Add documentation and metadata fields to EndpointManifest

examples/src/main/java/my/restate/sdk/examples/Counter.java

@@ -19,31 +19,36 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
+/** Counter virtual object */
 @VirtualObject(name = "Counter")
 public class Counter {
 
   private static final Logger LOG = LogManager.getLogger(Counter.class);
 
   private static final StateKey<Long> TOTAL = StateKey.of("total", JsonSerdes.LONG);
 
+  /** Reset the counter. */
   @Handler
   public void reset(ObjectContext ctx) {
     ctx.clearAll();
   }
 
+  /** Add the given value to the count. */
   @Handler
   public void add(ObjectContext ctx, long request) {
     long currentValue = ctx.get(TOTAL).orElse(0L);
     long newValue = currentValue + request;
     ctx.set(TOTAL, newValue);
   }
 
+  /** Get the current counter value. */
   @Shared
   @Handler
   public long get(SharedObjectContext ctx) {
     return ctx.get(TOTAL).orElse(0L);
   }
 
+  /** Add a value, and get both the previous value and the new value. */
   @Handler
   public CounterUpdateResult getAndAdd(ObjectContext ctx, long request) {
     LOG.info("Invoked get and add with {}", request);

sdk-api-gen-common/src/main/java/dev/restate/sdk/gen/model/Handler.java

@@ -18,18 +18,21 @@ public class Handler {
   private final @Nullable String inputAccept;
   private final PayloadType inputType;
   private final PayloadType outputType;
+  private final @Nullable String documentation;
 
   public Handler(
       CharSequence name,
       HandlerType handlerType,
       @Nullable String inputAccept,
       PayloadType inputType,
-      PayloadType outputType) {
+      PayloadType outputType,
+      @Nullable String documentation) {
     this.name = name;
     this.handlerType = handlerType;
     this.inputAccept = inputAccept;
     this.inputType = inputType;
     this.outputType = outputType;
+    this.documentation = documentation;
   }
 
   public CharSequence getName() {
@@ -40,6 +43,7 @@ public HandlerType getHandlerType() {
     return handlerType;
   }
 
+  @Nullable
   public String getInputAccept() {
     return inputAccept;
   }
@@ -52,6 +56,10 @@ public PayloadType getOutputType() {
     return outputType;
   }
 
+  public @Nullable String getDocumentation() {
+    return documentation;
+  }
+
   public static Builder builder() {
     return new Builder();
   }
@@ -62,6 +70,7 @@ public static class Builder {
     private String inputAccept;
     private PayloadType inputType;
     private PayloadType outputType;
+    private String documentation;
 
     public Builder withName(CharSequence name) {
       this.name = name;
@@ -88,6 +97,11 @@ public Builder withOutputType(PayloadType outputType) {
       return this;
     }
 
+    public Builder withDocumentation(String documentation) {
+      this.documentation = documentation;
+      return this;
+    }
+
     public CharSequence getName() {
       return name;
     }
@@ -117,7 +131,8 @@ public Handler validateAndBuild() {
           Objects.requireNonNull(handlerType),
           inputAccept,
           inputType,
-          outputType);
+          outputType,
+          documentation);
     }
   }
 }

sdk-api-gen-common/src/main/java/dev/restate/sdk/gen/model/Service.java

@@ -14,6 +14,7 @@
 import java.util.List;
 import java.util.Objects;
 import java.util.stream.Collectors;
+import org.jspecify.annotations.Nullable;
 
 public class Service {
 
@@ -22,19 +23,22 @@ public class Service {
   private final String serviceName;
   private final ServiceType serviceType;
   private final List<Handler> handlers;
+  private final @Nullable String documentation;
 
   public Service(
       CharSequence targetPkg,
       CharSequence targetFqcn,
       String serviceName,
       ServiceType serviceType,
-      List<Handler> handlers) {
+      List<Handler> handlers,
+      @Nullable String documentation) {
     this.targetPkg = targetPkg;
     this.targetFqcn = targetFqcn;
     this.serviceName = serviceName;
 
     this.serviceType = serviceType;
     this.handlers = handlers;
+    this.documentation = documentation;
   }
 
   public CharSequence getTargetPkg() {
@@ -68,6 +72,10 @@ public List<Handler> getMethods() {
     return handlers;
   }
 
+  public @Nullable String getDocumentation() {
+    return documentation;
+  }
+
   public static Builder builder() {
     return new Builder();
   }
@@ -78,6 +86,7 @@ public static class Builder {
     private String serviceName;
     private ServiceType serviceType;
     private final List<Handler> handlers = new ArrayList<>();
+    private String documentation;
 
     public Builder withTargetPkg(CharSequence targetPkg) {
       this.targetPkg = targetPkg;
@@ -109,6 +118,11 @@ public Builder withHandler(Handler handler) {
       return this;
     }
 
+    public Builder withDocumentation(String documentation) {
+      this.documentation = documentation;
+      return this;
+    }
+
     public CharSequence getTargetPkg() {
       return targetPkg;
     }
@@ -155,7 +169,8 @@ public Service validateAndBuild() {
           Objects.requireNonNull(targetFqcn),
           Objects.requireNonNull(serviceName),
           Objects.requireNonNull(serviceType),
-          handlers);
+          handlers,
+          documentation);
     }
   }
 }

sdk-api-gen-common/src/main/java/dev/restate/sdk/gen/template/HandlebarsTemplateEngine.java

@@ -13,6 +13,7 @@
 import com.github.jknack.handlebars.Template;
 import com.github.jknack.handlebars.context.FieldValueResolver;
 import com.github.jknack.handlebars.helper.StringHelpers;
+import com.github.jknack.handlebars.internal.text.StringEscapeUtils;
 import com.github.jknack.handlebars.io.TemplateLoader;
 import dev.restate.sdk.common.ServiceType;
 import dev.restate.sdk.common.function.ThrowingFunction;
@@ -60,6 +61,7 @@ public HandlebarsTemplateEngine(
           }
           throw new IllegalStateException();
         });
+    handlebars.registerHelpers(StringEscapeUtils.class);
 
     this.templates =
         templates.entrySet().stream()
@@ -104,6 +106,8 @@ static class ServiceTemplateModel {
     public final String generatedClassSimpleNamePrefix;
     public final String generatedClassSimpleName;
     public final String serviceName;
+    public final String documentation;
+
     public final String serviceType;
     public final boolean isWorkflow;
     public final boolean isObject;
@@ -119,6 +123,8 @@ private ServiceTemplateModel(
       this.generatedClassSimpleName = this.generatedClassSimpleNamePrefix + baseTemplateName;
       this.serviceName = inner.getFullyQualifiedServiceName();
 
+      this.documentation = inner.getDocumentation();
+
       this.serviceType = inner.getServiceType().toString();
       this.isWorkflow = inner.getServiceType() == ServiceType.WORKFLOW;
       this.isObject = inner.getServiceType() == ServiceType.VIRTUAL_OBJECT;
@@ -149,6 +155,7 @@ static class HandlerTemplateModel {
 
     private final ServiceType serviceType;
     private final String definitionsClass;
+    public final String documentation;
 
     public final boolean inputEmpty;
     public final String inputFqcn;
@@ -180,6 +187,7 @@ private HandlerTemplateModel(
 
       this.serviceType = serviceType;
       this.definitionsClass = definitionsClass;
+      this.documentation = inner.getDocumentation();
 
       this.inputEmpty = inner.getInputType().isEmpty();
       this.inputFqcn = inner.getInputType().getName();

sdk-api-gen/src/main/java/dev/restate/sdk/gen/ElementConverter.java

@@ -100,6 +100,7 @@ Service fromTypeElement(MetaRestateAnnotation metaAnnotation, TypeElement elemen
           .withTargetPkg(targetPkg)
           .withTargetFqcn(targetFqcn)
           .withServiceName(serviceName)
+          .withDocumentation(sanitizeJavadoc(elements.getDocComment(element)))
           .withServiceType(metaAnnotation.getServiceType())
           .withHandlers(handlers)
           .validateAndBuild();
@@ -181,6 +182,7 @@ private Handler fromExecutableElement(ServiceType serviceType, ExecutableElement
       return new Handler.Builder()
           .withName(element.getSimpleName())
           .withHandlerType(handlerType)
+          .withDocumentation(sanitizeJavadoc(elements.getDocComment(element)))
           .withInputAccept(inputAcceptFromParameterList(element.getParameters()))
           .withInputType(inputPayloadFromParameterList(element.getParameters()))
           .withOutputType(outputPayloadFromExecutableElement(element))
@@ -390,4 +392,10 @@ private static String boxedType(TypeMirror ty) {
         return ty.toString();
     }
   }
+
+  private static String sanitizeJavadoc(String documentation) {
+    // TODO this needs probably a bit more work, but eventually people will use markdown for
+    // javadocs anyway!
+    return documentation == null ? null : documentation.trim().replaceAll("[\t\n\r] *", "\n");
+  }
 }

sdk-api-gen/src/main/resources/templates/ServiceDefinitionFactory.hbs

@@ -15,12 +15,12 @@ public class {{generatedClassSimpleName}} implements dev.restate.sdk.common.sysc
                 {{#if isExclusive}}dev.restate.sdk.common.HandlerType.EXCLUSIVE{{else if isWorkflow}}dev.restate.sdk.common.HandlerType.WORKFLOW{{else}}dev.restate.sdk.common.HandlerType.SHARED{{/if}},
                 {{inputSerdeRef}},
                 {{outputSerdeRef}}
-                ){{#if inputAcceptContentType}}.withAcceptContentType("{{inputAcceptContentType}}"){{/if}},
+                ){{#if inputAcceptContentType}}.withAcceptContentType("{{inputAcceptContentType}}"){{/if}}{{#if documentation}}.withDocumentation("{{escapeJava documentation}}"){{/if}},
                 dev.restate.sdk.HandlerRunner.of(bindableService::{{name}})
                 ){{#unless @last}},{{/unless}}
             {{/handlers}}
             )
-        );
+        ){{#if documentation}}.withDocumentation("{{escapeJava documentation}}"){{/if}};
     }
 
     @java.lang.Override

sdk-common/src/main/java/dev/restate/sdk/common/syscalls/HandlerSpecification.java

@@ -10,6 +10,8 @@
 
 import dev.restate.sdk.common.HandlerType;
 import dev.restate.sdk.common.Serde;
+import java.util.Collections;
+import java.util.Map;
 import java.util.Objects;
 import org.jspecify.annotations.Nullable;
 
@@ -20,23 +22,30 @@ public final class HandlerSpecification<REQ, RES> {
   private final @Nullable String acceptContentType;
   private final Serde<REQ> requestSerde;
   private final Serde<RES> responseSerde;
+  private final @Nullable String documentation;
+  private final Map<String, String> metadata;
 
   HandlerSpecification(
       String name,
       HandlerType handlerType,
       @Nullable String acceptContentType,
       Serde<REQ> requestSerde,
-      Serde<RES> responseSerde) {
+      Serde<RES> responseSerde,
+      @Nullable String documentation,
+      Map<String, String> metadata) {
     this.name = name;
     this.handlerType = handlerType;
     this.acceptContentType = acceptContentType;
     this.requestSerde = requestSerde;
     this.responseSerde = responseSerde;
+    this.documentation = documentation;
+    this.metadata = metadata;
   }
 
   public static <T, R> HandlerSpecification<T, R> of(
       String method, HandlerType handlerType, Serde<T> requestSerde, Serde<R> responseSerde) {
-    return new HandlerSpecification<>(method, handlerType, null, requestSerde, responseSerde);
+    return new HandlerSpecification<>(
+        method, handlerType, null, requestSerde, responseSerde, null, Collections.emptyMap());
   }
 
   public String getName() {
@@ -59,32 +68,47 @@ public Serde<RES> getResponseSerde() {
     return responseSerde;
   }
 
+  public @Nullable String getDocumentation() {
+    return documentation;
+  }
+
+  public Map<String, String> getMetadata() {
+    return metadata;
+  }
+
   public HandlerSpecification<REQ, RES> withAcceptContentType(String acceptContentType) {
     return new HandlerSpecification<>(
-        name, handlerType, acceptContentType, requestSerde, responseSerde);
+        name, handlerType, acceptContentType, requestSerde, responseSerde, documentation, metadata);
+  }
+
+  public HandlerSpecification<REQ, RES> withDocumentation(@Nullable String documentation) {
+    return new HandlerSpecification<>(
+        name, handlerType, acceptContentType, requestSerde, responseSerde, documentation, metadata);
+  }
+
+  public HandlerSpecification<REQ, RES> withMetadata(Map<String, String> metadata) {
+    return new HandlerSpecification<>(
+        name, handlerType, acceptContentType, requestSerde, responseSerde, documentation, metadata);
   }
 
   @Override
   public boolean equals(Object o) {
     if (this == o) return true;
-    if (o == null || getClass() != o.getClass()) return false;
-
+    if (!(o instanceof HandlerSpecification)) return false;
     HandlerSpecification<?, ?> that = (HandlerSpecification<?, ?>) o;
     return Objects.equals(name, that.name)
         && handlerType == that.handlerType
         && Objects.equals(acceptContentType, that.acceptContentType)
         && Objects.equals(requestSerde, that.requestSerde)
-        && Objects.equals(responseSerde, that.responseSerde);
+        && Objects.equals(responseSerde, that.responseSerde)
+        && Objects.equals(documentation, that.documentation)
+        && Objects.equals(metadata, that.metadata);
   }
 
   @Override
   public int hashCode() {
-    int result = Objects.hashCode(name);
-    result = 31 * result + Objects.hashCode(handlerType);
-    result = 31 * result + Objects.hashCode(acceptContentType);
-    result = 31 * result + Objects.hashCode(requestSerde);
-    result = 31 * result + Objects.hashCode(responseSerde);
-    return result;
+    return Objects.hash(
+        name, handlerType, acceptContentType, requestSerde, responseSerde, documentation, metadata);
   }
 
   @Override
@@ -102,6 +126,10 @@ public String toString() {
         + requestSerde.contentType()
         + ", responseContentType="
         + responseSerde.contentType()
+        + ", documentation="
+        + documentation
+        + ", metadata="
+        + metadata
         + '}';
   }
 }