Add details in Metadata extraction problem

Closes #200

Author: ArtDu

CHANGELOG.md

@@ -2,9 +2,10 @@
 
 ## [Unreleased]
 - Remove config request timeout as default parameter in crud client
+- Add details for the case of space metadata fetching failure ([#200](https://github.com/tarantool/cartridge-java/issues/200))
 - Close public access to TarantoolResult*Impl ([#326](https://github.com/tarantool/cartridge-java/issues/326))
 - Split retrying into more detailed modules ([#341](https://github.com/tarantool/cartridge-java/issues/341))
-- Add deep copy instead of shallow copy in default message pack mapper
+- Add deep copy instead of shallow copy in default message pack mapper ([#166](https://github.com/tarantool/cartridge-java/issues/166))
 - Add a factory builder for constructing mapper hierarchies
 
 ## [0.10.1] - 2023-01-13

src/main/java/io/tarantool/driver/core/metadata/DDLTarantoolSpaceMetadataConverter.java

@@ -6,11 +6,13 @@
 import io.tarantool.driver.api.metadata.TarantoolIndexType;
 import io.tarantool.driver.api.metadata.TarantoolMetadataContainer;
 import io.tarantool.driver.exceptions.TarantoolClientException;
+import io.tarantool.driver.exceptions.TarantoolEmptyMetadataException;
 import io.tarantool.driver.mappers.converters.ValueConverter;
 import org.msgpack.value.ArrayValue;
 import org.msgpack.value.StringValue;
 import org.msgpack.value.Value;
 import org.msgpack.value.ValueFactory;
+import org.msgpack.value.ValueType;
 
 import java.util.HashMap;
 import java.util.List;
@@ -59,7 +61,11 @@ private DDLTarantoolSpaceMetadataConverter() {
     public TarantoolMetadataContainer fromValue(Value value) {
 
         if (!value.isMapValue()) {
-            throw new TarantoolClientException("Unsupported space metadata format: expected map");
+            if (value.getValueType().equals(ValueType.ARRAY) && value.asArrayValue().size() == 0) {
+                throw new TarantoolEmptyMetadataException();
+            }
+            throw new TarantoolClientException("Unsupported space metadata format: expected map, got %s",
+                value.getValueType());
         }
 
         Map<Value, Value> spacesMap = value.asMapValue().map();

src/main/java/io/tarantool/driver/core/metadata/TarantoolMetadata.java

@@ -1,10 +1,14 @@
 package io.tarantool.driver.core.metadata;
 
+import io.tarantool.driver.api.TarantoolClient;
 import io.tarantool.driver.api.metadata.TarantoolIndexMetadata;
 import io.tarantool.driver.api.metadata.TarantoolMetadataOperations;
 import io.tarantool.driver.api.metadata.TarantoolMetadataProvider;
 import io.tarantool.driver.api.metadata.TarantoolSpaceMetadata;
 import io.tarantool.driver.exceptions.TarantoolClientException;
+import io.tarantool.driver.exceptions.TarantoolEmptyMetadataException;
+import io.tarantool.driver.exceptions.TarantoolFunctionCallException;
+import io.tarantool.driver.exceptions.TarantoolMetadataRequestException;
 import io.tarantool.driver.exceptions.TarantoolNoSuchProcedureException;
 import io.tarantool.driver.utils.Assert;
 
@@ -97,6 +101,9 @@ private CompletableFuture<Void> populateMetadata() {
         CompletableFuture<Void> result = new CompletableFuture<>();
         try {
             result = metadataProvider.getMetadata().thenAccept(container -> {
+                if (container == null) {
+                    throw new TarantoolEmptyMetadataException();
+                }
                 spaceMetadataByName.clear();
                 spaceMetadataById.clear();
                 indexMetadataBySpaceName.clear();

src/main/java/io/tarantool/driver/exceptions/TarantoolEmptyMetadataException.java

@@ -0,0 +1,14 @@
+package io.tarantool.driver.exceptions;
+
+/**
+ * The exception occurs when no metadata returned by proxy function when expected something
+ *
+ * @author Artyom Dubinin
+ */
+public class TarantoolEmptyMetadataException extends TarantoolClientException {
+    private static final String message = "No space metadata returned";
+
+    public TarantoolEmptyMetadataException() {
+        super(message);
+    }
+}

src/test/java/io/tarantool/driver/integration/TarantoolErrorsIT.java

@@ -7,9 +7,14 @@
 import io.tarantool.driver.core.ProxyTarantoolTupleClient;
 import io.tarantool.driver.exceptions.TarantoolAccessDeniedException;
 import io.tarantool.driver.exceptions.TarantoolClientException;
+import io.tarantool.driver.exceptions.TarantoolEmptyMetadataException;
+import io.tarantool.driver.exceptions.TarantoolFunctionCallException;
 import io.tarantool.driver.exceptions.TarantoolInternalException;
 import io.tarantool.driver.exceptions.TarantoolInternalNetworkException;
+import io.tarantool.driver.exceptions.TarantoolMetadataRequestException;
 import io.tarantool.driver.exceptions.TarantoolNoSuchProcedureException;
+import io.tarantool.driver.exceptions.TarantoolSpaceNotFoundException;
+
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 
@@ -213,4 +218,40 @@ void test_should_throwTarantoolAccessDenied_ifUserHasRestrictions() {
         assertTrue(cause.getMessage()
             .contains("Execute access to function 'ddl.get_schema' is denied for user 'restricted_user'"));
     }
+
+    @Test
+    void test_failedToRefreshMetadata_shouldHasReasonOfException_ifDdlReturnNull() {
+        ProxyTarantoolTupleClient adminClient = setupAdminClient();
+
+        adminClient.eval("true_ddl = ddl; " +
+                             "ddl = {get_schema = function() return nil end}").join();
+
+        TarantoolClientException exception = assertThrows(TarantoolClientException.class,
+            () -> adminClient.space("test_space").select(Conditions.any()));
+        assertEquals("Failed to refresh spaces and indexes metadata", exception.getMessage());
+        Throwable cause = exception.getCause();
+        assertEquals(TarantoolEmptyMetadataException.class, cause.getClass());
+        assertEquals("No space metadata returned", cause.getMessage());
+        adminClient.eval("ddl = true_ddl").join();
+    }
+
+    @Test
+    void test_failedToRefreshMetadata_shouldHasReasonOfException_ifDdlReturnEmptyTable() {
+        ProxyTarantoolTupleClient adminClient = setupAdminClient();
+
+        adminClient.eval("true_ddl = ddl; " +
+                             "ddl = {get_schema = function() return {} end}").join();
+
+        TarantoolClientException exception = assertThrows(TarantoolClientException.class,
+            () -> adminClient.space("test_space").select(Conditions.any()));
+        assertEquals("Failed to refresh spaces and indexes metadata", exception.getMessage());
+        Throwable cause = exception.getCause();
+        assertEquals(TarantoolMetadataRequestException.class, cause.getClass());
+        cause = cause.getCause();
+        assertEquals(CompletionException.class, cause.getClass());
+        cause = cause.getCause();
+        assertEquals(TarantoolEmptyMetadataException.class, cause.getClass());
+        assertEquals("No space metadata returned", cause.getMessage());
+        adminClient.eval("ddl = true_ddl").join();
+    }
 }