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mirror of https://github.com/octoleo/restic.git synced 2024-11-02 11:46:36 +00:00

Move RandReader to repository package

This commit is contained in:
Alexander Neumann 2016-07-31 10:29:53 +02:00
parent f59ffcaeae
commit 14db71d3fa
2 changed files with 80 additions and 72 deletions

View File

@ -0,0 +1,79 @@
package repository
import (
"io"
"math/rand"
)
// RandReader allows reading from a rand.Rand.
type RandReader struct {
rnd *rand.Rand
buf []byte
}
// NewRandReader creates a new Reader from a random source.
func NewRandReader(rnd *rand.Rand) io.Reader {
return &RandReader{rnd: rnd, buf: make([]byte, 0, 7)}
}
func (rd *RandReader) read(p []byte) (n int, err error) {
if len(p)%7 != 0 {
panic("invalid buffer length, not multiple of 7")
}
rnd := rd.rnd
for i := 0; i < len(p); i += 7 {
val := rnd.Int63()
p[i+0] = byte(val >> 0)
p[i+1] = byte(val >> 8)
p[i+2] = byte(val >> 16)
p[i+3] = byte(val >> 24)
p[i+4] = byte(val >> 32)
p[i+5] = byte(val >> 40)
p[i+6] = byte(val >> 48)
}
return len(p), nil
}
func (rd *RandReader) Read(p []byte) (int, error) {
// first, copy buffer to p
pos := copy(p, rd.buf)
copy(rd.buf, rd.buf[pos:])
// shorten buf and p accordingly
rd.buf = rd.buf[:len(rd.buf)-pos]
p = p[pos:]
// if this is enough to fill p, return
if len(p) == 0 {
return pos, nil
}
// load multiple of 7 byte
l := (len(p) / 7) * 7
n, err := rd.read(p[:l])
pos += n
if err != nil {
return pos, err
}
p = p[n:]
// load 7 byte to temp buffer
rd.buf = rd.buf[:7]
n, err = rd.read(rd.buf)
if err != nil {
return pos, err
}
// copy the remaining bytes from the buffer to p
n = copy(p, rd.buf)
pos += n
// save the remaining bytes in rd.buf
n = copy(rd.buf, rd.buf[n:])
rd.buf = rd.buf[:n]
return pos, nil
}

View File

@ -13,80 +13,9 @@ import (
"github.com/restic/chunker"
)
type randReader struct {
rnd *rand.Rand
buf []byte
}
func newRandReader(rnd *rand.Rand) io.Reader {
return &randReader{rnd: rnd, buf: make([]byte, 0, 7)}
}
func (rd *randReader) read(p []byte) (n int, err error) {
if len(p)%7 != 0 {
panic("invalid buffer length, not multiple of 7")
}
rnd := rd.rnd
for i := 0; i < len(p); i += 7 {
val := rnd.Int63()
p[i+0] = byte(val >> 0)
p[i+1] = byte(val >> 8)
p[i+2] = byte(val >> 16)
p[i+3] = byte(val >> 24)
p[i+4] = byte(val >> 32)
p[i+5] = byte(val >> 40)
p[i+6] = byte(val >> 48)
}
return len(p), nil
}
func (rd *randReader) Read(p []byte) (int, error) {
// first, copy buffer to p
pos := copy(p, rd.buf)
copy(rd.buf, rd.buf[pos:])
// shorten buf and p accordingly
rd.buf = rd.buf[:len(rd.buf)-pos]
p = p[pos:]
// if this is enough to fill p, return
if len(p) == 0 {
return pos, nil
}
// load multiple of 7 byte
l := (len(p) / 7) * 7
n, err := rd.read(p[:l])
pos += n
if err != nil {
return pos, err
}
p = p[n:]
// load 7 byte to temp buffer
rd.buf = rd.buf[:7]
n, err = rd.read(rd.buf)
if err != nil {
return pos, err
}
// copy the remaining bytes from the buffer to p
n = copy(p, rd.buf)
pos += n
// save the remaining bytes in rd.buf
n = copy(rd.buf, rd.buf[n:])
rd.buf = rd.buf[:n]
return pos, nil
}
// fakeFile returns a reader which yields deterministic pseudo-random data.
func fakeFile(t testing.TB, seed, size int64) io.Reader {
return io.LimitReader(newRandReader(rand.New(rand.NewSource(seed))), size)
return io.LimitReader(repository.NewRandReader(rand.New(rand.NewSource(seed))), size)
}
// saveFile reads from rd and saves the blobs in the repository. The list of