Add isConsistentReadGuaranteed() to StorageInfo

core/src/integration-test/java/com/scalar/db/storage/cassandra/CassandraMutationAtomicityUnitIntegrationTest.java → core/src/integration-test/java/com/scalar/db/storage/cassandra/CassandraAtomicityUnitIntegrationTest.java

@@ -1,12 +1,12 @@
 package com.scalar.db.storage.cassandra;
 
-import com.scalar.db.api.DistributedStorageMutationAtomicityUnitIntegrationTestBase;
+import com.scalar.db.api.DistributedStorageAtomicityUnitIntegrationTestBase;
 import java.util.Collections;
 import java.util.Map;
 import java.util.Properties;
 
-public class CassandraMutationAtomicityUnitIntegrationTest
-    extends DistributedStorageMutationAtomicityUnitIntegrationTestBase {
+public class CassandraAtomicityUnitIntegrationTest
+    extends DistributedStorageAtomicityUnitIntegrationTestBase {
 
   @Override
   protected Properties getProperties(String testName) {

core/src/integration-test/java/com/scalar/db/storage/cosmos/CosmosMutationAtomicityUnitIntegrationTest.java → core/src/integration-test/java/com/scalar/db/storage/cosmos/CosmosAtomicityUnitIntegrationTest.java

@@ -1,12 +1,12 @@
 package com.scalar.db.storage.cosmos;
 
-import com.scalar.db.api.DistributedStorageMutationAtomicityUnitIntegrationTestBase;
+import com.scalar.db.api.DistributedStorageAtomicityUnitIntegrationTestBase;
 import java.util.Map;
 import java.util.Properties;
 import org.junit.jupiter.api.Disabled;
 
-public class CosmosMutationAtomicityUnitIntegrationTest
-    extends DistributedStorageMutationAtomicityUnitIntegrationTestBase {
+public class CosmosAtomicityUnitIntegrationTest
+    extends DistributedStorageAtomicityUnitIntegrationTestBase {
 
   @Override
   protected Properties getProperties(String testName) {
@@ -20,6 +20,5 @@ protected Map<String, String> getCreationOptions() {
 
   @Disabled("This test fails. It might be a bug")
   @Override
-  public void
-      mutate_MutationsWithinRecordGiven_ShouldBehaveCorrectlyBaseOnMutationAtomicityUnit() {}
+  public void mutate_MutationsWithinRecordGiven_ShouldBehaveCorrectlyBaseOnAtomicityUnit() {}
 }

core/src/integration-test/java/com/scalar/db/storage/dynamo/DynamoMutationAtomicityUnitIntegrationTest.java → core/src/integration-test/java/com/scalar/db/storage/dynamo/DynamoAtomicityUnitIntegrationTest.java

@@ -1,12 +1,12 @@
 package com.scalar.db.storage.dynamo;
 
-import com.scalar.db.api.DistributedStorageMutationAtomicityUnitIntegrationTestBase;
+import com.scalar.db.api.DistributedStorageAtomicityUnitIntegrationTestBase;
 import java.util.Map;
 import java.util.Properties;
 import org.junit.jupiter.api.Disabled;
 
-public class DynamoMutationAtomicityUnitIntegrationTest
-    extends DistributedStorageMutationAtomicityUnitIntegrationTestBase {
+public class DynamoAtomicityUnitIntegrationTest
+    extends DistributedStorageAtomicityUnitIntegrationTestBase {
 
   @Override
   protected Properties getProperties(String testName) {
@@ -20,6 +20,5 @@ protected Map<String, String> getCreationOptions() {
 
   @Disabled("Transaction request cannot include multiple operations on one item in DynamoDB")
   @Override
-  public void
-      mutate_MutationsWithinRecordGiven_ShouldBehaveCorrectlyBaseOnMutationAtomicityUnit() {}
+  public void mutate_MutationsWithinRecordGiven_ShouldBehaveCorrectlyBaseOnAtomicityUnit() {}
 }

core/src/integration-test/java/com/scalar/db/storage/jdbc/JdbcDatabaseAtomicityUnitIntegrationTest.java

@@ -0,0 +1,13 @@
+package com.scalar.db.storage.jdbc;
+
+import com.scalar.db.api.DistributedStorageAtomicityUnitIntegrationTestBase;
+import java.util.Properties;
+
+public class JdbcDatabaseAtomicityUnitIntegrationTest
+    extends DistributedStorageAtomicityUnitIntegrationTestBase {
+
+  @Override
+  protected Properties getProperties(String testName) {
+    return JdbcEnv.getProperties(testName);
+  }
+}

core/src/integration-test/java/com/scalar/db/storage/multistorage/MultiStorageMutationAtomicityUnitIntegrationTest.java → core/src/integration-test/java/com/scalar/db/storage/multistorage/MultiStorageAtomicityUnitIntegrationTest.java

@@ -2,7 +2,7 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-import com.scalar.db.api.DistributedStorageMutationAtomicityUnitIntegrationTestBase;
+import com.scalar.db.api.DistributedStorageAtomicityUnitIntegrationTestBase;
 import com.scalar.db.api.Put;
 import com.scalar.db.config.DatabaseConfig;
 import com.scalar.db.exception.storage.ExecutionException;
@@ -12,8 +12,8 @@
 import org.assertj.core.api.Assertions;
 import org.junit.jupiter.api.Test;
 
-public class MultiStorageMutationAtomicityUnitIntegrationTest
-    extends DistributedStorageMutationAtomicityUnitIntegrationTestBase {
+public class MultiStorageAtomicityUnitIntegrationTest
+    extends DistributedStorageAtomicityUnitIntegrationTestBase {
 
   @Override
   public Properties getProperties(String testName) {
@@ -61,7 +61,7 @@ public Properties getProperties(String testName) {
   }
 
   @Test
-  public void mutate_MutationsAcrossStorageGiven_ShouldBehaveCorrectlyBaseOnMutationAtomicityUnit()
+  public void mutate_MutationsAcrossStorageGiven_ShouldBehaveCorrectlyBaseOnAtomicityUnit()
       throws ExecutionException {
     // Arrange
     Put put1 =

core/src/integration-test/java/com/scalar/db/storage/objectstorage/ObjectStorageMutationAtomicityUnitIntegrationTest.java

@@ -1,11 +1,11 @@
 package com.scalar.db.storage.objectstorage;
 
-import com.scalar.db.api.DistributedStorageMutationAtomicityUnitIntegrationTestBase;
+import com.scalar.db.api.DistributedStorageAtomicityUnitIntegrationTestBase;
 import java.util.Map;
 import java.util.Properties;
 
 public class ObjectStorageMutationAtomicityUnitIntegrationTest
-    extends DistributedStorageMutationAtomicityUnitIntegrationTestBase {
+    extends DistributedStorageAtomicityUnitIntegrationTestBase {
 
   @Override
   protected Properties getProperties(String testName) {

core/src/main/java/com/scalar/db/api/DistributedStorage.java

@@ -182,10 +182,10 @@ public interface DistributedStorage extends AutoCloseable {
    * Mutates entries of the underlying storage with the specified list of {@link Mutation} commands.
    *
    * <p>Note that this method only supports mutations within the atomicity unit specified by {@link
-   * StorageInfo#getMutationAtomicityUnit()}. For example, if the atomicity unit of the storage is
-   * {@link StorageInfo.MutationAtomicityUnit#PARTITION}, the mutations must occur within the same
-   * partition. Also note that the maximum number of mutations that can be performed atomically is
-   * defined by {@link StorageInfo#getMaxAtomicMutationsCount()}.
+   * StorageInfo#getAtomicityUnit()}. For example, if the atomicity unit of the storage is {@link
+   * StorageInfo.AtomicityUnit#PARTITION}, the mutations must occur within the same partition. Also
+   * note that the maximum number of mutations that can be performed atomically is defined by {@link
+   * StorageInfo#getMaxAtomicMutationsCount()}.
    *
    * <p>To retrieve storage information, use {@link DistributedStorageAdmin#getStorageInfo(String)}.
    *

core/src/main/java/com/scalar/db/api/DistributedStorageAdmin.java

@@ -47,6 +47,9 @@ public interface DistributedStorageAdmin extends Admin, AutoCloseable {
   /**
    * Returns the storage information.
    *
+   * <p>Note: This feature is primarily for internal use. Breaking changes can and will be
+   * introduced to it. Users should not depend on it.
+   *
    * @param namespace the namespace to get the storage information for
    * @return the storage information
    * @throws ExecutionException if the operation fails

core/src/main/java/com/scalar/db/api/StorageInfo.java

@@ -1,5 +1,6 @@
 package com.scalar.db.api;
 
+/** Represents storage information. */
 public interface StorageInfo {
   /**
    * Returns the storage name.
@@ -9,11 +10,11 @@ public interface StorageInfo {
   String getStorageName();
 
   /**
-   * Returns the mutation atomicity unit of the storage.
+   * Returns the atomicity unit of the storage.
    *
-   * @return the mutation atomicity unit of the storage
+   * @return the atomicity unit of the storage
    */
-  MutationAtomicityUnit getMutationAtomicityUnit();
+  AtomicityUnit getAtomicityUnit();
 
   /**
    * Returns the maximum number of mutations that can be performed atomically in the storage.
@@ -23,38 +24,45 @@ public interface StorageInfo {
   int getMaxAtomicMutationsCount();
 
   /**
-   * The mutation atomicity unit of the storage.
+   * Returns whether the storage guarantees consistent reads within its atomicity unit.
    *
-   * <p>This enum defines the atomicity unit for mutations in the storage. It determines the scope
-   * of atomicity for mutations such as put and delete.
+   * @return true if the storage guarantees consistent reads within its atomicity unit, false
+   *     otherwise
    */
-  enum MutationAtomicityUnit {
+  boolean isConsistentReadGuaranteed();
+
+  /**
+   * The atomicity unit of the storage.
+   *
+   * <p>This enum defines the atomicity unit for operations in the storage.
+   */
+  enum AtomicityUnit {
     /**
-     * The atomicity unit is at the record level, meaning that mutations are performed atomically
+     * The atomicity unit is at the record level, meaning that operations are performed atomically
      * for each record.
      */
     RECORD,
 
     /**
-     * The atomicity unit is at the partition level, meaning that mutations are performed atomically
-     * for each partition.
+     * The atomicity unit is at the partition level, meaning that operations are performed
+     * atomically for each partition.
      */
     PARTITION,
 
     /**
-     * The atomicity unit is at the table level, meaning that mutations are performed atomically for
-     * each table.
+     * The atomicity unit is at the table level, meaning that operations are performed atomically
+     * for each table.
      */
     TABLE,
 
     /**
-     * The atomicity unit is at the namespace level, meaning that mutations are performed atomically
-     * for each namespace.
+     * The atomicity unit is at the namespace level, meaning that operations are performed
+     * atomically for each namespace.
      */
     NAMESPACE,
 
     /**
-     * The atomicity unit is at the storage level, meaning that mutations are performed atomically
+     * The atomicity unit is at the storage level, meaning that operations are performed atomically
      * for the entire storage.
      */
     STORAGE

core/src/main/java/com/scalar/db/common/CommonDistributedStorageAdmin.java

@@ -513,23 +513,23 @@ public void createVirtualTable(
       Map<String, String> options)
       throws ExecutionException {
     StorageInfo storageInfo = getStorageInfo(leftSourceNamespace);
-    switch (storageInfo.getMutationAtomicityUnit()) {
+    switch (storageInfo.getAtomicityUnit()) {
       case STORAGE:
         break;
       case NAMESPACE:
         if (!leftSourceNamespace.equals(rightSourceNamespace)) {
           throw new IllegalArgumentException(
               CoreError.VIRTUAL_TABLE_SOURCE_TABLES_OUTSIDE_OF_ATOMICITY_UNIT.buildMessage(
                   storageInfo.getStorageName(),
-                  storageInfo.getMutationAtomicityUnit(),
+                  storageInfo.getAtomicityUnit(),
                   ScalarDbUtils.getFullTableName(leftSourceNamespace, leftSourceTable),
                   ScalarDbUtils.getFullTableName(rightSourceNamespace, rightSourceTable)));
         }
         break;
       default:
         throw new UnsupportedOperationException(
             CoreError.VIRTUAL_TABLE_NOT_SUPPORTED_IN_STORAGE.buildMessage(
-                storageInfo.getStorageName(), storageInfo.getMutationAtomicityUnit()));
+                storageInfo.getStorageName(), storageInfo.getAtomicityUnit()));
     }
 
     if (!namespaceExists(namespace)) {

core/src/main/java/com/scalar/db/common/StorageInfoImpl.java

@@ -9,16 +9,19 @@
 public class StorageInfoImpl implements StorageInfo {
 
   private final String storageName;
-  private final MutationAtomicityUnit mutationAtomicityUnit;
+  private final AtomicityUnit atomicityUnit;
   private final int maxAtomicMutationsCount;
+  private final boolean consistentReadGuaranteed;
 
   public StorageInfoImpl(
       String storageName,
-      MutationAtomicityUnit mutationAtomicityUnit,
-      int maxAtomicMutationsCount) {
+      AtomicityUnit atomicityUnit,
+      int maxAtomicMutationsCount,
+      boolean consistentReadGuaranteed) {
     this.storageName = storageName;
-    this.mutationAtomicityUnit = mutationAtomicityUnit;
+    this.atomicityUnit = atomicityUnit;
     this.maxAtomicMutationsCount = maxAtomicMutationsCount;
+    this.consistentReadGuaranteed = consistentReadGuaranteed;
   }
 
   @Override
@@ -27,15 +30,20 @@ public String getStorageName() {
   }
 
   @Override
-  public MutationAtomicityUnit getMutationAtomicityUnit() {
-    return mutationAtomicityUnit;
+  public AtomicityUnit getAtomicityUnit() {
+    return atomicityUnit;
   }
 
   @Override
   public int getMaxAtomicMutationsCount() {
     return maxAtomicMutationsCount;
   }
 
+  @Override
+  public boolean isConsistentReadGuaranteed() {
+    return consistentReadGuaranteed;
+  }
+
   @Override
   public boolean equals(Object o) {
     if (this == o) {
@@ -47,20 +55,26 @@ public boolean equals(Object o) {
     StorageInfoImpl that = (StorageInfoImpl) o;
     return getMaxAtomicMutationsCount() == that.getMaxAtomicMutationsCount()
         && Objects.equals(getStorageName(), that.getStorageName())
-        && getMutationAtomicityUnit() == that.getMutationAtomicityUnit();
+        && getAtomicityUnit() == that.getAtomicityUnit()
+        && isConsistentReadGuaranteed() == that.isConsistentReadGuaranteed();
   }
 
   @Override
   public int hashCode() {
-    return Objects.hash(getStorageName(), getMutationAtomicityUnit(), getMaxAtomicMutationsCount());
+    return Objects.hash(
+        getStorageName(),
+        getAtomicityUnit(),
+        getMaxAtomicMutationsCount(),
+        isConsistentReadGuaranteed());
   }
 
   @Override
   public String toString() {
     return MoreObjects.toStringHelper(this)
         .add("storageName", storageName)
-        .add("mutationAtomicityUnit", mutationAtomicityUnit)
+        .add("atomicityUnit", atomicityUnit)
         .add("maxAtomicMutationsCount", maxAtomicMutationsCount)
+        .add("consistentReadGuaranteed", consistentReadGuaranteed)
         .toString();
   }
 }

core/src/main/java/com/scalar/db/common/checker/OperationChecker.java

@@ -373,7 +373,7 @@ private boolean isOutOfAtomicityUnit(
         && mutation2.forNamespace().isPresent()
         && mutation2.forTable().isPresent();
 
-    switch (storageInfo1.getMutationAtomicityUnit()) {
+    switch (storageInfo1.getAtomicityUnit()) {
       case RECORD:
         if (!mutation1.getClusteringKey().equals(mutation2.getClusteringKey())) {
           return true; // Different clustering keys
@@ -402,16 +402,15 @@ private boolean isOutOfAtomicityUnit(
         }
         break;
       default:
-        throw new AssertionError(
-            "Unknown mutation atomicity unit: " + storageInfo1.getMutationAtomicityUnit());
+        throw new AssertionError("Unknown atomicity unit: " + storageInfo1.getAtomicityUnit());
     }
 
     return false;
   }
 
   private String getErrorMessageForOutOfAtomicityUnit(
       StorageInfo storageInfo, List<? extends Mutation> mutations) {
-    switch (storageInfo.getMutationAtomicityUnit()) {
+    switch (storageInfo.getAtomicityUnit()) {
       case RECORD:
         return CoreError.OPERATION_CHECK_ERROR_MULTI_RECORD_MUTATION.buildMessage(
             storageInfo.getStorageName(), mutations);
@@ -427,8 +426,7 @@ private String getErrorMessageForOutOfAtomicityUnit(
       case STORAGE:
         return CoreError.OPERATION_CHECK_ERROR_MULTI_STORAGE_MUTATION.buildMessage(mutations);
       default:
-        throw new AssertionError(
-            "Unknown mutation atomicity unit: " + storageInfo.getMutationAtomicityUnit());
+        throw new AssertionError("Unknown atomicity unit: " + storageInfo.getAtomicityUnit());
     }
   }
 

core/src/main/java/com/scalar/db/storage/cassandra/CassandraAdmin.java

@@ -55,9 +55,10 @@ public class CassandraAdmin implements DistributedStorageAdmin {
   private static final StorageInfo STORAGE_INFO =
       new StorageInfoImpl(
           "cassandra",
-          StorageInfo.MutationAtomicityUnit.PARTITION,
+          StorageInfo.AtomicityUnit.PARTITION,
           // No limit on the number of mutations
-          Integer.MAX_VALUE);
+          Integer.MAX_VALUE,
+          true);
 
   private final ClusterManager clusterManager;
   private final String metadataKeyspace;