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

138 lines
3.3 KiB
Go

// Copyright 2019+ Klaus Post. All rights reserved.
// License information can be found in the LICENSE file.
// Based on work by Yann Collet, released under BSD License.
package zstd
import (
"encoding/binary"
"fmt"
"io"
"math"
"math/bits"
)
type frameHeader struct {
ContentSize uint64
WindowSize uint32
SingleSegment bool
Checksum bool
DictID uint32
}
const maxHeaderSize = 14
func (f frameHeader) appendTo(dst []byte) []byte {
dst = append(dst, frameMagic...)
var fhd uint8
if f.Checksum {
fhd |= 1 << 2
}
if f.SingleSegment {
fhd |= 1 << 5
}
var dictIDContent []byte
if f.DictID > 0 {
var tmp [4]byte
if f.DictID < 256 {
fhd |= 1
tmp[0] = uint8(f.DictID)
dictIDContent = tmp[:1]
} else if f.DictID < 1<<16 {
fhd |= 2
binary.LittleEndian.PutUint16(tmp[:2], uint16(f.DictID))
dictIDContent = tmp[:2]
} else {
fhd |= 3
binary.LittleEndian.PutUint32(tmp[:4], f.DictID)
dictIDContent = tmp[:4]
}
}
var fcs uint8
if f.ContentSize >= 256 {
fcs++
}
if f.ContentSize >= 65536+256 {
fcs++
}
if f.ContentSize >= 0xffffffff {
fcs++
}
fhd |= fcs << 6
dst = append(dst, fhd)
if !f.SingleSegment {
const winLogMin = 10
windowLog := (bits.Len32(f.WindowSize-1) - winLogMin) << 3
dst = append(dst, uint8(windowLog))
}
if f.DictID > 0 {
dst = append(dst, dictIDContent...)
}
switch fcs {
case 0:
if f.SingleSegment {
dst = append(dst, uint8(f.ContentSize))
}
// Unless SingleSegment is set, framessizes < 256 are not stored.
case 1:
f.ContentSize -= 256
dst = append(dst, uint8(f.ContentSize), uint8(f.ContentSize>>8))
case 2:
dst = append(dst, uint8(f.ContentSize), uint8(f.ContentSize>>8), uint8(f.ContentSize>>16), uint8(f.ContentSize>>24))
case 3:
dst = append(dst, uint8(f.ContentSize), uint8(f.ContentSize>>8), uint8(f.ContentSize>>16), uint8(f.ContentSize>>24),
uint8(f.ContentSize>>32), uint8(f.ContentSize>>40), uint8(f.ContentSize>>48), uint8(f.ContentSize>>56))
default:
panic("invalid fcs")
}
return dst
}
const skippableFrameHeader = 4 + 4
// calcSkippableFrame will return a total size to be added for written
// to be divisible by multiple.
// The value will always be > skippableFrameHeader.
// The function will panic if written < 0 or wantMultiple <= 0.
func calcSkippableFrame(written, wantMultiple int64) int {
if wantMultiple <= 0 {
panic("wantMultiple <= 0")
}
if written < 0 {
panic("written < 0")
}
leftOver := written % wantMultiple
if leftOver == 0 {
return 0
}
toAdd := wantMultiple - leftOver
for toAdd < skippableFrameHeader {
toAdd += wantMultiple
}
return int(toAdd)
}
// skippableFrame will add a skippable frame with a total size of bytes.
// total should be >= skippableFrameHeader and < math.MaxUint32.
func skippableFrame(dst []byte, total int, r io.Reader) ([]byte, error) {
if total == 0 {
return dst, nil
}
if total < skippableFrameHeader {
return dst, fmt.Errorf("requested skippable frame (%d) < 8", total)
}
if int64(total) > math.MaxUint32 {
return dst, fmt.Errorf("requested skippable frame (%d) > max uint32", total)
}
dst = append(dst, 0x50, 0x2a, 0x4d, 0x18)
f := uint32(total - skippableFrameHeader)
dst = append(dst, uint8(f), uint8(f>>8), uint8(f>>16), uint8(f>>24))
start := len(dst)
dst = append(dst, make([]byte, f)...)
_, err := io.ReadFull(r, dst[start:])
return dst, err
}