Generate schemas as on-demand hydration from tuples

codegen/core/src/main/java/software/amazon/smithy/python/codegen/RuntimeTypes.java

@@ -23,6 +23,14 @@ public final class RuntimeTypes {
     public static final Symbol API_OPERATION =
             createSymbol("schemas", "APIOperation", SmithyPythonDependency.SMITHY_CORE);
 
+    // smithy_core._schema_compact
+    public static final Symbol HYDRATE =
+            createSymbol("_schema_compact", "hydrate", SmithyPythonDependency.SMITHY_CORE);
+    public static final Symbol STATIC_SCHEMA =
+            createSymbol("_schema_compact", "StaticSchema", SmithyPythonDependency.SMITHY_CORE);
+    public static final Symbol STATIC_OPERATION_SCHEMA =
+            createSymbol("_schema_compact", "StaticOperationSchema", SmithyPythonDependency.SMITHY_CORE);
+
     // smithy_core.shapes
     public static final Symbol SHAPE_ID = createSymbol("shapes", "ShapeID", SmithyPythonDependency.SMITHY_CORE);
     public static final Symbol SHAPE_TYPE = createSymbol("shapes", "ShapeType", SmithyPythonDependency.SMITHY_CORE);

codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/AbstractMemberGenerator.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.python.codegen.generators;
+
+import software.amazon.smithy.codegen.core.CodegenException;
+import software.amazon.smithy.model.shapes.MemberShape;
+import software.amazon.smithy.model.shapes.Shape;
+import software.amazon.smithy.model.shapes.ShapeVisitor;
+import software.amazon.smithy.python.codegen.GenerationContext;
+import software.amazon.smithy.python.codegen.writer.PythonWriter;
+import software.amazon.smithy.utils.SmithyInternalApi;
+
+/**
+ * Shared base for the member serializer and deserializer generators, holding the
+ * schema-location logic that is identical between the two directions.
+ */
+@SmithyInternalApi
+abstract class AbstractMemberGenerator extends ShapeVisitor.DataShapeVisitor<Void> {
+
+    protected final GenerationContext context;
+    protected final PythonWriter writer;
+    protected final MemberShape member;
+
+    AbstractMemberGenerator(GenerationContext context, PythonWriter writer, MemberShape member) {
+        this.context = context;
+        this.writer = writer;
+        this.member = member;
+    }
+
+    /** A list/map member reaches its schema through the container's element schema. */
+    protected void writeSchema() {
+        var parent = context.model().expectShape(member.getContainer());
+        if (parent.isListShape()) {
+            writer.writeInline("member_schema");
+        } else if (parent.isMapShape()) {
+            writer.writeInline("value_schema");
+        } else {
+            writer.writeInline("members[$L]", Integer.toString(memberIndex(parent)));
+        }
+    }
+
+    protected int memberIndex(Shape parent) {
+        int index = 0;
+        for (var m : parent.members()) {
+            if (m.getMemberName().equals(member.getMemberName())) {
+                return index;
+            }
+            index++;
+        }
+        throw new CodegenException("Member not found in container: " + member.getId());
+    }
+}

codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/ListGenerator.java

@@ -42,7 +42,7 @@ private void generateSerializer() {
         var memberTarget = context.model().expectShape(shape.getMember().getTarget());
         writer.write("""
                 def $1L(serializer: $2T, schema: $3T, value: $4T) -> None:
-                    member_schema = schema.members["member"]
+                    member_schema = schema.members_by_index[0]
                     with serializer.begin_list(schema, len(value)) as ls:
                         for e in value:
                             ${?sparse}
@@ -79,7 +79,7 @@ private void generateDeserializer() {
                 def $1L(deserializer: $2T, schema: $3T) -> $4T:
                     result: $4T = []
                     ${?includeSchema}
-                    member_schema = schema.members["member"]
+                    member_schema = schema.members_by_index[0]
                     ${/includeSchema}
                     def _read_value(d: $2T):
                         if d.is_null():

codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/MapGenerator.java

@@ -46,7 +46,7 @@ private void generateSerializer() {
         writer.write("""
                 def $1L(serializer: $2T, schema: $3T, value: $4T) -> None:
                     with serializer.begin_map(schema, len(value)) as m:
-                        value_schema = schema.members["value"]
+                        value_schema = schema.members_by_index[1]
                         for k, v in value.items():
                             ${?sparse}
                             if v is None:
@@ -80,7 +80,7 @@ private void generateDeserializer() {
         writer.write("""
                 def $1L(deserializer: $2T, schema: $3T) -> $4T:
                     result: $4T = {}
-                    value_schema = schema.members["value"]
+                    value_schema = schema.members_by_index[1]
                     def _read_value(k: str, d: $2T):
                         if d.is_null():
                             d.read_null()

codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/MemberDeserializerGenerator.java

@@ -22,7 +22,6 @@
 import software.amazon.smithy.model.shapes.MapShape;
 import software.amazon.smithy.model.shapes.MemberShape;
 import software.amazon.smithy.model.shapes.Shape;
-import software.amazon.smithy.model.shapes.ShapeVisitor;
 import software.amazon.smithy.model.shapes.ShortShape;
 import software.amazon.smithy.model.shapes.StringShape;
 import software.amazon.smithy.model.shapes.StructureShape;
@@ -38,11 +37,8 @@
  * Generates calls to shape serializers for member shapes.
  */
 @SmithyInternalApi
-public class MemberDeserializerGenerator extends ShapeVisitor.DataShapeVisitor<Void> {
+public class MemberDeserializerGenerator extends AbstractMemberGenerator {
 
-    private final GenerationContext context;
-    private final PythonWriter writer;
-    private final MemberShape member;
     private final String deserializerName;
 
     public MemberDeserializerGenerator(
@@ -51,9 +47,7 @@ public MemberDeserializerGenerator(
             MemberShape member,
             String deserializerName
     ) {
-        this.context = context;
-        this.writer = writer;
-        this.member = member;
+        super(context, writer, member);
         this.deserializerName = deserializerName;
     }
 
@@ -88,17 +82,6 @@ private void writeDeserializer(String shapeTypeName) {
         //writer.popState();
     }
 
-    private void writeSchema() {
-        var parent = context.model().expectShape(member.getContainer());
-        if (parent.isListShape()) {
-            writer.writeInline("member_schema");
-        } else if (parent.isMapShape()) {
-            writer.writeInline("value_schema");
-        } else {
-            writer.writeInline("${schema:T}.members[${member:S}]");
-        }
-    }
-
     @Override
     public Void blobShape(BlobShape shape) {
         if (shape.hasTrait(StreamingTrait.class)) {

codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/MemberSerializerGenerator.java

@@ -5,7 +5,6 @@
 package software.amazon.smithy.python.codegen.generators;
 
 import java.util.Locale;
-import java.util.logging.Logger;
 import software.amazon.smithy.codegen.core.CodegenException;
 import software.amazon.smithy.model.shapes.BigDecimalShape;
 import software.amazon.smithy.model.shapes.BigIntegerShape;
@@ -23,7 +22,6 @@
 import software.amazon.smithy.model.shapes.MapShape;
 import software.amazon.smithy.model.shapes.MemberShape;
 import software.amazon.smithy.model.shapes.Shape;
-import software.amazon.smithy.model.shapes.ShapeVisitor;
 import software.amazon.smithy.model.shapes.ShortShape;
 import software.amazon.smithy.model.shapes.StringShape;
 import software.amazon.smithy.model.shapes.StructureShape;
@@ -39,13 +37,8 @@
  * Generates calls to shape serializers for member shapes.
  */
 @SmithyInternalApi
-public final class MemberSerializerGenerator extends ShapeVisitor.DataShapeVisitor<Void> {
+public final class MemberSerializerGenerator extends AbstractMemberGenerator {
 
-    private static final Logger LOGGER = Logger.getLogger(MemberSerializerGenerator.class.getName());
-
-    private final GenerationContext context;
-    private final PythonWriter writer;
-    private final MemberShape member;
     private final String serializerName;
 
     public MemberSerializerGenerator(
@@ -54,9 +47,7 @@ public MemberSerializerGenerator(
             MemberShape member,
             String serializerName
     ) {
-        this.context = context;
-        this.writer = writer;
-        this.member = member;
+        super(context, writer, member);
         this.serializerName = serializerName;
     }
 
@@ -95,17 +86,6 @@ private void writeSerializer(String typeName) {
 
     }
 
-    private void writeSchema() {
-        var parent = context.model().expectShape(member.getContainer());
-        if (parent.isListShape()) {
-            writer.writeInline("member_schema");
-        } else if (parent.isMapShape()) {
-            writer.writeInline("value_schema");
-        } else {
-            writer.writeInline("${schema:T}.members[${member:S}]");
-        }
-    }
-
     @Override
     public Void blobShape(BlobShape shape) {
         if (shape.hasTrait(StreamingTrait.class)) {

codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/OperationGenerator.java

@@ -50,31 +50,23 @@ public void run() {
                 $1L = $2T(
                         input = $3T,
                         output = $4T,
-                        schema = $5T,
-                        input_schema = $6T,
-                        output_schema = $7T,
-                        error_registry = $8T({
-                            $9C
+                        static_schema = $5T,
+                        error_registry = $6T({
+                            $7C
                         }),
                         effective_auth_schemes = [
-                            ${10C}
+                            ${8C}
                         ],
-                        error_schemas = [
-                            ${11C}
-                        ]
                 )
                 """,
                 opSymbol.getName(),
                 RuntimeTypes.API_OPERATION,
                 inSymbol,
                 outSymbol,
                 opSymbol.expectProperty(SymbolProperties.SCHEMA),
-                inSymbol.expectProperty(SymbolProperties.SCHEMA),
-                outSymbol.expectProperty(SymbolProperties.SCHEMA),
                 RuntimeTypes.TYPE_REGISTRY,
                 writer.consumer(this::writeErrorTypeRegistry),
-                writer.consumer(this::writeAuthSchemes),
-                writer.consumer(this::writeErrorSchemas));
+                writer.consumer(this::writeAuthSchemes));
     }
 
     private void writeErrorTypeRegistry(PythonWriter writer) {
@@ -85,13 +77,6 @@ private void writeErrorTypeRegistry(PythonWriter writer) {
         }
     }
 
-    private void writeErrorSchemas(PythonWriter writer) {
-        for (var error : shape.getErrors()) {
-            var errSymbol = symbolProvider.toSymbol(model.expectShape(error));
-            writer.write("$T,", errSymbol.expectProperty(SymbolProperties.SCHEMA));
-        }
-    }
-
     private void writeAuthSchemes(PythonWriter writer) {
         var authSchemes = ServiceIndex.of(model)
                 .getEffectiveAuthSchemes(context.settings().service(),