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package buf
import (
"io"
"v2ray.com/core/common"
"v2ray.com/core/common/errors"
"v2ray.com/core/common/serial"
)
// ReadAllToBytes reads all content from the reader into a byte array, until EOF.
func ReadAllToBytes(reader io.Reader) ([]byte, error) {
mb, err := ReadFrom(reader)
if err != nil {
return nil, err
}
if mb.Len() == 0 {
return nil, nil
}
b := make([]byte, mb.Len())
mb, _ = SplitBytes(mb, b)
ReleaseMulti(mb)
return b, nil
}
// MultiBuffer is a list of Buffers. The order of Buffer matters.
type MultiBuffer []*Buffer
// MergeMulti merges content from src to dest, and returns the new address of dest and src
func MergeMulti(dest MultiBuffer, src MultiBuffer) (MultiBuffer, MultiBuffer) {
dest = append(dest, src...)
for idx := range src {
src[idx] = nil
}
return dest, src[:0]
}
// MergeBytes merges the given bytes into MultiBuffer and return the new address of the merged MultiBuffer.
func MergeBytes(dest MultiBuffer, src []byte) MultiBuffer {
n := len(dest)
if n > 0 && !(dest)[n-1].IsFull() {
nBytes, _ := (dest)[n-1].Write(src)
src = src[nBytes:]
}
for len(src) > 0 {
b := New()
nBytes, _ := b.Write(src)
src = src[nBytes:]
dest = append(dest, b)
}
return dest
}
// ReleaseMulti release all content of the MultiBuffer, and returns an empty MultiBuffer.
func ReleaseMulti(mb MultiBuffer) MultiBuffer {
for i := range mb {
mb[i].Release()
mb[i] = nil
}
return mb[:0]
}
// Copy copied the beginning part of the MultiBuffer into the given byte array.
func (mb MultiBuffer) Copy(b []byte) int {
total := 0
for _, bb := range mb {
nBytes := copy(b[total:], bb.Bytes())
total += nBytes
if int32(nBytes) < bb.Len() {
break
}
}
return total
}
// ReadFrom reads all content from reader until EOF.
func ReadFrom(reader io.Reader) (MultiBuffer, error) {
mb := make(MultiBuffer, 0, 16)
for {
b := New()
_, err := b.ReadFullFrom(reader, Size)
if b.IsEmpty() {
b.Release()
} else {
mb = append(mb, b)
}
if err != nil {
if errors.Cause(err) == io.EOF || errors.Cause(err) == io.ErrUnexpectedEOF {
return mb, nil
}
return mb, err
}
}
}
// SplitBytes splits the given amount of bytes from the beginning of the MultiBuffer.
// It returns the new address of MultiBuffer leftover, and number of bytes written into the input byte slice.
func SplitBytes(mb MultiBuffer, b []byte) (MultiBuffer, int) {
totalBytes := 0
endIndex := -1
for i := range mb {
pBuffer := mb[i]
nBytes, _ := pBuffer.Read(b)
totalBytes += nBytes
b = b[nBytes:]
if !pBuffer.IsEmpty() {
endIndex = i
break
}
pBuffer.Release()
mb[i] = nil
}
if endIndex == -1 {
mb = mb[:0]
} else {
mb = mb[endIndex:]
}
return mb, totalBytes
}
// SplitFirstBytes splits the first buffer from MultiBuffer, and then copy its content into the given slice.
func SplitFirstBytes(mb MultiBuffer, p []byte) (MultiBuffer, int) {
mb, b := SplitFirst(mb)
if b == nil {
return mb, 0
}
n := copy(p, b.Bytes())
b.Release()
return mb, n
}
// Compact returns another MultiBuffer by merging all content of the given one together.
func Compact(mb MultiBuffer) MultiBuffer {
if len(mb) == 0 {
return mb
}
mb2 := make(MultiBuffer, 0, len(mb))
last := mb[0]
for i := 1; i < len(mb); i++ {
curr := mb[i]
if last.Len()+curr.Len() > Size {
mb2 = append(mb2, last)
last = curr
} else {
common.Must2(last.ReadFrom(curr))
curr.Release()
}
}
mb2 = append(mb2, last)
return mb2
}
// SplitFirst splits the first Buffer from the beginning of the MultiBuffer.
func SplitFirst(mb MultiBuffer) (MultiBuffer, *Buffer) {
if len(mb) == 0 {
return mb, nil
}
b := mb[0]
mb[0] = nil
mb = mb[1:]
return mb, b
}
// SplitSize splits the beginning of the MultiBuffer into another one, for at most size bytes.
func SplitSize(mb MultiBuffer, size int32) (MultiBuffer, MultiBuffer) {
if len(mb) == 0 {
return mb, nil
}
if mb[0].Len() > size {
b := New()
copy(b.Extend(size), mb[0].BytesTo(size))
mb[0].Advance(size)
return mb, MultiBuffer{b}
}
totalBytes := int32(0)
var r MultiBuffer
endIndex := -1
for i := range mb {
if totalBytes+mb[i].Len() > size {
endIndex = i
break
}
totalBytes += mb[i].Len()
r = append(r, mb[i])
mb[i] = nil
}
if endIndex == -1 {
// To reuse mb array
mb = mb[:0]
} else {
mb = mb[endIndex:]
}
return mb, r
}
// WriteMultiBuffer writes all buffers from the MultiBuffer to the Writer one by one, and return error if any, with leftover MultiBuffer.
func WriteMultiBuffer(writer io.Writer, mb MultiBuffer) (MultiBuffer, error) {
for {
mb2, b := SplitFirst(mb)
mb = mb2
if b == nil {
break
}
_, err := writer.Write(b.Bytes())
b.Release()
if err != nil {
return mb, err
}
}
return nil, nil
}
// Len returns the total number of bytes in the MultiBuffer.
func (mb MultiBuffer) Len() int32 {
if mb == nil {
return 0
}
size := int32(0)
for _, b := range mb {
size += b.Len()
}
return size
}
// IsEmpty return true if the MultiBuffer has no content.
func (mb MultiBuffer) IsEmpty() bool {
for _, b := range mb {
if !b.IsEmpty() {
return false
}
}
return true
}
// String returns the content of the MultiBuffer in string.
func (mb MultiBuffer) String() string {
v := make([]interface{}, len(mb))
for i, b := range mb {
v[i] = b
}
return serial.Concat(v...)
}
// MultiBufferContainer is a ReadWriteCloser wrapper over MultiBuffer.
type MultiBufferContainer struct {
MultiBuffer
}
// Read implements io.Reader.
func (c *MultiBufferContainer) Read(b []byte) (int, error) {
if c.MultiBuffer.IsEmpty() {
return 0, io.EOF
}
mb, nBytes := SplitBytes(c.MultiBuffer, b)
c.MultiBuffer = mb
return nBytes, nil
}
// ReadMultiBuffer implements Reader.
func (c *MultiBufferContainer) ReadMultiBuffer() (MultiBuffer, error) {
mb := c.MultiBuffer
c.MultiBuffer = nil
return mb, nil
}
// Write implements io.Writer.
func (c *MultiBufferContainer) Write(b []byte) (int, error) {
c.MultiBuffer = MergeBytes(c.MultiBuffer, b)
return len(b), nil
}
// WriteMultiBuffer implement Writer.
func (c *MultiBufferContainer) WriteMultiBuffer(b MultiBuffer) error {
mb, _ := MergeMulti(c.MultiBuffer, b)
c.MultiBuffer = mb
return nil
}
// Close implement io.Closer.
func (c *MultiBufferContainer) Close() error {
c.MultiBuffer = ReleaseMulti(c.MultiBuffer)
return nil
}
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