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import endians
proc swapEndian16*(outp, inp: pointer) =
## copies `inp` to `outp` swapping bytes. Both buffers are supposed to
## contain at least 2 bytes.
var i = cast[cstring](inp)
var o = cast[cstring](outp)
o[0] = i[1]
o[1] = i[0]
when cpuEndian == bigEndian:
proc bigEndian16(outp, inp: pointer) {.inline.} = copyMem(outp, inp, 2)
else:
proc bigEndian16*(outp, inp: pointer) {.inline.} = swapEndian16(outp, inp)
import enet
type
PBuffer* = ref object
data*: string
pos: int
proc free(b: PBuffer) =
GCunref b.data
proc newBuffer*(len: int): PBuffer =
new result, free
result.data = newString(len)
proc newBuffer*(pkt: PPacket): PBuffer =
new result, free
result.data = newString(pkt.dataLength)
copyMem(addr result.data[0], pkt.data, pkt.dataLength)
proc toPacket*(buffer: PBuffer; flags: TPacketFlag): PPacket =
buffer.data.setLen buffer.pos
result = createPacket(cstring(buffer.data), buffer.pos, flags)
proc isDirty*(buffer: PBuffer): bool {.inline.} =
result = (buffer.pos != 0)
proc atEnd*(buffer: PBuffer): bool {.inline.} =
result = (buffer.pos == buffer.data.len)
proc reset*(buffer: PBuffer) {.inline.} =
buffer.pos = 0
proc flush*(buf: PBuffer) =
buf.pos = 0
buf.data.setLen(0)
proc send*(peer: PPeer; channel: cuchar; buf: PBuffer; flags: TPacketFlag): cint {.discardable.} =
result = send(peer, channel, buf.toPacket(flags))
proc read*[T: int16|uint16](buffer: PBuffer; outp: var T) =
bigEndian16(addr outp, addr buffer.data[buffer.pos])
inc buffer.pos, 2
proc read*[T: float32|int32|uint32](buffer: PBuffer; outp: var T) =
bigEndian32(addr outp, addr buffer.data[buffer.pos])
inc buffer.pos, 4
proc read*[T: float64|int64|uint64](buffer: PBuffer; outp: var T) =
bigEndian64(addr outp, addr buffer.data[buffer.pos])
inc buffer.pos, 8
proc read*[T: int8|uint8|byte|bool|char](buffer: PBuffer; outp: var T) =
copyMem(addr outp, addr buffer.data[buffer.pos], 1)
inc buffer.pos, 1
proc writeBE*[T: int16|uint16](buffer: PBuffer; val: var T) =
setLen buffer.data, buffer.pos + 2
bigEndian16(addr buffer.data[buffer.pos], addr val)
inc buffer.pos, 2
proc writeBE*[T: int32|uint32|float32](buffer: PBuffer; val: var T) =
setLen buffer.data, buffer.pos + 4
bigEndian32(addr buffer.data[buffer.pos], addr val)
inc buffer.pos, 4
proc writeBE*[T: int64|uint64|float64](buffer: PBuffer; val: var T) =
setLen buffer.data, buffer.pos + 8
bigEndian64(addr buffer.data[buffer.pos], addr val)
inc buffer.pos, 8
proc writeBE*[T: char|int8|uint8|byte|bool](buffer: PBuffer; val: var T) =
setLen buffer.data, buffer.pos + 1
copyMem(addr buffer.data[buffer.pos], addr val, 1)
inc buffer.pos, 1
proc write*(buffer: PBuffer; val: var string) =
var length = len(val).uint16
writeBE buffer, length
setLen buffer.data, buffer.pos + length.int
copyMem(addr buffer.data[buffer.pos], addr val[0], length.int)
inc buffer.pos, length.int
proc write*[T: TNumber|bool|char|byte](buffer: PBuffer; val: T) =
var v: T
shallowCopy v, val
writeBE buffer, v
proc readInt8*(buffer: PBuffer): int8 =
read buffer, result
proc readInt16*(buffer: PBuffer): int16 =
read buffer, result
proc readInt32*(buffer: PBuffer): int32 =
read buffer, result
proc readInt64*(buffer: PBuffer): int64 =
read buffer, result
proc readFloat32*(buffer: PBuffer): float32 =
read buffer, result
proc readFloat64*(buffer: PBuffer): float64 =
read buffer, result
proc readStr*(buffer: PBuffer): string =
let len = readInt16(buffer).int
result = ""
if len > 0:
result.setLen len
copyMem(addr result[0], addr buffer.data[buffer.pos], len)
inc buffer.pos, len
proc readChar*(buffer: PBuffer): char {.inline.} = return readInt8(buffer).char
proc readBool*(buffer: PBuffer): bool {.inline.} = return readInt8(buffer).bool
when isMainModule:
var b = newBuffer(100)
var str = "hello there"
b.write str
echo(repr(b))
b.pos = 0
echo(repr(b.readStr()))
b.flush()
echo "flushed"
b.writeC([1,2,3])
echo(repr(b))
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