64 lines
1.3 KiB
Go
64 lines
1.3 KiB
Go
package zim
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import (
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"io"
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"github.com/pkg/errors"
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)
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type UncompressedBlobReader struct {
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reader *Reader
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blobStartOffset uint64
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blobEndOffset uint64
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blobSize int
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readOffset uint64
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}
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// Size implements BlobReader.
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func (r *UncompressedBlobReader) Size() (int64, error) {
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return int64(r.blobEndOffset - r.blobStartOffset), nil
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}
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// Close implements io.ReadCloser.
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func (*UncompressedBlobReader) Close() error {
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return nil
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}
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// Read implements io.ReadCloser.
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func (r *UncompressedBlobReader) Read(p []byte) (n int, err error) {
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len := len(p)
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remaining := int(r.blobEndOffset - (r.blobStartOffset + r.readOffset))
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if len > remaining {
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len = remaining
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}
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data := make([]byte, len)
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err = r.reader.readRange(int64(r.blobStartOffset+r.readOffset), data)
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if err != nil {
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return len, errors.WithStack(err)
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}
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r.readOffset += uint64(len)
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copy(p, data)
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if len == remaining {
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return len, io.EOF
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}
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return len, nil
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}
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func NewUncompressedBlobReader(reader *Reader, blobStartOffset, blobEndOffset uint64, blobSize int) *UncompressedBlobReader {
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return &UncompressedBlobReader{
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reader: reader,
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blobStartOffset: blobStartOffset,
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blobEndOffset: blobEndOffset,
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blobSize: blobSize,
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readOffset: 0,
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}
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}
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var _ BlobReader = &UncompressedBlobReader{}
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