minio/vendor/github.com/inconshreveable/go-update/internal/binarydist/seek.go
Harshavardhana eb7c690ea9 Support in-place upgrades of new minio binary and releases. (#4961)
This PR allows 'minio update' to not only shows update banner
but also allows for in-place upgrades.

Updates are done safely by validating the downloaded
sha256 of the binary.

Fixes #4781
2017-12-15 12:33:42 -08:00

44 lines
774 B
Go

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