Matheus Sampaio Queiroga
1cd953f90f
Signed-off-by: Matheus Sampaio Queiroga <srherobrine20@gmail.com>
60 lines
1.2 KiB
Go
60 lines
1.2 KiB
Go
package ar
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import (
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"io"
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)
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type Reader struct {
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currentHeader *Header // Current node header
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r io.Reader // Original reader
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limit int64 // Reader
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}
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func NewReader(r io.Reader) (*Reader, error) {
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read := make([]byte, len(arMagic))
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if n, err := r.Read(read); err != nil {
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return nil, err
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} else if n != len(arMagic) {
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return nil, ErrInvalidFile
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}
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return &Reader{
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currentHeader: nil,
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r: r,
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}, nil
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}
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// Read data from the current ar file
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func (r *Reader) Read(p []byte) (n int, err error) {
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if r.limit <= 0 {
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return 0, io.EOF
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}
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if int64(len(p)) > r.limit {
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p = p[0:r.limit]
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}
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n, err = r.r.Read(p)
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r.limit -= int64(n)
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if r.limit == 0 && (r.currentHeader.Size&1) == 1 {
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r.r.Read(make([]byte, 1)) // Ignore the last byte if the size is odd
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}
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return
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}
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// Read the next ar file header if available
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func (r *Reader) Next() (*Header, error) {
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if r.limit > 0 {
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return nil, io.EOF
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}
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head := make([]byte, 60)
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if n, err := r.r.Read(head); err != nil {
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return nil, err
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} else if n != 60 {
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return nil, ErrInvalidFile
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}
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r.currentHeader = &Header{}
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r.currentHeader.parseGnuHeader(head)
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r.limit = r.currentHeader.Size
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return r.currentHeader, nil
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}
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