From 7e31c4d930efa3f80d0f03c93e788ba73b847fd8 Mon Sep 17 00:00:00 2001 From: Tim Swast Date: Fri, 20 Nov 2015 15:32:53 -0800 Subject: Add a Go language example. This follows the other examples so that it can be used as a tutorial, such as the ones at: https://developers.google.com/protocol-buffers/docs/tutorials Even though Go generally does not use Makefiles, I added targets for the Go examples to be consistent with the other languages. Edit: Fix Travis run. Change to use $HOME instead of ~. Add protoc to path. GOPATH entry cannot start with shell metacharacter '~': "~/gocode" Edit(2): Fix Go code style to address comments. --- examples/Makefile | 21 +++++++ examples/README.txt | 25 +++++++++ examples/add_person.go | 128 +++++++++++++++++++++++++++++++++++++++++++ examples/add_person_test.go | 58 ++++++++++++++++++++ examples/list_people.go | 59 ++++++++++++++++++++ examples/list_people_test.go | 96 ++++++++++++++++++++++++++++++++ 6 files changed, 387 insertions(+) create mode 100644 examples/add_person.go create mode 100644 examples/add_person_test.go create mode 100644 examples/list_people.go create mode 100644 examples/list_people_test.go (limited to 'examples') diff --git a/examples/Makefile b/examples/Makefile index 8dc90836..51f13426 100644 --- a/examples/Makefile +++ b/examples/Makefile @@ -5,6 +5,8 @@ all: cpp java python cpp: add_person_cpp list_people_cpp +go: add_person_go list_people_go +gotest: add_person_gotest list_people_gotest java: add_person_java list_people_java python: add_person_python list_people_python @@ -13,6 +15,8 @@ clean: rm -f javac_middleman AddPerson*.class ListPeople*.class com/example/tutorial/*.class rm -f protoc_middleman addressbook.pb.cc addressbook.pb.h addressbook_pb2.py com/example/tutorial/AddressBookProtos.java rm -f *.pyc + rm -f protoc_middleman_go tutorial/*.pb.go add_person_go list_people_go + rmdir tutorial 2>/dev/null || true rmdir com/example/tutorial 2>/dev/null || true rmdir com/example 2>/dev/null || true rmdir com 2>/dev/null || true @@ -21,6 +25,11 @@ protoc_middleman: addressbook.proto protoc --cpp_out=. --java_out=. --python_out=. addressbook.proto @touch protoc_middleman +protoc_middleman_go: addressbook.proto + mkdir tutorial # make directory for go package + protoc --go_out=tutorial addressbook.proto + @touch protoc_middleman_go + add_person_cpp: add_person.cc protoc_middleman pkg-config --cflags protobuf # fails if protobuf is not installed c++ add_person.cc addressbook.pb.cc -o add_person_cpp `pkg-config --cflags --libs protobuf` @@ -29,6 +38,18 @@ list_people_cpp: list_people.cc protoc_middleman pkg-config --cflags protobuf # fails if protobuf is not installed c++ list_people.cc addressbook.pb.cc -o list_people_cpp `pkg-config --cflags --libs protobuf` +add_person_go: add_person.go protoc_middleman_go + go build -o add_person_go add_person.go + +add_person_gotest: add_person_test.go add_person_go + go test add_person.go add_person_test.go + +list_people_go: list_people.go protoc_middleman_go + go build -o list_people_go list_people.go + +list_people_gotest: list_people.go list_people_go + go test list_people.go list_people_test.go + javac_middleman: AddPerson.java ListPeople.java protoc_middleman javac AddPerson.java ListPeople.java com/example/tutorial/AddressBookProtos.java @touch javac_middleman diff --git a/examples/README.txt b/examples/README.txt index f5530a5e..e6f30370 100644 --- a/examples/README.txt +++ b/examples/README.txt @@ -27,3 +27,28 @@ These examples are part of the Protocol Buffers tutorial, located at: * Note that on some platforms you may have to edit the Makefile and remove "-lpthread" from the linker commands (perhaps replacing it with something else). We didn't do this automatically because we wanted to keep the example simple. + +## Go ## + +The Go example requires a plugin to the protocol buffer compiler, so it is not +build with all the other examples. See: + https://github.com/golang/protobuf +for more information about Go protocol buffer support. + +First, install the the Protocol Buffers compiler (protoc). +Then, install the Go Protocol Buffers plugin +($GOPATH/bin must be in your $PATH for protoc to find it): + go get github.com/golang/protobuf/protoc-gen-go + +Build the Go samples in this directory with "make go". This creates the +following executable files in the current directory: + add_person_go list_people_go +To run the example: + ./add_person_go addressbook.data +to add a person to the protocol buffer encoded file addressbook.data. The file +is created if it does not exist. To view the data, run: + ./list_people_go addressbook.data + +Observe that the C++, Python, and Java examples in this directory run in a +similar way and can view/modify files created by the Go example and vice +versa. diff --git a/examples/add_person.go b/examples/add_person.go new file mode 100644 index 00000000..6b2d3d69 --- /dev/null +++ b/examples/add_person.go @@ -0,0 +1,128 @@ +package main + +import ( + "bufio" + "fmt" + "io" + "io/ioutil" + "log" + "os" + "strings" + + "github.com/golang/protobuf/proto" + pb "github.com/google/protobuf/examples/tutorial" +) + +func promptForAddress(r io.Reader) (*pb.Person, error) { + // A protocol buffer can be created like any struct. + p := &pb.Person{} + + rd := bufio.NewReader(r) + fmt.Print("Enter person ID number: ") + // An int32 field in the .proto file is represented as an int32 field + // in the generated Go struct. + if _, err := fmt.Fscanf(rd, "%d\n", &p.Id); err != nil { + return p, err + } + + fmt.Print("Enter name: ") + name, err := rd.ReadString('\n') + if err != nil { + return p, err + } + // A string field in the .proto file results in a string field in Go. + // We trim the whitespace because rd.ReadString includes the trailing + // newline character in its output. + p.Name = strings.TrimSpace(name) + + fmt.Print("Enter email address (blank for none): ") + email, err := rd.ReadString('\n') + if err != nil { + return p, err + } + p.Email = strings.TrimSpace(email) + + for { + fmt.Print("Enter a phone number (or leave blank to finish): ") + phone, err := rd.ReadString('\n') + if err != nil { + return p, err + } + phone = strings.TrimSpace(phone) + if phone == "" { + break + } + // The PhoneNumber message type is nested within the Person + // message in the .proto file. This results in a Go struct + // named using the name of the parent prefixed to the name of + // the nested message. Just as with pb.Person, it can be + // created like any other struct. + pn := &pb.Person_PhoneNumber{ + Number: phone, + } + + fmt.Print("Is this a mobile, home, or work phone? ") + ptype, err := rd.ReadString('\n') + if err != nil { + return p, err + } + ptype = strings.TrimSpace(ptype) + + // A proto enum results in a Go constant for each enum value. + switch ptype { + case "mobile": + pn.Type = pb.Person_MOBILE + case "home": + pn.Type = pb.Person_HOME + case "work": + pn.Type = pb.Person_WORK + default: + fmt.Printf("Unknown phone type %q. Using default.\n", ptype) + } + + // A repeated proto field maps to a slice field in Go. We can + // append to it like any other slice. + p.Phones = append(p.Phones, pn) + } + + return p, nil +} + +// Main reads the entire address book from a file, adds one person based on +// user input, then writes it back out to the same file. +func main() { + if len(os.Args) != 2 { + log.Fatalf("Usage: %s ADDRESS_BOOK_FILE\n", os.Args[0]) + } + fname := os.Args[1] + + // Read the existing address book. + in, err := ioutil.ReadFile(fname) + if err != nil { + if os.IsNotExist(err) { + fmt.Printf("%s: File not found. Creating new file.\n", fname) + } else { + log.Fatalln("Error reading file:", err) + } + } + book := &pb.AddressBook{} + if err := proto.Unmarshal(in, book); err != nil { + log.Fatalln("Failed to parse address book:", err) + } + + // Add an address. + addr, err := promptForAddress(os.Stdin) + if err != nil { + log.Fatalln("Error with address:", err) + } + book.People = append(book.People, addr) + + // Write the new address book back to disk. + out, err := proto.Marshal(book) + if err != nil { + log.Fatalln("Failed to encode address book:", err) + } + if err := ioutil.WriteFile(fname, out, 0644); err != nil { + log.Fatalln("Failed to write address book:", err) + } +} diff --git a/examples/add_person_test.go b/examples/add_person_test.go new file mode 100644 index 00000000..0507db6f --- /dev/null +++ b/examples/add_person_test.go @@ -0,0 +1,58 @@ +package main + +import ( + "strings" + "testing" + + "github.com/golang/protobuf/proto" + pb "github.com/google/protobuf/examples/tutorial" +) + +func TestPromptForAddressReturnsAddress(t *testing.T) { + in := `12345 +Example Name +name@example.com +123-456-7890 +home +222-222-2222 +mobile +111-111-1111 +work +777-777-7777 +unknown + +` + got, err := promptForAddress(strings.NewReader(in)) + if err != nil { + t.Fatalf("promptForAddress(%q) had unexpected error: %s", in, err.Error()) + } + if got.Id != 12345 { + t.Errorf("promptForAddress(%q) got %d, want ID %d", in, got.Id, 12345) + } + if got.Name != "Example Name" { + t.Errorf("promptForAddress(%q) => want name %q, got %q", "Example Name", got.Name) + } + if got.Email != "name@example.com" { + t.Errorf("promptForAddress(%q) => want email %q, got %q", "name@example.com", got.Email) + } + + want := []*pb.Person_PhoneNumber{ + {Number: "123-456-7890", Type: pb.Person_HOME}, + {Number: "222-222-2222", Type: pb.Person_MOBILE}, + {Number: "111-111-1111", Type: pb.Person_WORK}, + {Number: "777-777-7777", Type: pb.Person_MOBILE}, + } + if len(got.Phones) != len(want) { + t.Errorf("want %d phone numbers, got %d", len(want), len(got.Phones)) + } + phones := len(got.Phones) + if phones > len(want) { + phones = len(want) + } + for i := 0; i < phones; i++ { + if !proto.Equal(got.Phones[i], want[i]) { + t.Errorf("want phone %q, got %q", *want[i], *got.Phones[i]) + } + + } +} diff --git a/examples/list_people.go b/examples/list_people.go new file mode 100644 index 00000000..48b1fbfa --- /dev/null +++ b/examples/list_people.go @@ -0,0 +1,59 @@ +package main + +import ( + "fmt" + "io" + "io/ioutil" + "log" + "os" + + "github.com/golang/protobuf/proto" + pb "github.com/google/protobuf/examples/tutorial" +) + +func listPeople(w io.Writer, book *pb.AddressBook) { + for _, p := range book.People { + fmt.Fprintln(w, "Person ID:", p.Id) + fmt.Fprintln(w, " Name:", p.Name) + if p.Email != "" { + fmt.Fprintln(w, " E-mail address:", p.Email) + } + + for _, pn := range p.Phones { + switch pn.Type { + case pb.Person_MOBILE: + fmt.Fprint(w, " Mobile phone #: ") + case pb.Person_HOME: + fmt.Fprint(w, " Home phone #: ") + case pb.Person_WORK: + fmt.Fprint(w, " Work phone #: ") + } + fmt.Fprintln(w, pn.Number) + } + } +} + +// Main reads the entire address book from a file and prints all the +// information inside. +func main() { + if len(os.Args) != 2 { + log.Fatalf("Usage: %s ADDRESS_BOOK_FILE\n", os.Args[0]) + } + fname := os.Args[1] + + // Read the existing address book. + in, err := ioutil.ReadFile(fname) + if err != nil { + if os.IsNotExist(err) { + fmt.Printf("%s: File not found. Creating new file.\n", fname) + } else { + log.Fatalln("Error reading file:", err) + } + } + book := &pb.AddressBook{} + if err := proto.Unmarshal(in, book); err != nil { + log.Fatalln("Failed to parse address book:", err) + } + + listPeople(os.Stdout, book) +} diff --git a/examples/list_people_test.go b/examples/list_people_test.go new file mode 100644 index 00000000..721d3555 --- /dev/null +++ b/examples/list_people_test.go @@ -0,0 +1,96 @@ +package main + +import ( + "bytes" + "strings" + "testing" + + pb "github.com/google/protobuf/examples/tutorial" +) + +func TestListPeopleWritesList(t *testing.T) { + buf := new(bytes.Buffer) + in := pb.AddressBook{[]*pb.Person{ + { + Name: "John Doe", + Id: 101, + Email: "john@example.com", + }, + { + Name: "Jane Doe", + Id: 102, + }, + { + Name: "Jack Doe", + Id: 201, + Email: "jack@example.com", + Phones: []*pb.Person_PhoneNumber{ + {Number: "555-555-5555", Type: pb.Person_WORK}, + }, + }, + { + Name: "Jack Buck", + Id: 301, + Email: "buck@example.com", + Phones: []*pb.Person_PhoneNumber{ + {Number: "555-555-0000", Type: pb.Person_HOME}, + {Number: "555-555-0001", Type: pb.Person_MOBILE}, + {Number: "555-555-0002", Type: pb.Person_WORK}, + }, + }, + { + Name: "Janet Doe", + Id: 1001, + Email: "janet@example.com", + Phones: []*pb.Person_PhoneNumber{ + {Number: "555-777-0000"}, + {Number: "555-777-0001", Type: pb.Person_HOME}, + }, + }, + }} + listPeople(buf, &in) + want := strings.Split(`Person ID: 101 + Name: John Doe + E-mail address: john@example.com +Person ID: 102 + Name: Jane Doe +Person ID: 201 + Name: Jack Doe + E-mail address: jack@example.com + Work phone #: 555-555-5555 +Person ID: 301 + Name: Jack Buck + E-mail address: buck@example.com + Home phone #: 555-555-0000 + Mobile phone #: 555-555-0001 + Work phone #: 555-555-0002 +Person ID: 1001 + Name: Janet Doe + E-mail address: janet@example.com + Mobile phone #: 555-777-0000 + Home phone #: 555-777-0001 +`, "\n") + got := strings.Split(buf.String(), "\n") + if len(got) != len(want) { + t.Errorf( + "listPeople(%s) =>\n\t%q has %d lines, want %d", + in.String(), + buf.String(), + len(got), + len(want)) + } + lines := len(got) + if lines > len(want) { + lines = len(want) + } + for i := 0; i < lines; i++ { + if got[i] != want[i] { + t.Errorf( + "listPeople(%s) =>\n\tline %d %q, want %q", + in.String(), + i, + got[i], + want[i]) + } + } +} -- cgit v1.2.3