58 lines
1.4 KiB
Go
58 lines
1.4 KiB
Go
package chunk
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import (
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"io"
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)
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// Chunk1 is a type 1 chunk.
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// The message stream ID is not
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// included; this chunk takes the same stream ID as the preceding chunk.
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// Streams with variable-sized messages (for example, many video
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// formats) SHOULD use this format for the first chunk of each new
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// message after the first.
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type Chunk1 struct {
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ChunkStreamID byte
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TimestampDelta uint32
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Type MessageType
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BodyLen uint32
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Body []byte
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}
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// Read reads the chunk.
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func (c *Chunk1) Read(r io.Reader, chunkMaxBodyLen uint32) error {
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header := make([]byte, 8)
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_, err := io.ReadFull(r, header)
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if err != nil {
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return err
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}
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c.ChunkStreamID = header[0] & 0x3F
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c.TimestampDelta = uint32(header[1])<<16 | uint32(header[2])<<8 | uint32(header[3])
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c.BodyLen = uint32(header[4])<<16 | uint32(header[5])<<8 | uint32(header[6])
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c.Type = MessageType(header[7])
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chunkBodyLen := (c.BodyLen)
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if chunkBodyLen > chunkMaxBodyLen {
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chunkBodyLen = chunkMaxBodyLen
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}
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c.Body = make([]byte, chunkBodyLen)
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_, err = io.ReadFull(r, c.Body)
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return err
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}
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// Marshal writes the chunk.
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func (c Chunk1) Marshal() ([]byte, error) {
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buf := make([]byte, 8+len(c.Body))
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buf[0] = 1<<6 | c.ChunkStreamID
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buf[1] = byte(c.TimestampDelta >> 16)
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buf[2] = byte(c.TimestampDelta >> 8)
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buf[3] = byte(c.TimestampDelta)
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buf[4] = byte(c.BodyLen >> 16)
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buf[5] = byte(c.BodyLen >> 8)
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buf[6] = byte(c.BodyLen)
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buf[7] = byte(c.Type)
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copy(buf[8:], c.Body)
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return buf, nil
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}
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