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Diffstat (limited to 'contracts/core/contracts/utils/LibBytes/LibBytes.sol')
-rw-r--r-- | contracts/core/contracts/utils/LibBytes/LibBytes.sol | 567 |
1 files changed, 0 insertions, 567 deletions
diff --git a/contracts/core/contracts/utils/LibBytes/LibBytes.sol b/contracts/core/contracts/utils/LibBytes/LibBytes.sol deleted file mode 100644 index 369f588ad..000000000 --- a/contracts/core/contracts/utils/LibBytes/LibBytes.sol +++ /dev/null @@ -1,567 +0,0 @@ -/* - - Copyright 2018 ZeroEx Intl. - - 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. - -*/ - -pragma solidity 0.4.24; - - -library LibBytes { - - using LibBytes for bytes; - - /// @dev Gets the memory address for a byte array. - /// @param input Byte array to lookup. - /// @return memoryAddress Memory address of byte array. This - /// points to the header of the byte array which contains - /// the length. - function rawAddress(bytes memory input) - internal - pure - returns (uint256 memoryAddress) - { - assembly { - memoryAddress := input - } - return memoryAddress; - } - - /// @dev Gets the memory address for the contents of a byte array. - /// @param input Byte array to lookup. - /// @return memoryAddress Memory address of the contents of the byte array. - function contentAddress(bytes memory input) - internal - pure - returns (uint256 memoryAddress) - { - assembly { - memoryAddress := add(input, 32) - } - return memoryAddress; - } - - /// @dev Copies `length` bytes from memory location `source` to `dest`. - /// @param dest memory address to copy bytes to. - /// @param source memory address to copy bytes from. - /// @param length number of bytes to copy. - function memCopy( - uint256 dest, - uint256 source, - uint256 length - ) - internal - pure - { - if (length < 32) { - // Handle a partial word by reading destination and masking - // off the bits we are interested in. - // This correctly handles overlap, zero lengths and source == dest - assembly { - let mask := sub(exp(256, sub(32, length)), 1) - let s := and(mload(source), not(mask)) - let d := and(mload(dest), mask) - mstore(dest, or(s, d)) - } - } else { - // Skip the O(length) loop when source == dest. - if (source == dest) { - return; - } - - // For large copies we copy whole words at a time. The final - // word is aligned to the end of the range (instead of after the - // previous) to handle partial words. So a copy will look like this: - // - // #### - // #### - // #### - // #### - // - // We handle overlap in the source and destination range by - // changing the copying direction. This prevents us from - // overwriting parts of source that we still need to copy. - // - // This correctly handles source == dest - // - if (source > dest) { - assembly { - // We subtract 32 from `sEnd` and `dEnd` because it - // is easier to compare with in the loop, and these - // are also the addresses we need for copying the - // last bytes. - length := sub(length, 32) - let sEnd := add(source, length) - let dEnd := add(dest, length) - - // Remember the last 32 bytes of source - // This needs to be done here and not after the loop - // because we may have overwritten the last bytes in - // source already due to overlap. - let last := mload(sEnd) - - // Copy whole words front to back - // Note: the first check is always true, - // this could have been a do-while loop. - // solhint-disable-next-line no-empty-blocks - for {} lt(source, sEnd) {} { - mstore(dest, mload(source)) - source := add(source, 32) - dest := add(dest, 32) - } - - // Write the last 32 bytes - mstore(dEnd, last) - } - } else { - assembly { - // We subtract 32 from `sEnd` and `dEnd` because those - // are the starting points when copying a word at the end. - length := sub(length, 32) - let sEnd := add(source, length) - let dEnd := add(dest, length) - - // Remember the first 32 bytes of source - // This needs to be done here and not after the loop - // because we may have overwritten the first bytes in - // source already due to overlap. - let first := mload(source) - - // Copy whole words back to front - // We use a signed comparisson here to allow dEnd to become - // negative (happens when source and dest < 32). Valid - // addresses in local memory will never be larger than - // 2**255, so they can be safely re-interpreted as signed. - // Note: the first check is always true, - // this could have been a do-while loop. - // solhint-disable-next-line no-empty-blocks - for {} slt(dest, dEnd) {} { - mstore(dEnd, mload(sEnd)) - sEnd := sub(sEnd, 32) - dEnd := sub(dEnd, 32) - } - - // Write the first 32 bytes - mstore(dest, first) - } - } - } - } - - /// @dev Returns a slices from a byte array. - /// @param b The byte array to take a slice from. - /// @param from The starting index for the slice (inclusive). - /// @param to The final index for the slice (exclusive). - /// @return result The slice containing bytes at indices [from, to) - function slice( - bytes memory b, - uint256 from, - uint256 to - ) - internal - pure - returns (bytes memory result) - { - require( - from <= to, - "FROM_LESS_THAN_TO_REQUIRED" - ); - require( - to < b.length, - "TO_LESS_THAN_LENGTH_REQUIRED" - ); - - // Create a new bytes structure and copy contents - result = new bytes(to - from); - memCopy( - result.contentAddress(), - b.contentAddress() + from, - result.length - ); - return result; - } - - /// @dev Returns a slice from a byte array without preserving the input. - /// @param b The byte array to take a slice from. Will be destroyed in the process. - /// @param from The starting index for the slice (inclusive). - /// @param to The final index for the slice (exclusive). - /// @return result The slice containing bytes at indices [from, to) - /// @dev When `from == 0`, the original array will match the slice. In other cases its state will be corrupted. - function sliceDestructive( - bytes memory b, - uint256 from, - uint256 to - ) - internal - pure - returns (bytes memory result) - { - require( - from <= to, - "FROM_LESS_THAN_TO_REQUIRED" - ); - require( - to < b.length, - "TO_LESS_THAN_LENGTH_REQUIRED" - ); - - // Create a new bytes structure around [from, to) in-place. - assembly { - result := add(b, from) - mstore(result, sub(to, from)) - } - return result; - } - - /// @dev Pops the last byte off of a byte array by modifying its length. - /// @param b Byte array that will be modified. - /// @return The byte that was popped off. - function popLastByte(bytes memory b) - internal - pure - returns (bytes1 result) - { - require( - b.length > 0, - "GREATER_THAN_ZERO_LENGTH_REQUIRED" - ); - - // Store last byte. - result = b[b.length - 1]; - - assembly { - // Decrement length of byte array. - let newLen := sub(mload(b), 1) - mstore(b, newLen) - } - return result; - } - - /// @dev Pops the last 20 bytes off of a byte array by modifying its length. - /// @param b Byte array that will be modified. - /// @return The 20 byte address that was popped off. - function popLast20Bytes(bytes memory b) - internal - pure - returns (address result) - { - require( - b.length >= 20, - "GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED" - ); - - // Store last 20 bytes. - result = readAddress(b, b.length - 20); - - assembly { - // Subtract 20 from byte array length. - let newLen := sub(mload(b), 20) - mstore(b, newLen) - } - return result; - } - - /// @dev Tests equality of two byte arrays. - /// @param lhs First byte array to compare. - /// @param rhs Second byte array to compare. - /// @return True if arrays are the same. False otherwise. - function equals( - bytes memory lhs, - bytes memory rhs - ) - internal - pure - returns (bool equal) - { - // Keccak gas cost is 30 + numWords * 6. This is a cheap way to compare. - // We early exit on unequal lengths, but keccak would also correctly - // handle this. - return lhs.length == rhs.length && keccak256(lhs) == keccak256(rhs); - } - - /// @dev Reads an address from a position in a byte array. - /// @param b Byte array containing an address. - /// @param index Index in byte array of address. - /// @return address from byte array. - function readAddress( - bytes memory b, - uint256 index - ) - internal - pure - returns (address result) - { - require( - b.length >= index + 20, // 20 is length of address - "GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED" - ); - - // Add offset to index: - // 1. Arrays are prefixed by 32-byte length parameter (add 32 to index) - // 2. Account for size difference between address length and 32-byte storage word (subtract 12 from index) - index += 20; - - // Read address from array memory - assembly { - // 1. Add index to address of bytes array - // 2. Load 32-byte word from memory - // 3. Apply 20-byte mask to obtain address - result := and(mload(add(b, index)), 0xffffffffffffffffffffffffffffffffffffffff) - } - return result; - } - - /// @dev Writes an address into a specific position in a byte array. - /// @param b Byte array to insert address into. - /// @param index Index in byte array of address. - /// @param input Address to put into byte array. - function writeAddress( - bytes memory b, - uint256 index, - address input - ) - internal - pure - { - require( - b.length >= index + 20, // 20 is length of address - "GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED" - ); - - // Add offset to index: - // 1. Arrays are prefixed by 32-byte length parameter (add 32 to index) - // 2. Account for size difference between address length and 32-byte storage word (subtract 12 from index) - index += 20; - - // Store address into array memory - assembly { - // The address occupies 20 bytes and mstore stores 32 bytes. - // First fetch the 32-byte word where we'll be storing the address, then - // apply a mask so we have only the bytes in the word that the address will not occupy. - // Then combine these bytes with the address and store the 32 bytes back to memory with mstore. - - // 1. Add index to address of bytes array - // 2. Load 32-byte word from memory - // 3. Apply 12-byte mask to obtain extra bytes occupying word of memory where we'll store the address - let neighbors := and( - mload(add(b, index)), - 0xffffffffffffffffffffffff0000000000000000000000000000000000000000 - ) - - // Make sure input address is clean. - // (Solidity does not guarantee this) - input := and(input, 0xffffffffffffffffffffffffffffffffffffffff) - - // Store the neighbors and address into memory - mstore(add(b, index), xor(input, neighbors)) - } - } - - /// @dev Reads a bytes32 value from a position in a byte array. - /// @param b Byte array containing a bytes32 value. - /// @param index Index in byte array of bytes32 value. - /// @return bytes32 value from byte array. - function readBytes32( - bytes memory b, - uint256 index - ) - internal - pure - returns (bytes32 result) - { - require( - b.length >= index + 32, - "GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED" - ); - - // Arrays are prefixed by a 256 bit length parameter - index += 32; - - // Read the bytes32 from array memory - assembly { - result := mload(add(b, index)) - } - return result; - } - - /// @dev Writes a bytes32 into a specific position in a byte array. - /// @param b Byte array to insert <input> into. - /// @param index Index in byte array of <input>. - /// @param input bytes32 to put into byte array. - function writeBytes32( - bytes memory b, - uint256 index, - bytes32 input - ) - internal - pure - { - require( - b.length >= index + 32, - "GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED" - ); - - // Arrays are prefixed by a 256 bit length parameter - index += 32; - - // Read the bytes32 from array memory - assembly { - mstore(add(b, index), input) - } - } - - /// @dev Reads a uint256 value from a position in a byte array. - /// @param b Byte array containing a uint256 value. - /// @param index Index in byte array of uint256 value. - /// @return uint256 value from byte array. - function readUint256( - bytes memory b, - uint256 index - ) - internal - pure - returns (uint256 result) - { - result = uint256(readBytes32(b, index)); - return result; - } - - /// @dev Writes a uint256 into a specific position in a byte array. - /// @param b Byte array to insert <input> into. - /// @param index Index in byte array of <input>. - /// @param input uint256 to put into byte array. - function writeUint256( - bytes memory b, - uint256 index, - uint256 input - ) - internal - pure - { - writeBytes32(b, index, bytes32(input)); - } - - /// @dev Reads an unpadded bytes4 value from a position in a byte array. - /// @param b Byte array containing a bytes4 value. - /// @param index Index in byte array of bytes4 value. - /// @return bytes4 value from byte array. - function readBytes4( - bytes memory b, - uint256 index - ) - internal - pure - returns (bytes4 result) - { - require( - b.length >= index + 4, - "GREATER_OR_EQUAL_TO_4_LENGTH_REQUIRED" - ); - - // Arrays are prefixed by a 32 byte length field - index += 32; - - // Read the bytes4 from array memory - assembly { - result := mload(add(b, index)) - // Solidity does not require us to clean the trailing bytes. - // We do it anyway - result := and(result, 0xFFFFFFFF00000000000000000000000000000000000000000000000000000000) - } - return result; - } - - /// @dev Reads nested bytes from a specific position. - /// @dev NOTE: the returned value overlaps with the input value. - /// Both should be treated as immutable. - /// @param b Byte array containing nested bytes. - /// @param index Index of nested bytes. - /// @return result Nested bytes. - function readBytesWithLength( - bytes memory b, - uint256 index - ) - internal - pure - returns (bytes memory result) - { - // Read length of nested bytes - uint256 nestedBytesLength = readUint256(b, index); - index += 32; - - // Assert length of <b> is valid, given - // length of nested bytes - require( - b.length >= index + nestedBytesLength, - "GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED" - ); - - // Return a pointer to the byte array as it exists inside `b` - assembly { - result := add(b, index) - } - return result; - } - - /// @dev Inserts bytes at a specific position in a byte array. - /// @param b Byte array to insert <input> into. - /// @param index Index in byte array of <input>. - /// @param input bytes to insert. - function writeBytesWithLength( - bytes memory b, - uint256 index, - bytes memory input - ) - internal - pure - { - // Assert length of <b> is valid, given - // length of input - require( - b.length >= index + 32 + input.length, // 32 bytes to store length - "GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED" - ); - - // Copy <input> into <b> - memCopy( - b.contentAddress() + index, - input.rawAddress(), // includes length of <input> - input.length + 32 // +32 bytes to store <input> length - ); - } - - /// @dev Performs a deep copy of a byte array onto another byte array of greater than or equal length. - /// @param dest Byte array that will be overwritten with source bytes. - /// @param source Byte array to copy onto dest bytes. - function deepCopyBytes( - bytes memory dest, - bytes memory source - ) - internal - pure - { - uint256 sourceLen = source.length; - // Dest length must be >= source length, or some bytes would not be copied. - require( - dest.length >= sourceLen, - "GREATER_OR_EQUAL_TO_SOURCE_BYTES_LENGTH_REQUIRED" - ); - memCopy( - dest.contentAddress(), - source.contentAddress(), - sourceLen - ); - } -} |