diff options
| -rw-r--r-- | lib/pure/streams.nim | 112 |
1 files changed, 111 insertions, 1 deletions
diff --git a/lib/pure/streams.nim b/lib/pure/streams.nim index e706f2016..798c587a1 100644 --- a/lib/pure/streams.nim +++ b/lib/pure/streams.nim @@ -1,7 +1,7 @@ # # # Nim's Runtime Library -# (c) Copyright 2012 Andreas Rumpf +# (c) Copyright 2015 Andreas Rumpf # # See the file "copying.txt", included in this # distribution, for details about the copyright. @@ -31,6 +31,8 @@ type getPositionImpl*: proc (s: Stream): int {.nimcall, tags: [], gcsafe.} readDataImpl*: proc (s: Stream, buffer: pointer, bufLen: int): int {.nimcall, tags: [ReadIOEffect], gcsafe.} + peekDataImpl*: proc (s: Stream, buffer: pointer, + bufLen: int): int {.nimcall, tags: [ReadIOEffect], gcsafe.} writeDataImpl*: proc (s: Stream, buffer: pointer, bufLen: int) {.nimcall, tags: [WriteIOEffect], gcsafe.} flushImpl*: proc (s: Stream) {.nimcall, tags: [WriteIOEffect], gcsafe.} @@ -84,6 +86,11 @@ proc readData*(s, unused: Stream, buffer: pointer, ## low level proc that reads data into an untyped `buffer` of `bufLen` size. result = s.readDataImpl(s, buffer, bufLen) +proc peekData*(s: Stream, buffer: pointer, bufLen: int): int = + ## low level proc that reads data into an untyped `buffer` of `bufLen` size + ## without moving stream position + result = s.peekDataImpl(s, buffer, bufLen) + proc writeData*(s: Stream, buffer: pointer, bufLen: int) = ## low level proc that writes an untyped `buffer` of `bufLen` size ## to the stream `s`. @@ -121,39 +128,77 @@ proc read[T](s: Stream, result: var T) = if readData(s, addr(result), sizeof(T)) != sizeof(T): raise newEIO("cannot read from stream") +proc peek[T](s: Stream, result: var T) = + ## generic peek procedure. Peeks `result` from the stream `s`. + if peekData(s, addr(result), sizeof(T)) != sizeof(T): + raise newEIO("cannot read from stream") + proc readChar*(s: Stream): char = ## reads a char from the stream `s`. Raises `EIO` if an error occurred. ## Returns '\0' as an EOF marker. if readData(s, addr(result), sizeof(result)) != 1: result = '\0' +proc peekChar*(s: Stream): char = + ## peeks a char from the stream `s`. Raises `EIO` if an error occurred. + ## Returns '\0' as an EOF marker. + if peekData(s, addr(result), sizeof(result)) != 1: result = '\0' + proc readBool*(s: Stream): bool = ## reads a bool from the stream `s`. Raises `EIO` if an error occurred. read(s, result) +proc peekBool*(s: Stream): bool = + ## peeks a bool from the stream `s`. Raises `EIO` if an error occured. + peek(s, result) + proc readInt8*(s: Stream): int8 = ## reads an int8 from the stream `s`. Raises `EIO` if an error occurred. read(s, result) +proc peekInt8*(s: Stream): int8 = + ## peeks an int8 from the stream `s`. Raises `EIO` if an error occurred. + peek(s, result) + proc readInt16*(s: Stream): int16 = ## reads an int16 from the stream `s`. Raises `EIO` if an error occurred. read(s, result) +proc peekInt16*(s: Stream): int16 = + ## peeks an int16 from the stream `s`. Raises `EIO` if an error occurred. + peek(s, result) + proc readInt32*(s: Stream): int32 = ## reads an int32 from the stream `s`. Raises `EIO` if an error occurred. read(s, result) +proc peekInt32*(s: Stream): int32 = + ## peeks an int32 from the stream `s`. Raises `EIO` if an error occurred. + peek(s, result) + proc readInt64*(s: Stream): int64 = ## reads an int64 from the stream `s`. Raises `EIO` if an error occurred. read(s, result) +proc peekInt64*(s: Stream): int64 = + ## peeks an int64 from the stream `s`. Raises `EIO` if an error occurred. + peek(s, result) + proc readFloat32*(s: Stream): float32 = ## reads a float32 from the stream `s`. Raises `EIO` if an error occurred. read(s, result) +proc peekFloat32*(s: Stream): float32 = + ## peeks a float32 from the stream `s`. Raises `EIO` if an error occurred. + peek(s, result) + proc readFloat64*(s: Stream): float64 = ## reads a float64 from the stream `s`. Raises `EIO` if an error occurred. read(s, result) +proc peekFloat64*(s: Stream): float64 = + ## peeks a float64 from the stream `s`. Raises `EIO` if an error occurred. + peek(s, result) + proc readStr*(s: Stream, length: int): TaintedString = ## reads a string of length `length` from the stream `s`. Raises `EIO` if ## an error occurred. @@ -161,6 +206,13 @@ proc readStr*(s: Stream, length: int): TaintedString = var L = readData(s, addr(string(result)[0]), length) if L != length: setLen(result.string, L) +proc peekStr*(s: Stream, length: int): TaintedString = + ## peeks a string of length `length` from the stream `s`. Raises `EIO` if + ## an error occurred. + result = newString(length).TaintedString + var L = peekData(s, addr(string(result)[0]), length) + if L != length: setLen(result.string, L) + proc readLine*(s: Stream, line: var TaintedString): bool = ## reads a line of text from the stream `s` into `line`. `line` must not be ## ``nil``! May throw an IO exception. @@ -181,6 +233,30 @@ proc readLine*(s: Stream, line: var TaintedString): bool = line.string.add(c) result = true +proc peekLine*(s: Stream, line: var TaintedString): bool = + ## peeks a line of text from the stream `s` into `line`. `line` must not be + ## ``nil``! May throw an IO exception. + ## A line of text may be delimited by ``CR``, ``LF`` or + ## ``CRLF``. The newline character(s) are not part of the returned string. + ## Returns ``false`` if the end of the file has been reached, ``true`` + ## otherwise. If ``false`` is returned `line` contains no new data. + line.string.setLen(0) + let pos = getPosition(s) + while true: + var c = readChar(s) + if c == '\c': + c = readChar(s) + break + elif c == '\L': break + elif c == '\0': + if line.len > 0: break + else: + setPosition(s, pos) + return false + line.string.add(c) + setPosition(s, pos) + result = true + proc readLine*(s: Stream): TaintedString = ## Reads a line from a stream `s`. Note: This is not very efficient. Raises ## `EIO` if an error occurred. @@ -195,6 +271,23 @@ proc readLine*(s: Stream): TaintedString = else: result.string.add(c) +proc peekLine*(s: Stream): TaintedString = + ## Peeks a line from a stream `s`. Note: This is not very efficient. Raises + ## `EIO` if an error occurred. + result = TaintedString"" + let pos = getPosition(s) + while true: + var c = readChar(s) + if c == '\c': + c = readChar(s) + setPosition(s, pos) + break + if c == '\L' or c == '\0': + setPosition(s, pos) + break + else: + result.string.add(c) + type StringStream* = ref StringStreamObj ## a stream that encapsulates a string StringStreamObj* = object of StreamObj @@ -222,6 +315,12 @@ proc ssReadData(s: Stream, buffer: pointer, bufLen: int): int = copyMem(buffer, addr(s.data[s.pos]), result) inc(s.pos, result) +proc ssPeekData(s: Stream, buffer: pointer, bufLen: int): int = + var s = StringStream(s) + result = min(bufLen, s.data.len - s.pos) + if result > 0: + copyMem(buffer, addr(s.data[s.pos]), result) + proc ssWriteData(s: Stream, buffer: pointer, bufLen: int) = var s = StringStream(s) if bufLen <= 0: @@ -245,6 +344,7 @@ proc newStringStream*(s: string = ""): StringStream = result.setPositionImpl = ssSetPosition result.getPositionImpl = ssGetPosition result.readDataImpl = ssReadData + result.peekDataImpl = ssPeekData result.writeDataImpl = ssWriteData when not defined(js): @@ -266,6 +366,11 @@ when not defined(js): proc fsReadData(s: Stream, buffer: pointer, bufLen: int): int = result = readBuffer(FileStream(s).f, buffer, bufLen) + + proc fsPeekData(s: Stream, buffer: pointer, bufLen: int): int = + let pos = fsGetPosition(s) + result = readBuffer(FileStream(s).f, buffer, bufLen) + fsSetPosition(s, pos) proc fsWriteData(s: Stream, buffer: pointer, bufLen: int) = if writeBuffer(FileStream(s).f, buffer, bufLen) != bufLen: @@ -280,6 +385,7 @@ when not defined(js): result.setPositionImpl = fsSetPosition result.getPositionImpl = fsGetPosition result.readDataImpl = fsReadData + result.peekDataImpl = fsPeekData result.writeDataImpl = fsWriteData result.flushImpl = fsFlush @@ -329,6 +435,9 @@ else: proc hsReadData(s: FileHandleStream, buffer: pointer, bufLen: int): int = result = posix.read(s.handle, buffer, bufLen) inc(s.pos, result) + + proc hsPeekData(s: FileHandleStream, buffer: pointer, bufLen: int): int = + result = posix.read(s.handle, buffer, bufLen) proc hsWriteData(s: FileHandleStream, buffer: pointer, bufLen: int) = if posix.write(s.handle, buffer, bufLen) != bufLen: @@ -344,6 +453,7 @@ else: result.setPosition = hsSetPosition result.getPosition = hsGetPosition result.readData = hsReadData + result.peekData = hsPeekData result.writeData = hsWriteData proc newFileHandleStream*(filename: string, |