Merge pull request #1 from gomicro/multiblocker

Multiblocker and DB Blocker

Author: dan9186

.travis.yml

@@ -0,0 +1,9 @@
+language: go
+go:
+  - 1.9
+  - tip
+script:
+  - go test -v $(go list ./... | grep -v /vendor/)
+notifications:
+  slack:
+    secure: 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

Gopkg.lock

@@ -0,0 +1,42 @@
+# Gopkg.toml example
+#
+# Refer to https://github.com/golang/dep/blob/master/docs/Gopkg.toml.md
+# for detailed Gopkg.toml documentation.
+#
+# required = ["github.com/user/thing/cmd/thing"]
+# ignored = ["github.com/user/project/pkgX", "bitbucket.org/user/project/pkgA/pkgY"]
+#
+# [[constraint]]
+#   name = "github.com/user/project"
+#   version = "1.0.0"
+#
+# [[constraint]]
+#   name = "github.com/user/project2"
+#   branch = "dev"
+#   source = "github.com/myfork/project2"
+#
+# [[override]]
+#   name = "github.com/x/y"
+#   version = "2.4.0"
+#
+# [prune]
+#   non-go = false
+#   go-tests = true
+#   unused-packages = true
+
+
+[[constraint]]
+  name = "github.com/franela/goblin"
+  version = "0.0.2"
+
+[[constraint]]
+  name = "github.com/onsi/gomega"
+  version = "1.4.1"
+
+[[constraint]]
+  name = "gopkg.in/DATA-DOG/go-sqlmock.v1"
+  version = "1.3.0"
+
+[prune]
+  go-tests = true
+  unused-packages = true

Gopkg.toml

@@ -0,0 +1,7 @@
+package blockit
+
+// Blocker represents an object that will have a Blockit function as a method
+// for determining when the object is done with a given task.
+type Blocker interface {
+	Blockit() <-chan bool
+}

blocker.go

@@ -0,0 +1,40 @@
+package db
+
+import (
+	"database/sql"
+	"time"
+)
+
+// Blocker represents a SQL database connection to monitor for connectivity
+// and block until a connection is established.
+type Blocker struct {
+	db *sql.DB
+}
+
+// New takes a SQL database object and returns a newly instantiated Blocker
+func New(db *sql.DB) *Blocker {
+	return &Blocker{db: db}
+}
+
+// Blockit meets the blocker interface. It returns a read only channel that will
+// receive true when the database is connected.
+func (d *Blocker) Blockit() <-chan bool {
+	connected := make(chan bool)
+
+	go func() {
+		for {
+			err := d.db.Ping()
+			if err != nil {
+				<-time.After(1 * time.Second)
+				continue
+			}
+
+			connected <- true
+			close(connected)
+
+			break
+		}
+	}()
+
+	return connected
+}

db/db.go

@@ -0,0 +1,25 @@
+package db_test
+
+import (
+	"testing"
+
+	"github.com/gomicro/blockit/db"
+
+	. "github.com/franela/goblin"
+	. "github.com/onsi/gomega"
+	"gopkg.in/DATA-DOG/go-sqlmock.v1"
+)
+
+func TestDefaultBlockers(t *testing.T) {
+	g := Goblin(t)
+	RegisterFailHandler(func(m string, _ ...int) { g.Fail(m) })
+
+	g.Describe("DB Blocking", func() {
+		g.It("should block until connected to the db", func() {
+			mockDB, _, _ := sqlmock.New()
+
+			b := db.New(mockDB)
+			Eventually(<-b.Blockit()).Should(BeTrue())
+		})
+	})
+}

db/db_test.go

@@ -0,0 +1,44 @@
+package blockit
+
+// MultiBlocker represent many blockers to monitor and determine when they are
+// done.
+type MultiBlocker struct {
+	blockers []Blocker
+}
+
+// Add takes one to many blockers to append into the multiblocker
+func (b *MultiBlocker) Add(blocker ...Blocker) {
+	b.blockers = append(b.blockers, blocker...)
+}
+
+// Blockit meets the blocker interface and summarizes multiple blockers into a
+// single channel for blocking on.
+func (b *MultiBlocker) Blockit() <-chan bool {
+	out := make(chan bool)
+
+	dones := make([]chan bool, len(b.blockers))
+	for i := range dones {
+		dones[i] = make(chan bool)
+	}
+
+	for i := range b.blockers {
+		go func(j int) {
+			<-b.blockers[j].Blockit()
+			dones[j] <- true
+		}(i)
+	}
+
+	go func() {
+		done := false
+		for i := range dones {
+			done = <-dones[i]
+		}
+
+		if done {
+			out <- true
+		}
+		close(out)
+	}()
+
+	return out
+}

multiblocker.go

@@ -0,0 +1,69 @@
+package blockit_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/gomicro/blockit"
+	"github.com/gomicro/blockit/db"
+
+	. "github.com/franela/goblin"
+	. "github.com/onsi/gomega"
+	"gopkg.in/DATA-DOG/go-sqlmock.v1"
+)
+
+func TestMultiBlocker(t *testing.T) {
+	g := Goblin(t)
+	RegisterFailHandler(func(m string, _ ...int) { g.Fail(m) })
+
+	g.Describe("MultiBlocker", func() {
+		g.Describe("Multiple Blockers", func() {
+			g.It("should block with several blockers", func() {
+				b := blockit.MultiBlocker{}
+
+				f := &foo{}
+				b.Add(f)
+
+				ba := &bar{}
+				b.Add(ba)
+
+				Eventually(<-b.Blockit()).Should(BeTrue())
+			})
+		})
+
+		g.Describe("DB Blocker", func() {
+			g.It("should work in a multiblocker", func() {
+				mockDB, _, _ := sqlmock.New()
+
+				b := blockit.MultiBlocker{}
+				b.Add(db.New(mockDB))
+				Eventually(<-b.Blockit()).Should(BeTrue())
+			})
+		})
+	})
+}
+
+type foo struct{}
+type bar struct{}
+
+func (f *foo) Blockit() <-chan bool {
+	out := make(chan bool)
+
+	go func() {
+		<-time.After(1 * time.Second)
+		close(out)
+	}()
+
+	return out
+}
+
+func (b *bar) Blockit() <-chan bool {
+	out := make(chan bool)
+
+	go func() {
+		<-time.After(3 * time.Second)
+		close(out)
+	}()
+
+	return out
+}