Skip to content

Commit

Permalink
fix: shift with BigInt instead of JS number (#7703)
Browse files Browse the repository at this point in the history 
Co-authored-by: Begoña Álvarez de la Cruz <[email protected]>
  • Loading branch information
@Tuditi @begonaalvarezd
Tuditi and begonaalvarezd authored Nov 16, 2023
1 parent c9559f0 commit a56001b
Showing 1 changed file with 20 additions and 106 deletions.
126 changes: 20 additions & 106 deletions packages/shared/lib/core/layer-2/classes/special-stream.class.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -46,127 +46,41 @@ export class ReadSpecialStream extends ReadStream {
}
}

function shiftRight(s: bigint, n: bigint): bigint {
const result = BigInteger(s).divide(BigInteger(2).pow(BigInteger(n)))
return BigInt(result.toString())
function shiftRight(n: bigint, shift: bigint): bigint {
return n >> shift
}
// from https://github.com/iotaledger/wasp/blob/12845adea4fc097813a30a061853af4a43407d3c/packages/util/rwutil/convert.go#L113

function size64Encode(n: bigint): Buffer {
if (n < BigInt(0x80)) {
return Buffer.from([Number(n)])
} else if (n < BigInt(0x4000)) {
return Buffer.from([Number(n | BigInt(0x80)), Number(shiftRight(n, BigInt(7)))])
} else if (n < BigInt(0x20_0000)) {
return Buffer.from([
Number(n | BigInt(0x80)),
Number(shiftRight(n, BigInt(7)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(14))),
])
} else if (n < BigInt(0x1000_0000)) {
return Buffer.from([
Number(n | BigInt(0x80)),
Number(shiftRight(n, BigInt(7)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(14)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(21))),
])
} else if (n < BigInt(0x8_0000_0000)) {
return Buffer.from([
Number(n | BigInt(0x80)),
Number(shiftRight(n, BigInt(7)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(14)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(21)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(28))),
])
} else if (n < BigInt(0x400_0000_0000)) {
return Buffer.from([
Number(n | BigInt(0x80)),
Number(shiftRight(n, BigInt(7)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(14)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(21)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(28)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(35))),
])
} else if (n < BigInt(0x2_0000_0000_0000)) {
return Buffer.from([
Number(n | BigInt(0x80)),
Number(shiftRight(n, BigInt(7)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(14)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(21)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(28)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(35)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(42))),
])
} else if (n < BigInt(0x100_0000_0000_0000)) {
return Buffer.from([
Number(n | BigInt(0x80)),
Number(shiftRight(n, BigInt(7)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(14)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(21)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(28)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(35)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(42)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(49))),
])
} else if (n < BigInt(0x8000_0000_0000_0000)) {
return Buffer.from([
Number(n | BigInt(0x80)),
Number(shiftRight(n, BigInt(7)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(14)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(21)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(28)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(35)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(42)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(49)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(56))),
])
} else {
return Buffer.from([
Number(n | BigInt(0x80)),
Number(shiftRight(n, BigInt(7)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(14)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(21)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(28)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(35)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(42)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(49)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(56)) | BigInt(0x80)),
Number(shiftRight(n, BigInt(63))),
])
const parts: number[] = []
while (n >= 0x80) {
parts.push(Number((n & BigInt(0x7f)) | BigInt(0x80)))
n = shiftRight(n, BigInt(7))
}
parts.push(Number(n)) // Last byte, without the continuation bit

return Buffer.from(parts)
}

// Adapted from WASP golang implementation https://github.com/iotaledger/wasp/blob/7f880a7983d24d0dcd225e994d67b29741b318bc/packages/util/rwutil/convert.go#L76
function size64Decode(readByte: () => number): [bigint, null | Error] {
let byte = readByte()

if (!byte) {
return [BigInt(0), new Error('no more bytes')]
}

if (byte < 0x80) {
return [BigInt(byte), null]
}

let value = BigInt(byte) & BigInt(0x7f)

for (let shift = 7; shift < 63; shift += 7) {
let value = BigInt(byte & 0x7f)
let shift = 7
while (shift < 64) {
byte = readByte()
if (!byte) {
return [BigInt(0), new Error('no more bytes')]
if (byte === -1) {
// Assuming -1 signifies end of data or error in readByte
return [BigInt(0), new Error('Unexpected end of data')]
}
value |= BigInt(byte & 0x7f) << BigInt(shift)
if (byte < 0x80) {
return [value | (BigInt(byte) << BigInt(shift)), null]
return [value, null]
}
value |= (BigInt(byte) & BigInt(0x7f)) << BigInt(shift)
}

byte = readByte()
if (!byte) {
return [BigInt(0), new Error('no more bytes')]
}
if (byte > 0x01) {
return [BigInt(0), new Error('size64 overflow')]
shift += 7
}

return [value | (BigInt(byte) << BigInt(63)), null]
return [BigInt(0), new Error('size64 overflow')]
}

0 comments on commit a56001b

Please sign in to comment.