Struct libbpf_rs::Map

pub struct Map { /* fields omitted */ }

Represents a created map.

Some methods require working with raw bytes. You may find libraries such as plain helpful.

Implementations

impl Map

pub fn name(&self) -> &str

pub fn fd(&self) -> i32

Returns a file descriptor to the underlying map.

pub fn map_type(&self) -> MapType

pub fn key_size(&self) -> u32

Key size in bytes

pub fn value_size(&self) -> u32

Value size in bytes

pub fn pin<P: AsRef<Path>>(&mut self, path: P) -> Result<()>

Pin this map to bpffs.

pub fn unpin<P: AsRef<Path>>(&mut self, path: P) -> Result<()>

Unpin from bpffs

pub fn lookup(&self, key: &[u8], flags: MapFlags) -> Result<Option<Vec<u8>>>

Returns map value as Vec of u8.

key must have exactly Map::key_size() elements.

If the map is one of the per-cpu data structures, the function Map::lookup_percpu() must be used.

pub fn lookup_percpu(
    &self,
    key: &[u8],
    flags: MapFlags
) -> Result<Option<Vec<Vec<u8>>>>

Returns one value per cpu as Vec of Vec of u8 for per per-cpu maps.

For normal maps, Map::lookup() must be used.

pub fn delete(&mut self, key: &[u8]) -> Result<()>

Deletes an element from the map.

key must have exactly Map::key_size() elements.

pub fn lookup_and_delete(&mut self, key: &[u8]) -> Result<Option<Vec<u8>>>

Same as Map::lookup() except this also deletes the key from the map.

Note that this operation is currently only implemented in the kernel for MapType::Queue and MapType::Stack.

key must have exactly Map::key_size() elements.

pub fn update(
    &mut self,
    key: &[u8],
    value: &[u8],
    flags: MapFlags
) -> Result<()>

Update an element.

key must have exactly Map::key_size() elements. value must have exactly Map::value_size() elements.

For per-cpu maps, Map::update_percpu() must be used.

pub fn update_percpu(
    &mut self,
    key: &[u8],
    values: &[Vec<u8>],
    flags: MapFlags
) -> Result<()>

Update an element in an per-cpu map with one value per cpu.

key must have exactly Map::key_size() elements. value must have one element per cpu (see num_possible_cpus()) with exactly Map::value_size() elements each.

For per-cpu maps, Map::update_percpu() must be used.

pub fn keys(&self) -> MapKeyIter<'_>

Returns an iterator over keys in this map

Note that if the map is not stable (stable meaning no updates or deletes) during iteration, iteration can skip keys, restart from the beginning, or duplicate keys. In other words, iteration becomes unpredictable.