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44 lines
774 B
44 lines
774 B
7 years ago
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package binarydist
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import (
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"errors"
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)
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type seekBuffer struct {
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buf []byte
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pos int
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}
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func (b *seekBuffer) Write(p []byte) (n int, err error) {
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n = copy(b.buf[b.pos:], p)
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if n == len(p) {
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b.pos += n
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return n, nil
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}
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b.buf = append(b.buf, p[n:]...)
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b.pos += len(p)
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return len(p), nil
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}
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func (b *seekBuffer) Seek(offset int64, whence int) (ret int64, err error) {
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var abs int64
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switch whence {
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case 0:
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abs = offset
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case 1:
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abs = int64(b.pos) + offset
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case 2:
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abs = int64(len(b.buf)) + offset
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default:
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return 0, errors.New("binarydist: invalid whence")
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}
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if abs < 0 {
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return 0, errors.New("binarydist: negative position")
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}
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if abs >= 1<<31 {
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return 0, errors.New("binarydist: position out of range")
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}
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b.pos = int(abs)
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return abs, nil
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}
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