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fix conversions to uint in varints.nim (#12564)

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Arne Döring
2019-11-04 13:06:08 +01:00
committed by Andreas Rumpf
parent 62fc3db9d7
commit 992f0a7756
1 changed files with 22 additions and 22 deletions
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44
lib/std/varints.nim
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@@ -49,57 +49,57 @@ proc readVu64*(z: openArray[byte]; pResult: var uint64): int =
return 9
proc varintWrite32(z: var openArray[byte]; y: uint32) =
z[0] = uint8(y shr 24)
z[1] = uint8(y shr 16)
z[2] = uint8(y shr 8)
z[3] = uint8(y)
z[0] = cast[uint8](y shr 24)
z[1] = cast[uint8](y shr 16)
z[2] = cast[uint8](y shr 8)
z[3] = cast[uint8](y)
proc writeVu64*(z: var openArray[byte], x: uint64): int =
## Write a varint into z. The buffer z must be at least 9 characters
## long to accommodate the largest possible varint. Returns the number of
## bytes used.
if x <= 240:
z[0] = uint8 x
z[0] = cast[uint8](x)
return 1
if x <= 2287:
let y = uint32(x - 240)
z[0] = uint8(y shr 8 + 241)
z[1] = uint8(y and 255)
let y = cast[uint32](x - 240)
z[0] = cast[uint8](y shr 8 + 241)
z[1] = cast[uint8](y and 255)
return 2
if x <= 67823:
let y = uint32(x - 2288)
let y = cast[uint32](x - 2288)
z[0] = 249
z[1] = uint8(y shr 8)
z[2] = uint8(y and 255)
z[1] = cast[uint8](y shr 8)
z[2] = cast[uint8](y and 255)
return 3
let y = uint32 x
let w = uint32(x shr 32)
let y = cast[uint32](x)
let w = cast[uint32](x shr 32)
if w == 0:
if y <= 16777215:
z[0] = 250
z[1] = uint8(y shr 16)
z[2] = uint8(y shr 8)
z[3] = uint8(y)
z[1] = cast[uint8](y shr 16)
z[2] = cast[uint8](y shr 8)
z[3] = cast[uint8](y)
return 4
z[0] = 251
varintWrite32(toOpenArray(z, 1, z.high-1), y)
return 5
if w <= 255:
z[0] = 252
z[1] = uint8 w
z[1] = cast[uint8](w)
varintWrite32(toOpenArray(z, 2, z.high-2), y)
return 6
if w <= 65535:
z[0] = 253
z[1] = uint8(w shr 8)
z[2] = uint8 w
z[1] = cast[uint8](w shr 8)
z[2] = cast[uint8](w)
varintWrite32(toOpenArray(z, 3, z.high-3), y)
return 7
if w <= 16777215:
z[0] = 254
z[1] = uint8(w shr 16)
z[2] = uint8(w shr 8)
z[3] = uint8 w
z[1] = cast[uint8](w shr 16)
z[2] = cast[uint8](w shr 8)
z[3] = cast[uint8](w)
varintWrite32(toOpenArray(z, 4, z.high-4), y)
return 8
z[0] = 255