From d2bc6f6cd350949e58632d25fb1501fa6aec5ef1 Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <brad@danga.com>
Date: Mon, 18 Feb 2013 10:17:38 -0800
Subject: [PATCH] fs: use schema.DirReader, rather than doing it by hand

Change-Id: I7e79621d621314ed1f50219f0cafc44b1b82ab1f
---
 pkg/fs/fs.go            | 61 +++++++----------------------------------
 pkg/schema/dirreader.go | 36 ++++++++++++++++++++----
 2 files changed, 41 insertions(+), 56 deletions(-)

diff --git a/pkg/fs/fs.go b/pkg/fs/fs.go
index 45bc46595..cb9436ca6 100644
--- a/pkg/fs/fs.go
+++ b/pkg/fs/fs.go
@@ -227,65 +227,24 @@ func (n *node) ReadDir(intr fuse.Intr) ([]fuse.Dirent, fuse.Error) {
 
 	ss, err := n.schema()
 	if err != nil {
+		log.Printf("camli.ReadDir error on %v: %v", n.blobref, err)
 		return nil, fuse.EIO
 	}
-	setRef := ss.DirectoryEntries()
-	if setRef == nil {
-		return nil, nil
-	}
-	log.Printf("fetching setref: %v...", setRef)
-	setss, err := n.fs.fetchSchemaMeta(setRef)
+	dr, err := schema.NewDirReader(n.fs.fetcher, ss.BlobRef())
 	if err != nil {
-		log.Printf("fetching %v for readdir on %v: %v", setRef, n.blobref, err)
+		log.Printf("camli.ReadDir error on %v: %v", n.blobref, err)
 		return nil, fuse.EIO
 	}
-	if setss.Type() != "static-set" {
-		log.Printf("%v is not a static-set in readdir; is a %q", setRef, setss.Type())
+	schemaEnts, err := dr.Readdir(-1)
+	if err != nil {
+		log.Printf("camli.ReadDir error on %v: %v", n.blobref, err)
 		return nil, fuse.EIO
 	}
-
-	// TODO(bradfitz): push down information to the fetcher
-	// (cachingfetcher -> remote client http) that we're going to load a
-	// bunch, so the HTTP client (if not using SPDY) can do discovery
-	// and see if the server supports a batch handler, then get them all
-	// in one round-trip, rather than attacking the server with hundreds
-	// of parallel TLS setups.
-
-	// res is the result of fetchSchemaMeta.  the ssc slice of channels keeps them ordered
-	// the same as they're listed in the schema's Members.
-	type res struct {
-		*blobref.BlobRef
-		*schema.Blob
-		error
-	}
-	var ssc []chan res
-	for _, memberRef := range setss.StaticSetMembers() {
-		ch := make(chan res, 1)
-		ssc = append(ssc, ch)
-		// TODO: move the cmd/camput/chanworker.go into its own package, and use it here. only
-		// have 10 or so of these loading at once.  for now we do them all.
-		go func(memberRef *blobref.BlobRef) {
-			mss, err := n.fs.fetchSchemaMeta(memberRef)
-			if err != nil {
-				log.Printf("error reading entry %v in readdir: %v", memberRef, err)
-			}
-			ch <- res{memberRef, mss, err}
-		}(memberRef)
-	}
-
 	n.dirents = make([]fuse.Dirent, 0)
-	for i, ch := range ssc {
-		log.Printf("CAMLI dir %v set %v, waiting on entry %d/%d", n.blobref, setRef, i+1, len(ssc))
-		r := <-ch
-		memberRef, mss, err := r.BlobRef, r.Blob, r.error
-		if err != nil {
-			return nil, fuse.EIO
-		}
-		if filename := mss.FileName(); filename != "" {
-			n.addLookupEntry(filename, memberRef)
-			n.dirents = append(n.dirents, fuse.Dirent{
-				Name: mss.FileName(),
-			})
+	for _, sent := range schemaEnts {
+		if name := sent.FileName(); name != "" {
+			n.addLookupEntry(name, sent.BlobRef())
+			n.dirents = append(n.dirents, fuse.Dirent{Name: name})
 		}
 	}
 	return n.dirents, nil
diff --git a/pkg/schema/dirreader.go b/pkg/schema/dirreader.go
index d8addf4eb..3b0acdb5e 100644
--- a/pkg/schema/dirreader.go
+++ b/pkg/schema/dirreader.go
@@ -126,12 +126,38 @@ func (dr *DirReader) Readdir(n int) (entries []DirectoryEntry, err error) {
 			up = len(sts)
 		}
 	}
-	for _, entryBref := range sts[dr.current:up] {
-		entry, err := NewDirectoryEntryFromBlobRef(dr.fetcher, entryBref)
-		if err != nil {
+
+	// TODO(bradfitz): push down information to the fetcher
+	// (e.g. cachingfetcher -> remote client http) that we're
+	// going to load a bunch, so the HTTP client (if not using
+	// SPDY) can do discovery and see if the server supports a
+	// batch handler, then get them all in one round-trip, rather
+	// than attacking the server with hundreds of parallel TLS
+	// setups.
+
+	type res struct {
+		ent DirectoryEntry
+		err error
+	}
+	var cs []chan res
+
+	// Kick off all directory entry loads.
+	// TODO: bound this?
+	for _, entRef := range sts[dr.current:up] {
+		c := make(chan res, 1)
+		cs = append(cs, c)
+		go func(entRef *blobref.BlobRef) {
+			entry, err := NewDirectoryEntryFromBlobRef(dr.fetcher, entRef)
+			c <- res{entry, err}
+		}(entRef)
+	}
+
+	for _, c := range cs {
+		res := <-c
+		if res.err != nil {
 			return nil, fmt.Errorf("schema/filereader: can't create dirEntry: %v\n", err)
 		}
-		entries = append(entries, entry)
+		entries = append(entries, res.ent)
 	}
-	return entries, err
+	return entries, nil
 }