71 lines
1.4 KiB
Go
71 lines
1.4 KiB
Go
package aprs
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import (
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"errors"
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"strings"
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)
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var (
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ErrPayloadMarker = errors.New("aprs: can't find payload marker")
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ErrDestinationMarker = errors.New("aprs: can't find destination marker")
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ErrPathLength = errors.New("aprs: invalid path length")
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)
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// Frame represents a single APRS frame.
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type Frame struct {
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// Addressing
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Source Address `json:"source"`
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Destination Address `json:"destination"`
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Path Path `json:"path"`
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// Raw payload
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Raw Raw `json:"raw"`
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// Data contained in the raw payload.
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Data Data `json:"data,omitempty"`
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// Data extracted
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Latitude float64
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Longitude float64
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Altitude float64
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Symbol string
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Comment string
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}
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func Parse(s string) (*Frame, error) {
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i := strings.IndexByte(s, ':')
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if i == -1 {
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return nil, ErrPayloadMarker
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}
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var (
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route = s[:i]
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frame = &Frame{Raw: Raw(s[i+1:])}
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)
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if i = strings.IndexByte(route, '>'); i == -1 {
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return nil, ErrDestinationMarker
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}
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frame.Source, route = ParseAddress(route[:i]), route[i+1:]
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path := strings.Split(route, ",")
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if len(path) == 0 || len(path) > 9 {
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return nil, ErrPathLength
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}
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frame.Destination = ParseAddress(path[0])
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for i, l := 1, len(path); i < l; i++ {
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addr := ParseAddress(path[i])
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frame.Path = append(frame.Path, addr)
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}
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var err error
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for _, d := range decoders {
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if d.CanDecode(frame) {
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if frame.Data, err = d.Decode(frame); err == nil {
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break
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}
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}
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}
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return frame, nil
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}
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