Struct swiss_army_knife::hash_map_and_hash_set::FastSecureHashMap [−][src]
Expand description
Fast, secure HashMap currently built atop hashbrown (SwissTable) using a secure AHash.
Implementations
With capacity.
Methods from Deref<Target = HashMap<K, V>>
Returns a reference to the map’s BuildHasher
.
Examples
use hashbrown::HashMap; use hashbrown::hash_map::DefaultHashBuilder; let hasher = DefaultHashBuilder::default(); let map: HashMap<i32, i32> = HashMap::with_hasher(hasher); let hasher: &DefaultHashBuilder = map.hasher();
Returns the number of elements the map can hold without reallocating.
This number is a lower bound; the HashMap<K, V>
might be able to hold
more, but is guaranteed to be able to hold at least this many.
Examples
use hashbrown::HashMap; let map: HashMap<i32, i32> = HashMap::with_capacity(100); assert!(map.capacity() >= 100);
An iterator visiting all keys in arbitrary order.
The iterator element type is &'a K
.
Examples
use hashbrown::HashMap; let mut map = HashMap::new(); map.insert("a", 1); map.insert("b", 2); map.insert("c", 3); for key in map.keys() { println!("{}", key); }
An iterator visiting all values in arbitrary order.
The iterator element type is &'a V
.
Examples
use hashbrown::HashMap; let mut map = HashMap::new(); map.insert("a", 1); map.insert("b", 2); map.insert("c", 3); for val in map.values() { println!("{}", val); }
An iterator visiting all values mutably in arbitrary order.
The iterator element type is &'a mut V
.
Examples
use hashbrown::HashMap; let mut map = HashMap::new(); map.insert("a", 1); map.insert("b", 2); map.insert("c", 3); for val in map.values_mut() { *val = *val + 10; } for val in map.values() { println!("{}", val); }
An iterator visiting all key-value pairs in arbitrary order.
The iterator element type is (&'a K, &'a V)
.
Examples
use hashbrown::HashMap; let mut map = HashMap::new(); map.insert("a", 1); map.insert("b", 2); map.insert("c", 3); for (key, val) in map.iter() { println!("key: {} val: {}", key, val); }
An iterator visiting all key-value pairs in arbitrary order,
with mutable references to the values.
The iterator element type is (&'a K, &'a mut V)
.
Examples
use hashbrown::HashMap; let mut map = HashMap::new(); map.insert("a", 1); map.insert("b", 2); map.insert("c", 3); // Update all values for (_, val) in map.iter_mut() { *val *= 2; } for (key, val) in &map { println!("key: {} val: {}", key, val); }
Returns the number of elements in the map.
Examples
use hashbrown::HashMap; let mut a = HashMap::new(); assert_eq!(a.len(), 0); a.insert(1, "a"); assert_eq!(a.len(), 1);
Returns true
if the map contains no elements.
Examples
use hashbrown::HashMap; let mut a = HashMap::new(); assert!(a.is_empty()); a.insert(1, "a"); assert!(!a.is_empty());
Clears the map, returning all key-value pairs as an iterator. Keeps the allocated memory for reuse.
Examples
use hashbrown::HashMap; let mut a = HashMap::new(); a.insert(1, "a"); a.insert(2, "b"); for (k, v) in a.drain().take(1) { assert!(k == 1 || k == 2); assert!(v == "a" || v == "b"); } assert!(a.is_empty());
Retains only the elements specified by the predicate.
In other words, remove all pairs (k, v)
such that f(&k,&mut v)
returns false
.
Examples
use hashbrown::HashMap; let mut map: HashMap<i32, i32> = (0..8).map(|x|(x, x*10)).collect(); map.retain(|&k, _| k % 2 == 0); assert_eq!(map.len(), 4);
pub fn drain_filter<F>(&mut self, f: F) -> DrainFilter<'_, K, V, F> where
F: FnMut(&K, &mut V) -> bool,
pub fn drain_filter<F>(&mut self, f: F) -> DrainFilter<'_, K, V, F> where
F: FnMut(&K, &mut V) -> bool,
Drains elements which are true under the given predicate, and returns an iterator over the removed items.
In other words, move all pairs (k, v)
such that f(&k,&mut v)
returns true
out
into another iterator.
When the returned DrainedFilter is dropped, any remaining elements that satisfy the predicate are dropped from the table.
Examples
use hashbrown::HashMap; let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x)).collect(); let drained: HashMap<i32, i32> = map.drain_filter(|k, _v| k % 2 == 0).collect(); let mut evens = drained.keys().cloned().collect::<Vec<_>>(); let mut odds = map.keys().cloned().collect::<Vec<_>>(); evens.sort(); odds.sort(); assert_eq!(evens, vec![0, 2, 4, 6]); assert_eq!(odds, vec![1, 3, 5, 7]);
Reserves capacity for at least additional
more elements to be inserted
in the HashMap
. The collection may reserve more space to avoid
frequent reallocations.
Panics
Panics if the new allocation size overflows usize
.
Examples
use hashbrown::HashMap; let mut map: HashMap<&str, i32> = HashMap::new(); map.reserve(10);
Tries to reserve capacity for at least additional
more elements to be inserted
in the given HashMap<K,V>
. The collection may reserve more space to avoid
frequent reallocations.
Errors
If the capacity overflows, or the allocator reports a failure, then an error is returned.
Examples
use hashbrown::HashMap; let mut map: HashMap<&str, isize> = HashMap::new(); map.try_reserve(10).expect("why is the test harness OOMing on 10 bytes?");
Shrinks the capacity of the map as much as possible. It will drop down as much as possible while maintaining the internal rules and possibly leaving some space in accordance with the resize policy.
Examples
use hashbrown::HashMap; let mut map: HashMap<i32, i32> = HashMap::with_capacity(100); map.insert(1, 2); map.insert(3, 4); assert!(map.capacity() >= 100); map.shrink_to_fit(); assert!(map.capacity() >= 2);
Shrinks the capacity of the map with a lower limit. It will drop down no lower than the supplied limit while maintaining the internal rules and possibly leaving some space in accordance with the resize policy.
This function does nothing if the current capacity is smaller than the supplied minimum capacity.
Examples
use hashbrown::HashMap; let mut map: HashMap<i32, i32> = HashMap::with_capacity(100); map.insert(1, 2); map.insert(3, 4); assert!(map.capacity() >= 100); map.shrink_to(10); assert!(map.capacity() >= 10); map.shrink_to(0); assert!(map.capacity() >= 2); map.shrink_to(10); assert!(map.capacity() >= 2);
Gets the given key’s corresponding entry in the map for in-place manipulation.
Examples
use hashbrown::HashMap; let mut letters = HashMap::new(); for ch in "a short treatise on fungi".chars() { let counter = letters.entry(ch).or_insert(0); *counter += 1; } assert_eq!(letters[&'s'], 2); assert_eq!(letters[&'t'], 3); assert_eq!(letters[&'u'], 1); assert_eq!(letters.get(&'y'), None);
Returns a reference to the value corresponding to the key.
The key may be any borrowed form of the map’s key type, but
Hash
and Eq
on the borrowed form must match those for
the key type.
Examples
use hashbrown::HashMap; let mut map = HashMap::new(); map.insert(1, "a"); assert_eq!(map.get(&1), Some(&"a")); assert_eq!(map.get(&2), None);
Returns the key-value pair corresponding to the supplied key.
The supplied key may be any borrowed form of the map’s key type, but
Hash
and Eq
on the borrowed form must match those for
the key type.
Examples
use hashbrown::HashMap; let mut map = HashMap::new(); map.insert(1, "a"); assert_eq!(map.get_key_value(&1), Some((&1, &"a"))); assert_eq!(map.get_key_value(&2), None);
Returns the key-value pair corresponding to the supplied key, with a mutable reference to value.
The supplied key may be any borrowed form of the map’s key type, but
Hash
and Eq
on the borrowed form must match those for
the key type.
Examples
use hashbrown::HashMap; let mut map = HashMap::new(); map.insert(1, "a"); let (k, v) = map.get_key_value_mut(&1).unwrap(); assert_eq!(k, &1); assert_eq!(v, &mut "a"); *v = "b"; assert_eq!(map.get_key_value_mut(&1), Some((&1, &mut "b"))); assert_eq!(map.get_key_value_mut(&2), None);
Returns true
if the map contains a value for the specified key.
The key may be any borrowed form of the map’s key type, but
Hash
and Eq
on the borrowed form must match those for
the key type.
Examples
use hashbrown::HashMap; let mut map = HashMap::new(); map.insert(1, "a"); assert_eq!(map.contains_key(&1), true); assert_eq!(map.contains_key(&2), false);
Returns a mutable reference to the value corresponding to the key.
The key may be any borrowed form of the map’s key type, but
Hash
and Eq
on the borrowed form must match those for
the key type.
Examples
use hashbrown::HashMap; let mut map = HashMap::new(); map.insert(1, "a"); if let Some(x) = map.get_mut(&1) { *x = "b"; } assert_eq!(map[&1], "b");
Inserts a key-value pair into the map.
If the map did not have this key present, None
is returned.
If the map did have this key present, the value is updated, and the old
value is returned. The key is not updated, though; this matters for
types that can be ==
without being identical. See the module-level
documentation for more.
Examples
use hashbrown::HashMap; let mut map = HashMap::new(); assert_eq!(map.insert(37, "a"), None); assert_eq!(map.is_empty(), false); map.insert(37, "b"); assert_eq!(map.insert(37, "c"), Some("b")); assert_eq!(map[&37], "c");
Removes a key from the map, returning the value at the key if the key was previously in the map.
The key may be any borrowed form of the map’s key type, but
Hash
and Eq
on the borrowed form must match those for
the key type.
Examples
use hashbrown::HashMap; let mut map = HashMap::new(); map.insert(1, "a"); assert_eq!(map.remove(&1), Some("a")); assert_eq!(map.remove(&1), None);
Removes a key from the map, returning the stored key and value if the key was previously in the map.
The key may be any borrowed form of the map’s key type, but
Hash
and Eq
on the borrowed form must match those for
the key type.
Examples
use hashbrown::HashMap; let mut map = HashMap::new(); map.insert(1, "a"); assert_eq!(map.remove_entry(&1), Some((1, "a"))); assert_eq!(map.remove(&1), None);
Creates a raw entry builder for the HashMap.
Raw entries provide the lowest level of control for searching and manipulating a map. They must be manually initialized with a hash and then manually searched. After this, insertions into a vacant entry still require an owned key to be provided.
Raw entries are useful for such exotic situations as:
- Hash memoization
- Deferring the creation of an owned key until it is known to be required
- Using a search key that doesn’t work with the Borrow trait
- Using custom comparison logic without newtype wrappers
Because raw entries provide much more low-level control, it’s much easier
to put the HashMap into an inconsistent state which, while memory-safe,
will cause the map to produce seemingly random results. Higher-level and
more foolproof APIs like entry
should be preferred when possible.
In particular, the hash used to initialized the raw entry must still be consistent with the hash of the key that is ultimately stored in the entry. This is because implementations of HashMap may need to recompute hashes when resizing, at which point only the keys are available.
Raw entries give mutable access to the keys. This must not be used to modify how the key would compare or hash, as the map will not re-evaluate where the key should go, meaning the keys may become “lost” if their location does not reflect their state. For instance, if you change a key so that the map now contains keys which compare equal, search may start acting erratically, with two keys randomly masking each other. Implementations are free to assume this doesn’t happen (within the limits of memory-safety).
Creates a raw immutable entry builder for the HashMap.
Raw entries provide the lowest level of control for searching and manipulating a map. They must be manually initialized with a hash and then manually searched.
This is useful for
- Hash memoization
- Using a search key that doesn’t work with the Borrow trait
- Using custom comparison logic without newtype wrappers
Unless you are in such a situation, higher-level and more foolproof APIs like
get
should be preferred.
Immutable raw entries have very limited use; you might instead want raw_entry_mut
.
Trait Implementations
impl<'de, K: Eq + Hash, V> Deserialize<'de> for FastSecureHashMap<K, V> where
K: Deserialize<'de>,
V: Deserialize<'de>,
impl<'de, K: Eq + Hash, V> Deserialize<'de> for FastSecureHashMap<K, V> where
K: Deserialize<'de>,
V: Deserialize<'de>,
fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
__D: Deserializer<'de>,
fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
__D: Deserializer<'de>,
Deserialize this value from the given Serde deserializer. Read more
Extends a collection with the contents of an iterator. Read more
extend_one
)Extends a collection with exactly one element.
extend_one
)Reserves capacity in a collection for the given number of additional elements. Read more
Extends a collection with the contents of an iterator. Read more
extend_one
)Extends a collection with exactly one element.
extend_one
)Reserves capacity in a collection for the given number of additional elements. Read more
impl<K: Eq + Hash, V: PartialEq> PartialEq<FastSecureHashMap<K, V>> for FastSecureHashMap<K, V>
impl<K: Eq + Hash, V: PartialEq> PartialEq<FastSecureHashMap<K, V>> for FastSecureHashMap<K, V>
Auto Trait Implementations
impl<K, V> RefUnwindSafe for FastSecureHashMap<K, V> where
K: RefUnwindSafe,
V: RefUnwindSafe,
impl<K, V> Send for FastSecureHashMap<K, V> where
K: Send,
V: Send,
impl<K, V> Sync for FastSecureHashMap<K, V> where
K: Sync,
V: Sync,
impl<K, V> Unpin for FastSecureHashMap<K, V> where
K: Unpin,
V: Unpin,
impl<K, V> UnwindSafe for FastSecureHashMap<K, V> where
K: UnwindSafe,
V: UnwindSafe,
Blanket Implementations
Mutably borrows from an owned value. Read more