Module concread::internals::hashmap [−][src]
Expand description
HashMap - A concurrently readable HashMap
This is a specialisation of the BptreeMap, allowing a concurrently readable
HashMap. Unlike a traditional hashmap it does not have O(1) lookup, as it
internally uses a tree-like structure to store a series of buckets. However
if you do not need key-ordering, due to the storage of the hashes as u64
the operations in the tree to seek the bucket is much faster than the use of
the same key in the BptreeMap.
For more details. see the BptreeMap
This structure is very different to the im crate. The im crate is
sync + send over individual operations. This means that multiple writes can
be interleaved atomicly and safely, and the readers always see the latest
data. While this is potentially useful to a set of problems, transactional
structures are suited to problems where readers have to maintain consistent
data views for a duration of time, cpu cache friendly behaviours and
database like transaction properties (ACID).