fix(refresh): force assets to refresh via Lookup (#23)

Previously it was entirely possible for `ReadAll` to be repeatedly
invoked without refreshing the assets, since `Lookup` only `.get`
instead of `.refresh()`.

Since there is a refresh threshold now, it is better to do a refresh
if the threshold has exceeded, to prevent issues with asset of similar
name being deleted and re-added, or if the asset is removed all
together, which can be detected at the filesystem level instead.

Also fix when status code is non-200 to return as error instead.

Allow the refresh threshold to be specified as arg, though it defaults
to the current 30 seconds.

ghafs.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"fmt"
 	"io/ioutil"
 	"log"
 	"net/http"
@@ -61,7 +62,7 @@ func (r root) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) {
 }
 
 func (r root) Lookup(ctx context.Context, name string) (fs.Node, error) {
-	releases, err := r.mgmt.releases.get()
+	releases, err := r.mgmt.releases.refresh()
 
 	if err != nil {
 		return nil, err
@@ -93,7 +94,7 @@ func (t tagDir) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) {
 }
 
 func (t tagDir) Lookup(ctx context.Context, name string) (fs.Node, error) {
-	assets, err := t.assets.get()
+	assets, err := t.assets.refresh()
 
 	if err != nil {
 		return nil, err
@@ -128,6 +129,10 @@ func (f assetFile) ReadAll(ctx context.Context) ([]byte, error) {
 		return nil, err
 	}
 
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("Status Code: %v, message: %v", resp.StatusCode, resp.Status)
+	}
+
 	log.Printf("Asset URL: %v, Content-Length: %v", f.asset.GetURL(), resp.ContentLength)
 
 	body, err := ioutil.ReadAll(resp.Body)

main.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"net/http"
+	"time"
 
 	"github.com/alexflint/go-arg"
 
@@ -15,19 +16,20 @@ import (
 )
 
 type args struct {
-	Mountpoint  string `arg:"positional,required"`
-	Owner       string `arg:"positional,required"`
-	Repo        string `arg:"positional,required"`
-	AccessToken string `arg:"--token" help:"GitHub access token for authorization"`
-	AllowOther  bool   `arg:"--allow-other" help:"use FUSE allow_other mode (allow_root doesn't work, so not available)"`
+	Mountpoint       string `arg:"positional,required"`
+	Owner            string `arg:"positional,required"`
+	Repo             string `arg:"positional,required"`
+	AccessToken      string `arg:"--token" help:"GitHub access token for authorization"`
+	AllowOther       bool   `arg:"--allow-other" help:"use FUSE allow_other mode (allow_root doesn't work, so not available)"`
+	RefreshThreshold uint32 `arg:"--refresh" default:"30" help:"number of seconds that must elapsed before subsequent assets refresh can occur"`
 }
 
 func (args) Description() string {
 	return "GitHub Release Assets FUSE CLI"
 }
 
 func (args) Version() string {
-	return "ghafs 0.1.1"
+	return "ghafs 0.1.2"
 }
 
 func main() {
@@ -46,7 +48,7 @@ func main() {
 	}
 
 	client := github.NewClient(tc)
-	mgmt := makeReleaseMgmt(makeGhContext(ctx, client, args.Owner, args.Repo))
+	mgmt := makeReleaseMgmt(makeGhContext(ctx, client, args.Owner, args.Repo, time.Duration(args.RefreshThreshold)*time.Second))
 
 	mountOptions := []fuse.MountOption{
 		fuse.FSName("ghafs"),

releaseAssets.go

@@ -12,16 +12,13 @@ import (
 // https://developer.github.com/v3/#pagination
 const PageLimit = 100
 
-// LastUpdatedThreshold sets the period threshold to allow the next update to
-// the items in seconds
-const LastUpdatedThreshold = 30 * time.Second
-
 // GhContext contains the necessary inputs to invoke the Gitub library
 type GhContext struct {
-	ctx    context.Context
-	client *github.Client
-	owner  string
-	repo   string
+	ctx              context.Context
+	client           *github.Client
+	owner            string
+	repo             string
+	refreshThreshold time.Duration
 }
 
 // ReleaseMgmt forms the root level to be able to generate the entire release
@@ -59,8 +56,8 @@ type AssetsWrap struct {
 	m           sync.Mutex
 }
 
-func makeGhContext(ctx context.Context, client *github.Client, owner string, repo string) *GhContext {
-	return &GhContext{ctx, client, owner, repo}
+func makeGhContext(ctx context.Context, client *github.Client, owner string, repo string, refreshThreshold time.Duration) *GhContext {
+	return &GhContext{ctx, client, owner, repo, refreshThreshold}
 }
 
 func makeReleaseMgmt(ghc *GhContext) *ReleaseMgmt {
@@ -118,7 +115,7 @@ func (w *ReleasesWrap) refreshImpl() (map[string]*Release, error) {
 	timeNow := time.Now()
 
 	// Adhere to the update threshold
-	if w.lastUpdated.Add(LastUpdatedThreshold).Before(timeNow) {
+	if w.lastUpdated.Add(w.ghc.refreshThreshold).Before(timeNow) {
 		releases, err := loopListReleases(w)
 
 		if err != nil {
@@ -141,17 +138,6 @@ func (w *ReleasesWrap) refresh() (map[string]*Release, error) {
 	return w.refreshImpl()
 }
 
-func (w *ReleasesWrap) get() (map[string]*Release, error) {
-	w.m.Lock()
-	defer w.m.Unlock()
-
-	if len(w.tagReleases) == 0 {
-		return w.refreshImpl()
-	}
-
-	return w.tagReleases, nil
-}
-
 func loopListReleaseAssets(w *AssetsWrap) ([]*github.ReleaseAsset, error) {
 	var assets []*github.ReleaseAsset
 
@@ -183,7 +169,7 @@ func (w *AssetsWrap) refreshImpl() ([]*github.ReleaseAsset, error) {
 	timeNow := time.Now()
 
 	// Adhere to the update threshold
-	if w.lastUpdated.Add(LastUpdatedThreshold).Before(timeNow) {
+	if w.lastUpdated.Add(w.ghc.refreshThreshold).Before(timeNow) {
 		assets, err := loopListReleaseAssets(w)
 
 		if err != nil {
@@ -202,14 +188,3 @@ func (w *AssetsWrap) refresh() ([]*github.ReleaseAsset, error) {
 	defer w.m.Unlock()
 	return w.refreshImpl()
 }
-
-func (w *AssetsWrap) get() ([]*github.ReleaseAsset, error) {
-	w.m.Lock()
-	defer w.m.Unlock()
-
-	if len(w.assets) == 0 {
-		return w.refreshImpl()
-	}
-
-	return w.assets, nil
-}