[#53] object/util: Add seek range function to range traverser

Add SetSeekRange method to RangeTraverser that switches traverser to work
with provided object payload range.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
This commit is contained in:
Leonard Lyubich 2020-09-28 16:11:59 +03:00 committed by Alex Vanin
parent 8791c4f0a5
commit 834a8597c5

View file

@ -104,3 +104,33 @@ func (c *RangeTraverser) PushSuccessSize(sz uint64) {
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
}