Caleb Gardner
16ef5838c3
This is largely a move to simplify a lot of the readers Also further breaks out functions.
61 lines
1.0 KiB
Go
61 lines
1.0 KiB
Go
package metadata
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import (
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"encoding/binary"
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"io"
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"github.com/CalebQ42/squashfs/internal/decompress"
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)
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type Reader struct {
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master io.Reader
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cur io.Reader
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d decompress.Decompressor
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}
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func NewReader(r io.Reader, d decompress.Decompressor) (*Reader, error) {
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var out Reader
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out.d = d
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out.master = r
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return &out, out.Advance()
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}
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func (r *Reader) Advance() error {
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if clr, ok := r.cur.(io.Closer); ok {
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clr.Close()
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}
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var size uint16
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err := binary.Read(r.master, binary.LittleEndian, &size)
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if err != nil {
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return err
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}
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comp := size&0x8000 != 0x8000
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size &^= 0x8000
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r.cur = io.LimitReader(r.master, int64(size))
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if comp {
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r.cur, err = r.d.Reader(r.cur)
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if err != nil {
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return err
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}
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}
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return nil
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}
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func (r Reader) Read(p []byte) (n int, err error) {
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n, err = r.cur.Read(p)
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if err == io.EOF {
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err = r.Advance()
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if err != nil {
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return
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}
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var tmpN int
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tmp := make([]byte, len(p)-n)
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tmpN, err = r.Read(tmp)
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for i := range tmp {
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p[n+i] = tmp[i]
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}
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n += tmpN
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}
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return
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}
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