65 lines
2.1 KiB
Nim
65 lines
2.1 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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sequtils, stint,
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../constants, ../errors, ../logging, ../validation, ../utils/bytes,
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./utils/utils_numeric
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type
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Memory* = ref object
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logger*: Logger
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bytes*: seq[byte]
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proc newMemory*: Memory =
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new(result)
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result.bytes = @[]
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result.logger = logging.getLogger("memory.Memory")
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proc len*(memory: Memory): int =
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result = memory.bytes.len
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proc extend*(memory: var Memory; startPosition: Natural; size: Natural) =
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if size == 0:
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return
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var newSize = ceil32(startPosition + size)
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if newSize <= len(memory):
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return
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var sizeToExtend = newSize - len(memory)
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memory.bytes = memory.bytes.concat(repeat(0.byte, sizeToExtend))
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proc newMemory*(size: Natural): Memory =
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result = newMemory()
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result.extend(0, size)
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proc read*(memory: var Memory, startPosition: Natural, size: Natural): seq[byte] =
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result = memory.bytes[startPosition ..< (startPosition + size)]
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proc write*(memory: var Memory, startPosition: Natural, value: openarray[byte]) =
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let size = value.len
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if size == 0:
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return
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#echo size
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#echo startPosition
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#validateGte(startPosition, 0)
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#validateGte(size, 0)
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validateLte(startPosition + size, memory.len)
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let index = memory.len
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if memory.len < startPosition + size:
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memory.bytes = memory.bytes.concat(repeat(0.byte, memory.len - (startPosition + size))) # TODO: better logarithmic scaling?
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for z, b in value:
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memory.bytes[z + startPosition] = b
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template write*(memory: var Memory, startPosition: Natural, size: Natural, value: cstring) =
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memory.write(startPosition, value.toBytes)
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# TODO ~ O(n^3):
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# - there is a string allocation with $ (?)
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# - then a conversion to seq (= new allocation) with toBytes
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# - then writing to memory
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