Struct redis::InfoDict

pub struct InfoDict { /* private fields */ }

An info dictionary type.

Implementations

impl InfoDict

This type provides convenient access to key/value data returned by the “INFO” command. It acts like a regular mapping but also has a convenience method get which can return data in the appropriate type.

For instance this can be used to query the server for the role it’s in (master, slave) etc:

let info : redis::InfoDict = redis::cmd("INFO").query(&mut con)?;
let role : Option<String> = info.get("role");

pub fn new(kvpairs: &str) -> InfoDict

Creates a new info dictionary from a string in the response of the INFO command. Each line is a key, value pair with the key and value separated by a colon (:). Lines starting with a hash (#) are ignored.

pub fn get<T: FromRedisValue>(&self, key: &str) -> Option<T>

Fetches a value by key and converts it into the given type. Typical types are String, bool and integer types.

pub fn find(&self, key: &&str) -> Option<&Value>

Looks up a key in the info dict.

pub fn contains_key(&self, key: &&str) -> bool

Checks if a key is contained in the info dicf.

pub fn len(&self) -> usize

Returns the size of the info dict.

pub fn is_empty(&self) -> bool

Checks if the dict is empty.

Methods from Deref<Target = HashMap<String, Value>>

pub fn capacity(&self) -> usize

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 std::collections::HashMap;
let map: HashMap<i32, i32> = HashMap::with_capacity(100);
assert!(map.capacity() >= 100);

pub fn keys(&self) -> Keys<'_, K, V>

An iterator visiting all keys in arbitrary order. The iterator element type is &'a K.

Examples

use std::collections::HashMap;

let map = HashMap::from([
    ("a", 1),
    ("b", 2),
    ("c", 3),
]);

for key in map.keys() {
    println!("{key}");
}

Performance

In the current implementation, iterating over keys takes O(capacity) time instead of O(len) because it internally visits empty buckets too.

pub fn values(&self) -> Values<'_, K, V>

An iterator visiting all values in arbitrary order. The iterator element type is &'a V.

Examples

use std::collections::HashMap;

let map = HashMap::from([
    ("a", 1),
    ("b", 2),
    ("c", 3),
]);

for val in map.values() {
    println!("{val}");
}

Performance

In the current implementation, iterating over values takes O(capacity) time instead of O(len) because it internally visits empty buckets too.

pub fn iter(&self) -> Iter<'_, K, V>

An iterator visiting all key-value pairs in arbitrary order. The iterator element type is (&'a K, &'a V).

Examples

use std::collections::HashMap;

let map = HashMap::from([
    ("a", 1),
    ("b", 2),
    ("c", 3),
]);

for (key, val) in map.iter() {
    println!("key: {key} val: {val}");
}

Performance

In the current implementation, iterating over map takes O(capacity) time instead of O(len) because it internally visits empty buckets too.

pub fn len(&self) -> usize

Returns the number of elements in the map.

Examples

use std::collections::HashMap;

let mut a = HashMap::new();
assert_eq!(a.len(), 0);
a.insert(1, "a");
assert_eq!(a.len(), 1);

pub fn is_empty(&self) -> bool

Returns true if the map contains no elements.

Examples

use std::collections::HashMap;

let mut a = HashMap::new();
assert!(a.is_empty());
a.insert(1, "a");
assert!(!a.is_empty());

pub fn hasher(&self) -> &S

Returns a reference to the map’s BuildHasher.

Examples

use std::collections::HashMap;
use std::hash::RandomState;

let hasher = RandomState::new();
let map: HashMap<i32, i32> = HashMap::with_hasher(hasher);
let hasher: &RandomState = map.hasher();

pub fn get<Q>(&self, k: &Q) -> Option<&V>

where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

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 std::collections::HashMap;

let mut map = HashMap::new();
map.insert(1, "a");
assert_eq!(map.get(&1), Some(&"a"));
assert_eq!(map.get(&2), None);

pub fn get_key_value<Q>(&self, k: &Q) -> Option<(&K, &V)>

where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

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 std::collections::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);

pub fn contains_key<Q>(&self, k: &Q) -> bool

where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

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 std::collections::HashMap;

let mut map = HashMap::new();
map.insert(1, "a");
assert_eq!(map.contains_key(&1), true);
assert_eq!(map.contains_key(&2), false);

pub fn raw_entry(&self) -> RawEntryBuilder<'_, K, V, S>

🔬This is a nightly-only experimental API. (hash_raw_entry)

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 Clone for InfoDict

fn clone(&self) -> InfoDict

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for InfoDict

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for InfoDict

type Target = HashMap<String, Value>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl FromRedisValue for InfoDict

fn from_redis_value(v: &Value) -> RedisResult<InfoDict>

Given a redis Value this attempts to convert it into the given destination type. If that fails because it’s not compatible an appropriate error is generated.

fn from_redis_values(items: &[Value]) -> RedisResult<Vec<Self>>

Similar to from_redis_value but constructs a vector of objects from another vector of values. This primarily exists internally to customize the behavior for vectors of tuples.

fn from_byte_vec(_vec: &[u8]) -> Option<Vec<Self>>

Convert bytes to a single element vector.