all: initial commit

.gitignore

@@ -0,0 +1 @@
+.idea/

LICENSE

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+MIT License
+
+Copyright (c) 2020 Kenta Iwasaki <[email protected]>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# flatend
+
+[![MIT License](https://img.shields.io/apm/l/atomic-design-ui.svg?)](LICENSE)
+[![go.dev reference](https://img.shields.io/badge/go.dev-reference-007d9c?logo=go&logoColor=white&style=flat-square)](https://pkg.go.dev/github.com/lithdew/flatend)
+[![Discord Chat](https://img.shields.io/discord/697002823123992617)](https://discord.gg/58dJzS)

cmd/flatend/main.go

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+package main
+
+import (
+	"fmt"
+	"github.com/lithdew/flatend"
+	flag "github.com/spf13/pflag"
+	"github.com/valyala/fasthttp/reuseport"
+	"net"
+	"os"
+	"os/signal"
+	"strconv"
+)
+
+const program = `
+http_get("hello_world")
+`
+
+func check(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+
+var (
+	bindHost string
+	bindPort uint16
+)
+
+func main() {
+	flag.StringVarP(&bindHost, "host", "h", "", "binding host")
+	flag.Uint16VarP(&bindPort, "port", "p", 0, "binding port")
+
+	flag.Parse()
+
+	addr := net.JoinHostPort(bindHost, strconv.FormatUint(uint64(bindPort), 10))
+
+	fmt.Printf("Bind address: %q\n", addr)
+
+	ln, err := reuseport.Listen("tcp4", addr)
+	check(err)
+
+	_, err = flatend.LoadConfig(program)
+	check(err)
+
+	srv := flatend.NewHTTP()
+	check(srv.Listen(ln))
+
+	defer func() {
+		check(srv.Close())
+	}()
+
+	ch := make(chan os.Signal, 1)
+	signal.Notify(ch, os.Interrupt)
+	<-ch
+
+	println()
+}

config.go

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+package flatend
+
+import (
+	"fmt"
+	"go.starlark.net/starlark"
+)
+
+type Config struct {
+	main     *starlark.Thread
+	vars     starlark.StringDict
+	handlers map[string]func()
+
+	program *starlark.Program
+}
+
+func (c *Config) declareBuiltins() {
+	c.vars["sql"] = starlark.NewBuiltin("sql", SQL)
+	c.vars["http_get"] = starlark.NewBuiltin("http_get", GET)
+}
+
+func LoadConfig(src interface{}) (*Config, error) {
+	cfg := &Config{
+		main:     &starlark.Thread{Name: "main"},
+		vars:     make(starlark.StringDict),
+		handlers: make(map[string]func()),
+	}
+
+	cfg.declareBuiltins()
+
+	_, program, err := starlark.SourceProgram("", src, cfg.vars.Has)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse config: %w", err)
+	}
+
+	cfg.program = program
+
+	_, err = program.Init(cfg.main, cfg.vars)
+	if err != nil {
+		return nil, fmt.Errorf("failed to init config: %w", err)
+	}
+
+	return cfg, nil
+}

go.mod

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+module github.com/lithdew/flatend
+
+go 1.14
+
+require (
+	github.com/spf13/pflag v1.0.5
+	github.com/valyala/fasthttp v1.9.0
+	go.starlark.net v0.0.0-20200330013621-be5394c419b6
+)

go.sum

@@ -0,0 +1,22 @@
+github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
+github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
+github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
+github.com/klauspost/compress v1.8.2 h1:Bx0qjetmNjdFXASH02NSAREKpiaDwkO1DRZ3dV2KCcs=
+github.com/klauspost/compress v1.8.2/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A=
+github.com/klauspost/cpuid v1.2.1 h1:vJi+O/nMdFt0vqm8NZBI6wzALWdA2X+egi0ogNyrC/w=
+github.com/klauspost/cpuid v1.2.1/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
+github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
+github.com/valyala/fasthttp v1.9.0 h1:hNpmUdy/+ZXYpGy0OBfm7K0UQTzb73W0T0U4iJIVrMw=
+github.com/valyala/fasthttp v1.9.0/go.mod h1:FstJa9V+Pj9vQ7OJie2qMHdwemEDaDiSdBnvPM1Su9w=
+github.com/valyala/tcplisten v0.0.0-20161114210144-ceec8f93295a h1:0R4NLDRDZX6JcmhJgXi5E4b8Wg84ihbmUKp/GvSPEzc=
+github.com/valyala/tcplisten v0.0.0-20161114210144-ceec8f93295a/go.mod h1:v3UYOV9WzVtRmSR+PDvWpU/qWl4Wa5LApYYX4ZtKbio=
+go.starlark.net v0.0.0-20200330013621-be5394c419b6 h1:S2s+dYPyDg/vF7KbcRIB2831xVimJoR4zebfoVBzn7Q=
+go.starlark.net v0.0.0-20200330013621-be5394c419b6/go.mod h1:nmDLcffg48OtT/PSW0Hg7FvpRQsQh5OSqIylirxKC7o=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/net v0.0.0-20190827160401-ba9fcec4b297/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20191002063906-3421d5a6bb1c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

script.go

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+package flatend
+
+import (
+	"errors"
+	"fmt"
+	"go.starlark.net/starlark"
+)
+
+func SQL(thread *starlark.Thread, fn *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
+	return nil, nil
+}
+
+func GET(thread *starlark.Thread, fn *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
+	if len(args) == 0 {
+		return nil, errors.New("http_get: route path must be specified")
+	}
+
+	path, ok := starlark.AsString(args[0])
+	if !ok {
+		return nil, errors.New("http_get: route path must be a string")
+	}
+
+	fmt.Printf("Registering HTTP GET route: %q\n", path)
+
+	return starlark.None, nil
+}

server.go

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+package flatend
+
+import (
+	"errors"
+	"fmt"
+	"github.com/valyala/fasthttp"
+	"net"
+	"sync"
+	"time"
+)
+
+type HTTP struct {
+	srv *fasthttp.Server
+
+	wg sync.WaitGroup
+	ch chan error
+
+	mu     sync.RWMutex
+	routes map[string]func()
+}
+
+func NewHTTP() *HTTP {
+	s := &HTTP{ch: make(chan error, 1)}
+	return s
+}
+
+func (s *HTTP) Load(cfg *Config) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	s.routes = make(map[string]func())
+
+	for route, fn := range cfg.handlers {
+		s.routes[route] = fn
+	}
+}
+
+func (s *HTTP) Listen(ln net.Listener) error {
+	if ln == nil {
+		return errors.New("net.Listener must not be nil")
+	}
+
+	s.wg.Add(1)
+
+	s.srv = &fasthttp.Server{
+		Name: "flatend",
+		Handler: func(ctx *fasthttp.RequestCtx) {
+			s.mu.RLock()
+			defer s.mu.RUnlock()
+
+			handler, exists := s.routes[string(ctx.Path())]
+			if !exists {
+				return
+			}
+
+			handler()
+		},
+		ReadTimeout:  5 * time.Second,
+		WriteTimeout: 3 * time.Second,
+	}
+
+	go func() {
+		defer s.wg.Done()
+		s.ch <- s.srv.Serve(ln)
+	}()
+
+	return nil
+}
+
+func (s *HTTP) Close() error {
+	if err := s.srv.Shutdown(); err != nil {
+		return fmt.Errorf("failed to shutdown http server: %w", err)
+	}
+
+	s.wg.Wait()
+
+	if err := <-s.ch; err != nil {
+		return fmt.Errorf("failed to close http server listener: %w", err)
+	}
+
+	return nil
+}