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Diffstat (limited to 'vendor/github.com/eapache/queue/queue.go')
-rw-r--r-- | vendor/github.com/eapache/queue/queue.go | 102 |
1 files changed, 0 insertions, 102 deletions
diff --git a/vendor/github.com/eapache/queue/queue.go b/vendor/github.com/eapache/queue/queue.go deleted file mode 100644 index 71d1acdf2..000000000 --- a/vendor/github.com/eapache/queue/queue.go +++ /dev/null @@ -1,102 +0,0 @@ -/* -Package queue provides a fast, ring-buffer queue based on the version suggested by Dariusz Górecki. -Using this instead of other, simpler, queue implementations (slice+append or linked list) provides -substantial memory and time benefits, and fewer GC pauses. - -The queue implemented here is as fast as it is for an additional reason: it is *not* thread-safe. -*/ -package queue - -// minQueueLen is smallest capacity that queue may have. -// Must be power of 2 for bitwise modulus: x % n == x & (n - 1). -const minQueueLen = 16 - -// Queue represents a single instance of the queue data structure. -type Queue struct { - buf []interface{} - head, tail, count int -} - -// New constructs and returns a new Queue. -func New() *Queue { - return &Queue{ - buf: make([]interface{}, minQueueLen), - } -} - -// Length returns the number of elements currently stored in the queue. -func (q *Queue) Length() int { - return q.count -} - -// resizes the queue to fit exactly twice its current contents -// this can result in shrinking if the queue is less than half-full -func (q *Queue) resize() { - newBuf := make([]interface{}, q.count<<1) - - if q.tail > q.head { - copy(newBuf, q.buf[q.head:q.tail]) - } else { - n := copy(newBuf, q.buf[q.head:]) - copy(newBuf[n:], q.buf[:q.tail]) - } - - q.head = 0 - q.tail = q.count - q.buf = newBuf -} - -// Add puts an element on the end of the queue. -func (q *Queue) Add(elem interface{}) { - if q.count == len(q.buf) { - q.resize() - } - - q.buf[q.tail] = elem - // bitwise modulus - q.tail = (q.tail + 1) & (len(q.buf) - 1) - q.count++ -} - -// Peek returns the element at the head of the queue. This call panics -// if the queue is empty. -func (q *Queue) Peek() interface{} { - if q.count <= 0 { - panic("queue: Peek() called on empty queue") - } - return q.buf[q.head] -} - -// Get returns the element at index i in the queue. If the index is -// invalid, the call will panic. This method accepts both positive and -// negative index values. Index 0 refers to the first element, and -// index -1 refers to the last. -func (q *Queue) Get(i int) interface{} { - // If indexing backwards, convert to positive index. - if i < 0 { - i += q.count - } - if i < 0 || i >= q.count { - panic("queue: Get() called with index out of range") - } - // bitwise modulus - return q.buf[(q.head+i)&(len(q.buf)-1)] -} - -// Remove removes and returns the element from the front of the queue. If the -// queue is empty, the call will panic. -func (q *Queue) Remove() interface{} { - if q.count <= 0 { - panic("queue: Remove() called on empty queue") - } - ret := q.buf[q.head] - q.buf[q.head] = nil - // bitwise modulus - q.head = (q.head + 1) & (len(q.buf) - 1) - q.count-- - // Resize down if buffer 1/4 full. - if len(q.buf) > minQueueLen && (q.count<<2) == len(q.buf) { - q.resize() - } - return ret -} |