diff options
Diffstat (limited to 'lib/pure/streams.nim')
| -rw-r--r-- | lib/pure/streams.nim | 184 |
1 files changed, 145 insertions, 39 deletions
diff --git a/lib/pure/streams.nim b/lib/pure/streams.nim index e706f2016..8aa8d35d8 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.} @@ -79,23 +81,28 @@ proc readData*(s: Stream, buffer: pointer, bufLen: int): int = ## low level proc that reads data into an untyped `buffer` of `bufLen` size. result = s.readDataImpl(s, buffer, bufLen) -proc readData*(s, unused: Stream, buffer: pointer, +proc readData*(s, unused: Stream, buffer: pointer, bufLen: int): int {.deprecated.} = ## 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`. s.writeDataImpl(s, buffer, bufLen) -proc writeData*(s, unused: Stream, buffer: pointer, +proc writeData*(s, unused: Stream, buffer: pointer, bufLen: int) {.deprecated.} = ## low level proc that writes an untyped `buffer` of `bufLen` size ## to the stream `s`. s.writeDataImpl(s, buffer, bufLen) -proc write*[T](s: Stream, x: T) = +proc write*[T](s: Stream, x: T) = ## generic write procedure. Writes `x` to the stream `s`. Implementation: ## ## .. code-block:: Nim @@ -105,62 +112,112 @@ proc write*[T](s: Stream, x: T) = shallowCopy(y, x) writeData(s, addr(y), sizeof(y)) -proc write*(s: Stream, x: string) = - ## writes the string `x` to the the stream `s`. No length field or +proc write*(s: Stream, x: string) = + ## writes the string `x` to the the stream `s`. No length field or ## terminating zero is written. writeData(s, cstring(x), x.len) -proc writeln*(s: Stream, args: varargs[string, `$`]) = +proc writeLn*(s: Stream, args: varargs[string, `$`]) {.deprecated.} = + ## **Deprecated since version 0.11.4:** Use **writeLine** instead. + for str in args: write(s, str) + write(s, "\n") + +proc writeLine*(s: Stream, args: varargs[string, `$`]) = ## writes one or more strings to the the stream `s` followed ## by a new line. No length field or terminating zero is written. for str in args: write(s, str) write(s, "\n") -proc read[T](s: Stream, result: var T) = +proc read[T](s: Stream, result: var T) = ## generic read procedure. Reads `result` from the stream `s`. 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 readBool*(s: Stream): bool = +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 readInt8*(s: Stream): int8 = +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 readInt16*(s: Stream): int16 = +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 readInt32*(s: Stream): int32 = +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 readInt64*(s: Stream): int64 = +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 readFloat32*(s: Stream): float32 = +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 readFloat64*(s: Stream): float64 = +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 readStr*(s: Stream, length: int): TaintedString = - ## reads a string of length `length` from the stream `s`. Raises `EIO` if +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. result = newString(length).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. @@ -171,7 +228,7 @@ proc readLine*(s: Stream, line: var TaintedString): bool = line.string.setLen(0) while true: var c = readChar(s) - if c == '\c': + if c == '\c': c = readChar(s) break elif c == '\L': break @@ -181,13 +238,24 @@ 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. + let pos = getPosition(s) + defer: setPosition(s, pos) + result = readLine(s, line) + proc readLine*(s: Stream): TaintedString = - ## Reads a line from a stream `s`. Note: This is not very efficient. Raises + ## Reads a line from a stream `s`. Note: This is not very efficient. Raises ## `EIO` if an error occurred. result = TaintedString"" while true: var c = readChar(s) - if c == '\c': + if c == '\c': c = readChar(s) break if c == '\L' or c == '\0': @@ -195,6 +263,13 @@ 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. + let pos = getPosition(s) + defer: setPosition(s, pos) + result = readLine(s) + type StringStream* = ref StringStreamObj ## a stream that encapsulates a string StringStreamObj* = object of StreamObj @@ -206,10 +281,10 @@ type proc ssAtEnd(s: Stream): bool = var s = StringStream(s) return s.pos >= s.data.len - -proc ssSetPosition(s: Stream, pos: int) = + +proc ssSetPosition(s: Stream, pos: int) = var s = StringStream(s) - s.pos = clamp(pos, 0, s.data.high) + s.pos = clamp(pos, 0, s.data.len) proc ssGetPosition(s: Stream): int = var s = StringStream(s) @@ -218,11 +293,17 @@ proc ssGetPosition(s: Stream): int = proc ssReadData(s: Stream, buffer: pointer, bufLen: int): int = var s = StringStream(s) result = min(bufLen, s.data.len - s.pos) - if result > 0: + if result > 0: copyMem(buffer, addr(s.data[s.pos]), result) inc(s.pos, result) -proc ssWriteData(s: Stream, buffer: pointer, bufLen: int) = +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: return @@ -235,7 +316,7 @@ proc ssClose(s: Stream) = var s = StringStream(s) s.data = nil -proc newStringStream*(s: string = ""): StringStream = +proc newStringStream*(s: string = ""): StringStream = ## creates a new stream from the string `s`. new(result) result.data = s @@ -245,12 +326,13 @@ proc newStringStream*(s: string = ""): StringStream = result.setPositionImpl = ssSetPosition result.getPositionImpl = ssGetPosition result.readDataImpl = ssReadData + result.peekDataImpl = ssPeekData result.writeDataImpl = ssWriteData when not defined(js): type - FileStream* = ref FileStreamObj ## a stream that encapsulates a `TFile` + FileStream* = ref FileStreamObj ## a stream that encapsulates a `File` FileStreamObj* = object of Stream f: File {.deprecated: [PFileStream: FileStream, TFileStream: FileStreamObj].} @@ -267,6 +349,11 @@ 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) + defer: fsSetPosition(s, pos) + result = readBuffer(FileStream(s).f, buffer, bufLen) + proc fsWriteData(s: Stream, buffer: pointer, bufLen: int) = if writeBuffer(FileStream(s).f, buffer, bufLen) != bufLen: raise newEIO("cannot write to stream") @@ -280,6 +367,7 @@ when not defined(js): result.setPositionImpl = fsSetPosition result.getPositionImpl = fsGetPosition result.readDataImpl = fsReadData + result.peekDataImpl = fsPeekData result.writeDataImpl = fsWriteData result.flushImpl = fsFlush @@ -300,14 +388,14 @@ else: handle*: FileHandle pos: int - {.deprecated: [PFileHandleStream: FileHandleStream, + {.deprecated: [PFileHandleStream: FileHandleStream, TFileHandleStream: FileHandleStreamObj].} proc newEOS(msg: string): ref OSError = new(result) result.msg = msg - proc hsGetPosition(s: FileHandleStream): int = + proc hsGetPosition(s: FileHandleStream): int = return s.pos when defined(windows): @@ -315,27 +403,30 @@ else: discard else: import posix - - proc hsSetPosition(s: FileHandleStream, pos: int) = + + proc hsSetPosition(s: FileHandleStream, pos: int) = discard lseek(s.handle, pos, SEEK_SET) proc hsClose(s: FileHandleStream) = discard close(s.handle) - proc hsAtEnd(s: FileHandleStream): bool = + proc hsAtEnd(s: FileHandleStream): bool = var pos = hsGetPosition(s) var theEnd = lseek(s.handle, 0, SEEK_END) result = pos >= theEnd hsSetPosition(s, pos) # set position back - proc hsReadData(s: FileHandleStream, buffer: pointer, bufLen: int): int = + proc hsReadData(s: FileHandleStream, buffer: pointer, bufLen: int): int = result = posix.read(s.handle, buffer, bufLen) inc(s.pos, result) - - proc hsWriteData(s: FileHandleStream, buffer: pointer, bufLen: int) = - if posix.write(s.handle, buffer, bufLen) != bufLen: + + 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: raise newEIO("cannot write to stream") inc(s.pos, bufLen) - proc newFileHandleStream*(handle: FileHandle): FileHandleStream = + proc newFileHandleStream*(handle: FileHandle): FileHandleStream = new(result) result.handle = handle result.pos = 0 @@ -344,10 +435,11 @@ else: result.setPosition = hsSetPosition result.getPosition = hsGetPosition result.readData = hsReadData + result.peekData = hsPeekData result.writeData = hsWriteData - proc newFileHandleStream*(filename: string, - mode: FileMode): FileHandleStream = + proc newFileHandleStream*(filename: string, + mode: FileMode): FileHandleStream = when defined(windows): discard else: @@ -361,3 +453,17 @@ else: var handle = open(filename, flags) if handle < 0: raise newEOS("posix.open() call failed") result = newFileHandleStream(handle) + +when isMainModule and defined(testing): + var ss = newStringStream("The quick brown fox jumped over the lazy dog.\nThe lazy dog ran") + assert(ss.getPosition == 0) + assert(ss.peekStr(5) == "The q") + assert(ss.getPosition == 0) # haven't moved + assert(ss.readStr(5) == "The q") + assert(ss.getPosition == 5) # did move + assert(ss.peekLine() == "uick brown fox jumped over the lazy dog.") + assert(ss.getPosition == 5) # haven't moved + var str = newString(100) + assert(ss.peekLine(str)) + assert(str == "uick brown fox jumped over the lazy dog.") + assert(ss.getPosition == 5) # haven't moved |