pubsub 2.0 (#3227)

* green pubsub tests :OK:

* get rid of clientToQueryMap

* Subscribe and SubscribeUnbuffered

* start adapting other pkgs to new pubsub

* nope

* rename MsgAndTags to Message

* remove TagMap

it does not bring any additional benefits

* bring back EventSubscriber

* fix test

* fix data race in TestStartNextHeightCorrectly

```
Write at 0x00c0001c7418 by goroutine 796:
  github.com/tendermint/tendermint/consensus.TestStartNextHeightCorrectly()
      /go/src/github.com/tendermint/tendermint/consensus/state_test.go:1296 +0xad
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:827 +0x162

Previous read at 0x00c0001c7418 by goroutine 858:
  github.com/tendermint/tendermint/consensus.(*ConsensusState).addVote()
      /go/src/github.com/tendermint/tendermint/consensus/state.go:1631 +0x1366
  github.com/tendermint/tendermint/consensus.(*ConsensusState).tryAddVote()
      /go/src/github.com/tendermint/tendermint/consensus/state.go:1476 +0x8f
  github.com/tendermint/tendermint/consensus.(*ConsensusState).handleMsg()
      /go/src/github.com/tendermint/tendermint/consensus/state.go:667 +0xa1e
  github.com/tendermint/tendermint/consensus.(*ConsensusState).receiveRoutine()
      /go/src/github.com/tendermint/tendermint/consensus/state.go:628 +0x794

Goroutine 796 (running) created at:
  testing.(*T).Run()
      /usr/local/go/src/testing/testing.go:878 +0x659
  testing.runTests.func1()
      /usr/local/go/src/testing/testing.go:1119 +0xa8
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:827 +0x162
  testing.runTests()
      /usr/local/go/src/testing/testing.go:1117 +0x4ee
  testing.(*M).Run()
      /usr/local/go/src/testing/testing.go:1034 +0x2ee
  main.main()
      _testmain.go:214 +0x332

Goroutine 858 (running) created at:
  github.com/tendermint/tendermint/consensus.(*ConsensusState).startRoutines()
      /go/src/github.com/tendermint/tendermint/consensus/state.go:334 +0x221
  github.com/tendermint/tendermint/consensus.startTestRound()
      /go/src/github.com/tendermint/tendermint/consensus/common_test.go:122 +0x63
  github.com/tendermint/tendermint/consensus.TestStateFullRound1()
      /go/src/github.com/tendermint/tendermint/consensus/state_test.go:255 +0x397
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:827 +0x162
```

* fixes after my own review

* fix formatting

* wait 100ms before kicking a subscriber out

+ a test for indexer_service

* fixes after my second review

* no timeout

* add changelog entries

* fix merge conflicts

* fix typos after Thane's review

Co-Authored-By: melekes <anton.kalyaev@gmail.com>

* reformat code

* rewrite indexer service in the attempt to fix failing test

https://github.com/tendermint/tendermint/pull/3227/#issuecomment-462316527

* Revert "rewrite indexer service in the attempt to fix failing test"

This reverts commit 0d9107a098.

* another attempt to fix indexer

* fixes after Ethan's review

* use unbuffered channel when indexing transactions

Refs https://github.com/tendermint/tendermint/pull/3227#discussion_r258786716

* add a comment for EventBus#SubscribeUnbuffered

* format code

libs/pubsub/query/empty.go

@@ -1,13 +1,11 @@
 package query
 
-import "github.com/tendermint/tendermint/libs/pubsub"
-
 // Empty query matches any set of tags.
 type Empty struct {
 }
 
 // Matches always returns true.
-func (Empty) Matches(tags pubsub.TagMap) bool {
+func (Empty) Matches(tags map[string]string) bool {
 	return true
 }
 

libs/pubsub/query/empty_test.go

@@ -5,14 +5,13 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
-	"github.com/tendermint/tendermint/libs/pubsub"
 	"github.com/tendermint/tendermint/libs/pubsub/query"
 )
 
 func TestEmptyQueryMatchesAnything(t *testing.T) {
 	q := query.Empty{}
-	assert.True(t, q.Matches(pubsub.NewTagMap(map[string]string{})))
-	assert.True(t, q.Matches(pubsub.NewTagMap(map[string]string{"Asher": "Roth"})))
-	assert.True(t, q.Matches(pubsub.NewTagMap(map[string]string{"Route": "66"})))
-	assert.True(t, q.Matches(pubsub.NewTagMap(map[string]string{"Route": "66", "Billy": "Blue"})))
+	assert.True(t, q.Matches(map[string]string{}))
+	assert.True(t, q.Matches(map[string]string{"Asher": "Roth"}))
+	assert.True(t, q.Matches(map[string]string{"Route": "66"}))
+	assert.True(t, q.Matches(map[string]string{"Route": "66", "Billy": "Blue"}))
 }

libs/pubsub/query/query.go

@@ -14,8 +14,6 @@ import (
 	"strconv"
 	"strings"
 	"time"
-
-	"github.com/tendermint/tendermint/libs/pubsub"
 )
 
 // Query holds the query string and the query parser.
@@ -154,8 +152,8 @@ func (q *Query) Conditions() []Condition {
 //
 // For example, query "name=John" matches tags = {"name": "John"}. More
 // examples could be found in parser_test.go and query_test.go.
-func (q *Query) Matches(tags pubsub.TagMap) bool {
-	if tags.Len() == 0 {
+func (q *Query) Matches(tags map[string]string) bool {
+	if len(tags) == 0 {
 		return false
 	}
 
@@ -240,9 +238,9 @@ func (q *Query) Matches(tags pubsub.TagMap) bool {
 // value from it to the operand using the operator.
 //
 // "tx.gas", "=", "7", { "tx.gas": 7, "tx.ID": "4AE393495334" }
-func match(tag string, op Operator, operand reflect.Value, tags pubsub.TagMap) bool {
+func match(tag string, op Operator, operand reflect.Value, tags map[string]string) bool {
 	// look up the tag from the query in tags
-	value, ok := tags.Get(tag)
+	value, ok := tags[tag]
 	if !ok {
 		return false
 	}

libs/pubsub/query/query_test.go

@@ -8,7 +8,6 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/tendermint/tendermint/libs/pubsub"
 	"github.com/tendermint/tendermint/libs/pubsub/query"
 )
 
@@ -53,9 +52,9 @@ func TestMatches(t *testing.T) {
 		}
 
 		if tc.matches {
-			assert.True(t, q.Matches(pubsub.NewTagMap(tc.tags)), "Query '%s' should match %v", tc.s, tc.tags)
+			assert.True(t, q.Matches(tc.tags), "Query '%s' should match %v", tc.s, tc.tags)
 		} else {
-			assert.False(t, q.Matches(pubsub.NewTagMap(tc.tags)), "Query '%s' should not match %v", tc.s, tc.tags)
+			assert.False(t, q.Matches(tc.tags), "Query '%s' should not match %v", tc.s, tc.tags)
 		}
 	}
 }