Support compressing backups

http/query_params.go

@@ -103,6 +103,11 @@ func (qp QueryParams) Vacuum() bool {
 	return qp.HasKey("vacuum")
 }
 
+// Compress returns true if the query parameters request compression.
+func (qp QueryParams) Compress() bool {
+	return qp.HasKey("compress")
+}
+
 // Key returns the value of the key named "key".
 func (qp QueryParams) Key() string {
 	return qp["key"]

http/service.go

@@ -600,9 +600,10 @@ func (s *Service) handleBackup(w http.ResponseWriter, r *http.Request, qp QueryP
 	}
 
 	br := &proto.BackupRequest{
-		Format: qp.BackupFormat(),
-		Leader: !qp.NoLeader(),
-		Vacuum: qp.Vacuum(),
+		Format:   qp.BackupFormat(),
+		Leader:   !qp.NoLeader(),
+		Vacuum:   qp.Vacuum(),
+		Compress: qp.Compress(),
 	}
 	addBackupFormatHeader(w, qp)