46 lines
1.5 KiB
Nim
46 lines
1.5 KiB
Nim
# Nimbus
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# Copyright (c) 2018 Status Research & Development GmbH
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# Licensed under either of
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# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
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# * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
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# at your option. This file may not be copied, modified, or distributed except according to those terms.
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import
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stint, strformat, strutils, sequtils, endians, macros, rlp,
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../../constants, ../../utils/padding
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# some methods based on py-evm utils/numeric
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proc bigEndianToInt*(value: openarray[byte]): UInt256 =
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if value.len == 32:
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readUintBE[256](value)
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else:
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readUintBE[256](padLeft(@value, 32, 0.byte))
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proc log256*(value: UInt256): Natural =
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(255 - value.countLeadingZeroBits) div 8 # Compilers optimize to `shr 3`
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proc unsignedToPseudoSigned*(value: UInt256): UInt256 =
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result = value
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if value > INT_256_MAX_AS_UINT256:
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result -= INT_256_MAX_AS_UINT256
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proc pseudoSignedToUnsigned*(value: UInt256): UInt256 =
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result = value
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if value > INT_256_MAX_AS_UINT256:
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result += INT_256_MAX_AS_UINT256
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func ceil32*(value: Natural): Natural {.inline.}=
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# Round input to the nearest bigger multiple of 32
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result = value
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let remainder = result and 31 # equivalent to modulo 32
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if remainder != 0:
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return value + 32 - remainder
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func wordCount*(length: Natural): Natural {.inline.}=
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# Returns the number of EVM words corresponding to a specific size.
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# EVM words is rounded up
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length.ceil32 shr 5 # equivalent to `div 32` (32 = 2^5)
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