Rust High Performance

Maps

There are two kinds of maps: HashMap and BTreeMap. The main difference between them is how they order themselves in memory. They have similar methods to insert and retrieve elements, but their performance changes a lot depending on the operation.

HashMap creates an index, where for every key a hash points to the element. That way, you do not need to check the whole key for every new insert/delete/get operation. You simply hash it and search it in the index. If it exists, it can be retrieved, modified, or deleted; if it doesn't, it can be inserted. It is pretty fast to insert new elements. It's as simple as adding it to the index. Retrieving it is also pretty much the same: just get the value if the hashed index exists; all operations ...