abstract rtconst class std::Buf

sys::Obj
  std::Buf

@NoPeer

Buf is used to model a block of bytes with random access. Buf is typically backed by a block of memory, but can also be backed by a file:

Buf provides an InStream and OutStream to read and write into the buffer using a configurable position accessed via Buf.pos and Buf.seek.

When using an InStream, bytes are read starting at pos where pos is advanced after each read. The end of stream is reached when pos reaches size. When using the OutStream, bytes are written starting at pos with pos advanced after each write. If pos is less then size then the existing bytes are rewritten and size is not advanced, otherwise the buffer is automatically grown and size is advanced as bytes are appended. It is common to write bytes into the buffer using the OutStream, then call Buf.flip to prepare the buffer to be used for reading.

bytesEqual

Bool bytesEqual(Buf that)

Return if the buffer contents are the same size and same bytes. Note this could be an extremely expensive call for non-memory buffers.

capacity

abstract Int capacity

The number of bytes this buffer can hold without allocating more memory. Capacity is always greater or equal to size. If adding a large number of bytes, it may be more efficient to manually set capacity. See the trim method to automatically set capacity to size. Throw ArgErr if attempting to set capacity less than size. This method is ignored on a file buffer, and unsupported on mmap.

charset

abstract Charset charset

Character set for both the OutStream and InStream.

clear

This clear()

Read the buffer for a fresh read by reseting the buffer's pos and size to zero. The buffer's capacity remains the same. Return this.

close

abstract Bool close()

If this buffer is backed by a file, then close it. If a memory buffer then do nothing. This method is guaranteed to never throw an IOErr. Return true if the buffer was closed successfully or false if closed abnormally.

dup

virtual Buf dup()

Create a new buffer in memory which deeply clones this buffer.

eachLine

Void eachLine(Func<Void,Str> f)

Convenience for in.eachLine

endian

abstract Endian endian

Byte order mode for both OutStream and InStream. Default is Endian.big (network byte order).

equals

virtual override Bool equals(Obj? that)

Buf equality is based on reference equality using the === operator.

fill

virtual This fill(Int b, Int times)

Write the specified byte to the end of the buffer using given count.

Examples:

Buf().fill(0xff, 4)  =>  0xffffffff
flip

This flip()

Flip a buffer from write-mode to read-mode. This method sets total size to current position, and position to 0. Return this.

fromHex

static Buf fromHex(Str s)

Decode the specified hexadecimal string into its binary contents. Any characters which are not included in the set "0-9, a-f, A-F" are ignored as long as they appear between bytes (hi and lo nibbles must be contiguous).

Example:

Buf.make.print("\r\n").toHex   => "0d0a"
Buf.fromHex("0d0a").readAllStr => "\r\n"
get

@Operator
Int get(Int pos)

Get the byte at the specified absolute index. A negative index may be used to access from the end of the buffer. For example get(-1) is translated into get(size()-1). This method accesses the buffer absolutely independent of current position. The get method is accessed via the [] shortcut operator. Throw IndexErr if index out of range.

getByte

protected abstract Int getByte(Int pos)

getBytes

protected abstract Int getBytes(Int pos, Array<Int8> dst, Int off, Int len)

getRange

@Operator
virtual Buf getRange(Range range)

Return a new buffer containing the bytes in the specified absolute range. Negative indexes may be used to access from the end of the buf. This method accesses the buffer absolutely independent of current position. This method is accessed via the [] operator. Throw IndexErr if range illegal.

Examples:

buf := Buf.make
buf.write(0xaa).write(0xbb).write(0xcc).write(0xdd)
buf[0..2]   => 0x[aabbcc]
buf[3..3]   => 0x[dd]
buf[-2..-1] => 0x[ccdd]
buf[0..<2]  => 0x[aabb]
buf[1..-2]  => 0x[bbcc]
in

virtual InStream in()

Get the InStream which reads from this buffer. This method always returns the same instance. If this buffer is backed by a file, then in.close will not close the file - you must use Buf.close.

isEmpty

Bool isEmpty()

Return if size() == 0.

make

static new make(Int capacity := 1024)

Allocate a byte buffer in RAM with the initial given capacity.

more

Bool more()

Return if more bytes are available to read: remaining() > 0.

out

virtual OutStream out()

Get the OutStream which writes to this buffer. This method always returns the same instance. If this buffer is backed by a file, then out.close will not close the file - you must use Buf.close.

peek

Int peek()

Convenience for in.peek

peekChar

Int peekChar()

Convenience for in.peekChar

pipeFrom

protected virtual Int pipeFrom(InStream in, Int len)

pipeTo

protected virtual Void pipeTo(OutStream out, Int len)

pos

abstract Int pos { internal set }

Return the current position for the next read or write. The position is always between 0 and size. If pos is less then size then future writes will rewrite the existing bytes without growing size. Change the position with seek.

print

This print(Obj? s)

Convenience for out.print Return this.

printLine

This printLine(Obj? obj := "")

Convenience for out.printLine Return this.

privateMake

new privateMake()

random

static Buf random(Int size)

Generate a random series of bytes.

Example:

Buf.random(8).toHex  => "d548b54989028b90"
read

Int read()

Convenience for in.read

readAllBuf

Buf readAllBuf()

Convenience for in.readAllBuf

readAllLines

List<Str> readAllLines()

Convenience for in.readAllLines

readAllStr

Str readAllStr(Bool normalizeNewlines := true)

Convenience for in.readAllStr

readBool

Bool readBool()

Convenience for in.readBool

readBuf

Int? readBuf(Buf buf, Int n)

Convenience for in.readBuf

readBufFully

Buf readBufFully(Buf? buf, Int n)

Convenience for in.readBufFully

readChar

Int readChar()

Convenience for in.readChar

readChars

Str readChars(Int n)

Convenience for in.readChars

readF4

Float readF4()

Convenience for in.readF4

readF8

Float readF8()

Convenience for in.readF8

readLine

Str? readLine(Int max := -1)

Convenience for in.readLine

readS1

Int readS1()

Convenience for in.readS1

readS2

Int readS2()

Convenience for in.readS2

readS4

Int readS4()

Convenience for in.readS4

readS8

Int readS8()

Convenience for in.readS8

readStrToken

Str? readStrToken(Int? max := -1, Func<Bool,Int>? c := null)

Convenience for in.readStrToken

readU1

Int readU1()

Convenience for in.readU1

readU2

Int readU2()

Convenience for in.readU2

readU4

Int readU4()

Convenience for in.readU4

readUtf

Str readUtf()

Convenience for in.readUtf

remaining

Int remaining()

Return the remaining number of bytes to read: size-pos.

safeArray

protected virtual Array<Int8> safeArray()

seek

This seek(Int pos)

Set the current position to the specified byte offset. A negative index may be used to access from the end of the buffer. For example seek(-1) is translated into seek(size-1). Return this.

set

@Operator
This set(Int pos, Int byte)

Set is used to overwrite the byte at the specified the index. A negative index may be used to access an index from the end of the buffer. The set method is accessed via the []= shortcut operator. Return this. Throw IndexErr if index is out of range.

setByte

protected abstract Void setByte(Int pos, Int v)

setBytes

protected abstract Void setBytes(Int pos, Array<Int8> src, Int off, Int len)

size

abstract Int size

Return the total number of bytes in the buffer. If the size is set greater than capacity then the buffer's capacity is automatically grown, otherwise capacity remains the same. Setting size does not actually change any bytes in the buffer. A mmap buffer can never be increased from its initial size.

sync

abstract This sync()

If this Buf is backed by a file, then fsync all changes to the storage device. Throw IOErr on error. Return this.

toFile

virtual File toFile(Uri uri)

Create an in-memory File instance for this buffer with the given file URI. The buffer must be a RAM based buffer which is converted to an immutable buffer via Obj.toImmutable semantics. The current time is used for the file's modified time.

toHex

virtual Str toHex()

Encode the buffer contents from 0 to size into a hexadecimal string. This method is unsupported for mmap buffers.

Example:

Buf.make.print("\r\n").toHex   => "0d0a"
Buf.fromHex("0d0a").readAllStr => "\r\n"
toStr

virtual override Str toStr()

Return string summary of the buffer.

trim

virtual This trim()

Trim the capacity such that the underlying storage is optimized for the current size. Return this.

unread

This unread(Int b)

Convenience for in.unread Memory backed buffers support a stack based pushback model like IO streams. File backed buffers will simply rewrite the last position in the file. Return this.

unreadChar

This unreadChar(Int b)

Convenience for in.unreadChar Memory backed buffers support a stack based pushback model like IO streams. File backed buffers will simply rewrite the last position in the file. Return this.

unsafeArray

protected virtual Array<Int8>? unsafeArray()

Convenience for in.readObj

write

This write(Int byte)

Convenience for out.write Return this.

writeBool

This writeBool(Bool b)

Convenience for out.writeBool Return this.

writeBuf

This writeBuf(Buf buf, Int n := buf.remaining())

Convenience for out.writeBuf Return this.

writeChar

This writeChar(Int char)

Convenience for out.writeChar Return this.

writeChars

This writeChars(Str str, Int off := 0, Int len := str.size() - off)

Convenience for out.writeChars Return this.

writeF4

This writeF4(Float r)

Convenience for out.writeF4 Return this.

writeF8

This writeF8(Float r)

Convenience for out.writeF8 Return this.

writeI2

This writeI2(Int n)

Convenience for out.writeI2 Return this.

writeI4

This writeI4(Int n)

Convenience for out.writeI4 Return this.

writeI8

This writeI8(Int n)

Convenience for out.writeI8 Return this.

writeUtf

This writeUtf(Str s)

Convenience for out.writeUtf Return this.

Source

Static Slots

Instance Slots