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#
#
# The Nimrod Compiler
# (c) Copyright 2009 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
# Low-level streams for high performance.
import
strutils
type
TLLStreamKind* = enum # stream encapsulates stdin
llsNone, # null stream: reading and writing has no effect
llsString, # stream encapsulates a string
llsFile, # stream encapsulates a file
llsStdIn
TLLStream* = object of TObject
kind*: TLLStreamKind # accessible for low-level access (lexbase uses this)
f*: tfile
s*: string
rd*, wr*: int # for string streams
PLLStream* = ref TLLStream
proc LLStreamOpen*(data: string): PLLStream
proc LLStreamOpen*(f: var tfile): PLLStream
proc LLStreamOpen*(filename: string, mode: TFileMode): PLLStream
proc LLStreamOpen*(): PLLStream
proc LLStreamOpenStdIn*(): PLLStream
proc LLStreamClose*(s: PLLStream)
proc LLStreamRead*(s: PLLStream, buf: pointer, bufLen: int): int
proc LLStreamReadLine*(s: PLLStream): string
proc LLStreamReadAll*(s: PLLStream): string
proc LLStreamWrite*(s: PLLStream, data: string)
proc LLStreamWrite*(s: PLLStream, data: Char)
proc LLStreamWrite*(s: PLLStream, buf: pointer, buflen: int)
proc LLStreamWriteln*(s: PLLStream, data: string)
proc LLStreamAtEnd*(s: PLLStream): bool
# implementation
proc LLStreamOpen(data: string): PLLStream =
new(result)
result.s = data
result.kind = llsString
proc LLStreamOpen(f: var tfile): PLLStream =
new(result)
result.f = f
result.kind = llsFile
proc LLStreamOpen(filename: string, mode: TFileMode): PLLStream =
new(result)
result.kind = llsFile
if not open(result.f, filename, mode): result = nil
proc LLStreamOpen(): PLLStream =
new(result)
result.kind = llsNone
proc LLStreamOpenStdIn(): PLLStream =
new(result)
result.kind = llsStdIn
result.s = ""
proc LLStreamClose(s: PLLStream) =
case s.kind
of llsNone, llsString, llsStdIn:
nil
of llsFile:
close(s.f)
proc LLreadFromStdin(s: PLLStream, buf: pointer, bufLen: int): int =
var
line: string
L: int
s.s = ""
s.rd = 0
while true:
write(stdout, "Nimrod> ")
line = readLine(stdin)
L = len(line)
add(s.s, line)
add(s.s, "\n")
if (L > 0) and (line[L - 1 + 0] == '#'): break
result = min(bufLen, len(s.s) - s.rd)
if result > 0:
copyMem(buf, addr(s.s[0 + s.rd]), result)
inc(s.rd, result)
proc LLStreamRead(s: PLLStream, buf: pointer, bufLen: int): int =
case s.kind
of llsNone:
result = 0
of llsString:
result = min(bufLen, len(s.s) - s.rd)
if result > 0:
copyMem(buf, addr(s.s[0 + s.rd]), result)
inc(s.rd, result)
of llsFile:
result = readBuffer(s.f, buf, bufLen)
of llsStdIn:
result = LLreadFromStdin(s, buf, bufLen)
proc LLStreamReadLine(s: PLLStream): string =
case s.kind
of llsNone:
result = ""
of llsString:
result = ""
while s.rd < len(s.s):
case s.s[s.rd + 0]
of '\x0D':
inc(s.rd)
if s.s[s.rd + 0] == '\x0A': inc(s.rd)
break
of '\x0A':
inc(s.rd)
break
else:
add(result, s.s[s.rd + 0])
inc(s.rd)
of llsFile:
result = readLine(s.f)
of llsStdIn:
result = readLine(stdin)
proc LLStreamAtEnd(s: PLLStream): bool =
case s.kind
of llsNone: result = true
of llsString: result = s.rd >= len(s.s)
of llsFile: result = endOfFile(s.f)
of llsStdIn: result = false
proc LLStreamWrite(s: PLLStream, data: string) =
case s.kind
of llsNone, llsStdIn:
nil
of llsString:
add(s.s, data)
inc(s.wr, len(data))
of llsFile:
write(s.f, data)
proc LLStreamWriteln(s: PLLStream, data: string) =
LLStreamWrite(s, data)
LLStreamWrite(s, "\n")
proc LLStreamWrite(s: PLLStream, data: Char) =
var c: char
case s.kind
of llsNone, llsStdIn:
nil
of llsString:
add(s.s, data)
inc(s.wr)
of llsFile:
c = data
discard writeBuffer(s.f, addr(c), sizeof(c))
proc LLStreamWrite(s: PLLStream, buf: pointer, buflen: int) =
case s.kind
of llsNone, llsStdIn:
nil
of llsString:
if bufLen > 0:
setlen(s.s, len(s.s) + bufLen)
copyMem(addr(s.s[0 + s.wr]), buf, bufLen)
inc(s.wr, bufLen)
of llsFile:
discard writeBuffer(s.f, buf, bufLen)
proc LLStreamReadAll(s: PLLStream): string =
const
bufSize = 2048
var bytes, i: int
case s.kind
of llsNone, llsStdIn:
result = ""
of llsString:
if s.rd == 0: result = s.s
else: result = copy(s.s, s.rd + 0)
s.rd = len(s.s)
of llsFile:
result = newString(bufSize)
bytes = readBuffer(s.f, addr(result[0]), bufSize)
i = bytes
while bytes == bufSize:
setlen(result, i + bufSize)
bytes = readBuffer(s.f, addr(result[i + 0]), bufSize)
inc(i, bytes)
setlen(result, i)
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