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dagstore pieceReader: Cleanup reader nil check

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This commit is contained in:
Łukasz Magiera 2021-11-29 15:32:27 +01:00
parent 05aa860459
commit 4bcde2f0ff
1 changed files with 5 additions and 8 deletions
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13
markets/dagstore/piecereader.go
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@ -95,14 +95,11 @@ func (p *pieceReader) ReadAt(b []byte, off int64) (n int, err error) {
return 0, err
}
// get the backing reader into the correct position
if p.r == nil {
p.rAt = MaxPieceReaderBurnBytes * -2
}
// 1. Get the backing reader into the correct position
// if the backing reader is ahead of the offset we want, or more than
// MaxPieceReaderBurnBytes behind, reset the reader
if p.rAt > off || p.rAt+MaxPieceReaderBurnBytes < off {
if p.r == nil || p.rAt > off || p.rAt+MaxPieceReaderBurnBytes < off {
if p.r != nil {
if err := p.r.Close(); err != nil {
return 0, xerrors.Errorf("closing backing reader: %w", err)
@ -119,7 +116,7 @@ func (p *pieceReader) ReadAt(b []byte, off int64) (n int, err error) {
}
}
// check if we need to burn some bytes
// 2. Check if we need to burn some bytes
if off > p.rAt {
n, err := io.CopyN(io.Discard, p.r, off-p.rAt)
p.rAt += n
@ -128,12 +125,12 @@ func (p *pieceReader) ReadAt(b []byte, off int64) (n int, err error) {
}
}
// sanity check
// 3. Sanity check
if off != p.rAt {
return 0, xerrors.Errorf("bad reader offset; requested %d; at %d", off, p.rAt)
}
// Read!
// 4. Read!
n, err = p.r.Read(b)
p.rAt += int64(n)
return n, err