39 lines
746 B
Go
39 lines
746 B
Go
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package padreader
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import (
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"io"
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"math/bits"
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sectorbuilder "github.com/filecoin-project/go-sectorbuilder"
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)
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func PaddedSize(size uint64) uint64 {
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logv := 64 - bits.LeadingZeros64(size)
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sectSize := uint64(1 << logv)
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bound := sectorbuilder.GetMaxUserBytesPerStagedSector(sectSize)
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if size <= bound {
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return bound
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}
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return sectorbuilder.GetMaxUserBytesPerStagedSector(1 << (logv + 1))
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}
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type nullReader struct{}
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func (nr nullReader) Read(b []byte) (int, error) {
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for i := range b {
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b[i] = 0
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}
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return len(b), nil
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}
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func New(r io.Reader, size uint64) (io.Reader, uint64) {
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padSize := PaddedSize(size)
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return io.MultiReader(
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io.LimitReader(r, int64(size)),
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io.LimitReader(nullReader{}, int64(padSize-size)),
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), padSize
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}
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