Initial commit

vendor/github.com/mafik/pulseaudio/format.go

@@ -0,0 +1,229 @@
+package pulseaudio
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+)
+
+type tagType byte
+
+const (
+	invalidTag    tagType = 0
+	stringTag     tagType = 't'
+	stringNullTag tagType = 'N'
+	uint32Tag     tagType = 'L'
+	uint8Tag      tagType = 'B'
+	uint64Tag     tagType = 'R'
+	int64Tag      tagType = 'r'
+	sampleSpecTag tagType = 'a'
+	arbitraryTag  tagType = 'x'
+	trueTag       tagType = '1'
+	falseTag      tagType = '0'
+	timeTag       tagType = 'T'
+	usecTag       tagType = 'U'
+	channelMapTag tagType = 'm'
+	cvolumeTag    tagType = 'v'
+	propListTag   tagType = 'P'
+	volumeTag     tagType = 'V'
+	formatInfoTag tagType = 'f'
+)
+
+func (t tagType) String() string {
+	switch t {
+	case invalidTag:
+		return "invalidTag"
+	case stringTag:
+		return "stringTag"
+	case stringNullTag:
+		return "stringNullTag"
+	case uint32Tag:
+		return "uint32Tag"
+	case uint8Tag:
+		return "uint8Tag"
+	case uint64Tag:
+		return "uint64Tag"
+	case int64Tag:
+		return "int64Tag"
+	case sampleSpecTag:
+		return "sampleSpecTag"
+	case arbitraryTag:
+		return "arbitraryTag"
+	case trueTag:
+		return "trueTag"
+	case falseTag:
+		return "falseTag"
+	case timeTag:
+		return "timeTag"
+	case usecTag:
+		return "usecTag"
+	case channelMapTag:
+		return "channelMapTag"
+	case cvolumeTag:
+		return "cvolumeTag"
+	case propListTag:
+		return "propListTag"
+	case volumeTag:
+		return "volumeTag"
+	case formatInfoTag:
+		return "formatInfoTag"
+	default:
+		return fmt.Sprintf("UnknownValue(%d)", t)
+	}
+}
+
+type binaryReader interface {
+	readFrom(r io.Reader, c *Client) error
+}
+
+func bwrite(w io.Writer, data ...interface{}) error {
+	for _, v := range data {
+		if propList, ok := v.(map[string]string); ok {
+			err := bwrite(w, propListTag)
+			if err != nil {
+				return err
+			}
+			for k, v := range propList {
+				if v == "" {
+					continue
+				}
+
+				l := uint32(len(v) + 1) // +1 for null at the end of string
+				err := bwrite(w,
+					stringTag, []byte(k), byte(0),
+					uint32Tag, l,
+					arbitraryTag, l,
+					[]byte(v), byte(0),
+				)
+				if err != nil {
+					return err
+				}
+			}
+			err = bwrite(w, stringNullTag)
+			if err != nil {
+				return err
+			}
+			continue
+		}
+
+		if cvolume, ok := v.(cvolume); ok {
+			arr := []uint32(cvolume)
+			err := bwrite(w, cvolumeTag, byte(len(arr)), arr)
+			if err != nil {
+				return err
+			}
+			continue
+		}
+
+		if err := binary.Write(w, binary.BigEndian, v); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func bread(r io.Reader, data ...interface{}) error {
+	for _, v := range data {
+		t, ok := v.(tagType)
+		if ok {
+			var tt tagType
+			if err := binary.Read(r, binary.BigEndian, &tt); err != nil {
+				return err
+			}
+			if tt != t {
+				return fmt.Errorf("Protcol error: Got type %s but expected %s", tt, t)
+			}
+			continue
+		}
+
+		sptr, ok := v.(*string)
+		if ok {
+			buf := make([]byte, 1024) // max string length i guess.
+			i := 0
+			for {
+				_, err := r.Read(buf[i : i+1])
+				if err != nil {
+					return err
+				}
+				if buf[i] == 0 {
+					*sptr = string(buf[:i])
+					break
+				} else {
+					if i > len(buf) {
+						return fmt.Errorf("String is too long (max %d bytes)", len(buf))
+					}
+					i++
+				}
+			}
+			continue
+		}
+
+		propList, ok := v.(*map[string]string)
+		if ok {
+			*propList = make(map[string]string)
+			err := bread(r, propListTag)
+			if err != nil {
+				return err
+			}
+			for {
+				var t tagType
+				if err = bread(r, &t); err != nil {
+					return err
+				}
+				if t == stringNullTag {
+					// end of the proplist.
+					break
+				}
+				if t != stringTag {
+					return fmt.Errorf("Protcol error: Got type %s but expected %s", t, stringTag)
+				}
+
+				var k, v string
+				var l1, l2 uint32
+				if err = bread(r,
+					&k,
+					uint32Tag, &l1,
+					arbitraryTag, &l2,
+					&v,
+				); err != nil {
+					return err
+				}
+				if len(v) != int(l1-1) || len(v) != int(l2-1) {
+					return fmt.Errorf("Protocol error: Proplist value length mismatch (len %d, arb len %d, value len %d)",
+						l1, l2, len(v))
+				}
+				(*propList)[k] = v
+			}
+			continue
+		}
+
+		rdr, ok := v.(io.ReaderFrom)
+		if ok {
+			if _, err := rdr.ReadFrom(r); err != nil {
+				return err
+			}
+			continue
+		}
+
+		bptr, ok := v.(*bool)
+		if ok {
+			var tt tagType
+			if err := binary.Read(r, binary.BigEndian, &tt); err != nil {
+				return err
+			}
+			if tt == trueTag {
+				*bptr = true
+			} else if tt == falseTag {
+				*bptr = false
+			} else {
+				return fmt.Errorf("Protcol error: Got type %s but expected boolean true or false", tt)
+			}
+			continue
+		}
+
+		if err := binary.Read(r, binary.BigEndian, v); err != nil {
+			return err
+		}
+	}
+	return nil
+}