Serve cached files from disk

githandler.go

@@ -18,6 +18,7 @@ import (
 	"path"
 	"strings"
 	"syscall"
+	"time"
 )
 
 type gitHandler struct {
@@ -205,6 +206,23 @@ func handleGetInfoRefs(env gitEnv, _ string, repoPath string, w http.ResponseWri
 }
 
 func handleGetArchive(env gitEnv, format string, repoPath string, w http.ResponseWriter, r *http.Request) {
+	archiveFilename := path.Base(env.ArchivePath)
+	w.Header().Add("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, archiveFilename))
+	if format == "zip" {
+		w.Header().Add("Content-Type", "application/zip")
+	} else {
+		w.Header().Add("Content-Type", "application/octet-stream")
+	}
+	w.Header().Add("Content-Transfer-Encoding", "binary")
+	w.Header().Add("Cache-Control", "private")
+
+	if f, err := os.Open(env.ArchivePath); err == nil {
+		defer f.Close()
+		log.Printf("Serving cached file %q", env.ArchivePath)
+		http.ServeContent(w, r, archiveFilename, time.Unix(0, 0), f)
+		return
+	}
+
 	var compressCmd *exec.Cmd
 	var archiveFormat string
 	switch format {
@@ -222,8 +240,6 @@ func handleGetArchive(env gitEnv, format string, repoPath string, w http.Respons
 		compressCmd = nil
 	}
 
-	archiveFilename := path.Base(env.ArchivePath)
-
 	archiveCmd := gitCommand(env, "git", "--git-dir="+repoPath, "archive", "--format="+archiveFormat, "--prefix="+env.ArchivePrefix+"/", env.CommitId)
 	archiveStdout, err := archiveCmd.StdoutPipe()
 	if err != nil {
@@ -260,14 +276,6 @@ func handleGetArchive(env gitEnv, format string, repoPath string, w http.Respons
 	}
 
 	// Start writing the response
-	if format == "zip" {
-		w.Header().Add("Content-Type", "application/zip")
-	} else {
-		w.Header().Add("Content-Type", "application/octet-stream")
-	}
-	w.Header().Add("Content-Transfer-Encoding", "binary")
-	w.Header().Add("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, archiveFilename))
-	w.Header().Add("Cache-Control", "private")
 	w.WriteHeader(200) // Don't bother with HTTP 500 from this point on, just return
 	if _, err := io.Copy(w, stdout); err != nil {
 		logContext("handleGetArchive read from subprocess", err)

main_test.go

 package main
 
 import (
+	"bytes"
 	"fmt"
+	"io/ioutil"
 	"net"
 	"net/http"
 	"net/http/httptest"
@@ -23,6 +25,7 @@ const testProject = "test"
 
 var remote = fmt.Sprintf("http://%s/%s", servAddr, testRepo)
 var checkoutDir = path.Join(scratchDir, "test")
+var cacheDir = path.Join(scratchDir, "cache")
 
 func TestAllowedClone(t *testing.T) {
 	// Prepare clone directory
@@ -187,6 +190,36 @@ func TestAllowedApiDownloadZip(t *testing.T) {
 	runOrFail(t, extractCmd)
 }
 
+func TestDownloadCacheHit(t *testing.T) {
+	prepareDownloadDir(t)
+
+	// Prepare test server and backend
+	archiveName := "foobar.zip"
+	ts := testAuthServer(200, archiveOkBody(t, archiveName))
+	defer ts.Close()
+	defer cleanUpProcessGroup(startServerOrFail(t, ts))
+
+	if err := os.MkdirAll(cacheDir, 0755); err != nil {
+		t.Fatal(err)
+	}
+	cachedContent := []byte{'c', 'a', 'c', 'h', 'e', 'd'}
+	if err := ioutil.WriteFile(path.Join(cacheDir, archiveName), cachedContent, 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	downloadCmd := exec.Command("curl", "-J", "-O", fmt.Sprintf("http://%s/api/v3/projects/123/repository/archive.zip", servAddr))
+	downloadCmd.Dir = scratchDir
+	runOrFail(t, downloadCmd)
+
+	actual, err := ioutil.ReadFile(path.Join(scratchDir, archiveName))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if bytes.Compare(actual, cachedContent) != 0 {
+		t.Fatal("Unexpected file contents in download")
+	}
+}
+
 func prepareDownloadDir(t *testing.T) {
 	if err := os.RemoveAll(scratchDir); err != nil {
 		t.Fatal(err)
@@ -264,10 +297,10 @@ func archiveOkBody(t *testing.T, archiveName string) string {
 	if err != nil {
 		t.Fatal(err)
 	}
-	archivePath := path.Join(cwd, scratchDir, "cache", archiveName)
+	archivePath := path.Join(cwd, cacheDir, archiveName)
 	jsonString := `{
 		"RepoPath":"%s",
-		"ArchivePath":"/tmp/%s",
+		"ArchivePath":"%s",
 		"CommitId":"c7fbe50c7c7419d9701eebe64b1fdacc3df5b9dd",
 		"ArchivePrefix":"foobar123"
 	}`