Vendor main dependencies.

vendor/github.com/eapache/channels/resizable_channel.go

@@ -0,0 +1,109 @@
+package channels
+
+import "github.com/eapache/queue"
+
+// ResizableChannel implements the Channel interface with a resizable buffer between the input and the output.
+// The channel initially has a buffer size of 1, but can be resized by calling Resize().
+//
+// Resizing to a buffer capacity of None is, unfortunately, not supported and will panic
+// (see https://github.com/eapache/channels/issues/1).
+// Resizing back and forth between a finite and infinite buffer is fully supported.
+type ResizableChannel struct {
+	input, output    chan interface{}
+	length           chan int
+	capacity, resize chan BufferCap
+	size             BufferCap
+	buffer           *queue.Queue
+}
+
+func NewResizableChannel() *ResizableChannel {
+	ch := &ResizableChannel{
+		input:    make(chan interface{}),
+		output:   make(chan interface{}),
+		length:   make(chan int),
+		capacity: make(chan BufferCap),
+		resize:   make(chan BufferCap),
+		size:     1,
+		buffer:   queue.New(),
+	}
+	go ch.magicBuffer()
+	return ch
+}
+
+func (ch *ResizableChannel) In() chan<- interface{} {
+	return ch.input
+}
+
+func (ch *ResizableChannel) Out() <-chan interface{} {
+	return ch.output
+}
+
+func (ch *ResizableChannel) Len() int {
+	return <-ch.length
+}
+
+func (ch *ResizableChannel) Cap() BufferCap {
+	val, open := <-ch.capacity
+	if open {
+		return val
+	} else {
+		return ch.size
+	}
+}
+
+func (ch *ResizableChannel) Close() {
+	close(ch.input)
+}
+
+func (ch *ResizableChannel) Resize(newSize BufferCap) {
+	if newSize == None {
+		panic("channels: ResizableChannel does not support unbuffered behaviour")
+	}
+	if newSize < 0 && newSize != Infinity {
+		panic("channels: invalid negative size trying to resize channel")
+	}
+	ch.resize <- newSize
+}
+
+func (ch *ResizableChannel) magicBuffer() {
+	var input, output, nextInput chan interface{}
+	var next interface{}
+	nextInput = ch.input
+	input = nextInput
+
+	for input != nil || output != nil {
+		select {
+		case elem, open := <-input:
+			if open {
+				ch.buffer.Add(elem)
+			} else {
+				input = nil
+				nextInput = nil
+			}
+		case output <- next:
+			ch.buffer.Remove()
+		case ch.size = <-ch.resize:
+		case ch.length <- ch.buffer.Length():
+		case ch.capacity <- ch.size:
+		}
+
+		if ch.buffer.Length() == 0 {
+			output = nil
+			next = nil
+		} else {
+			output = ch.output
+			next = ch.buffer.Peek()
+		}
+
+		if ch.size != Infinity && ch.buffer.Length() >= int(ch.size) {
+			input = nil
+		} else {
+			input = nextInput
+		}
+	}
+
+	close(ch.output)
+	close(ch.resize)
+	close(ch.length)
+	close(ch.capacity)
+}