Extract github.com/calmh/xdr

Godeps/_workspace/src/github.com/calmh/xdr/reader.go

@@ -0,0 +1,169 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+package xdr
+
+import (
+	"errors"
+	"io"
+)
+
+var ErrElementSizeExceeded = errors.New("element size exceeded")
+
+type Reader struct {
+	r   io.Reader
+	err error
+	b   [8]byte
+	sb  []byte
+}
+
+func NewReader(r io.Reader) *Reader {
+	return &Reader{
+		r: r,
+	}
+}
+
+func (r *Reader) ReadRaw(bs []byte) (int, error) {
+	if r.err != nil {
+		return 0, r.err
+	}
+
+	var n int
+	n, r.err = io.ReadFull(r.r, bs)
+	return n, r.err
+}
+
+func (r *Reader) ReadString() string {
+	if r.sb == nil {
+		r.sb = make([]byte, 64)
+	} else {
+		r.sb = r.sb[:cap(r.sb)]
+	}
+	r.sb = r.ReadBytesInto(r.sb)
+	return string(r.sb)
+}
+
+func (r *Reader) ReadStringMax(max int) string {
+	if r.sb == nil {
+		r.sb = make([]byte, 64)
+	} else {
+		r.sb = r.sb[:cap(r.sb)]
+	}
+	r.sb = r.ReadBytesMaxInto(max, r.sb)
+	return string(r.sb)
+}
+
+func (r *Reader) ReadBytes() []byte {
+	return r.ReadBytesInto(nil)
+}
+
+func (r *Reader) ReadBytesMax(max int) []byte {
+	return r.ReadBytesMaxInto(max, nil)
+}
+
+func (r *Reader) ReadBytesInto(dst []byte) []byte {
+	return r.ReadBytesMaxInto(0, dst)
+}
+
+func (r *Reader) ReadBytesMaxInto(max int, dst []byte) []byte {
+	if r.err != nil {
+		return nil
+	}
+
+	l := int(r.ReadUint32())
+	if r.err != nil {
+		return nil
+	}
+	if max > 0 && l > max {
+		r.err = ErrElementSizeExceeded
+		return nil
+	}
+
+	if l+pad(l) > len(dst) {
+		dst = make([]byte, l+pad(l))
+	} else {
+		dst = dst[:l+pad(l)]
+	}
+
+	var n int
+	n, r.err = io.ReadFull(r.r, dst)
+	if r.err != nil {
+		if debug {
+			dl.Printf("rd bytes (%d): %v", len(dst), r.err)
+		}
+		return nil
+	}
+
+	if debug {
+		if n > maxDebugBytes {
+			dl.Printf("rd bytes (%d): %x...", len(dst), dst[:maxDebugBytes])
+		} else {
+			dl.Printf("rd bytes (%d): %x", len(dst), dst)
+		}
+	}
+	return dst[:l]
+}
+
+func (r *Reader) ReadBool() bool {
+	return r.ReadUint8() != 0
+}
+
+func (r *Reader) ReadUint32() uint32 {
+	if r.err != nil {
+		return 0
+	}
+
+	_, r.err = io.ReadFull(r.r, r.b[:4])
+	if r.err != nil {
+		if debug {
+			dl.Printf("rd uint32: %v", r.err)
+		}
+		return 0
+	}
+
+	v := uint32(r.b[3]) | uint32(r.b[2])<<8 | uint32(r.b[1])<<16 | uint32(r.b[0])<<24
+
+	if debug {
+		dl.Printf("rd uint32=%d (0x%08x)", v, v)
+	}
+	return v
+}
+
+func (r *Reader) ReadUint64() uint64 {
+	if r.err != nil {
+		return 0
+	}
+
+	_, r.err = io.ReadFull(r.r, r.b[:8])
+	if r.err != nil {
+		if debug {
+			dl.Printf("rd uint64: %v", r.err)
+		}
+		return 0
+	}
+
+	v := uint64(r.b[7]) | uint64(r.b[6])<<8 | uint64(r.b[5])<<16 | uint64(r.b[4])<<24 |
+		uint64(r.b[3])<<32 | uint64(r.b[2])<<40 | uint64(r.b[1])<<48 | uint64(r.b[0])<<56
+
+	if debug {
+		dl.Printf("rd uint64=%d (0x%016x)", v, v)
+	}
+	return v
+}
+
+type XDRError struct {
+	op  string
+	err error
+}
+
+func (e XDRError) Error() string {
+	return "xdr " + e.op + ": " + e.err.Error()
+}
+
+func (r *Reader) Error() error {
+	if r.err == nil {
+		return nil
+	}
+	return XDRError{"read", r.err}
+}