Add cache attribute

CONFIGURATION.md

@@ -65,7 +65,8 @@ and the private key file at `certs/live/$DOMAIN/privkey.pem` to twins.
 ### DisableSize
 
 The size of the response body is included in the media type header by default.
-Set this option to `true` to disable this feature.
+Set this option to `true` to disable this feature. See [PROPOSALS.md](https://gitlab.com/tslocum/twins/blob/master/PROPOSALS.md)
+for more information.
 
 ### Path
 
@@ -95,6 +96,12 @@ argument to the command, otherwise user input is passed via standard input.
 
 Any number of attributes may be defined for a path.
 
+##### Cache
+
+Cache duration (in seconds). Set to `0` to disable caching entirely. This is an
+out-of-spec feature. See [PROPOSALS.md](https://gitlab.com/tslocum/twins/blob/master/PROPOSALS.md)
+for more information.
+
 ##### ListDirectory
 
 Directory listing may be enabled by adding `listdirectory: true`.
@@ -124,9 +131,8 @@ A `Root` attribute must also be specified to use `FastCGI`.
 The Gemini protocol requires `\r\n` (CRLF) as the end-of-line indicator. This
 convention is carried over from protocol specifications **first written in the
 1970s**. This requirement is antithetic to the spirit of Gemini (to improve
-upon the Finger and Gopher protocols) because it unnecessarily tacks on ancient
+upon the Finger and Gopher protocols), increasing the complexity of client and
-baggage. This baggage has caused (and continues to cause) increased complexity in
+server implementations unnecessarily.
-client and server implementations, which naturally gives rise to more bugs.
 
 In anticipation of an improvement to the Gemini specification, administrators
 may configure twins to send standard `\n` (LF) line endings by setting
@@ -157,6 +163,7 @@ hosts:
       -
         path: /sites
         root: /home/geminirocks/data
+        cache: 604800 # Cache for 1 week
         listdirectory: true
       -
         path: ^/(help|info)$
@@ -167,6 +174,7 @@ hosts:
       -
         path: ^/cmd-example$
         command: uname -a
+        cache: 0 # Do not cache
       -
         path: /
         root: /home/geminirocks/data/home

config.go

@@ -37,6 +37,9 @@ type pathConfig struct {
 	// Content type
 	Type string
 
+	// Cache duration
+	Cache int64 `default:"-1965"`
+
 	// FastCGI server address
 	FastCGI string
 

go.mod

@@ -6,6 +6,6 @@ require (
 	github.com/h2non/filetype v1.1.0
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/yookoala/gofast v0.4.1-0.20201013050739-975113c54107
-	golang.org/x/tools v0.0.0-20201104193857-22bd85271a8b // indirect
+	golang.org/x/tools v0.0.0-20201110030525-169ad6d6ecb2 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776
 )

go.sum

@@ -34,8 +34,8 @@ golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGm
 golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20200908211811-12e1bf57a112/go.mod h1:Cj7w3i3Rnn0Xh82ur9kSqwfTHTeVxaDqrfMjpcNT6bE=
-golang.org/x/tools v0.0.0-20201104193857-22bd85271a8b h1:ILx+nYAUTq4JtXxrXKQ82j7nruEwlXRfUn+kxtsnElg=
+golang.org/x/tools v0.0.0-20201110030525-169ad6d6ecb2 h1:5GmCe1Mc5HsGGl6E0kOVQRzVp+AgZf4Ffw4DadiVpd4=
-golang.org/x/tools v0.0.0-20201104193857-22bd85271a8b/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
+golang.org/x/tools v0.0.0-20201110030525-169ad6d6ecb2/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

serve_command.go

@@ -9,7 +9,7 @@ import (
 	"strings"
 )
 
-func serveCommand(c net.Conn, request *url.URL, command []string) {
+func serveCommand(c net.Conn, serve *pathConfig, request *url.URL, command []string) {
 	var args []string
 	if len(command) > 0 {
 		args = command[1:]
@@ -34,7 +34,7 @@ func serveCommand(c net.Conn, request *url.URL, command []string) {
 		return
 	}
 
-	writeHeader(c, statusSuccess, "text/gemini; charset=utf-8")
+	writeSuccess(c, serve, geminiType, int64(buf.Len()))
 	c.Write(buf.Bytes())
 
 	if verbose {

serve_file.go

@@ -13,7 +13,7 @@ import (
 	"github.com/h2non/filetype"
 )
 
-func serveDirList(c net.Conn, request *url.URL, dirPath string) {
+func serveDirList(c net.Conn, serve *pathConfig, request *url.URL, dirPath string) {
 	var (
 		files    []os.FileInfo
 		numDirs  int
@@ -50,7 +50,7 @@ func serveDirList(c net.Conn, request *url.URL, dirPath string) {
 		return i < j
 	})
 
-	writeHeader(c, statusSuccess, "text/gemini; charset=utf-8")
+	writeSuccess(c, serve, geminiType, -1)
 
 	fmt.Fprintf(c, "# %s%s", request.Path, newLine)
 	if numDirs == 1 {
@@ -93,7 +93,7 @@ func serveDirList(c net.Conn, request *url.URL, dirPath string) {
 	}
 }
 
-func serveFile(c net.Conn, filePath string) {
+func serveFile(c net.Conn, serve *pathConfig, filePath string) {
 	// Open file
 	file, _ := os.Open(filePath)
 	defer file.Close()
@@ -103,32 +103,26 @@ func serveFile(c net.Conn, filePath string) {
 	n, _ := file.Read(buf)
 
 	// Write response header
+	var contentType string
+	if strings.HasSuffix(filePath, ".html") && strings.HasSuffix(filePath, ".htm") {
+		contentType = "text/html; charset=utf-8"
+	} else if strings.HasSuffix(filePath, ".txt") && strings.HasSuffix(filePath, ".text") {
+		contentType = "text/plain; charset=utf-8"
+	} else if !strings.HasSuffix(filePath, ".gmi") && !strings.HasSuffix(filePath, ".gemini") {
+		kind, _ := filetype.Match(buf[:n])
+		if kind != filetype.Unknown {
+			contentType = kind.MIME.Value
+		}
+	}
+	if contentType == "" {
+		contentType = geminiType
+	}
 	size := int64(-1)
 	info, err := file.Stat()
 	if err == nil {
 		size = info.Size()
 	}
-	var mimeType string
+	writeSuccess(c, serve, contentType, size)
-	if strings.HasSuffix(filePath, ".html") && strings.HasSuffix(filePath, ".htm") {
-		mimeType = "text/html; charset=utf-8"
-	} else if strings.HasSuffix(filePath, ".txt") && strings.HasSuffix(filePath, ".text") {
-		mimeType = "text/plain; charset=utf-8"
-	} else if !strings.HasSuffix(filePath, ".gmi") && !strings.HasSuffix(filePath, ".gemini") {
-		kind, _ := filetype.Match(buf[:n])
-		if kind != filetype.Unknown {
-			mimeType = kind.MIME.Value
-		}
-	}
-	if mimeType == "" {
-		mimeType = "text/gemini; charset=utf-8"
-	}
-	var meta string
-	if !config.DisableSize && size >= 0 {
-		meta = fmt.Sprintf("%s; size=%d", mimeType, size)
-	} else {
-		meta = mimeType
-	}
-	writeHeader(c, statusSuccess, meta)
 
 	// Write body
 	c.Write(buf[:n])

server.go

@@ -22,6 +22,8 @@ const (
 	readTimeout = 30 * time.Second
 
 	urlMaxLength = 1024
+
+	geminiType = "text/gemini; charset=utf-8"
 )
 
 const (
@@ -74,6 +76,23 @@ func writeStatus(c net.Conn, code int) {
 	writeHeader(c, code, meta)
 }
 
+func writeSuccess(c net.Conn, serve *pathConfig, contentType string, size int64) {
+	meta := contentType
+	if serve.Type != "" {
+		meta = serve.Type
+	}
+
+	if !config.DisableSize && size >= 0 {
+		meta += fmt.Sprintf("; size=%d", size)
+	}
+
+	if serve.Cache != -1965 {
+		meta += fmt.Sprintf("; cache=%d", serve.Cache)
+	}
+
+	writeHeader(c, statusSuccess, meta)
+}
+
 func scanCRLF(data []byte, atEOF bool) (advance int, token []byte, err error) {
 	if atEOF && len(data) == 0 {
 		return 0, nil, nil
@@ -138,11 +157,11 @@ func servePath(c *tls.Conn, request *url.URL, serve *pathConfig) {
 			return
 		}
 
-		contentType := "text/gemini; charset=utf-8"
+		contentType := geminiType
 		if serve.Type != "" {
 			contentType = serve.Type
 		}
-		writeHeader(c, statusSuccess, contentType)
+		writeSuccess(c, serve, contentType, -1)
 
 		serveFastCGI(c, config.fcgiPools[serve.FastCGI], request, filePath)
 		return
@@ -151,11 +170,11 @@ func servePath(c *tls.Conn, request *url.URL, serve *pathConfig) {
 		if requireInput {
 			newCommand := replaceWithUserInput(serve.cmd, request)
 			if newCommand != nil {
-				serveCommand(c, request, newCommand)
+				serveCommand(c, serve, request, newCommand)
 				return
 			}
 		}
-		serveCommand(c, request, serve.cmd)
+		serveCommand(c, serve, request, serve.cmd)
 		return
 	}
 
@@ -183,7 +202,7 @@ func servePath(c *tls.Conn, request *url.URL, serve *pathConfig) {
 			_, err := os.Stat(path.Join(filePath, "index.gemini"))
 			if err != nil {
 				if serve.ListDirectory {
-					serveDirList(c, request, filePath)
+					serveDirList(c, serve, request, filePath)
 					return
 				}
 				writeStatus(c, statusNotFound)
@@ -199,7 +218,7 @@ func servePath(c *tls.Conn, request *url.URL, serve *pathConfig) {
 		return
 	}
 
-	serveFile(c, filePath)
+	serveFile(c, serve, filePath)
 }
 
 func serveConn(c *tls.Conn) {