cmd/flatend, codec, config, handler, http: temporarily disable csv co…

…dec, remove default handlers, add sqlite example

cmd/flatend/main.go

@@ -3,6 +3,8 @@ package main
 import (
 	"errors"
 	"github.com/lithdew/flatend"
+	_ "github.com/mattn/go-sqlite3"
+	"github.com/xo/dburl"
 	"io"
 	"log"
 	"net"
@@ -11,6 +13,38 @@ import (
 	"os/signal"
 )
 
+func main() {
+	ln, err := net.Listen("tcp", ":44444")
+	check(err)
+	defer wrap(ln.Close)
+
+	db, err := dburl.Open("sqlite://:memory:")
+	check(err)
+	defer wrap(db.Close)
+
+	stmt, err := db.Prepare("SELECT sqlite_version()")
+	check(err)
+	defer wrap(stmt.Close)
+
+	srv := &flatend.Server{}
+	srv.Register(
+		&flatend.ContentType{},
+		&flatend.ContentLength{Max: 10 * 1024 * 1024},
+		&flatend.ContentDecode{},
+		&flatend.QuerySQL{MaxNumRows: 1000, Stmt: stmt},
+		&flatend.ContentEncode{},
+	)
+
+	go func() { check(srv.Serve(ln)) }()
+	defer wrap(srv.Shutdown)
+
+	log.Printf("Listening for connections on %q.", ln.Addr())
+
+	ch := make(chan os.Signal, 1)
+	signal.Notify(ch, os.Interrupt)
+	<-ch
+}
+
 func isEOF(err error) bool {
 	if errors.Is(err, io.EOF) {
 		return true
@@ -37,19 +71,3 @@ func check(err error) {
 func wrap(fn func() error) {
 	check(fn())
 }
-
-func main() {
-	ln, err := net.Listen("tcp", ":44444")
-	check(err)
-	defer wrap(ln.Close)
-
-	srv := &flatend.Server{}
-	go func() { check(srv.Serve(ln)) }()
-	defer wrap(srv.Shutdown)
-
-	log.Printf("Listening for connections on %q.", ln.Addr())
-
-	ch := make(chan os.Signal, 1)
-	signal.Notify(ch, os.Interrupt)
-	<-ch
-}

codec.go

@@ -2,10 +2,8 @@ package flatend
 
 import (
 	"bytes"
-	"encoding/csv"
 	"encoding/gob"
 	"encoding/json"
-	"fmt"
 	"github.com/BurntSushi/toml"
 	"gopkg.in/yaml.v3"
 )
@@ -37,7 +35,7 @@ func init() {
 	registerCodec(newCodec(tomlEncoder, tomlDecoder,
 		"application/x-toml", "text/x-toml", "application/toml", "text/x-toml",
 	))
-	registerCodec(newCodec(csvEncoder, csvDecoder, "application/csv", "text/csv"))
+	//registerCodec(newCodec(csvEncoder, csvDecoder, "application/csv", "text/csv"))
 	registerCodec(newCodec(gobEncoder, gobDecoder, "application/x-gob", "text/x-gob"))
 }
 
@@ -68,43 +66,47 @@ func marshalEncoder(f func(src interface{}) ([]byte, error)) EncodeFunc {
 	}
 }
 
-func csvEncoder(values Values) ([]byte, error) {
-	records := [][]string{make([]string, 0, len(values)), make([]string, 0, len(values))}
-
-	for k, v := range values {
-		records[0] = append(records[0], k)
-		records[1] = append(records[1], fmt.Sprint(v))
-	}
-
-	var b bytes.Buffer
-	if err := csv.NewWriter(&b).WriteAll(records); err != nil {
-		return nil, err
-	}
-
-	return b.Bytes(), nil
-}
-
-func csvDecoder(src []byte, values Values) error {
-	r := csv.NewReader(bytes.NewReader(src))
-
-	keys, err := r.Read()
-	if err != nil {
-		return fmt.Errorf("csv: failed to read keys: %w", err)
-	}
-
-	r.FieldsPerRecord = len(keys)
-
-	vals, err := r.Read()
-	if err != nil {
-		return fmt.Errorf("csv: failed to read values: %w", err)
-	}
-
-	for i := 0; i < len(keys); i++ {
-		values[keys[i]] = vals[i]
-	}
-
-	return nil
-}
+//func csvEncoder(values Values) ([]byte, error) {
+//	records := [][]string{make([]string, 0, len(values)), make([]string, 0, len(values))}
+//
+//	for k, v := range values {
+//		s, ok := v.(fmt.Stringer)
+//		if !ok {
+//			continue
+//		}
+//		records[0] = append(records[0], k)
+//		records[1] = append(records[1], s.String())
+//	}
+//
+//	var b bytes.Buffer
+//	if err := csv.NewWriter(&b).WriteAll(records); err != nil {
+//		return nil, err
+//	}
+//
+//	return b.Bytes(), nil
+//}
+//
+//func csvDecoder(src []byte, values Values) error {
+//	r := csv.NewReader(bytes.NewReader(src))
+//
+//	keys, err := r.Read()
+//	if err != nil {
+//		return fmt.Errorf("csv: failed to read keys: %w", err)
+//	}
+//
+//	r.FieldsPerRecord = len(keys)
+//
+//	vals, err := r.Read()
+//	if err != nil {
+//		return fmt.Errorf("csv: failed to read values: %w", err)
+//	}
+//
+//	for i := 0; i < len(keys); i++ {
+//		values[keys[i]] = vals[i]
+//	}
+//
+//	return nil
+//}
 
 func gobEncoder(values Values) ([]byte, error) {
 	var b bytes.Buffer

config.go

@@ -12,12 +12,5 @@ func NewDefaultConfig() *Config {
 	return &Config{
 		Codecs:     Codecs,
 		CodecTypes: CodecTypes,
-
-		Handlers: []Handler{
-			&ContentType{},
-			&ContentLength{Max: 10 * 1024 * 1024},
-			&ContentDecode{},
-			&ContentEncode{},
-		},
 	}
 }

go.mod

@@ -4,12 +4,14 @@ go 1.14
 
 require (
 	github.com/BurntSushi/toml v0.3.1
-	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/davecgh/go-spew v1.1.1
 	github.com/julienschmidt/httprouter v1.3.0
 	github.com/kr/pretty v0.1.0 // indirect
 	github.com/lithdew/bytesutil v0.0.0-20200409052507-d98389230a59
 	github.com/lithdew/sqlutil v0.0.0-20200508165435-ee5c68997a73
+	github.com/mattn/go-sqlite3 v2.0.3+incompatible
 	github.com/stretchr/testify v1.5.1
+	github.com/xo/dburl v0.0.0-20200124232849-e9ec94f52bc3
 	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
 	gopkg.in/yaml.v2 v2.2.8 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20200506231410-2ff61e1afc86

go.sum

@@ -14,12 +14,15 @@ github.com/lithdew/bytesutil v0.0.0-20200409052507-d98389230a59 h1:CQpoOQecHxhvg
 github.com/lithdew/bytesutil v0.0.0-20200409052507-d98389230a59/go.mod h1:89JlULMIJ/+YWzAp5aHXgAD2d02S2mY+a+PMgXDtoNs=
 github.com/lithdew/sqlutil v0.0.0-20200508165435-ee5c68997a73 h1:1dJYhA/dkVIRAjSLzwYVHjx+EXCqnU6NrU/gjAN/Y/4=
 github.com/lithdew/sqlutil v0.0.0-20200508165435-ee5c68997a73/go.mod h1:4DsjvJVgwIyR/cT5U7KiF1vQwB7zBMRISJO6wI9kwII=
+github.com/mattn/go-sqlite3 v2.0.3+incompatible h1:gXHsfypPkaMZrKbD5209QV9jbUTJKjyR5WD3HYQSd+U=
 github.com/mattn/go-sqlite3 v2.0.3+incompatible/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
+github.com/xo/dburl v0.0.0-20200124232849-e9ec94f52bc3 h1:NC3CI7do3KHtiuYhk1CdS9V2qS3jNa7Fs2Afcnnt+IE=
+github.com/xo/dburl v0.0.0-20200124232849-e9ec94f52bc3/go.mod h1:A47W3pdWONaZmXuLZgfKLAVgUY0qvfTRM5vVDKS40S4=
 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=

handler.go

@@ -153,8 +153,6 @@ func getBodyParams(r *http.Request, codec *Codec, values map[string]interface{})
 type ContentEncode struct{}
 
 func (h *ContentEncode) Serve(ctx *Context, w http.ResponseWriter, _ *http.Request) error {
-	ctx.Out = ctx.In
-
 	codec := ctx.Config.Codecs[w.Header().Get(HeaderContentType)]
 
 	if codec == nil {
@@ -177,15 +175,7 @@ func (h *ContentEncode) Serve(ctx *Context, w http.ResponseWriter, _ *http.Reque
 	return nil
 }
 
-type QuerySQL struct {
-	MinNumRows int
-	MaxNumRows int
-
-	Stmt   *sql.Stmt
-	Params []string
-}
-
-func (h *QuerySQL) handlePagination(ctx *Context) {
+func HandlePagination(ctx *Context, min, max int) {
 	offset, provided := ctx.In["offset"].(int)
 	if !provided || offset < 0 {
 		ctx.In["offset"] = 0
@@ -194,15 +184,23 @@ func (h *QuerySQL) handlePagination(ctx *Context) {
 	limit, provided := ctx.In["limit"].(int)
 
 	switch {
-	case !provided || limit < h.MinNumRows || limit < 0:
-		ctx.In["limit"] = h.MinNumRows
-	case limit > h.MaxNumRows:
-		ctx.In["limit"] = h.MaxNumRows
+	case !provided || limit < min || limit < 0:
+		ctx.In["limit"] = min
+	case limit > max:
+		ctx.In["limit"] = max
 	}
 }
 
-func (h *QuerySQL) Serve(ctx *Context, w http.ResponseWriter, _ *http.Request) error {
-	h.handlePagination(ctx)
+type QuerySQL struct {
+	MinNumRows int
+	MaxNumRows int
+
+	Stmt   *sql.Stmt
+	Params []string
+}
+
+func (h *QuerySQL) Serve(ctx *Context, _ http.ResponseWriter, _ *http.Request) error {
+	HandlePagination(ctx, h.MinNumRows, h.MaxNumRows)
 
 	params := acquireValueBuffer(len(h.Params))
 	for _, param := range h.Params {
@@ -212,18 +210,27 @@ func (h *QuerySQL) Serve(ctx *Context, w http.ResponseWriter, _ *http.Request) e
 	releaseValueBuffer(params)
 
 	if err != nil {
-		return &Error{Status: http.StatusInternalServerError, Err: fmt.Errorf("failed to execute query: %w", err)}
+		return &Error{
+			Status: http.StatusInternalServerError,
+			Err:    fmt.Errorf("failed to execute query: %w", err),
+		}
 	}
 
 	defer rows.Close()
 
 	keys, err := rows.Columns()
 	if err != nil {
-		return &Error{Status: http.StatusInternalServerError, Err: fmt.Errorf("failed to fetch columns: %w", err)}
+		return &Error{
+			Status: http.StatusInternalServerError,
+			Err:    fmt.Errorf("failed to fetch columns: %w", err),
+		}
 	}
 
 	if len(keys) == 0 {
-		return &Error{Status: http.StatusInternalServerError, Err: errors.New("zero columns resultant from sql query")}
+		return &Error{
+			Status: http.StatusInternalServerError,
+			Err:    errors.New("zero columns resultant from sql query"),
+		}
 	}
 
 	vals := acquireValueBuffer(len(keys))
@@ -234,7 +241,10 @@ func (h *QuerySQL) Serve(ctx *Context, w http.ResponseWriter, _ *http.Request) e
 	for i := 0; rows.Next() && i < h.MaxNumRows; i++ {
 		err := rows.Scan(vals...)
 		if err != nil {
-			return &Error{Status: http.StatusInternalServerError, Err: fmt.Errorf("got an error while scanning: %w", err)}
+			return &Error{
+				Status: http.StatusInternalServerError,
+				Err:    fmt.Errorf("got an error while scanning: %w", err),
+			}
 		}
 
 		result := make(map[string]interface{}, len(keys))
@@ -245,6 +255,7 @@ func (h *QuerySQL) Serve(ctx *Context, w http.ResponseWriter, _ *http.Request) e
 		results = append(results, result)
 	}
 
+	ctx.Out["status"] = http.StatusOK
 	ctx.Out["results"] = results
 
 	return nil

http.go

@@ -47,6 +47,11 @@ func (s *Server) init() {
 	}
 }
 
+func (s *Server) Register(handlers ...Handler) {
+	s.once.Do(s.init)
+	s.config.Handlers = append(s.config.Handlers, handlers...)
+}
+
 func (s *Server) Serve(ln net.Listener) error {
 	s.once.Do(s.init)
 	return s.srv.Serve(ln)
@@ -129,7 +134,7 @@ func (s *Server) writeError(w http.ResponseWriter, err *Error) {
 		return
 	}
 
-	w.Header().Set("X-Content-Type-Options", "nosniff")
+	w.Header().Set(HeaderContentTypeOptions, "nosniff")
 	w.WriteHeader(err.Status)
 	w.Write(buf)
 }