integrate the event bus, handle protocol update events, make identify…

… emit deltas (#659)

go.mod

@@ -9,16 +9,17 @@ require (
 	github.com/jbenet/go-cienv v0.1.0
 	github.com/jbenet/goprocess v0.1.3
 	github.com/libp2p/go-conn-security-multistream v0.1.0
+	github.com/libp2p/go-eventbus v0.0.2
 	github.com/libp2p/go-libp2p-autonat v0.1.0
-	github.com/libp2p/go-libp2p-blankhost v0.1.1
+	github.com/libp2p/go-libp2p-blankhost v0.1.3
 	github.com/libp2p/go-libp2p-circuit v0.1.0
-	github.com/libp2p/go-libp2p-core v0.0.1
+	github.com/libp2p/go-libp2p-core v0.0.6
 	github.com/libp2p/go-libp2p-discovery v0.1.0
 	github.com/libp2p/go-libp2p-loggables v0.1.0
 	github.com/libp2p/go-libp2p-mplex v0.2.1
 	github.com/libp2p/go-libp2p-nat v0.0.4
 	github.com/libp2p/go-libp2p-netutil v0.1.0
-	github.com/libp2p/go-libp2p-peerstore v0.1.0
+	github.com/libp2p/go-libp2p-peerstore v0.1.1
 	github.com/libp2p/go-libp2p-secio v0.1.0
 	github.com/libp2p/go-libp2p-swarm v0.1.0
 	github.com/libp2p/go-libp2p-testing v0.0.4

go.sum

@@ -1,15 +1,21 @@
+cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 github.com/AndreasBriese/bbloom v0.0.0-20180913140656-343706a395b7/go.mod h1:bOvUY6CB00SOBii9/FifXqc0awNKxLFCL/+pkDPuyl8=
+github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/Kubuxu/go-os-helper v0.0.1/go.mod h1:N8B+I7vPCT80IcP58r50u4+gEEcsZETFUpAzWW2ep1Y=
 github.com/aead/siphash v1.0.1/go.mod h1:Nywa3cDsYNNK3gaciGTWPwHt0wlpNV15vwmswBAUSII=
 github.com/btcsuite/btcd v0.0.0-20190213025234-306aecffea32 h1:qkOC5Gd33k54tobS36cXdAzJbeHaduLtnLQQwNoIi78=
 github.com/btcsuite/btcd v0.0.0-20190213025234-306aecffea32/go.mod h1:DrZx5ec/dmnfpw9KyYoQyYo7d0KEvTkk/5M/vbZjAr8=
+github.com/btcsuite/btcd v0.0.0-20190523000118-16327141da8c h1:aEbSeNALREWXk0G7UdNhR3ayBV7tZ4M2PNmnrCAph6Q=
+github.com/btcsuite/btcd v0.0.0-20190523000118-16327141da8c/go.mod h1:3J08xEfcugPacsc34/LKRU2yO7YmuT8yt28J8k2+rrI=
 github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f/go.mod h1:TdznJufoqS23FtqVCzL0ZqgP5MqXbb4fg/WgDys70nA=
 github.com/btcsuite/btcutil v0.0.0-20190207003914-4c204d697803/go.mod h1:+5NJ2+qvTyV9exUAL/rxXi3DcLg2Ts+ymUAY5y4NvMg=
+github.com/btcsuite/btcutil v0.0.0-20190425235716-9e5f4b9a998d/go.mod h1:+5NJ2+qvTyV9exUAL/rxXi3DcLg2Ts+ymUAY5y4NvMg=
 github.com/btcsuite/go-socks v0.0.0-20170105172521-4720035b7bfd/go.mod h1:HHNXQzUsZCxOoE+CPiyCTO6x34Zs86zZUiwtpXoGdtg=
 github.com/btcsuite/goleveldb v0.0.0-20160330041536-7834afc9e8cd/go.mod h1:F+uVaaLLH7j4eDXPRvw78tMflu7Ie2bzYOH4Y8rRKBY=
 github.com/btcsuite/snappy-go v0.0.0-20151229074030-0bdef8d06723/go.mod h1:8woku9dyThutzjeg+3xrA5iCpBRH8XEEg3lh6TiUghc=
 github.com/btcsuite/websocket v0.0.0-20150119174127-31079b680792/go.mod h1:ghJtEyQwv5/p4Mg4C0fgbePVuGr935/5ddU9Z3TmDRY=
 github.com/btcsuite/winsvc v1.0.0/go.mod h1:jsenWakMcC0zFBFurPLEAyrnc/teJEM1O46fmI40EZs=
+github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/coreos/go-semver v0.3.0 h1:wkHLiw0WNATZnSG7epLsujiMCgPAc9xhjJ4tgnAxmfM=
 github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/davecgh/go-spew v0.0.0-20171005155431-ecdeabc65495/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -23,10 +29,14 @@ github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMo
 github.com/go-check/check v0.0.0-20180628173108-788fd7840127/go.mod h1:9ES+weclKsC9YodN5RgxqK/VD9HM9JsCSh7rNhMZE98=
 github.com/gogo/protobuf v1.2.1 h1:/s5zKNz0uPFCZ5hddgPdo2TK2TVrUNMn0OOX8/aZMTE=
 github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
+github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
+github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.0 h1:kbxbvI4Un1LUWKxufD+BiE6AEExYYgkQLQmLFqA1LFk=
 github.com/golang/protobuf v1.3.0/go.mod h1:Qd/q+1AKNOZr9uGQzbzCmRO6sUih6GTPZv6a1/R87v0=
 github.com/golang/snappy v0.0.0-20180518054509-2e65f85255db/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
+github.com/google/go-cmp v0.2.0 h1:+dTQ8DZQJz0Mb/HjFlkptS1FeQ4cWSnN941F8aEG4SQ=
+github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
 github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gorilla/websocket v1.4.0 h1:WDFjx/TMzVgy9VdMMQi2K2Emtwi2QcUQsztZ/zLaH/Q=
@@ -35,6 +45,8 @@ github.com/gxed/hashland/keccakpg v0.0.1 h1:wrk3uMNaMxbXiHibbPO4S0ymqJMm41WiudyF
 github.com/gxed/hashland/keccakpg v0.0.1/go.mod h1:kRzw3HkwxFU1mpmPP8v1WyQzwdGfmKFJ6tItnhQ67kU=
 github.com/gxed/hashland/murmur3 v0.0.1 h1:SheiaIt0sda5K+8FLz952/1iWS9zrnKsEJaOJu4ZbSc=
 github.com/gxed/hashland/murmur3 v0.0.1/go.mod h1:KjXop02n4/ckmZSnY2+HKcLud/tcmvhST0bie/0lS48=
+github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
+github.com/hashicorp/golang-lru v0.5.1 h1:0hERBMJE1eitiLkihrMvRVBYAkpHzc/J3QdDN+dAcgU=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hpcloud/tail v1.0.0 h1:nfCOvKYfkgYP8hkirhJocXT2+zOD8yUNjXaWfTlyFKI=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
@@ -85,16 +97,24 @@ github.com/libp2p/go-buffer-pool v0.0.2 h1:QNK2iAFa8gjAe1SPz6mHSMuCcjs+X1wlHzeOS
 github.com/libp2p/go-buffer-pool v0.0.2/go.mod h1:MvaB6xw5vOrDl8rYZGLFdKAuk/hRoRZd1Vi32+RXyFM=
 github.com/libp2p/go-conn-security-multistream v0.1.0 h1:aqGmto+ttL/uJgX0JtQI0tD21CIEy5eYd1Hlp0juHY0=
 github.com/libp2p/go-conn-security-multistream v0.1.0/go.mod h1:aw6eD7LOsHEX7+2hJkDxw1MteijaVcI+/eP2/x3J1xc=
+github.com/libp2p/go-eventbus v0.0.2 h1:L9eslON8FjFBJlyUs9fyEZKnxSqZd2AMDUNldPrqmZI=
+github.com/libp2p/go-eventbus v0.0.2/go.mod h1:Hr/yGlwxA/stuLnpMiu82lpNKpvRy3EaJxPu40XYOwk=
 github.com/libp2p/go-flow-metrics v0.0.1 h1:0gxuFd2GuK7IIP5pKljLwps6TvcuYgvG7Atqi3INF5s=
 github.com/libp2p/go-flow-metrics v0.0.1/go.mod h1:Iv1GH0sG8DtYN3SVJ2eG221wMiNpZxBdp967ls1g+k8=
 github.com/libp2p/go-libp2p-autonat v0.1.0 h1:aCWAu43Ri4nU0ZPO7NyLzUvvfqd0nE3dX0R/ZGYVgOU=
 github.com/libp2p/go-libp2p-autonat v0.1.0/go.mod h1:1tLf2yXxiE/oKGtDwPYWTSYG3PtvYlJmg7NeVtPRqH8=
 github.com/libp2p/go-libp2p-blankhost v0.1.1 h1:X919sCh+KLqJcNRApj43xCSiQRYqOSI88Fdf55ngf78=
 github.com/libp2p/go-libp2p-blankhost v0.1.1/go.mod h1:pf2fvdLJPsC1FsVrNP3DUUvMzUts2dsLLBEpo1vW1ro=
+github.com/libp2p/go-libp2p-blankhost v0.1.3 h1:0KycuXvPDhmehw0ASsg+s1o3IfXgCUDqfzAl94KEBOg=
+github.com/libp2p/go-libp2p-blankhost v0.1.3/go.mod h1:KML1//wiKR8vuuJO0y3LUd1uLv+tlkGTAr3jC0S5cLg=
 github.com/libp2p/go-libp2p-circuit v0.1.0 h1:eniLL3Y9aq/sryfyV1IAHj5rlvuyj3b7iz8tSiZpdhY=
 github.com/libp2p/go-libp2p-circuit v0.1.0/go.mod h1:Ahq4cY3V9VJcHcn1SBXjr78AbFkZeIRmfunbA7pmFh8=
 github.com/libp2p/go-libp2p-core v0.0.1 h1:HSTZtFIq/W5Ue43Zw+uWZyy2Vl5WtF0zDjKN8/DT/1I=
 github.com/libp2p/go-libp2p-core v0.0.1/go.mod h1:g/VxnTZ/1ygHxH3dKok7Vno1VfpvGcGip57wjTU4fco=
+github.com/libp2p/go-libp2p-core v0.0.4 h1:wNg7b2tKrZlSNibP+j7A1v8eatjf4+9+YRw0L3DUeFE=
+github.com/libp2p/go-libp2p-core v0.0.4/go.mod h1:jyuCQP356gzfCFtRKyvAbNkyeuxb7OlyhWZ3nls5d2I=
+github.com/libp2p/go-libp2p-core v0.0.6 h1:SsYhfWJ47vLP1Rd9/0hqEm/W/PlFbC/3YLZyLCcvo1w=
+github.com/libp2p/go-libp2p-core v0.0.6/go.mod h1:0d9xmaYAVY5qmbp/fcgxHT3ZJsLjYeYPMJAUKpaCHrE=
 github.com/libp2p/go-libp2p-crypto v0.1.0 h1:k9MFy+o2zGDNGsaoZl0MA3iZ75qXxr9OOoAZF+sD5OQ=
 github.com/libp2p/go-libp2p-crypto v0.1.0/go.mod h1:sPUokVISZiy+nNuTTH/TY+leRSxnFj/2GLjtOTW90hI=
 github.com/libp2p/go-libp2p-discovery v0.1.0 h1:j+R6cokKcGbnZLf4kcNwpx6mDEUPF3N6SrqMymQhmvs=
@@ -112,6 +132,8 @@ github.com/libp2p/go-libp2p-peer v0.2.0 h1:EQ8kMjaCUwt/Y5uLgjT8iY2qg0mGUT0N1zUje
 github.com/libp2p/go-libp2p-peer v0.2.0/go.mod h1:RCffaCvUyW2CJmG2gAWVqwePwW7JMgxjsHm7+J5kjWY=
 github.com/libp2p/go-libp2p-peerstore v0.1.0 h1:MKh7pRNPHSh1fLPj8u/M/s/napdmeNpoi9BRy9lPN0E=
 github.com/libp2p/go-libp2p-peerstore v0.1.0/go.mod h1:2CeHkQsr8svp4fZ+Oi9ykN1HBb6u0MOvdJ7YIsmcwtY=
+github.com/libp2p/go-libp2p-peerstore v0.1.1 h1:AJZF2sPpVo+0aAr3IrRiGVsPjJm1INlUQ9EGClgXJ4M=
+github.com/libp2p/go-libp2p-peerstore v0.1.1/go.mod h1:ojEWnwG7JpJLkJ9REWYXQslyu9ZLrPWPEcCdiZzEbSM=
 github.com/libp2p/go-libp2p-secio v0.1.0 h1:NNP5KLxuP97sE5Bu3iuwOWyT/dKEGMN5zSLMWdB7GTQ=
 github.com/libp2p/go-libp2p-secio v0.1.0/go.mod h1:tMJo2w7h3+wN4pgU2LSYeiKPrfqBgkOsdiKK77hE7c8=
 github.com/libp2p/go-libp2p-swarm v0.1.0 h1:HrFk2p0awrGEgch9JXK/qp/hfjqQfgNxpLWnCiWPg5s=
@@ -225,6 +247,8 @@ github.com/whyrusleeping/mdns v0.0.0-20180901202407-ef14215e6b30 h1:nMCC9Pwz1pxf
 github.com/whyrusleeping/mdns v0.0.0-20180901202407-ef14215e6b30/go.mod h1:j4l84WPFclQPj320J9gp0XwNKBb3U0zt5CBqjPp22G4=
 github.com/whyrusleeping/multiaddr-filter v0.0.0-20160516205228-e903e4adabd7 h1:E9S12nwJwEOXe2d6gT6qxdvqMnNq+VnSsKPgm2ZZNds=
 github.com/whyrusleeping/multiaddr-filter v0.0.0-20160516205228-e903e4adabd7/go.mod h1:X2c0RVCI1eSUFI8eLcY3c0423ykwiUdxLJtkDvruhjI=
+go.opencensus.io v0.21.0 h1:mU6zScU4U1YAFPHEHYk+3JC4SY7JxgkqS10ZOSyksNg=
+go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
 golang.org/x/crypto v0.0.0-20170930174604-9419663f5a44/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190211182817-74369b46fc67 h1:ng3VDlRp5/DHpSWl02R4rM9I+8M2rhmsuLwAMmkLQWE=
 golang.org/x/crypto v0.0.0-20190211182817-74369b46fc67/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
@@ -233,14 +257,28 @@ golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACk
 golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20190513172903-22d7a77e9e5f h1:R423Cnkcp5JABoeemiGEPlt9tHXFfw5kvc0yqlxRPWo=
 golang.org/x/crypto v0.0.0-20190513172903-22d7a77e9e5f/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20190618222545-ea8f1a30c443 h1:IcSOAf4PyMp3U3XbIEj1/xJ2BjNN2jWv7JoyOsMxXUU=
+golang.org/x/crypto v0.0.0-20190618222545-ea8f1a30c443/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
+golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
+golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvxsM5YxQ5yQlVC4a0KAMCusXpPoU=
+golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20181011144130-49bb7cea24b1/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190213061140-3a22650c66bd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190227160552-c95aed5357e7 h1:C2F/nMkR/9sfUTpvR3QrjBuTdvMUC/cFajkphs1YLQo=
 golang.org/x/net v0.0.0-20190227160552-c95aed5357e7/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 h1:0GoQqolDA55aaLxZyTzK/Y2ePZzZTUrRacwib7cNsYQ=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f h1:wMNYb4v58l5UBM7MYRLPG6ZhfOqbKu7X5eyFl8ZhKvA=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6 h1:bjcUS9ztw9kFmmIxJInhon/0Is3p+EHBKNgquIzo1OI=
+golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190219092855-153ac476189d/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -252,7 +290,14 @@ golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20180221164845-07fd8470d635/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20190226205152-f727befe758c/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=
+google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
+google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
+google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
 google.golang.org/genproto v0.0.0-20180831171423-11092d34479b/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
+google.golang.org/genproto v0.0.0-20190307195333-5fe7a883aa19/go.mod h1:VzzqZJRnGkLBvHegQrXjBqPurQTc5/KpmUdxsrq26oE=
+google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
@@ -262,3 +307,4 @@ gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 h1:uRGJdciOHaEIrze2W8Q3AKkep
 gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
 gopkg.in/yaml.v2 v2.2.1 h1:mUhvW9EsL+naU5Q3cakzfE91YhliOondGd6ZrsDBHQE=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=

p2p/host/basic/basic_host.go

@@ -7,21 +7,24 @@ import (
 	"sync"
 	"time"
 
+	"github.com/libp2p/go-libp2p/p2p/protocol/identify"
+	"github.com/libp2p/go-libp2p/p2p/protocol/ping"
+
 	"github.com/libp2p/go-libp2p-core/connmgr"
+	"github.com/libp2p/go-libp2p-core/event"
 	"github.com/libp2p/go-libp2p-core/host"
 	"github.com/libp2p/go-libp2p-core/network"
 	"github.com/libp2p/go-libp2p-core/peer"
 	"github.com/libp2p/go-libp2p-core/peerstore"
 	"github.com/libp2p/go-libp2p-core/protocol"
 
+	"github.com/libp2p/go-eventbus"
+	inat "github.com/libp2p/go-libp2p-nat"
+
 	logging "github.com/ipfs/go-log"
-	goprocess "github.com/jbenet/goprocess"
+	"github.com/jbenet/goprocess"
 	goprocessctx "github.com/jbenet/goprocess/context"
 
-	inat "github.com/libp2p/go-libp2p-nat"
-
-	identify "github.com/libp2p/go-libp2p/p2p/protocol/identify"
-	ping "github.com/libp2p/go-libp2p/p2p/protocol/ping"
 	ma "github.com/multiformats/go-multiaddr"
 	madns "github.com/multiformats/go-multiaddr-dns"
 	manet "github.com/multiformats/go-multiaddr-net"
@@ -69,6 +72,7 @@ type BasicHost struct {
 	natmgr     NATManager
 	maResolver *madns.Resolver
 	cmgr       connmgr.ConnManager
+	eventbus   event.Bus
 
 	AddrsFactory AddrsFactory
 
@@ -78,14 +82,16 @@ type BasicHost struct {
 
 	mx        sync.Mutex
 	lastAddrs []ma.Multiaddr
+	emitters  struct {
+		evtLocalProtocolsUpdated event.Emitter
+	}
 }
 
 var _ host.Host = (*BasicHost)(nil)
 
 // HostOpts holds options that can be passed to NewHost in order to
 // customize construction of the *BasicHost.
 type HostOpts struct {
-
 	// MultistreamMuxer is essential for the *BasicHost and will use a sensible default value if omitted.
 	MultistreamMuxer *msmux.MultistreamMuxer
 
@@ -125,6 +131,12 @@ func NewHost(ctx context.Context, net network.Network, opts *HostOpts) (*BasicHo
 		negtimeout:   DefaultNegotiationTimeout,
 		AddrsFactory: DefaultAddrsFactory,
 		maResolver:   madns.DefaultResolver,
+		eventbus:     eventbus.NewBus(),
+	}
+
+	var err error
+	if h.emitters.evtLocalProtocolsUpdated, err = h.eventbus.Emitter(&event.EvtLocalProtocolsUpdated{}); err != nil {
+		return nil, err
 	}
 
 	h.proc = goprocessctx.WithContextAndTeardown(ctx, func() error {
@@ -366,6 +378,10 @@ func (h *BasicHost) IDService() *identify.IDService {
 	return h.ids
 }
 
+func (h *BasicHost) EventBus() event.Bus {
+	return h.eventbus
+}
+
 // SetStreamHandler sets the protocol handler on the Host's Mux.
 // This is equivalent to:
 //   host.Mux().SetHandler(proto, handler)
@@ -377,6 +393,9 @@ func (h *BasicHost) SetStreamHandler(pid protocol.ID, handler network.StreamHand
 		handler(is)
 		return nil
 	})
+	h.emitters.evtLocalProtocolsUpdated.Emit(event.EvtLocalProtocolsUpdated{
+		Added: []protocol.ID{pid},
+	})
 }
 
 // SetStreamHandlerMatch sets the protocol handler on the Host's Mux
@@ -388,11 +407,17 @@ func (h *BasicHost) SetStreamHandlerMatch(pid protocol.ID, m func(string) bool,
 		handler(is)
 		return nil
 	})
+	h.emitters.evtLocalProtocolsUpdated.Emit(event.EvtLocalProtocolsUpdated{
+		Added: []protocol.ID{pid},
+	})
 }
 
 // RemoveStreamHandler returns ..
 func (h *BasicHost) RemoveStreamHandler(pid protocol.ID) {
 	h.Mux().RemoveHandler(string(pid))
+	h.emitters.evtLocalProtocolsUpdated.Emit(event.EvtLocalProtocolsUpdated{
+		Removed: []protocol.ID{pid},
+	})
 }
 
 // NewStream opens a new stream to given peer p, and writes a p2p/protocol
@@ -721,6 +746,7 @@ func (h *BasicHost) AllAddrs() []ma.Multiaddr {
 
 // Close shuts down the Host's services (network, etc).
 func (h *BasicHost) Close() error {
+	_ = h.emitters.evtLocalProtocolsUpdated.Close()
 	return h.proc.Close()
 }
 

p2p/host/basic/basic_host_test.go

@@ -4,10 +4,13 @@ import (
 	"bytes"
 	"context"
 	"io"
+	"reflect"
 	"sort"
 	"testing"
 	"time"
 
+	"github.com/libp2p/go-eventbus"
+	"github.com/libp2p/go-libp2p-core/event"
 	"github.com/libp2p/go-libp2p-core/helpers"
 	"github.com/libp2p/go-libp2p-core/host"
 	"github.com/libp2p/go-libp2p-core/network"
@@ -69,6 +72,43 @@ func TestHostSimple(t *testing.T) {
 	}
 }
 
+func TestProtocolHandlerEvents(t *testing.T) {
+	ctx := context.Background()
+	h := New(swarmt.GenSwarm(t, ctx))
+	defer h.Close()
+
+	sub, err := h.EventBus().Subscribe(&event.EvtLocalProtocolsUpdated{}, eventbus.BufSize(16))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer sub.Close()
+
+	assert := func(added, removed []protocol.ID) {
+		var next event.EvtLocalProtocolsUpdated
+		select {
+		case evt := <-sub.Out():
+			next = evt.(event.EvtLocalProtocolsUpdated)
+			break
+		case <-time.After(5 * time.Second):
+			t.Fatal("event not received in 5 seconds")
+		}
+
+		if !reflect.DeepEqual(added, next.Added) {
+			t.Errorf("expected added: %v; received: %v", added, next.Added)
+		}
+		if !reflect.DeepEqual(removed, next.Removed) {
+			t.Errorf("expected removed: %v; received: %v", removed, next.Removed)
+		}
+	}
+
+	h.SetStreamHandler(protocol.TestingID, func(s network.Stream) {})
+	assert([]protocol.ID{protocol.TestingID}, nil)
+	h.SetStreamHandler(protocol.ID("foo"), func(s network.Stream) {})
+	assert([]protocol.ID{protocol.ID("foo")}, nil)
+	h.RemoveStreamHandler(protocol.TestingID)
+	assert(nil, []protocol.ID{protocol.TestingID})
+}
+
 func TestHostAddrsFactory(t *testing.T) {
 	maddr := ma.StringCast("/ip4/1.2.3.4/tcp/1234")
 	addrsFactory := func(addrs []ma.Multiaddr) []ma.Multiaddr {