[RELAY] TextPrinter: Use Map Format (#2553)

src/relay/ir/text_printer.cc

@@ -42,11 +42,11 @@ inline std::ostream& operator<<(std::ostream& os, const TextValue& val) {  // NO
  * we support a meta-data section in the text format.
  * We allow the text format to refer to a node in the meta-data section.
  *
- * The meta-data section is a json serialized string of an Array<NodeRef>.
+ * The meta-data section is a json serialized string of an Map<string, Array<NodeRef>>.
  * Each element in the meta-data section can be referenced by the text format.
  * Each meta data node is printed in the following format.
  *
- * meta.<type-key-of-node>(<index-in-meta-section>)
+ * meta[type-key-of-node>][<index-in-meta-section>]
  *
  * Specifically, consider the following IR(constructed by python).
  *
@@ -63,7 +63,7 @@ inline std::ostream& operator<<(std::ostream& os, const TextValue& val) {  // NO
  *
  * \code
  *
- * fn (%x: Tensor[(meta.Variable(id=0),), float32]) {
+ * fn (%x: Tensor[(meta[Variable][0],), float32]) {
  *   %x
  * }
  * # Meta data section is a json-serialized string
@@ -74,7 +74,7 @@ inline std::ostream& operator<<(std::ostream& os, const TextValue& val) {  // NO
  *
  * Note that we store tvm.var("n") in the meta data section.
  * Since it is stored in the index-0 in the meta-data section,
- * we print it as meta.Variable(0).
+ * we print it as meta[Variable][0].
  *
  * The text parser can recover this object by loading from the corresponding
  * location in the meta data section.
@@ -91,18 +91,18 @@ class TextMetaDataContext {
    * \return A string representation of the meta node.
    */
   std::string GetMetaNode(const NodeRef& node) {
-    std::ostringstream os;
-    auto it = meta_index_.find(node);
-    int64_t index;
-    if (it != meta_index_.end()) {
-      index = it->second;
-    } else {
-      index = static_cast<int64_t>(meta_data_.size());
-      meta_data_.push_back(node);
-      meta_index_[node] = index;
+    auto it = meta_repr_.find(node);
+    if (it != meta_repr_.end()) {
+      return it->second;
     }
-    os << "meta." << node->type_key() << "(id=" << index << ")";
-    return os.str();
+    Array<NodeRef>& mvector =
+        meta_data_[node->type_key()];
+    int64_t index = static_cast<int64_t>(mvector.size());
+    mvector.push_back(node);
+    std::ostringstream os;
+    os << "meta[" << node->type_key() << "][" << index << "]";
+    meta_repr_[node] = os.str();
+    return meta_repr_[node];
   }
   /*!
    * \brief Get the metadata section in json format.
@@ -110,7 +110,8 @@ class TextMetaDataContext {
    */
   std::string GetMetaSection() const {
     if (meta_data_.size() == 0) return std::string();
-    return SaveJSON(Array<NodeRef>(meta_data_));
+    return SaveJSON(Map<std::string, NodeRef>(
+        meta_data_.begin(), meta_data_.end()));
   }
 
   /*! \return whether the meta data context is empty. */
@@ -120,9 +121,9 @@ class TextMetaDataContext {
 
  private:
   /*! \brief additional metadata stored in TVM json format */
-  std::vector<NodeRef> meta_data_;
-  /*! \brief map from meta data into its index */
-  std::unordered_map<NodeRef, int64_t, NodeHash, NodeEqual> meta_index_;
+  std::unordered_map<std::string, Array<NodeRef> > meta_data_;
+  /*! \brief map from meta data into its string representation */
+  std::unordered_map<NodeRef, std::string, NodeHash, NodeEqual> meta_repr_;
 };
 
 class TextPrinter :

tests/python/relay/test_ir_text_printer.py

@@ -48,11 +48,11 @@ def test_meta_data():
     f = relay.Function([x, w], z)
     text = f.astext()
     assert "channels=2" in text
-    assert "meta.Variable(id=0)" in text
+    assert "meta[Variable][0]" in text
     show(text)
 
     text = relay.const([1,2,3]).astext()
-    assert "meta.relay.Constant(id=0)" in text
+    assert "meta[relay.Constant][0]" in text
     show(text)