136 lines
2.5 KiB
Go
136 lines
2.5 KiB
Go
package util
|
|
|
|
import (
|
|
"fmt"
|
|
|
|
objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
|
|
|
|
"github.com/nspcc-dev/neofs-node/pkg/core/object"
|
|
)
|
|
|
|
type RangeTraverser struct {
|
|
chain *rangeChain
|
|
|
|
seekBounds *rangeBounds
|
|
}
|
|
|
|
type rangeBounds struct {
|
|
left, right uint64
|
|
}
|
|
|
|
type rangeChain struct {
|
|
next, prev *rangeChain
|
|
|
|
bounds *rangeBounds
|
|
|
|
id *objectSDK.ID
|
|
}
|
|
|
|
func NewRangeTraverser(originSize uint64, rightElement *object.Object, rngSeek *objectSDK.Range) *RangeTraverser {
|
|
right := &rangeChain{
|
|
bounds: &rangeBounds{
|
|
left: originSize - rightElement.PayloadSize(),
|
|
right: originSize,
|
|
},
|
|
id: rightElement.ID(),
|
|
}
|
|
|
|
left := &rangeChain{
|
|
id: rightElement.PreviousID(),
|
|
}
|
|
|
|
left.next, right.prev = right, left
|
|
|
|
return &RangeTraverser{
|
|
chain: right,
|
|
seekBounds: &rangeBounds{
|
|
left: rngSeek.GetOffset(),
|
|
right: rngSeek.GetOffset() + rngSeek.GetLength(),
|
|
},
|
|
}
|
|
}
|
|
|
|
func (c *RangeTraverser) Next() (id *objectSDK.ID, rng *objectSDK.Range) {
|
|
left := c.chain.bounds.left
|
|
seekLeft := c.seekBounds.left
|
|
|
|
if left > seekLeft {
|
|
id = c.chain.prev.id
|
|
} else {
|
|
id = c.chain.id
|
|
rng = objectSDK.NewRange()
|
|
rng.SetOffset(seekLeft - left)
|
|
rng.SetLength(min(c.chain.bounds.right, c.seekBounds.right) - seekLeft)
|
|
}
|
|
|
|
return
|
|
}
|
|
|
|
func min(a, b uint64) uint64 {
|
|
if a < b {
|
|
return a
|
|
}
|
|
|
|
return b
|
|
}
|
|
|
|
func (c *RangeTraverser) PushHeader(obj *object.Object) {
|
|
id := obj.ID()
|
|
if !id.Equal(c.chain.prev.id) {
|
|
panic(fmt.Sprintf("(%T) unexpected identifier in header", c))
|
|
}
|
|
|
|
sz := obj.PayloadSize()
|
|
|
|
c.chain.prev.bounds = &rangeBounds{
|
|
left: c.chain.bounds.left - sz,
|
|
right: c.chain.bounds.left,
|
|
}
|
|
|
|
c.chain = c.chain.prev
|
|
|
|
if prev := obj.PreviousID(); prev != nil {
|
|
c.chain.prev = &rangeChain{
|
|
next: c.chain,
|
|
id: prev,
|
|
}
|
|
}
|
|
}
|
|
|
|
func (c *RangeTraverser) PushSuccessSize(sz uint64) {
|
|
c.seekBounds.left += sz
|
|
|
|
if c.seekBounds.left >= c.chain.bounds.right && c.chain.next != nil {
|
|
c.chain = c.chain.next
|
|
}
|
|
}
|
|
|
|
// SetSeekRange moves the chain to the specified range.
|
|
// The range is expected to be within the filled chain.
|
|
func (c *RangeTraverser) SetSeekRange(r *objectSDK.Range) {
|
|
ln, off := r.GetLength(), r.GetOffset()
|
|
|
|
for {
|
|
if off < c.chain.bounds.left {
|
|
if c.chain.prev == nil {
|
|
break
|
|
}
|
|
|
|
c.chain = c.chain.prev
|
|
} else if off >= c.chain.bounds.left && off < c.chain.bounds.right {
|
|
break
|
|
} else if off >= c.chain.bounds.right {
|
|
if c.chain.next == nil {
|
|
break
|
|
}
|
|
|
|
c.chain = c.chain.next
|
|
}
|
|
}
|
|
|
|
if c.seekBounds == nil {
|
|
c.seekBounds = new(rangeBounds)
|
|
}
|
|
|
|
c.seekBounds.left, c.seekBounds.right = off, off+ln
|
|
}
|