HTTP handlers cleanup etc.

Author: bep

lib/cache.go

@@ -67,17 +67,17 @@ type readSeekCloser interface {
 	io.Closer
 }
 
-type cacheHandler struct {
+type cache struct {
 	cfg     Config
 	logger  *Logger
 	storage s3Client
 }
 
-func newCacheHandler(cfg Config, logger *Logger) *cacheHandler {
-	return &cacheHandler{cfg: cfg, logger: logger, storage: s3Client{cfg: cfg, logger: logger}}
+func newCache(cfg Config, logger *Logger) *cache {
+	return &cache{cfg: cfg, logger: logger, storage: s3Client{cfg: cfg, logger: logger}}
 }
 
-func (c *cacheHandler) handleRequest(rw http.ResponseWriter, req *http.Request) error {
+func (c *cache) handleRequest(rw http.ResponseWriter, req *http.Request) error {
 	urlPath := strings.TrimLeft(req.URL.Path, " /")
 
 	if urlPath == "" || strings.HasSuffix(urlPath, "/") {
@@ -135,7 +135,7 @@ func (c *cacheHandler) handleRequest(rw http.ResponseWriter, req *http.Request)
 	return err
 }
 
-func (c *cacheHandler) getFileMeta(relPath string) (*fileMeta, error) {
+func (c *cache) getFileMeta(relPath string) (*fileMeta, error) {
 	db, err := c.openDB()
 	if err != nil {
 		return nil, err
@@ -155,7 +155,7 @@ func (c *cacheHandler) getFileMeta(relPath string) (*fileMeta, error) {
 	return &fm, nil
 }
 
-func (c *cacheHandler) getAndWriteFile(
+func (c *cache) getAndWriteFile(
 	urlPath string, host Host,
 	rw http.ResponseWriter, req *http.Request) (*fileMeta, error) {
 
@@ -180,7 +180,7 @@ func (c *cacheHandler) getAndWriteFile(
 
 }
 
-func (c *cacheHandler) getFile(relPath string) (readSeekCloser, error) {
+func (c *cache) getFile(relPath string) (readSeekCloser, error) {
 	filename := filepath.Join(c.cfg.CacheDir, filepath.FromSlash(relPath))
 	f, err := os.Open(filename)
 	if err != nil {
@@ -193,7 +193,7 @@ func (c *cacheHandler) getFile(relPath string) (readSeekCloser, error) {
 }
 
 // TODO(bep) transactions
-func (c *cacheHandler) doWithDB(f func(db *storm.DB) error) error {
+func (c *cache) doWithDB(f func(db *storm.DB) error) error {
 	db, err := c.openDB()
 	if err != nil {
 		return err
@@ -202,26 +202,6 @@ func (c *cacheHandler) doWithDB(f func(db *storm.DB) error) error {
 	return f(db)
 }
 
-func (c *cacheHandler) openDB() (*storm.DB, error) {
-	return storm.Open(c.cfg.DBFilename, storm.BoltOptions(0600, &bolt.Options{Timeout: 5 * time.Second}))
+func (c *cache) openDB() (*storm.DB, error) {
+	return storm.Open(c.cfg.DBFilename, storm.BoltOptions(0600, &bolt.Options{Timeout: 10 * time.Second}))
 }
-
-// Plans:
-//
-// Request file:
-// If db.File => if os.File => OK
-// If db.File => if !os.File => delete db.File => stream and save db.File and os.File
-// If !db.File  => stream and save db.File and os.File
-
-// On server start:
-// For each os.File:
-// If not in db.File => delete os.File
-// For each db.File:
-// If not in os.File => delete db.File
-// Else: Set some in memory size counter.
-
-// On free space:
-// Order by CreatedAt asc
-
-// On Garbage Collect:
-//

lib/cache_maintenance.go

@@ -22,7 +22,7 @@ import (
 	"github.com/asdine/storm/q"
 )
 
-func (c *cacheHandler) purgePrefix(prefix string) error {
+func (c *cache) purgePrefix(prefix string) error {
 	db, err := c.openDB()
 	if err != nil {
 		return err
@@ -58,7 +58,7 @@ func (c *cacheHandler) purgePrefix(prefix string) error {
 
 // This is a Least Recently Used (LRU) cache.
 // So: Sort by created and delete until we reach the target.
-func (c *cacheHandler) shrinkTo(target int64) error {
+func (c *cache) shrinkTo(target int64) error {
 	db, err := c.openDB()
 	if err != nil {
 		return err

lib/server.go

@@ -16,13 +16,20 @@ package lib
 
 import (
 	"context"
+	"fmt"
 	"net/http"
+	"path"
 
 	"crypto/tls"
 
 	"golang.org/x/crypto/acme/autocert"
 )
 
+const (
+	// Make it unlikely that this clashes with some other static resource.
+	appNS = "__s3p"
+)
+
 // Server represents the caching HTTP server.
 type Server struct {
 	cfg        Config
@@ -34,35 +41,50 @@ type Server struct {
 }
 
 type httpHandlers struct {
-	c *cacheHandler
+	c *cache
 }
 
 func NewServer(cfg Config, logger *Logger) (*Server, error) {
 	// TODO(bep) validate config
 
-	h := http.NewServeMux()
-	c := newCacheHandler(cfg, logger)
-	mw := &httpHandlers{c: c}
+	var (
+		h  = http.NewServeMux()
+		c  = newCache(cfg, logger)
+		mw = &httpHandlers{c: c}
+	)
 
 	var purger http.HandlerFunc = func(w http.ResponseWriter, r *http.Request) {
 		prefix := r.FormValue("prefix")
-		if prefix != "" {
-			if err := c.purgePrefix(prefix); err != nil {
-				c.logger.Error("area", "cache", "tag", "purge", "prefix", prefix, "error", err)
-			}
+		host, found := cfg.host(r.Host)
+		if !found {
+			c.logger.Error("area", "cache", "tag", "purge", "host_not_found", r.Host)
+			return
 		}
+
+		prefix = path.Join(host.Name, prefix)
+
+		if err := c.purgePrefix(prefix); err != nil {
+			c.logger.Error("area", "cache", "tag", "purge", "prefix", prefix, "error", err)
+		}
+
 	}
 
 	var shrinker http.HandlerFunc = func(w http.ResponseWriter, r *http.Request) {
-		target := 50 << 10
+		target := 50 << 10 // TODO(bep) Take value from conf
 		if err := c.shrinkTo(int64(target)); err != nil {
 			c.logger.Error("area", "cache", "tag", "shrink", "error", err)
 		}
 	}
 
-	h.Handle("/purge", mw.secure(mw.validateSig(purger)))
-	h.Handle("/shrink", mw.secure(mw.validateSig(shrinker)))
-	h.Handle("/", mw.secure(mw.serveFile()))
+	var (
+		// Make the handler chaining a little bit more fluid.
+		secure      = mw.secure
+		validateSig = mw.validateSig
+	)
+
+	h.Handle(fmt.Sprintf("/%s/purge", appNS), secure(validateSig(purger)))
+	h.Handle(fmt.Sprintf("/%s/shrink", appNS), secure(validateSig(shrinker)))
+	h.Handle("/", secure(mw.serveFile()))
 
 	tlsEnabled, err := cfg.isTLSConfigured()
 	if err != nil {