Files
zeekay b61441f7d7 Volume: node-local persistent volumes, under our own name
A fork of Rancher's local-path-provisioner at v0.0.36. The behaviour is
unchanged and deliberately so — a directory on the node a pod lands on is
the right thing for a disk. What changes is identity.

The provisioner answers to hanzo.ai/volume rather than rancher.io/local-path.
That is not branding: two provisioners sharing one name race for the same
claims, and a stock k3s carries the upstream one, so a cluster running both
would settle our storage by chance. Data lives at /var/lib/hanzo/volume, so
reading a Hanzo cluster does not mean learning another vendor's directory.

Apache-2.0 as published, unaltered, with Rancher's attribution in NOTICE.

The README says what this is not: durability. A volume here dies with its
node. That is hanzoai/replicate's question, one layer up, and keeping the
two apart is what lets the disk stay this simple.
2026-09-07 17:30:01 -07:00

82 lines
2.4 KiB
Go

/*
Copyright 2014 Google Inc. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
// Package bytesource provides a rand.Source64 that is determined by a slice of bytes.
package bytesource
import (
"bytes"
"encoding/binary"
"io"
"math/rand"
)
// ByteSource implements rand.Source64 determined by a slice of bytes. The random numbers are
// generated from each 8 bytes in the slice, until the last bytes are consumed, from which a
// fallback pseudo random source is created in case more random numbers are required.
// It also exposes a `bytes.Reader` API, which lets callers consume the bytes directly.
type ByteSource struct {
*bytes.Reader
fallback rand.Source
}
// New returns a new ByteSource from a given slice of bytes.
func New(input []byte) *ByteSource {
s := &ByteSource{
Reader: bytes.NewReader(input),
fallback: rand.NewSource(0),
}
if len(input) > 0 {
s.fallback = rand.NewSource(int64(s.consumeUint64()))
}
return s
}
func (s *ByteSource) Uint64() uint64 {
// Return from input if it was not exhausted.
if s.Len() > 0 {
return s.consumeUint64()
}
// Input was exhausted, return random number from fallback (in this case fallback should not be
// nil). Try first having a Uint64 output (Should work in current rand implementation),
// otherwise return a conversion of Int63.
if s64, ok := s.fallback.(rand.Source64); ok {
return s64.Uint64()
}
return uint64(s.fallback.Int63())
}
func (s *ByteSource) Int63() int64 {
return int64(s.Uint64() >> 1)
}
func (s *ByteSource) Seed(seed int64) {
s.fallback = rand.NewSource(seed)
s.Reader = bytes.NewReader(nil)
}
// consumeUint64 reads 8 bytes from the input and convert them to a uint64. It assumes that the the
// bytes reader is not empty.
func (s *ByteSource) consumeUint64() uint64 {
var bytes [8]byte
_, err := s.Read(bytes[:])
if err != nil && err != io.EOF {
panic("failed reading source") // Should not happen.
}
return binary.BigEndian.Uint64(bytes[:])
}