search/publich: rename PathLookup to PathsLookup, add PathLookup

Change-Id: If6804af2229885cfa22d67d608d17e600d7402f3

lib/go/camli/mysqlindexer/search.go

@@ -397,7 +397,46 @@ func (mi *Indexer) PathsOfSignerTarget(signer, target *blobref.BlobRef) (paths [
 	return paths, nil
 }
 
-func (mi *Indexer) PathLookup(signer, base *blobref.BlobRef, suffix string) (paths []*search.Path, err os.Error) {
+func (mi *Indexer) PathLookup(signer, base *blobref.BlobRef, suffix string, at *time.Time) (*search.Path, os.Error) {
+	// TODO: pass along the at time to a new helper function to
+	// filter? maybe not worth it, since this list should be
+	// small.
+	paths, err := mi.PathsLookup(signer, base, suffix);
+	if err != nil {
+		return nil, err
+	}
+	var (
+		newest = int64(0)
+		atSeconds = int64(0)
+		best *search.Path
+	)
+	if at != nil {
+		atSeconds = at.Seconds()
+	}
+	for _, path := range paths {
+		t, err := time.Parse(time.RFC3339, trimRFC3339Subseconds(path.ClaimDate))
+		if err != nil {
+			continue
+		}
+		secs := t.Seconds()
+		if atSeconds != 0 && secs > atSeconds {
+			// Too new
+			continue
+		}
+		if newest > secs {
+			// Too old
+			continue
+		}
+		// Just right
+		newest, best = secs, path
+	}
+	if best == nil {
+		return nil, os.ENOENT
+	}
+	return best, nil
+}
+
+func (mi *Indexer) PathsLookup(signer, base *blobref.BlobRef, suffix string) (paths []*search.Path, err os.Error) {
 	keyId, err := mi.keyIdOfSigner(signer)
 	if err != nil {
 		return

lib/go/camli/search/search.go

@@ -96,5 +96,10 @@ type Index interface {
 
 	PathsOfSignerTarget(signer, target *blobref.BlobRef) ([]*Path, os.Error)
 
-	PathLookup(signer, base *blobref.BlobRef, suffix string) ([]*Path, os.Error)
+	// All Path claims for (signer, base, suffix)
+	PathsLookup(signer, base *blobref.BlobRef, suffix string) ([]*Path, os.Error)
+
+	// Most recent Path claim for (signer, base, suffix) as of
+	// provided time 'at', or most recent if 'at' is nil.
+	PathLookup(signer, base *blobref.BlobRef, suffix string, at *time.Time) (*Path, os.Error)
 }

server/go/camlistored/publish.go

@@ -111,14 +111,12 @@ func (pub *PublishHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request)
 
 	fmt.Fprintf(rw, "I am publish handler at base %q, serving root %q (permanode=%s), suffix %q<hr>",
 		base, pub.RootName, pn, html.EscapeString(suffix))
-	paths, err := pub.Search.Index().PathLookup(pub.Search.Owner(), pn, suffix)
+	path, err := pub.Search.Index().PathLookup(pub.Search.Owner(), pn, suffix, nil)
 	if err != nil {
 		fmt.Fprintf(rw, "<b>Error:</b> %v", err)
 		return
 	}
-	for _, path := range paths {
-		fmt.Fprintf(rw, "<p><b>Target:</b> <a href='/ui/?p=%s'>%s</a></p>", path.Target, path.Target)
-	}
+	fmt.Fprintf(rw, "<p><b>Target:</b> <a href='/ui/?p=%s'>%s</a></p>", path.Target, path.Target)
 }
 
 func (pub *PublishHandler) bootstrapPermanode(jsonSign *JSONSignHandler) os.Error {