From 6e15f9cb0dbac68992eb242282e725784fe72b32 Mon Sep 17 00:00:00 2001 From: Antonio Jesus Navarro Perez Date: Tue, 21 Feb 2017 14:53:30 +0100 Subject: cache: move package to plumbing Because cache package is only intended to be used at internal level, we move it to the plumbing package. --- plumbing/cache/queue.go | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 plumbing/cache/queue.go (limited to 'plumbing/cache/queue.go') diff --git a/plumbing/cache/queue.go b/plumbing/cache/queue.go new file mode 100644 index 0000000..8c6d7d3 --- /dev/null +++ b/plumbing/cache/queue.go @@ -0,0 +1,46 @@ +package cache + +import "srcd.works/go-git.v4/plumbing" + +// queue is a basic FIFO queue based on a circular list that resize as needed. +type queue struct { + elements []plumbing.Hash + size int + head int + tail int + count int +} + +// newQueue returns a queue with the specified initial size +func newQueue(size int) *queue { + return &queue{ + elements: make([]plumbing.Hash, size), + size: size, + } +} + +// Push adds a node to the queue. +func (q *queue) Push(h plumbing.Hash) { + if q.head == q.tail && q.count > 0 { + elements := make([]plumbing.Hash, len(q.elements)+q.size) + copy(elements, q.elements[q.head:]) + copy(elements[len(q.elements)-q.head:], q.elements[:q.head]) + q.head = 0 + q.tail = len(q.elements) + q.elements = elements + } + q.elements[q.tail] = h + q.tail = (q.tail + 1) % len(q.elements) + q.count++ +} + +// Pop removes and returns a Hash from the queue in first to last order. +func (q *queue) Pop() plumbing.Hash { + if q.count == 0 { + return plumbing.ZeroHash + } + node := q.elements[q.head] + q.head = (q.head + 1) % len(q.elements) + q.count-- + return node +} -- cgit