cli/pickle: More efficient tuples.

2 files changed, 23 insertions, 3 deletions

diff --git a/cli/cli_pickle.cpp b/cli/cli_pickle.cpp
index 4d62b1e9..6d368028 100644
--- a/cli/cli_pickle.cpp
+++ b/cli/cli_pickle.cpp
@@ -120,6 +120,7 @@ public:
 
     void visit(Struct *node) {
         if (false) {
+            // Structures as dictionaries
             writer.beginDict();
             for (unsigned i = 0; i < node->sig->num_members; ++i) {
                 writer.beginItem(node->sig->member_names[i]);
@@ -128,11 +129,13 @@ public:
             }
             writer.endDict();
         } else {
-            writer.beginTuple();
-            for (unsigned i = 0; i < node->sig->num_members; ++i) {
+            // Structures as tuples
+            unsigned num_members = node->sig->num_members;
+            writer.beginTuple(num_members);
+            for (unsigned i = 0; i < num_members; ++i) {
                 _visit(node->members[i]);
             }
-            writer.endTuple();
+            writer.endTuple(num_members);
         }
     }
 
diff --git a/cli/pickle.hpp b/cli/pickle.hpp
index 59af6a7b..aaecc188 100644
--- a/cli/pickle.hpp
+++ b/cli/pickle.hpp
@@ -162,6 +162,23 @@ public:
         os.put(TUPLE);
     }
 
+    inline void beginTuple(unsigned length) {
+        if (length >= 4) {
+            os.put(MARK);
+        }
+    }
+
+    inline void endTuple(unsigned length) {
+        static const Opcode ops[4] = {
+            EMPTY_TUPLE,
+            TUPLE1,
+            TUPLE2,
+            TUPLE3,
+        };
+        Opcode op = length < 4 ? ops[length] : TUPLE;
+        os.put(op);
+    }
+
     inline void writeString(const char *s, size_t length) {
         if (!s) {
             writeNone();