67 lines
1.2 KiB
Go
67 lines
1.2 KiB
Go
package internal
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import (
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"bytes"
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"encoding/binary"
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)
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/*
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ReadSizeBytes returns a uint32 allocator for a given set of data for preparation of packing into bytes.
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data can be one of:
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- string
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- byte/uint8
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- []byte/[]uint8
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- *bytes.Buffer
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- *bytes.Reader
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If pack is true, the original data will be appended to the returned allocated *bytes.Reader.
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NOTE: If data is a *bytes.Reader, the bytes WILL be consumed within that reader.
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*/
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func ReadSizeBytes(data interface{}, pack bool) (allocated *bytes.Reader, err error) {
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var u uint32
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var b []byte
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var sizer = make([]byte, 4)
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switch t := data.(type) {
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case string:
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b = []byte(t)
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case byte:
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// b = []byte{0x0, 0x0, 0x0, 0x1}
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b = []byte{t}
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case []byte:
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b = t
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case bytes.Buffer:
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t2 := &t
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b = t2.Bytes()
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case *bytes.Buffer:
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b = t.Bytes()
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case bytes.Reader:
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t2 := &t
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b = make([]byte, t2.Len())
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if _, err = t2.Read(b); err != nil {
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return
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}
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case *bytes.Reader:
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b = make([]byte, t.Len())
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if _, err = t.Read(b); err != nil {
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return
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}
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}
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u = uint32(len(b))
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binary.BigEndian.PutUint32(sizer, u)
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if !pack {
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allocated = bytes.NewReader(sizer)
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} else {
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b = append(sizer, b...)
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allocated = bytes.NewReader(b)
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}
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return
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}
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