Merge pull request #6394 from paritytech/trie_recursion

removed recursion from triedbmut::lookup
This commit is contained in:
Marek Kotewicz 2017-08-30 10:07:44 +02:00 committed by GitHub
commit da91a07906

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@ -367,44 +367,50 @@ impl<'a> TrieDBMut<'a> {
}
// walk the trie, attempting to find the key's node.
fn lookup<'x, 'key>(&'x self, partial: NibbleSlice<'key>, handle: &NodeHandle) -> super::Result<Option<DBValue>>
fn lookup<'x, 'key>(&'x self, mut partial: NibbleSlice<'key>, handle: &NodeHandle) -> super::Result<Option<DBValue>>
where 'x: 'key
{
match *handle {
NodeHandle::Hash(ref hash) => Lookup {
let mut handle = handle;
loop {
let (mid, child) = match *handle {
NodeHandle::Hash(ref hash) => return Lookup {
db: &*self.db,
query: DBValue::from_slice,
hash: hash.clone(),
}.look_up(partial),
NodeHandle::InMemory(ref handle) => match self.storage[handle] {
Node::Empty => Ok(None),
Node::Empty => return Ok(None),
Node::Leaf(ref key, ref value) => {
if NibbleSlice::from_encoded(key).0 == partial {
Ok(Some(DBValue::from_slice(value)))
return Ok(Some(DBValue::from_slice(value)));
} else {
Ok(None)
return Ok(None);
}
}
Node::Extension(ref slice, ref child) => {
let slice = NibbleSlice::from_encoded(slice).0;
if partial.starts_with(&slice) {
self.lookup(partial.mid(slice.len()), child)
(slice.len(), child)
} else {
Ok(None)
return Ok(None);
}
}
Node::Branch(ref children, ref value) => {
if partial.is_empty() {
Ok(value.as_ref().map(|v| DBValue::from_slice(v)))
return Ok(value.as_ref().map(|v| DBValue::from_slice(v)));
} else {
let idx = partial.at(0);
match children[idx as usize].as_ref() {
Some(child) => self.lookup(partial.mid(1), child),
None => Ok(None),
Some(child) => (1, child),
None => return Ok(None),
}
}
}
}
};
partial = partial.mid(mid);
handle = child;
}
}