initial

.gitignore

@@ -0,0 +1 @@
+/maxi

core/couchbase-sink.go

@@ -0,0 +1,218 @@
+package core
+
+import (
+	"log"
+	"../memcached"
+	"runtime"
+	// "time"
+	"sync/atomic"
+	"net"
+	"github.com/dustin/go-couchbase"
+	)
+
+type SinkChan chan *memcached.MCResponse
+
+type MCDSink interface {
+	SendRequest(req *memcached.MCRequest, callback MCDCallback)
+	// Stop()
+}
+
+type MCDCallback interface {
+	OnResponse(req *memcached.MCRequest, resp *memcached.MCResponse)
+}
+
+func (sc SinkChan) OnResponse(req *memcached.MCRequest, resp *memcached.MCResponse) {
+	sc <- resp
+}
+
+type request struct {
+	req *memcached.MCRequest
+	cb MCDCallback
+}
+
+type sink struct {
+	bucketInfo couchbase.Bucket
+	vbucketMap [][]int
+	numVBuckets int
+	serverList []string
+	subHandlers [][]chan request
+	connsPerDownstream int
+	connsRRCounter uint32
+}
+
+const QueueDepth = 1024
+const ConnsPerDownstream = 5
+
+var RequestsSent uint32
+var Sends uint32
+
+func NewCouchbaseSink(baseURL, bucketName string) (MCDSink, error) {
+	// if baseURL[0:len("http:\/\/")] != "http:\/\/" {
+	// 	baseURL = "http:\/\/" + baseURL
+	// }
+	bucketInfo, err := couchbase.GetBucket(baseURL, "default", bucketName)
+	if err != nil {
+		return nil, err
+	}
+	serverList := bucketInfo.VBucketServerMap.ServerList
+	subHandlers := make([][]chan request, len(bucketInfo.VBucketServerMap.ServerList))
+	vbucketMap := bucketInfo.VBucketServerMap.VBucketMap
+	h := sink {
+		bucketInfo: *bucketInfo,
+		vbucketMap: vbucketMap,
+		numVBuckets: len(vbucketMap),
+		serverList: serverList,
+		subHandlers: subHandlers,
+		connsPerDownstream: ConnsPerDownstream,
+	}
+	for i, hostname := range serverList {
+		allChans := make([]chan request, ConnsPerDownstream)
+		for k := 0; k < ConnsPerDownstream; k++ {
+			reqChan := make(chan request, QueueDepth)
+			spawnServerHandler(reqChan, hostname)
+			allChans[k] = reqChan
+		}
+		subHandlers[i] = allChans
+	}
+	return &h, nil
+}
+
+
+func spawnServerHandler(reqchan chan request, hostname string) {
+	sock, err := net.Dial("tcp", hostname)
+	if err != nil {
+		log.Panicf("Failed to connect %s: %v", hostname, err)
+	}
+	conn := memcached.ClientFromSock(sock)
+	go runDownstream(&conn, reqchan)
+}
+
+func runDownstreamReader(conn *memcached.Client, callbacks chan request) {
+	recver := &conn.Recver
+	for reqStruct := range callbacks {
+		// log.Printf("dreader: got some Reqstruct: %v, %p", reqStruct, reqStruct.cb)
+		mcresp := memcached.MCResponse{}
+		for {
+			actualResp, err := recver.TryUnpackResponse(&mcresp)
+			if err != nil {
+				log.Printf("Got error on reading downstream %v: %s", conn, err)
+				reqStruct.cb.OnResponse(reqStruct.req, nil)
+				close(callbacks)
+				return
+			}
+
+			if actualResp != nil {
+				break
+			}
+
+			// log.Printf("dreader: Entering fill: %p", reqStruct.cb)
+			recver.Fill()
+			// log.Printf("dreader: From fill: %p", reqStruct.cb)
+		}
+
+		// log.Printf("dreader: Got reply: %v: %p", mcresp, reqStruct.cb)
+		// log.Printf("State: %v", recver)
+
+		// TODO: exception handling?
+		reqStruct.cb.OnResponse(reqStruct.req, &mcresp)
+		// log.Printf("dreader: After onResponse: %p", reqStruct.cb)
+	}
+}
+
+func peekMoreReq(c chan request) (r request, ok bool) {
+	ok = false
+	select {
+	case r, ok = <- c:
+	default:
+	}
+	return
+}
+
+func runDownstream(conn *memcached.Client, reqchan chan request) {
+	defer conn.Close()
+
+	respChans := make(chan request, QueueDepth)
+	go runDownstreamReader(conn, respChans)
+
+	sender := conn.Sender
+	var err error
+
+	for req := range reqchan {
+	again:
+		// log.Printf("Sending req: %s", req.req)
+		// log.Printf("req-bytes: %v", req.req.Bytes())
+		succeeded := sender.TryEnqueueReq(req.req, true)
+		// time.Sleep(1*time.Millisecond)
+
+		if !succeeded {
+			log.Panicf("must succeed!")
+		}
+
+		atomic.AddUint32(&RequestsSent, 1)
+		// log.Printf("downstream: before trying to batch more: %p", req.cb)
+		respChans <- req
+		// try to batch some more requests
+		// log.Printf("downstream: trying to batch more: %p", req.cb)
+		var ok bool
+		var needRespChanSend bool = false
+	moreReqLoop:
+		for {
+			runtime.Gosched()
+			req, ok = peekMoreReq(reqchan)
+			if !ok {
+				break
+			}
+			succeeded = sender.TryEnqueueReq(req.req, false)
+			if !succeeded {
+				break
+			}
+			// log.Printf("downstream: Batched more: %p, %p", req.cb, req.req)
+			// runtime.Gosched()
+			atomic.AddUint32(&RequestsSent, 1)
+			select {
+			case respChans <- req:
+			default:
+				// log.Printf("downstream: But failed to send respChans: %p", req.cb)
+				needRespChanSend = true
+				break moreReqLoop
+			}
+		}
+		// log.Printf("downstream: Sending stuff actualy")
+		atomic.AddUint32(&Sends, 1)
+		err = sender.SendEnqueued()
+		if err != nil {
+			// TODO: better error handling
+			close(respChans)
+			log.Panicf("Got error while sending request: %v", err)
+		}
+
+		if (needRespChanSend) {
+			// log.Printf("downstream: Sending delayed thing to respChans: %p", req.cb)
+			respChans <- req
+			// log.Printf("downstream: Done sending to respChans")
+			continue
+		}
+
+		if ok {
+			// log.Printf("downstream: again")
+			goto again
+		}
+	}
+}
+
+func (s *sink) SendRequest(req *memcached.MCRequest, cb MCDCallback) {
+	// rch = make(chan *memcached.MCResponse, 1)
+	reqStruct := request {
+		req: req,
+		cb: cb,
+	}
+	hash := vbhash(req.Key)
+	vbid := hash & (uint16(s.numVBuckets)-1)
+	// log.Printf("K: %v, H: %d, vbid: %d", req.Key, hash, vbid)
+	req.VBucket = vbid
+	serverId := s.vbucketMap[vbid][0]
+	counter := atomic.AddUint32(&s.connsRRCounter, 1)
+	counter = counter % uint32(s.connsPerDownstream)
+	// log.Printf("Sending request %v to server: %s", reqStruct, s.serverList[serverId])
+	s.subHandlers[serverId][counter] <- reqStruct
+}

core/vbhash.go

@@ -0,0 +1,75 @@
+package core
+
+var crc32tab = []uint32{
+	0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
+	0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
+	0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+	0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
+	0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
+	0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+	0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
+	0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
+	0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+	0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+	0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
+	0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+	0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
+	0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
+	0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+	0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
+	0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a,
+	0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+	0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
+	0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+	0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+	0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
+	0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c,
+	0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+	0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
+	0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
+	0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+	0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
+	0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
+	0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+	0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4,
+	0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
+	0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+	0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
+	0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
+	0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+	0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe,
+	0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
+	0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+	0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+	0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252,
+	0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+	0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60,
+	0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
+	0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+	0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
+	0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
+	0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+	0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
+	0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+	0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+	0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
+	0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e,
+	0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+	0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
+	0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
+	0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+	0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
+	0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
+	0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+	0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
+	0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
+	0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+	0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d}
+
+func vbhash(key []byte) uint16 {
+	crc := uint32(0xffffffff)
+	for x := 0; x < len(key); x++ {
+		crc = (crc >> 8) ^ crc32tab[(uint64(crc)^uint64(key[x]))&0xff]
+	}
+	return uint16((^crc) >> 16)
+}