78 lines
1.6 KiB
Go
78 lines
1.6 KiB
Go
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package packer
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import (
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"context"
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"errors"
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"io"
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)
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// Decoder handles a ReadCloser stream containing mplexy-encoded clients
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type Decoder struct {
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ctx context.Context
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r io.ReadCloser
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}
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// NewDecoder returns an initialized Decoder
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func NewDecoder(ctx context.Context, r io.ReadCloser) *Decoder {
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return &Decoder{
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ctx: ctx,
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r: r,
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}
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}
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// StreamDecode will call WriteMessage as often as addressable data exists,
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// reading up to bufferSize (default 8192) at a time
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// (header + data, though headers are often sent separately from data).
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func (d *Decoder) StreamDecode(handler Handler, bufferSize int) error {
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p := NewParser(handler)
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rx := make(chan []byte)
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rxErr := make(chan error)
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if 0 == bufferSize {
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bufferSize = 8192
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}
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go func() {
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b := make([]byte, bufferSize)
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for {
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//fmt.Println("loopers gonna loop")
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n, err := d.r.Read(b)
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if n > 0 {
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rx <- b[:n]
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}
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if nil != err {
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rxErr <- err
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return
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}
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}
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}()
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for {
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//fmt.Println("poopers gonna poop")
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select {
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// TODO, do we actually need ctx here?
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// would it be sufficient to expect the reader to be closed by the caller instead?
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case <-d.ctx.Done():
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// TODO: verify that closing the reader will cause the goroutine to be released
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d.r.Close()
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return errors.New("cancelled by context")
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case b := <-rx:
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_, err := p.Write(b)
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if nil != err {
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// an error to write represents an unrecoverable error,
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// not just a downstream client error
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d.r.Close()
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return err
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}
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case err := <-rxErr:
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d.r.Close()
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if io.EOF == err {
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// it can be assumed that err will close though, right
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return nil
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}
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return err
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}
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}
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}
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