36 lines
1.3 KiB
Solidity
36 lines
1.3 KiB
Solidity
// SPDX-License-Identifier: MIT
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pragma solidity ^0.7.0;
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/**
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* @title Bytes
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* @dev Helper methods to transform bytes to other solidity types.
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*/
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library BytesHelper {
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/**
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* @dev Truncate bytes array if its size is more than 20 bytes.
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* NOTE: This function does not perform any checks on the received parameter.
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* Make sure that the _bytes argument has a correct length, not less than 20 bytes.
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* A case when _bytes has length less than 20 will lead to the undefined behaviour,
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* since assembly will read data from memory that is not related to the _bytes argument.
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* @param _bytes to be converted to address type
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* @return addr address included in the firsts 20 bytes of the bytes array in parameter.
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*/
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function bytesToAddress(bytes memory _bytes) internal pure returns (address addr) {
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assembly {
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addr := mload(add(_bytes, 20))
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}
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}
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/**
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* @param _bytes it's 32 length slice to be converted to uint type
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* @param _start start index of slice
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* @return x uint included in the 32 length slice of the bytes array in parameter.
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*/
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function sliceToUint(bytes memory _bytes, uint256 _start) internal pure returns (uint256 x) {
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require(_bytes.length >= _start + 32, "slicing out of range");
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assembly {
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x := mload(add(_bytes, add(0x20, _start)))
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}
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}
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}
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