From 35e059a950b1938e40085331e0c02e2d5240d3a6 Mon Sep 17 00:00:00 2001
From: Steve Yen <steve.yen@gmail.com>
Date: Tue, 28 Oct 2014 12:16:27 -0700
Subject: [PATCH] first attempt at simple, memory-only feed for testing

---
 feed_nil.go    |   1 +
 feed_simple.go | 146 +++++++++++++++++++++++++++++++++++++++++++++++++
 stream.go      |  17 +++++-
 3 files changed, 162 insertions(+), 2 deletions(-)
 create mode 100644 feed_simple.go

diff --git a/feed_nil.go b/feed_nil.go
index 29a8211..4c4bcd0 100644
--- a/feed_nil.go
+++ b/feed_nil.go
@@ -16,6 +16,7 @@ type NILFeed struct {
 	streams map[string]Stream
 }
 
+// A NILFeed never feeds any data to its streams.
 func NewNILFeed(name string, streams map[string]Stream) *NILFeed {
 	return &NILFeed{
 		name:    name,
diff --git a/feed_simple.go b/feed_simple.go
new file mode 100644
index 0000000..f983172
--- /dev/null
+++ b/feed_simple.go
@@ -0,0 +1,146 @@
+//  Copyright (c) 2014 Couchbase, Inc.
+//  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 main
+
+import (
+	"fmt"
+	log "github.com/couchbaselabs/clog"
+)
+
+// A SimpleFeed is uses a local, in-memory channel as its Stream
+// datasource.  It's useful, amongst other things, for testing.
+type SimpleFeed struct {
+	name    string
+	streams map[string]Stream
+	closeCh chan bool
+	doneCh  chan bool
+	doneErr error
+	doneMsg string
+	source  Stream
+	pf      StreamPartitionFunc
+}
+
+func (t *SimpleFeed) Source() Stream {
+	return t.source
+}
+
+func NewSimpleFeed(name string, source Stream, pf StreamPartitionFunc,
+	streams map[string]Stream) (*SimpleFeed, error) {
+	return &SimpleFeed{
+		name:    name,
+		streams: streams,
+		closeCh: make(chan bool),
+		doneCh:  make(chan bool),
+		doneErr: nil,
+		doneMsg: "",
+		source:  source,
+		pf:      pf,
+	}, nil
+}
+
+func (t *SimpleFeed) Name() string {
+	return t.name
+}
+
+func (t *SimpleFeed) Start() error {
+	log.Printf("SimpleFeed.Start, name: %s", t.Name())
+	go t.feed()
+	return nil
+}
+
+func (t *SimpleFeed) feed() {
+	for {
+		select {
+		case <-t.closeCh:
+			t.doneErr = nil
+			t.doneMsg = "closeCh closed"
+			close(t.doneCh)
+			return
+
+		case req, alive := <-t.source:
+			if !alive {
+				t.waitForClose("source closed", nil)
+				return
+			}
+
+			stream, err := t.pf(req, t.streams)
+			if err != nil {
+				t.waitForClose("partition func error",
+					fmt.Errorf("error: SimpleFeed pf on req: %#v, err: %v",
+						req, err))
+				return
+			}
+
+			var doneChOrig chan error
+			var doneCh chan error
+			wantWaitForClose := ""
+
+			switch req := req.(type) {
+			case *StreamEnd:
+				doneCh := make(chan error)
+				req.doneCh, doneChOrig = doneCh, req.doneCh
+				wantWaitForClose = "source stream end"
+
+			case *StreamFlush:
+				doneCh := make(chan error)
+				req.doneCh, doneChOrig = doneCh, req.doneCh
+
+			case *StreamRollback:
+				doneCh := make(chan error)
+				req.doneCh, doneChOrig = doneCh, req.doneCh
+				wantWaitForClose = "source stream rollback"
+
+			case *StreamSnapshot:
+				doneCh := make(chan error)
+				req.doneCh, doneChOrig = doneCh, req.doneCh
+
+			case *StreamUpdate:
+			case *StreamDelete:
+			}
+
+			stream <- req
+
+			if doneCh != nil {
+				err = <-doneCh
+			}
+
+			if doneChOrig != nil {
+				if err != nil {
+					doneChOrig <- err
+				}
+				close(doneChOrig)
+			}
+
+			if wantWaitForClose != "" {
+				t.waitForClose(wantWaitForClose, nil)
+				return
+			}
+		}
+	}
+}
+
+func (t *SimpleFeed) waitForClose(msg string, err error) {
+	<-t.closeCh
+	t.doneErr = err
+	t.doneMsg = msg
+	close(t.doneCh)
+}
+
+func (t *SimpleFeed) Close() error {
+	close(t.closeCh)
+	<-t.doneCh
+	return t.doneErr
+}
+
+func (t *SimpleFeed) Streams() map[string]Stream {
+	return t.streams
+}
diff --git a/stream.go b/stream.go
index 8d3d49d..655cc7e 100644
--- a/stream.go
+++ b/stream.go
@@ -13,25 +13,36 @@ package main
 
 type Stream chan StreamRequest
 
-type StreamRequest interface {
-}
+type StreamPartitionFunc func(StreamRequest, map[string]Stream) (Stream, error)
+
+type StreamRequest interface{}
+
+// ----------------------------------------------
 
 type StreamEnd struct {
 	doneCh chan error
 }
 
+// ----------------------------------------------
+
 type StreamFlush struct {
 	doneCh chan error
 }
 
+// ----------------------------------------------
+
 type StreamRollback struct {
 	doneCh chan error
 }
 
+// ----------------------------------------------
+
 type StreamSnapshot struct {
 	doneCh chan error
 }
 
+// ----------------------------------------------
+
 type StreamUpdate struct {
 	id   []byte
 	body []byte
@@ -45,6 +56,8 @@ func (s *StreamUpdate) Body() []byte {
 	return s.body
 }
 
+// ----------------------------------------------
+
 type StreamDelete struct {
 	id []byte
 }