brsg / ring_buffer

Implementation of a ring or circular buffer based on Erlang's :queue.

ring_buffer

RingBuffer is an implementation of a ring or circular buffer data structure, internally based on Erlang's :queue.

A RingBuffer has a :max_size which is specifed at creation via new/1.

Calling put/2 on a RingBuffer whose :size is less than its :max_size will:

• add the item to the buffer
• increment the :size of the buffer
• set :evicted to nil (since no item was evicted by the call to put/2)

Calling put/2 on a RingBuffer whose :size is equal to its :max_size will:

• add the item to the buffer
• maintain :size equal to :max_size
• set :evicted to the oldest item in the buffer preceding the call to put/2

Thus, this implementation offers the ability to access the item that was evicted from the buffer as the result of the the most recent call to put/2 (if any) via the :evicted field of the %RingBuffer{} struct.

See the doctests in RingBuffer.ex and test cases in ring_buffer_test.exs for examples of using RingBuffer.

License

Copyright 2021 Blue River Systems Group, LLC

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.