diff options
Diffstat (limited to 'vendor/k8s.io/client-go/util/buffer')
-rw-r--r-- | vendor/k8s.io/client-go/util/buffer/ring_growing.go | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/vendor/k8s.io/client-go/util/buffer/ring_growing.go b/vendor/k8s.io/client-go/util/buffer/ring_growing.go new file mode 100644 index 000000000..86965a513 --- /dev/null +++ b/vendor/k8s.io/client-go/util/buffer/ring_growing.go @@ -0,0 +1,72 @@ +/* +Copyright 2017 The Kubernetes Authors. + +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. +*/ + +package buffer + +// RingGrowing is a growing ring buffer. +// Not thread safe. +type RingGrowing struct { + data []interface{} + n int // Size of Data + beg int // First available element + readable int // Number of data items available +} + +// NewRingGrowing constructs a new RingGrowing instance with provided parameters. +func NewRingGrowing(initialSize int) *RingGrowing { + return &RingGrowing{ + data: make([]interface{}, initialSize), + n: initialSize, + } +} + +// ReadOne reads (consumes) first item from the buffer if it is available, otherwise returns false. +func (r *RingGrowing) ReadOne() (data interface{}, ok bool) { + if r.readable == 0 { + return nil, false + } + r.readable-- + element := r.data[r.beg] + r.data[r.beg] = nil // Remove reference to the object to help GC + if r.beg == r.n-1 { + // Was the last element + r.beg = 0 + } else { + r.beg++ + } + return element, true +} + +// WriteOne adds an item to the end of the buffer, growing it if it is full. +func (r *RingGrowing) WriteOne(data interface{}) { + if r.readable == r.n { + // Time to grow + newN := r.n * 2 + newData := make([]interface{}, newN) + to := r.beg + r.readable + if to <= r.n { + copy(newData, r.data[r.beg:to]) + } else { + copied := copy(newData, r.data[r.beg:]) + copy(newData[copied:], r.data[:(to%r.n)]) + } + r.beg = 0 + r.data = newData + r.n = newN + } + r.data[(r.readable+r.beg)%r.n] = data + r.readable++ +} |