io #

Description:

io provides common interfaces for buffered reading/writing of data.

fn cp(mut src Reader, mut dst Writer) ?

fn make_readerwriter(r Reader, w Writer) ReaderWriterImpl

make_readerwriter takes a rstream and a wstream and makes an rwstream with them

fn new_buffered_reader(o BufferedReaderConfig) &BufferedReader

new_buffered_reader creates new BufferedReader

fn new_multi_writer(writers ...Writer) Writer

new_multi_writer returns a Writer that writes to all writers. The write function of the returned Writer writes to all writers of the MultiWriter, returns the length of bytes written, and if any writer fails to write the full length an error is returned and writing to other writers stops, and if any writer returns an error the error is returned immediately and writing to other writers stops.

fn read_all(config ReadAllConfig) ?[]u8

read_all reads all bytes from a reader until either a 0 length read or if read_to_end_of_stream is true then the end of the stream (none)

fn read_any(mut r Reader) ?[]u8

read_any reads any available bytes from a reader (until the reader returns a read of 0 length)

interface RandomReader {
	read_from(pos u64, mut buf []u8) ?int
}

RandomReader represents a stream of data that can be read from at a random location

interface RandomWriter {
	write_to(pos u64, buf []u8) ?int
}

RandomWriter represents a stream of data that can be wrote to at a random pos

interface Reader {
// read reads up to buf.len bytes and places
// them into buf.
// A type that implements this should return
// `io.Eof` on end of stream (EOF) instead of just returning 0
mut:
	read(mut buf []u8) !int
}

Reader represents a stream of data that can be read

interface ReaderWriter {
	Reader
	Writer
}

ReaderWriter represents a stream that can be read from and wrote to

interface Writer {
mut:
	write(buf []u8) ?int
}

Writer represents a stream of data that can be wrote to

fn (mut r ReaderWriterImpl) read(mut buf []u8) !int

fn (mut r ReaderWriterImpl) write(buf []u8) ?int

struct BufferedReader {
mut:
	reader Reader
	buf    []u8
	offset int // current offset in the buffer
	len    int
	fails  int // how many times fill_buffer has read 0 bytes in a row
	mfails int // maximum fails, after which we can assume that the stream has ended
pub mut:
	end_of_stream bool // whether we reached the end of the upstream reader
}

BufferedReader provides a buffered interface for a reader

fn (mut r BufferedReader) read(mut buf []u8) !int

read fufills the Reader interface

fn (mut r BufferedReader) free()

fn (r BufferedReader) end_of_stream() bool

end_of_stream returns whether the end of the stream was reached

fn (mut r BufferedReader) read_line() ?string

read_line attempts to read a line from the buffered reader it will read until it finds a new line character (\n) or the end of stream

struct BufferedReaderConfig {
	reader  Reader
	cap     int = 128 * 1024 // large for fast reading of big(ish) files
	retries int = 2 // how many times to retry before assuming the stream ended
}

BufferedReaderConfig are options that can be given to a reader

struct Eof {
	Error
}

/ Eof error means that we reach the end of the stream.

struct MultiWriter {
pub mut:
	writers []Writer
}

MultiWriter writes to all its writers.

fn (mut m MultiWriter) write(buf []u8) ?int

write writes to all writers of the MultiWriter. Returns the length of bytes written. If any writer fails to write the full length an error is returned and writing to other writers stops. If any writer returns an error the error is returned immediately and writing to other writers stops.

struct NotExpected {
	cause string
	code  int
}

NotExpected is a generic error that means that we receave a not expecte error.

struct ReadAllConfig {
	read_to_end_of_stream bool
mut:
	reader Reader
}

ReadAllConfig allows options to be passed for the behaviour of read_all