Merge pull request #6 from matthazinski/metadata

Add preliminary metadata support

.gitignore

@@ -28,3 +28,4 @@ _testmain.go
 
 linx-server
 files/
+meta/

expiry.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"time"
+)
+
+// Get what the unix timestamp will be in "seconds".
+func getFutureTimestamp(seconds int32) (ts int32) {
+	now := int32(time.Now().Unix())
+
+	if seconds == 0 {
+		ts = 0
+	} else {
+		ts = now + seconds
+	}
+
+	return
+}
+
+// Determine if a file with expiry set to "ts" has expired yet
+func isTsExpired(ts int32) (expired bool) {
+	now := int32(time.Now().Unix())
+
+	if ts == 0 {
+		expired = false
+	} else if now > ts {
+		expired = true
+	} else {
+		expired = false
+	}
+
+	return
+}
+
+// Determine if the given filename is expired
+func isFileExpired(filename string) (bool, error) {
+	exp, err := metadataGetExpiry(filename)
+
+	if err != nil {
+		return true, err
+	} else {
+		return isTsExpired(exp), err
+	}
+}

fileserve.go

@@ -18,7 +18,17 @@ func fileServeHandler(c web.C, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// plug file expiry checking here
+	expired, expErr := isFileExpired(fileName)
+
+	if expErr != nil {
+		// Error reading metadata, pretend it's expired
+		notFoundHandler(c, w, r)
+		// TODO log error internally
+		return
+	} else if expired {
+		notFoundHandler(c, w, r)
+		// TODO delete the file
+	}
 
 	http.ServeFile(w, r, filePath)
 }

meta.go

@@ -0,0 +1,89 @@
+package main
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"os"
+	"path"
+	"strconv"
+)
+
+// Write metadata from Upload struct to file
+func metadataWrite(filename string, upload *Upload) error {
+	// Write metadata, overwriting if necessary
+
+	file, err := os.Create(path.Join(Config.metaDir, upload.Filename))
+	if err != nil {
+		return err
+	}
+
+	defer file.Close()
+
+	w := bufio.NewWriter(file)
+
+	fmt.Fprintln(w, upload.Expiry)
+	fmt.Fprintln(w, upload.DeleteKey)
+	fmt.Fprintln(w, upload.DebugInfo)
+
+	return w.Flush()
+}
+
+// Return list of strings from a filename's metadata source
+func metadataRead(filename string) ([]string, error) {
+	file, err := os.Create(path.Join(Config.metaDir, filename))
+
+	if err != nil {
+		return nil, err
+	}
+
+	defer file.Close()
+
+	var lines []string
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		lines = append(lines, scanner.Text())
+	}
+
+	return lines, scanner.Err()
+}
+
+func metadataGetExpiry(filename string) (int32, error) {
+	metadata, err := metadataRead(filename)
+
+	if len(metadata) < 1 {
+		err := errors.New("ERR: Metadata file does not contain expiry")
+		return 0, err
+	}
+
+	// XXX in this case it's up to the caller to determine proper behavior
+	// for a nonexistant metadata file or broken file
+
+	if err != nil {
+		return 0, err
+	}
+
+	var expiry int64
+	expiry, err = strconv.ParseInt(metadata[0], 10, 32)
+
+	if err != nil {
+		return 0, err
+	} else {
+		return int32(expiry), err
+	}
+}
+
+func metadataGetDeleteKey(filename string) (string, error) {
+	metadata, err := metadataRead(filename)
+
+	if len(metadata) < 2 {
+		err := errors.New("ERR: Metadata file does not contain deletion key")
+		return "", err
+	}
+
+	if err != nil {
+		return "", err
+	} else {
+		return metadata[1], err
+	}
+}

server.go

@@ -2,12 +2,12 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"log"
 	"net"
 	"net/http"
-	"regexp"
 	"os"
-	"fmt"
+	"regexp"
 
 	"github.com/flosch/pongo2"
 	"github.com/zenazn/goji"
@@ -17,6 +17,7 @@ import (
 var Config struct {
 	bind     string
 	filesDir string
+	metaDir  string
 	noLogs   bool
 	siteName string
 	siteURL  string
@@ -26,26 +27,41 @@ func main() {
 	flag.StringVar(&Config.bind, "b", "127.0.0.1:8080",
 		"host to bind to (default: 127.0.0.1:8080)")
 	flag.StringVar(&Config.filesDir, "filespath", "files/",
-		"path to files directory (including trailing slash)")
+		"path to files directory")
+	flag.StringVar(&Config.metaDir, "metapath", "meta/",
+		"path to metadata directory")
 	flag.BoolVar(&Config.noLogs, "nologs", false,
 		"remove stdout output for each request")
 	flag.StringVar(&Config.siteName, "sitename", "linx",
 		"name of the site")
 	flag.StringVar(&Config.siteURL, "siteurl", "http://"+Config.bind+"/",
-		"site base url (including trailing slash)")
+		"site base url")
 	flag.Parse()
 
 	if Config.noLogs {
 		goji.Abandon(middleware.Logger)
 	}
 
-	// make directory if needed
-	err := os.MkdirAll(Config.filesDir, 0755)
+	// make directories if needed
+	var err error
+
+	err = os.MkdirAll(Config.filesDir, 0755)
 	if err != nil {
-		fmt.Printf("Error: could not create files directory")
+		fmt.Printf("Error: could not create files directory\n")
 		os.Exit(1)
 	}
 
+	err = os.MkdirAll(Config.metaDir, 0700)
+	if err != nil {
+		fmt.Printf("Error: could not create metadata directory\n")
+		os.Exit(1)
+	}
+
+	// ensure siteURL ends wth '/'
+	if lastChar := Config.siteURL[len(Config.siteURL)-1:]; lastChar != "/" {
+		Config.siteURL = Config.siteURL + "/"
+	}
+
 	// Template Globals
 	pongo2.DefaultSet.Globals["sitename"] = Config.siteName
 

upload.go

@@ -15,21 +15,55 @@ import (
 	"github.com/zenazn/goji/web"
 )
 
+// Describes metadata directly from the user request
 type UploadRequest struct {
 	src            io.Reader
 	filename       string
-	expiry         int
+	expiry         int32 // Seconds until expiry, 0 = never
 	randomBarename bool
+	deletionKey    string // Empty string if not defined
 }
 
+// Metadata associated with a file as it would actually be stored
 type Upload struct {
-	Filename string
-	Size     int64
-	Expiry   int
+	Filename  string // Final filename on disk
+	Size      int64
+	Expiry    int32  // Unix timestamp of expiry, 0=never
+	DeleteKey string // Deletion key, one generated if not provided
+	DebugInfo string // Optional field to store whatever
+}
+
+func uploadHeaderProcess(r *http.Request, upReq *UploadRequest) {
+	// For legacy reasons
+	upReq.randomBarename = false
+	if r.Header.Get("X-Randomized-Filename") == "yes" {
+		upReq.randomBarename = true
+	}
+
+	if r.Header.Get("X-Randomized-Barename") == "yes" {
+		upReq.randomBarename = true
+	}
+
+	upReq.deletionKey = r.Header.Get("X-Delete-Key")
+
+	// Get seconds until expiry. Non-integer responses never expire.
+	expStr := r.Header.Get("X-File-Expiry")
+	if expStr == "" {
+		upReq.expiry = 0
+	} else {
+		expiry, err := strconv.ParseInt(expStr, 10, 32)
+		if err != nil {
+			upReq.expiry = 0
+		} else {
+			upReq.expiry = int32(expiry)
+		}
+	}
+
 }
 
 func uploadPostHandler(c web.C, w http.ResponseWriter, r *http.Request) {
 	upReq := UploadRequest{}
+	uploadHeaderProcess(r, &upReq)
 
 	if r.Header.Get("Content-Type") == "application/octet-stream" {
 		defer r.Body.Close()
@@ -71,6 +105,7 @@ func uploadPostHandler(c web.C, w http.ResponseWriter, r *http.Request) {
 
 func uploadPutHandler(c web.C, w http.ResponseWriter, r *http.Request) {
 	upReq := UploadRequest{}
+	uploadHeaderProcess(r, &upReq)
 
 	defer r.Body.Close()
 	upReq.filename = c.URLParams["name"]
@@ -86,6 +121,7 @@ func uploadPutHandler(c web.C, w http.ResponseWriter, r *http.Request) {
 }
 
 func processUpload(upReq UploadRequest) (upload Upload, err error) {
+	// Determine the appropriate filename, then write to disk
 	barename, extension := barePlusExt(upReq.filename)
 
 	if upReq.randomBarename || len(barename) == 0 {
@@ -120,6 +156,18 @@ func processUpload(upReq UploadRequest) (upload Upload, err error) {
 	}
 	defer dst.Close()
 
+	// Get the rest of the metadata needed for storage
+	upload.Expiry = getFutureTimestamp(upReq.expiry)
+
+	// If no delete key specified, pick a random one.
+	if upReq.deletionKey == "" {
+		upload.DeleteKey = uuid.New()[:30]
+	} else {
+		upload.DeleteKey = upReq.deletionKey
+	}
+
+	metadataWrite(upload.Filename, &upload)
+
 	bytes, err := io.Copy(dst, upReq.src)
 	if err != nil {
 		return