diff options
Diffstat (limited to 'database')
| -rw-r--r-- | database/src/kv/index.rs | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/database/src/kv/index.rs b/database/src/kv/index.rs index dd2471b..5505079 100644 --- a/database/src/kv/index.rs +++ b/database/src/kv/index.rs @@ -127,17 +127,21 @@ pub fn iter_index<'a>( } Sort::Value(value_sort) => { assert!(value_sort.offset.is_none(), "TODO"); - let mut start = prefix.clone(); + let (mut start, rev) = match value_sort.order { + SortOrder::Ascending => (prefix.clone(), false), + SortOrder::Descending => (inc_key(prefix.clone()), true), + }; if let Some(resume) = resume { - start.extend(resume); - start = inc_key(start); + start = prefix.iter().copied().chain(resume).collect(); + if rev { + start = dec_key(start); + } else { + start = inc_key(start); + } } Box::new( PrefixIterator { - inner: match value_sort.order { - SortOrder::Ascending => txn.iter(&start, false)?, - SortOrder::Descending => txn.iter(&inc_key(prefix.clone()), true)?, - }, + inner: txn.iter(&start, rev)?, prefix: prefix.clone().into(), } .map(move |k| { @@ -164,6 +168,16 @@ fn inc_key(mut k: Vec<u8>) -> Vec<u8> { } k } +fn dec_key(mut k: Vec<u8>) -> Vec<u8> { + for v in k.iter_mut().rev() { + let (nv, carry) = v.overflowing_sub(1); + *v = nv; + if !carry { + break; + } + } + k +} fn randomize(mut x: u64) -> u64 { for _ in 0..15 { |