Add a fuzzer to check that `IndexedMap` is equivalent to `BTreeMap`

[rust-lightning] / fuzz / src / indexedmap.rs

diff --git a/fuzz/src/indexedmap.rs b/fuzz/src/indexedmap.rs
new file mode 100644 (file)
index 0000000..795d617
--- /dev/null
+++ b/fuzz/src/indexedmap.rs
@@ -0,0 +1,137 @@
+// This file is Copyright its original authors, visible in version control
+// history.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+
+use lightning::util::indexed_map::{IndexedMap, self};
+use std::collections::{BTreeMap, btree_map};
+use hashbrown::HashSet;
+
+use crate::utils::test_logger;
+
+fn check_eq(btree: &BTreeMap<u8, u8>, indexed: &IndexedMap<u8, u8>) {
+       assert_eq!(btree.len(), indexed.len());
+       assert_eq!(btree.is_empty(), indexed.is_empty());
+
+       let mut btree_clone = btree.clone();
+       assert!(btree_clone == *btree);
+       let mut indexed_clone = indexed.clone();
+       assert!(indexed_clone == *indexed);
+
+       for k in 0..=255 {
+               assert_eq!(btree.contains_key(&k), indexed.contains_key(&k));
+               assert_eq!(btree.get(&k), indexed.get(&k));
+
+               let btree_entry = btree_clone.entry(k);
+               let indexed_entry = indexed_clone.entry(k);
+               match btree_entry {
+                       btree_map::Entry::Occupied(mut bo) => {
+                               if let indexed_map::Entry::Occupied(mut io) = indexed_entry {
+                                       assert_eq!(bo.get(), io.get());
+                                       assert_eq!(bo.get_mut(), io.get_mut());
+                               } else { panic!(); }
+                       },
+                       btree_map::Entry::Vacant(_) => {
+                               if let indexed_map::Entry::Vacant(_) = indexed_entry {
+                               } else { panic!(); }
+                       }
+               }
+       }
+
+       const STRIDE: u8 = 16;
+       for k in 0..=255/STRIDE {
+               let lower_bound = k * STRIDE;
+               let upper_bound = lower_bound + (STRIDE - 1);
+               let mut btree_iter = btree.range(lower_bound..=upper_bound);
+               let mut indexed_iter = indexed.range(lower_bound..=upper_bound);
+               loop {
+                       let b_v = btree_iter.next();
+                       let i_v = indexed_iter.next();
+                       assert_eq!(b_v, i_v);
+                       if b_v.is_none() { break; }
+               }
+       }
+
+       let mut key_set = HashSet::with_capacity(256);
+       for k in indexed.unordered_keys() {
+               assert!(key_set.insert(*k));
+               assert!(btree.contains_key(k));
+       }
+       assert_eq!(key_set.len(), btree.len());
+
+       key_set.clear();
+       for (k, v) in indexed.unordered_iter() {
+               assert!(key_set.insert(*k));
+               assert_eq!(btree.get(k).unwrap(), v);
+       }
+       assert_eq!(key_set.len(), btree.len());
+
+       key_set.clear();
+       for (k, v) in indexed_clone.unordered_iter_mut() {
+               assert!(key_set.insert(*k));
+               assert_eq!(btree.get(k).unwrap(), v);
+       }
+       assert_eq!(key_set.len(), btree.len());
+}
+
+#[inline]
+pub fn do_test(data: &[u8]) {
+       if data.len() % 2 != 0 { return; }
+       let mut btree = BTreeMap::new();
+       let mut indexed = IndexedMap::new();
+
+       // Read in k-v pairs from the input and insert them into the maps then check that the maps are
+       // equivalent in every way we can read them.
+       for tuple in data.windows(2) {
+               let prev_value_b = btree.insert(tuple[0], tuple[1]);
+               let prev_value_i = indexed.insert(tuple[0], tuple[1]);
+               assert_eq!(prev_value_b, prev_value_i);
+       }
+       check_eq(&btree, &indexed);
+
+       // Now, modify the maps in all the ways we have to do so, checking that the maps remain
+       // equivalent as we go.
+       for (k, v) in indexed.unordered_iter_mut() {
+               *v = *k;
+               *btree.get_mut(k).unwrap() = *k;
+       }
+       check_eq(&btree, &indexed);
+
+       for k in 0..=255 {
+               match btree.entry(k) {
+                       btree_map::Entry::Occupied(mut bo) => {
+                               if let indexed_map::Entry::Occupied(mut io) = indexed.entry(k) {
+                                       if k < 64 {
+                                               *io.get_mut() ^= 0xff;
+                                               *bo.get_mut() ^= 0xff;
+                                       } else if k < 128 {
+                                               *io.into_mut() ^= 0xff;
+                                               *bo.get_mut() ^= 0xff;
+                                       } else {
+                                               assert_eq!(bo.remove_entry(), io.remove_entry());
+                                       }
+                               } else { panic!(); }
+                       },
+                       btree_map::Entry::Vacant(bv) => {
+                               if let indexed_map::Entry::Vacant(iv) = indexed.entry(k) {
+                                       bv.insert(k);
+                                       iv.insert(k);
+                               } else { panic!(); }
+                       },
+               }
+       }
+       check_eq(&btree, &indexed);
+}
+
+pub fn indexedmap_test<Out: test_logger::Output>(data: &[u8], _out: Out) {
+       do_test(data);
+}
+
+#[no_mangle]
+pub extern "C" fn indexedmap_run(data: *const u8, datalen: usize) {
+       do_test(unsafe { std::slice::from_raw_parts(data, datalen) });
+}