Use advrefs in gituploadpackinfo (#92)

* add advrefs encoder and parser

* modify advrefs encoder to resemble json encoder

* turn advrefs parser into a decoder

* clean code

* improve documentation

* improve documentation

* clean code

* upgrade to new pktline.Add and add Flush const to easy integration

* gometalinter

* Use packp/advrefs for GitUploadPackInfo parsing

- GitUploadPackInfo now uses packp/advrefs instead of parsing the
  message by itself.

- Capabilities has been moved from clients/common to packp to avoid a
  circular import.

- Cleaning of advrefs_test code.

- Add support for prefix encoding and decoding in advrefs.

* clean advrefs test code

* clean advrefs test code

* clean advrefs test code

* gometalinter

* add pktline encoder

* change pktline.EncodeFlush to pktline.Flush

* make scanner tests use the encoder instead of Pktlines

* check errors on flush and clean constants

* ubstitute the PktLines type with a pktline.Encoder

* use pktline.Encoder in all go-git

* add example of pktline.Encodef()

* add package overview

* documentation

* support symbolic links other than HEAD

* simplify decoding of shallows

* packp: fix mcuadros comments

- all abbreviates removed (by visual inspection, some may remain)
- all empty maps are initialized using make
- simplify readRef with a switch
- make decodeShallow malformed error more verbose
- add pktline.Encoder.encodeLine
- remove infamous panic in checkPayloadLength by refactoring out
  the whole function

1 files changed, 0 insertions, 140 deletions

diff --git a/formats/packp/pktline/pktlines.go b/formats/packp/pktline/pktlines.go
deleted file mode 100644
index c19aa2e..0000000
--- a/formats/packp/pktline/pktlines.go
+++ /dev/null
@@ -1,140 +0,0 @@
-// Package pktline implements reading payloads form pkt-lines and creating pkt-lines from payloads.
-package pktline
-
-import (
-	"bytes"
-	"errors"
-	"io"
-	"strings"
-)
-
-const (
-	// MaxPayloadSize is the maximum payload size of a pkt-line in bytes.
-	MaxPayloadSize = 65516
-)
-
-var (
-	flush = []byte{'0', '0', '0', '0'}
-)
-
-// PktLines values represent a succession of pkt-lines.  Values from
-// this type are not zero-value safe, use the New function instead.
-type PktLines struct {
-	r io.Reader
-}
-
-var (
-	// ErrPayloadTooLong is returned by the Add methods when any of the
-	// provided payloads is bigger than MaxPayloadSize.
-	ErrPayloadTooLong = errors.New("payload is too long")
-	// ErrEmptyPayload is returned by the Add methods when an empty
-	// payload is provided.
-	ErrEmptyPayload = errors.New("cannot add empty payloads")
-)
-
-// New returns an empty PktLines (with no payloads) ready to be used.
-func New() *PktLines {
-	return &PktLines{
-		r: bytes.NewReader(nil),
-	}
-}
-
-// AddFlush adds a flush-pkt to p.
-func (p *PktLines) AddFlush() {
-	p.r = io.MultiReader(p.r, bytes.NewReader(flush))
-}
-
-// Add adds the slices in pp as the payloads of a
-// corresponding number of pktlines.
-func (p *PktLines) Add(pp ...[]byte) error {
-	tmp := []io.Reader{p.r}
-	for _, p := range pp {
-		if err := add(&tmp, p); err != nil {
-			return err
-		}
-	}
-	p.r = io.MultiReader(tmp...)
-
-	return nil
-}
-
-func add(dst *[]io.Reader, e []byte) error {
-	if err := checkPayloadLength(len(e)); err != nil {
-		return err
-	}
-
-	n := len(e) + 4
-	*dst = append(*dst, bytes.NewReader(asciiHex16(n)))
-	*dst = append(*dst, bytes.NewReader(e))
-
-	return nil
-}
-
-func checkPayloadLength(n int) error {
-	switch {
-	case n < 0:
-		panic("unexpected negative payload length")
-	case n == 0:
-		return ErrEmptyPayload
-	case n > MaxPayloadSize:
-		return ErrPayloadTooLong
-	default:
-		return nil
-	}
-}
-
-// Returns the hexadecimal ascii representation of the 16 less
-// significant bits of n.  The length of the returned slice will always
-// be 4.  Example: if n is 1234 (0x4d2), the return value will be
-// []byte{'0', '4', 'd', '2'}.
-func asciiHex16(n int) []byte {
-	var ret [4]byte
-	ret[0] = byteToASCIIHex(byte(n & 0xf000 >> 12))
-	ret[1] = byteToASCIIHex(byte(n & 0x0f00 >> 8))
-	ret[2] = byteToASCIIHex(byte(n & 0x00f0 >> 4))
-	ret[3] = byteToASCIIHex(byte(n & 0x000f))
-
-	return ret[:]
-}
-
-// turns a byte into its hexadecimal ascii representation.  Example:
-// from 11 (0xb) to 'b'.
-func byteToASCIIHex(n byte) byte {
-	if n < 10 {
-		return '0' + n
-	}
-
-	return 'a' - 10 + n
-}
-
-// AddString adds the strings in pp as payloads of a
-// corresponding number of pktlines.
-func (p *PktLines) AddString(pp ...string) error {
-	tmp := []io.Reader{p.r}
-	for _, p := range pp {
-		if err := addString(&tmp, p); err != nil {
-			return err
-		}
-	}
-
-	p.r = io.MultiReader(tmp...)
-
-	return nil
-}
-
-func addString(dst *[]io.Reader, s string) error {
-	if err := checkPayloadLength(len(s)); err != nil {
-		return err
-	}
-
-	n := len(s) + 4
-	*dst = append(*dst, bytes.NewReader(asciiHex16(n)))
-	*dst = append(*dst, strings.NewReader(s))
-
-	return nil
-}
-
-// Read reads the pktlines for the payloads added so far.
-func (p *PktLines) Read(b []byte) (n int, err error) {
-	return p.r.Read(b)
-}