isUTF16)

: offset_(offset), length_(length) {

if (isUTF16) {

length_ |= UTF16_MASK;

}

}

/// Default constructor needed for string table resizing.

StringTableEntry() = default;

/// \return the offset of this entry's string in its storage.

uint32_t getOffset() const {

return offset_;

}

/// \return the length of this entry's string.

uint32_t getLength() const {

return length_ & (~UTF16_MASK);

}

/// \return whether this entry is UTF16.

bool isUTF16() const {

return length_ & UTF16_MASK;

}

};

} // namespace hermes

#endif // HERMES_SUPPORT_STRINGTABLEENTRY_H