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nim-contract-abi
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Decoder: tuples do not have an offset, their elements do 

No longer read offset when starting dynamic tuple,
read it when reading a dynamic element in a tuple.

Remove Tuple.dynamic, because it's no longer needed.
This commit is contained in:
Mark Spanbroek 2021-12-02 11:13:50 +01:00
parent f40101100e
commit 46b1933aff
1 changed files with 26 additions and 34 deletions
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60
contractabi/decoding.nim
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@ -15,7 +15,6 @@ type
Tuple = object
start: int
index: int
dynamic: bool
Padding = enum
padLeft,
padRight
@ -23,11 +22,11 @@ type
func read*(decoder: var AbiDecoder, T: type): ?!T
func init(_: type Tuple, offset: int, dynamic: bool): Tuple =
Tuple(start: offset, index: offset, dynamic: dynamic)
func init(_: type Tuple, offset: int): Tuple =
Tuple(start: offset, index: offset)
func init(_: type AbiDecoder, bytes: seq[byte], offset=0): AbiDecoder =
AbiDecoder(bytes: bytes, stack: @[Tuple.init(offset, dynamic=false)])
AbiDecoder(bytes: bytes, stack: @[Tuple.init(offset)])
func currentTuple(decoder: var AbiDecoder): var Tuple =
decoder.stack[^1]
@ -105,42 +104,22 @@ func decode[I](decoder: var AbiDecoder, T: type array[I, byte]): ?!T =
arr[0..<arr.len] = ?decoder.read(arr.len, padRight)
success arr
func readOffset(decoder: var AbiDecoder): ?!int =
let offset = ?decoder.read(uint64)
success decoder.currentTuple.start + offset.int
func readTail(decoder: var AbiDecoder): ?!seq[byte] =
let offset = ?decoder.readOffset()
var tailDecoder = AbiDecoder.init(decoder.bytes, offset)
result = tailDecoder.read(seq[byte])
decoder.updateLast(tailDecoder.index)
func decode(decoder: var AbiDecoder, T: type seq[byte]): ?!T =
if decoder.currentTuple.dynamic:
decoder.readTail()
else:
let len = ?decoder.read(uint64)
decoder.read(len.int, padRight)
let len = ?decoder.read(uint64)
decoder.read(len.int, padRight)
func startTuple(decoder: var AbiDecoder, dynamic: bool): ?!void =
var start: int
if decoder.currentTuple.dynamic and dynamic:
start = ?decoder.readOffset()
else:
start = decoder.index
decoder.stack.add(Tuple.init(start, dynamic))
func startTuple(decoder: var AbiDecoder): ?!void =
decoder.stack.add(Tuple.init(decoder.index))
success()
func finishTuple(decoder: var AbiDecoder) =
doAssert decoder.stack.len > 1, "unable to finish a tuple that hasn't started"
let tupl = decoder.stack.pop()
if not tupl.dynamic:
decoder.index = tupl.index
decoder.index = tupl.index
func decode[T: tuple](decoder: var AbiDecoder, _: typedesc[T]): ?!T =
const dynamic = AbiEncoder.isDynamic(T)
var tupl: T
?decoder.startTuple(dynamic)
?decoder.startTuple()
for element in tupl.fields:
element = ?decoder.read(typeof(element))
decoder.finishTuple()
@ -157,7 +136,7 @@ func finish(decoder: var AbiDecoder): ?!void =
func decode[T](decoder: var AbiDecoder, _: type seq[T]): ?!seq[T] =
var sequence: seq[T]
let len = ?decoder.read(uint64)
?decoder.startTuple(dynamic=true)
?decoder.startTuple()
for _ in 0..<len:
sequence.add(?decoder.read(T))
decoder.finishTuple()
@ -165,8 +144,7 @@ func decode[T](decoder: var AbiDecoder, _: type seq[T]): ?!seq[T] =
func decode[I,T](decoder: var AbiDecoder, _: type array[I,T]): ?!array[I,T] =
var arr: array[I, T]
const dynamic = AbiEncoder.isDynamic(T)
?decoder.startTuple(dynamic)
?decoder.startTuple()
for i in 0..<arr.len:
arr[i] = ?decoder.read(T)
decoder.finishTuple()
@ -181,5 +159,19 @@ func decode*(_: type AbiDecoder, bytes: seq[byte], T: type): ?!T =
?decoder.finish()
success value
func readOffset(decoder: var AbiDecoder): ?!int =
let offset = ?decoder.read(uint64)
success decoder.currentTuple.start + offset.int
func readTail*(decoder: var AbiDecoder, T: type): ?!T =
let offset = ?decoder.readOffset()
var tailDecoder = AbiDecoder.init(decoder.bytes, offset.int)
result = tailDecoder.read(T)
decoder.updateLast(tailDecoder.last)
func read*(decoder: var AbiDecoder, T: type): ?!T =
decoder.decode(T)
const dynamic = AbiEncoder.isDynamic(typeof(!result))
if dynamic and decoder.stack.len > 1:
decoder.readTail(T)
else:
decoder.decode(T)