bpf_api/collections/
hashmap.rs

1use crate::error::Error;
2use crate::platform::{Map, MapType};
3
4/// A hashmap that exposes an idiomatic Rust interface to an underlying BPF hashmap.
5pub struct HashMap<K: Copy + Default, V: Copy + Default> {
6    map: Map<K, V>,
7}
8
9impl<K: Copy + Default, V: Copy + Default> HashMap<K, V> {
10    /// Creates a new BPF hashmap with `entries` elements.
11    ///
12    /// # Arguments
13    ///
14    /// * `entries` - The number of elements in the hashmap.
15    ///
16    /// # Example
17    /// ```
18    /// use bpf_api::collections::HashMap;
19    ///
20    /// let hashmap = HashMap::<u32, u32>::with_capacity(10).expect("Failed to create hashmap");
21    /// ```
22    pub fn with_capacity(entries: u32) -> Result<Self, Error> {
23        Ok(Self {
24            map: Map::with_capacity(MapType::Hash, entries)?,
25        })
26    }
27
28    /// Retrieves the value for a given key.
29    ///
30    /// # Arguments
31    ///
32    /// * `key` - The key associated with the value to be retrieved.
33    ///
34    /// # Example
35    /// ```
36    /// use bpf_api::collections::HashMap;
37    ///
38    /// let hashmap = HashMap::<u32, u32>::with_capacity(10).expect("Failed to create hashmap");
39    /// assert!(matches!(hashmap.get(1000), Err(_)));
40    /// ```
41    pub fn get(&self, key: K) -> Result<V, Error> {
42        self.map.get(&key)
43    }
44
45    /// Sets the value for a given key.
46    ///
47    /// # Arguments
48    ///
49    /// * `key` - The key associated with the value to be set.
50    /// * `value` - The new value.
51    ///
52    /// # Example
53    /// ```
54    /// use bpf_api::collections::HashMap;
55    ///
56    /// let hashmap = HashMap::<u32, u32>::with_capacity(10).expect("Failed to create hashmap");
57    /// assert!(matches!(hashmap.get(1000), Err(_)));
58    /// assert!(matches!(hashmap.insert(1000, 0xdeadbeef), Ok(_)));
59    /// assert!(matches!(hashmap.get(1000), Ok(0xdeadbeef)));
60    /// ```
61    pub fn insert(&self, key: K, val: V) -> Result<(), Error> {
62        self.map.set(&key, &val)
63    }
64
65    /// Deletes an entry from the hash map given a key.
66    ///
67    /// # Arguments
68    ///
69    /// * `key` - The key of the entry to be deleted.
70    ///
71    /// # Example
72    /// ```
73    /// use bpf_api::collections::HashMap;
74    ///
75    /// let hashmap = HashMap::<u32, u32>::with_capacity(10).expect("Failed to create hashmap");
76    /// assert!(matches!(hashmap.get(1000), Err(_)));
77    /// assert!(matches!(hashmap.insert(1000, 0xdeadbeef), Ok(_)));
78    /// assert!(matches!(hashmap.get(1000), Ok(0xdeadbeef)));
79    /// assert!(matches!(hashmap.remove(1000), Ok(_)));
80    /// assert!(matches!(hashmap.remove(1000), Err(_)));
81    /// ```
82    pub fn remove(&self, key: K) -> Result<(), Error> {
83        self.map.del(&key)
84    }
85
86    /// Retrieve the BPF identifier for this map. This is the underlying file
87    /// descriptor that's used in eBPF programs.
88    ///
89    /// # Example
90    /// ```
91    /// use bpf_api::collections::HashMap;
92    ///
93    /// let hashmap = HashMap::<u32, u32>::with_capacity(10).expect("Failed to create hashmap");
94    /// hashmap.get_identifier();
95    /// ```
96    pub fn get_identifier(&self) -> u32 {
97        self.map.get_identifier()
98    }
99}
bpf_api/collections/hashmap.rs

bpf_api/collections/
hashmap.rs
