Feature complete. I may change the names, and error-handling needs to be more robust. I feel pretty good about resisting bad input, but not so good about saving to or writing from complex data structures, or maps with interface{} elements.

This commit is contained in:
David Arroyo 2013-07-15 10:16:10 -04:00
parent a19bd721cd
commit 10567f459b
6 changed files with 375 additions and 181 deletions

View File

@ -1 +0,0 @@
package ndb

66
ndb.go
View File

@ -22,12 +22,12 @@
package ndb
import (
"reflect"
"bytes"
"bufio"
"net/textproto"
"bytes"
"fmt"
"io"
"net/textproto"
"reflect"
"unicode/utf8"
)
@ -52,7 +52,7 @@ func (e *TypeError) Error() string {
return fmt.Sprintf("Invalid type %s or nil pointer", e.Type.String())
}
func min(a,b int64) int64 {
func min(a, b int64) int64 {
if a < b {
return a
}
@ -61,8 +61,9 @@ func min(a,b int64) int64 {
func (e *SyntaxError) Error() string {
start := e.Offset
end := min(e.Offset + 10, int64(len(e.Data)))
end := min(e.Offset+10, int64(len(e.Data)))
if e.Data != nil {
// Make sure we're on utf8 boundaries
for !utf8.RuneStart(e.Data[start]) && start > 0 {
start--
@ -70,15 +71,17 @@ func (e *SyntaxError) Error() string {
for !utf8.Valid(e.Data[start:end]) && end < int64(len(e.Data)) {
end++
}
return fmt.Sprintf("%s\n\tat `%s'", e.Message, e.Data[start:end])
}
return e.Message
}
// An Encoder wraps an io.Writer and serializes Go values
// into ndb strings. Successive calls to the Encode() method
// append lines to the io.Writer.
type Encoder struct {
out bufio.Writer
start bool
out io.Writer
}
// A decoder wraps an io.Reader and decodes successive ndb strings
@ -123,9 +126,9 @@ func Parse(data []byte, v interface{}) error {
func NewDecoder(r io.Reader) *Decoder {
d := new(Decoder)
d.src = textproto.NewReader(bufio.NewReader(r))
d.attrs = make(map[string] struct{}, 8)
d.multi = make(map[string] struct{}, 8)
d.finfo = make(map[string] []int, 8)
d.attrs = make(map[string]struct{}, 8)
d.multi = make(map[string]struct{}, 8)
d.finfo = make(map[string][]int, 8)
return d
}
@ -142,7 +145,7 @@ func (d *Decoder) Decode(v interface{}) error {
if typ.Elem().Kind() == reflect.Slice {
return d.decodeSlice(val)
}
p,err := d.getPairs()
p, err := d.getPairs()
if err != nil {
return err
}
@ -154,12 +157,12 @@ func (d *Decoder) Decode(v interface{}) error {
if val.Elem().IsNil() {
val.Elem().Set(reflect.MakeMap(typ.Elem()))
}
return d.saveMap(p,val.Elem())
return d.saveMap(p, val.Elem())
case reflect.Struct:
if val.IsNil() {
return &TypeError{nil}
}
return d.saveStruct(p,val.Elem())
return d.saveStruct(p, val.Elem())
}
return nil
}
@ -174,7 +177,12 @@ func (d *Decoder) Decode(v interface{}) error {
// valid ndb strings, an error is returned. No guarantee is made about
// the order of the tuples.
func Emit(v interface{}) ([]byte, error) {
return nil,nil
var buf bytes.Buffer
e := NewEncoder(&buf)
if err := e.Encode(v); err != nil {
return nil, err
}
return buf.Bytes(), nil
}
// The Encode method will write the ndb encoding of the Go value v
@ -183,16 +191,32 @@ func Emit(v interface{}) ([]byte, error) {
// If the value cannot be fully encoded, an error is returned and
// no data will be written to the io.Writer.
func (e *Encoder) Encode(v interface{}) error {
return nil
val := reflect.ValueOf(v)
// Drill down to the concrete value
for val.Kind() == reflect.Ptr {
if val.IsNil() {
return &TypeError{nil}
} else {
val = val.Elem()
}
}
defer func() {
e.start = false
}()
switch val.Kind() {
case reflect.Slice:
return e.encodeSlice(val)
case reflect.Struct:
return e.encodeStruct(val)
case reflect.Map:
return e.encodeMap(val)
default:
return &TypeError{val.Type()}
}
}
// NewEncoder returns an Encoder that writes ndb output to an
// io.Writer
func NewEncoder(w io.Writer) *Encoder {
return nil
}
// Flush forces all outstanding data in an Encoder to be written to
// its backend io.Writer.
func (e *Encoder) Flush() {
return &Encoder{out: w}
}

69
read.go
View File

@ -1,14 +1,14 @@
package ndb
import (
"io"
"reflect"
"net/textproto"
"unicode"
"strconv"
"bytes"
"strings"
"fmt"
"io"
"net/textproto"
"reflect"
"strconv"
"strings"
"unicode"
)
type scanner struct {
@ -24,22 +24,22 @@ func (p pair) String() string {
}
func errBadAttr(line []byte, offset int64) error {
return &SyntaxError { line, offset, "Invalid attribute name" }
return &SyntaxError{line, offset, "Invalid attribute name"}
}
func errUnterminated(line []byte, offset int64) error {
return &SyntaxError { line, offset, "Unterminated quoted string" }
return &SyntaxError{line, offset, "Unterminated quoted string"}
}
func errBadUnicode(line []byte, offset int64) error {
return &SyntaxError { line, offset, "Invalid UTF8 input" }
return &SyntaxError{line, offset, "Invalid UTF8 input"}
}
func errMissingSpace(line []byte, offset int64) error {
return &SyntaxError { line, offset, "Missing white space between tuples" }
return &SyntaxError{line, offset, "Missing white space between tuples"}
}
func (d *Decoder) getPairs() ([]pair, error) {
line, err := d.src.ReadContinuedLineBytes()
if err != nil {
return nil,err
return nil, err
}
d.reset()
return d.parseLine(line)
@ -90,7 +90,7 @@ func (d *Decoder) saveMap(pairs []pair, val reflect.Value) error {
return &TypeError{val.Type()}
}
vv := reflect.New(val.Type().Elem().Elem())
for _,p := range pairs {
for _, p := range pairs {
if err := storeVal(kv, p.attr); err != nil {
return err
}
@ -107,7 +107,7 @@ func (d *Decoder) saveMap(pairs []pair, val reflect.Value) error {
}
} else {
vv := reflect.New(val.Type().Elem())
for _,p := range pairs {
for _, p := range pairs {
if err := storeVal(kv, p.attr); err != nil {
return err
}
@ -136,10 +136,10 @@ func (d *Decoder) saveStruct(pairs []pair, val reflect.Value) error {
d.finfo[field.Name] = field.Index
}
}
for _,p := range pairs {
if id,ok := d.finfo[string(p.attr)]; ok {
for _, p := range pairs {
if id, ok := d.finfo[string(p.attr)]; ok {
f := val.FieldByIndex(id)
if _,ok := d.multi[string(p.attr)]; ok {
if _, ok := d.multi[string(p.attr)]; ok {
if f.Kind() != reflect.Slice {
return &TypeError{f.Type()}
}
@ -203,6 +203,7 @@ func storeVal(dst reflect.Value, src []byte) error {
}
type scanState []int
func (s *scanState) push(n int) {
*s = append(*s, n)
}
@ -215,7 +216,7 @@ func (s scanState) top() int {
func (s *scanState) pop() int {
v := s.top()
if len(*s) > 0 {
*s = (*s)[0:len(*s)-1]
*s = (*s)[0 : len(*s)-1]
}
return v
}
@ -235,15 +236,15 @@ const (
// by copying Rob Pike's Go lexing talk.
func (d *Decoder) parseLine(line []byte) ([]pair, error) {
var add pair
var beg,offset int64
var beg, offset int64
var esc bool
state := make(scanState, 0, 3)
buf := bytes.NewReader(line)
for r,sz,err := buf.ReadRune(); err == nil; r,sz,err = buf.ReadRune() {
for r, sz, err := buf.ReadRune(); err == nil; r, sz, err = buf.ReadRune() {
if r == 0xFFFD && sz == 1 {
return nil,errBadUnicode(line, offset)
return nil, errBadUnicode(line, offset)
}
switch state.top() {
case scanNone:
@ -253,23 +254,23 @@ func (d *Decoder) parseLine(line []byte) ([]pair, error) {
state.push(scanAttr)
beg = offset
} else {
return nil,errBadAttr(line, offset)
return nil, errBadAttr(line, offset)
}
case scanAttr:
if unicode.IsSpace(r) {
add.attr = line[beg:offset]
d.pairbuf = append(d.pairbuf, add)
if _,ok := d.attrs[string(add.attr)]; ok {
if _, ok := d.attrs[string(add.attr)]; ok {
d.havemulti = true
d.multi[string(add.attr)] = struct{}{}
} else {
d.attrs[string(add.attr)] = struct{}{}
}
add.attr,add.val,esc = nil,nil,false
add.attr, add.val, esc = nil, nil, false
state.pop()
} else if r == '=' {
add.attr = line[beg:offset]
if _,ok := d.attrs[string(add.attr)]; ok {
if _, ok := d.attrs[string(add.attr)]; ok {
d.havemulti = true
d.multi[string(add.attr)] = struct{}{}
} else {
@ -277,8 +278,8 @@ func (d *Decoder) parseLine(line []byte) ([]pair, error) {
}
state.pop()
state.push(scanValueStart)
} else if !(unicode.IsLetter(r) || unicode.IsNumber(r)) {
return nil,errBadAttr(line, offset)
} else if !(r == '-' || unicode.IsLetter(r) || unicode.IsNumber(r)) {
return nil, errBadAttr(line, offset)
}
case scanValueStart:
beg = offset
@ -298,7 +299,7 @@ func (d *Decoder) parseLine(line []byte) ([]pair, error) {
add.val = bytes.Replace(add.val, []byte("''"), []byte("'"), -1)
}
d.pairbuf = append(d.pairbuf, add)
add.attr,add.val = nil,nil
add.attr, add.val = nil, nil
}
case scanQuoteClose:
state.pop()
@ -307,14 +308,14 @@ func (d *Decoder) parseLine(line []byte) ([]pair, error) {
state.push(scanQuoteValue)
} else if unicode.IsSpace(r) {
state.pop()
add.val = line[beg:offset-1]
add.val = line[beg : offset-1]
if esc {
add.val = bytes.Replace(add.val, []byte("''"), []byte("'"), -1)
}
d.pairbuf = append(d.pairbuf, add)
add.attr,add.val,esc = nil,nil,false
add.attr, add.val, esc = nil, nil, false
} else {
return nil,errMissingSpace(line, offset)
return nil, errMissingSpace(line, offset)
}
case scanQuoteStart:
state.pop()
@ -330,17 +331,17 @@ func (d *Decoder) parseLine(line []byte) ([]pair, error) {
state.pop()
state.push(scanQuoteClose)
} else if r == '\n' {
return nil,errUnterminated(line, offset)
return nil, errUnterminated(line, offset)
}
}
offset += int64(sz)
}
switch state.top() {
case scanQuoteValue, scanQuoteStart:
return nil,errUnterminated(line, offset)
return nil, errUnterminated(line, offset)
case scanAttr:
add.attr = line[beg:offset]
if _,ok := d.attrs[string(add.attr)]; ok {
if _, ok := d.attrs[string(add.attr)]; ok {
d.havemulti = true
d.multi[string(add.attr)] = struct{}{}
} else {
@ -360,5 +361,5 @@ func (d *Decoder) parseLine(line []byte) ([]pair, error) {
}
d.pairbuf = append(d.pairbuf, add)
}
return d.pairbuf,nil
return d.pairbuf, nil
}

View File

@ -1,31 +1,32 @@
package ndb
import (
"testing"
"bytes"
"fmt"
"testing"
)
type screenCfg struct {
Title string
Width, Height uint16
R,G,B,A uint16
R, G, B, A uint16
}
type netCfg struct {
Host string `ndb:"hostname"`
Host string `ndb:"host-name"`
Vlan []int `ndb:"vlan"`
Native int `ndb:"nativevlan"`
Native int `ndb:"native-vlan"`
}
var multiMap = []struct {
in string
out map[string] []string
out map[string][]string
}{
{
in: "user=clive user=david user=trenton group=dirty-dozen",
out: map[string] []string {
"user": []string {"clive", "david", "trenton"},
"group": []string {"dirty-dozen"},
out: map[string][]string{
"user": []string{"clive", "david", "trenton"},
"group": []string{"dirty-dozen"},
},
},
}
@ -34,10 +35,10 @@ var advancedTests = []struct {
in string
out netCfg
}{
{ in: "hostname=p2-jbs537 vlan=66 vlan=35 nativevlan=218",
out: netCfg {
{in: "host-name=p2-jbs537 vlan=66 vlan=35 native-vlan=218",
out: netCfg{
Host: "p2-jbs537",
Vlan: []int {66, 35},
Vlan: []int{66, 35},
Native: 218,
},
},
@ -49,7 +50,7 @@ var structTests = []struct {
}{
{
in: "Title='Hollywood movie' Width=640 Height=400 A=8",
out: screenCfg {
out: screenCfg{
Title: "Hollywood movie",
Width: 640,
Height: 400,
@ -60,11 +61,11 @@ var structTests = []struct {
var mapTests = []struct {
in string
out map[string] string
out map[string]string
}{
{
in: "ipnet=murrayhill ip=135.104.0.0 ipmask=255.255.0.0",
out: map[string] string {
in: "ipnet=murray-hill ip=135.104.0.0 ipmask=255.255.0.0",
out: map[string]string{
"ipnet": "murray-hill",
"ip": "135.104.0.0",
"ipmask": "255.255.0.0",
@ -75,7 +76,7 @@ var mapTests = []struct {
func TestStruct(t *testing.T) {
var cfg screenCfg
for _,tt := range structTests {
for _, tt := range structTests {
if err := Parse([]byte(tt.in), &cfg); err != nil {
t.Error(err)
} else if cfg != tt.out {
@ -85,20 +86,34 @@ func TestStruct(t *testing.T) {
}
}
func TestMap(t *testing.T) {
var net map[string] string
for _,tt := range mapTests {
var net map[string]string
for _, tt := range mapTests {
if err := Parse([]byte(tt.in), &net); err != nil {
t.Error(err)
} else if fmt.Sprint(net) != fmt.Sprint(tt.out) {
t.Errorf("Got %v, wanted %v", net, tt.out)
} else if !mapEquals(tt.out, net) {
t.Errorf("Got `%v`, wanted `%v`", net, tt.out)
}
t.Logf("%s == %v", tt.in, net)
}
}
func mapEquals(m1, m2 map[string] string) bool {
for k := range m1 {
if m1[k] != m2[k] {
return false
}
}
for k := range m2 {
if m1[k] != m2[k] {
return false
}
}
return true
}
func TestAdvanced(t *testing.T) {
var net netCfg
for _,tt := range advancedTests {
for _, tt := range advancedTests {
if err := Parse([]byte(tt.in), &net); err != nil {
t.Error(err)
} else if fmt.Sprint(tt.out) != fmt.Sprint(net) {
@ -109,8 +124,8 @@ func TestAdvanced(t *testing.T) {
}
func TestMultiMap(t *testing.T) {
var m map[string] []string
for _,tt := range multiMap {
var m map[string][]string
for _, tt := range multiMap {
if err := Parse([]byte(tt.in), &m); err != nil {
t.Error(err)
} else if fmt.Sprint(tt.out) != fmt.Sprint(m) {
@ -120,97 +135,68 @@ func TestMultiMap(t *testing.T) {
}
}
func netEqual(t *testing.T, n1, n2 netCfg) bool {
if len(n1.Vlan) != len(n2.Vlan) {
return false
}
for i := range n1.Vlan {
if n1.Vlan[i] != n2.Vlan[i] {
return false
}
}
return n1.Host == n2.Host && n1.Native == n2.Native
}
func mapEqual(t *testing.T, m1, m2 map[string] string) bool {
for k := range m1 {
if m1[k] != m2[k] {
t.Logf("%v != %v", m1[k], m2[k])
return false
}
}
return true
}
package ndb
import (
"testing"
"bytes"
)
var parseTests = []struct {
in []byte
out []pair
}{
{
in: []byte("key1=val1 key2=val2 key3=val3"),
out: []pair {
{[]byte("key1"),[]byte("val1")},
{[]byte("key2"),[]byte("val2")},
{[]byte("key3"),[]byte("val3")}},
out: []pair{
{[]byte("key1"), []byte("val1")},
{[]byte("key2"), []byte("val2")},
{[]byte("key3"), []byte("val3")}},
},
{
in: []byte("title='Some value with spaces' width=340 height=200"),
out: []pair {
{[]byte("title"),[]byte("Some value with spaces")},
{[]byte("width"),[]byte("340")},
{[]byte("height"),[]byte("200")}},
out: []pair{
{[]byte("title"), []byte("Some value with spaces")},
{[]byte("width"), []byte("340")},
{[]byte("height"), []byte("200")}},
},
{
in: []byte("title='Dave''s pasta' sq=Davis cost=$$"),
out: []pair {
{[]byte("title"),[]byte("Dave's pasta")},
{[]byte("sq"),[]byte("Davis")},
{[]byte("cost"),[]byte("$$")}},
out: []pair{
{[]byte("title"), []byte("Dave's pasta")},
{[]byte("sq"), []byte("Davis")},
{[]byte("cost"), []byte("$$")}},
},
{
in: []byte("action=''bradley key=jay mod=ctrl+alt+shift"),
out: []pair {
{[]byte("action"),[]byte("'bradley")},
{[]byte("key"),[]byte("jay")},
{[]byte("mod"),[]byte("ctrl+alt+shift")}},
out: []pair{
{[]byte("action"), []byte("'bradley")},
{[]byte("key"), []byte("jay")},
{[]byte("mod"), []byte("ctrl+alt+shift")}},
},
{
in: []byte("action=reload key='' mod=ctrl+alt+shift"),
out: []pair {
{[]byte("action"),[]byte("reload")},
{[]byte("key"),[]byte("'")},
{[]byte("mod"),[]byte("ctrl+alt+shift")}},
out: []pair{
{[]byte("action"), []byte("reload")},
{[]byte("key"), []byte("'")},
{[]byte("mod"), []byte("ctrl+alt+shift")}},
},
{
in: []byte("s='spaces and '' quotes'"),
out: []pair {
{[]byte("s"),[]byte("spaces and ' quotes")}},
out: []pair{
{[]byte("s"), []byte("spaces and ' quotes")}},
},
{
in: []byte("esc='Use '''' to escape a '''"),
out: []pair {
{[]byte("esc"),[]byte("Use '' to escape a '")}},
out: []pair{
{[]byte("esc"), []byte("Use '' to escape a '")}},
},
}
func Test_parsing(t *testing.T) {
for i,tt := range parseTests {
for i, tt := range parseTests {
d := NewDecoder(bytes.NewReader(tt.in))
p,err := d.getPairs()
p, err := d.getPairs()
if err != nil {
t.Error(err)
t.FailNow()
} else {
for j := range tt.out {
if j > len(p) || !match(p[j],tt.out[j]) {
t.Errorf("%d: getPairs %s => %v, want %v",i, tt.in, p, tt.out)
if j > len(p) || !match(p[j], tt.out[j]) {
t.Errorf("%d: getPairs %s => %v, want %v", i, tt.in, p, tt.out)
t.FailNow()
}
}

131
write.go
View File

@ -1 +1,132 @@
package ndb
import (
"bytes"
"fmt"
"reflect"
"unicode"
"unicode/utf8"
)
func (e *Encoder) encodeSlice(val reflect.Value) error {
for i := 0; i < val.Len(); i++ {
e.Encode(val.Index(i).Interface())
}
return nil
}
func (e *Encoder) encodeStruct(val reflect.Value) error {
typ := val.Type()
for i := 0; i < typ.NumField(); i++ {
ft := typ.Field(i)
attr := ft.Name
if tag := ft.Tag.Get("ndb"); tag != "" {
attr = tag
}
err := e.writeTuple(attr, val.Field(i))
if err != nil {
return err
}
}
return nil
}
func (e *Encoder) encodeMap(val reflect.Value) error {
for _, k := range val.MapKeys() {
v := val.MapIndex(k)
if err := e.writeTuple(k.Interface(), v); err != nil {
return err
}
}
return nil
}
func (e *Encoder) writeTuple(k interface{}, v reflect.Value) error {
var values reflect.Value
var attrBuf, valBuf bytes.Buffer
fmt.Fprint(&attrBuf, k)
attr := attrBuf.Bytes()
if v.Kind() != reflect.Slice && v.Kind() != reflect.Array {
sliceType := reflect.SliceOf(v.Type())
pv := reflect.New(sliceType)
pv.Elem().Set(reflect.MakeSlice(sliceType, 0, 1))
pv.Elem().Set(reflect.Append(pv.Elem(), v))
values = pv.Elem()
} else {
values = v
}
for i := 0; i < values.Len(); i++ {
fmt.Fprint(&valBuf, values.Index(i).Interface())
val := valBuf.Bytes()
if e.start {
if _, err := e.out.Write([]byte{' '}); err != nil {
return err
}
} else {
e.start = true
}
if !validAttr(attr) {
return &SyntaxError{nil, 0, fmt.Sprintf("Invalid attribute %s", attr)}
}
if !validVal(val) {
return &SyntaxError{nil, 0, fmt.Sprintf("Invalid value %s", val)}
}
if bytes.IndexByte(val, '\'') != -1 {
val = bytes.Replace(val, []byte{'\''}, []byte{'\'', '\''}, -1)
}
if _, err := e.out.Write(attr); err != nil {
return err
}
if _, err := e.out.Write([]byte{'='}); err != nil {
return err
}
x := bytes.IndexFunc(val, func(r rune) bool {
return unicode.IsSpace(r)
})
if x != -1 {
if _, err := e.out.Write([]byte{'\''}); err != nil {
return err
}
}
if _, err := e.out.Write(val); err != nil {
return err
}
if x != -1 {
if _, err := e.out.Write([]byte{'\''}); err != nil {
return err
}
}
valBuf.Reset()
}
return nil
}
func validAttr(attr []byte) bool {
if !utf8.Valid(attr) {
return false
}
x := bytes.IndexFunc(attr, func(r rune) bool {
switch {
case r == '\'':
return true
case unicode.IsSpace(r):
return true
}
return !unicode.IsLetter(r) &&
!unicode.IsNumber(r) &&
r != '-'
})
return x == -1
}
func validVal(val []byte) bool {
if !utf8.Valid(val) {
return false
}
return bytes.IndexByte(val, '\n') == -1
}

View File

@ -0,0 +1,53 @@
package ndb
import (
"testing"
)
var structWriteTests = []struct {
in netCfg
out string
}{
{
netCfg{"p2-jbs239", []int{64, 52, 100}, 666},
"host-name=p2-jbs239 vlan=64 vlan=52 vlan=100 native-vlan=666",
},
{
netCfg{"p2-cass304", []int{55, 10}, 1},
"host-name=p2-cass304 vlan=55 vlan=10 native-vlan=1",
},
}
var mapWriteTests = []struct {
in map[string] string
out string
}{
{
map[string] string {"user": "jenkins", "group": "jenkins"},
"user=jenkins group=jenkins",
},
}
func TestStructWrite(t *testing.T) {
for _, tt := range structWriteTests {
if b, err := Emit(tt.in); err != nil {
t.Error(err)
} else if string(b) != tt.out {
t.Errorf("Wanted %s, got %s", tt.out, string(b))
} else {
t.Logf("%v => %s", tt.in, string(b))
}
}
}
func TestMapWrite(t *testing.T) {
for _, tt := range mapWriteTests {
if b, err := Emit(tt.in); err != nil {
t.Error(err)
} else if string(b) != tt.out {
t.Errorf("Wanted %s, got %s", tt.out, string(b))
} else {
t.Logf("%v => %s", tt.in, string(b))
}
}
}