Merge pull request #11 from nfl/hash_size

BACKEND-2482: Documented the default hash size (and broke it out into

src/main/java/com/nfl/dm/shield/dynamic/config/HashConfig.java

@@ -0,0 +1,15 @@
+package com.nfl.dm.shield.dynamic.config;
+
+/**
+ * In order to get even distribution of hash codes (avoiding linear performance O(n)), it is best to initialize to
+ * a prime number.  As a hash table grows, one default algorithm increases size by 2n + 1.  Sun developers initially
+ * chose 101 as the default number.  However, the growth characteristics of 101 are not as good as other selections.
+ *
+ * The book Java 2 Performance and Idiom Guide on page 73 offers the following as optimal initial bucket size:
+ * 89, 179, 359, 719, 1439, 2879, 11519, 23029, 737279, 1474559, 2949119.
+ *
+ * We have chosen 89 as the starting place for all hash tables.
+ */
+public final class HashConfig {
+    public static final int DEFAULT_HASH_TABLE_SIZE = 89;
+}

src/main/java/com/nfl/dm/shield/dynamic/domain/instance/SchemaInstance.java

@@ -2,6 +2,8 @@
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 
+import static com.nfl.dm.shield.dynamic.config.HashConfig.*;
+
 public class SchemaInstance implements Map<String, Object> {
 
     public static final String ID = "id";
@@ -12,7 +14,7 @@ public class SchemaInstance implements Map<String, Object> {
 
     public static final String UPDATE_DATE_FIELD = "updateDate";
 
-    private Map<String, Object> fieldValues = new ConcurrentHashMap<>(89);
+    private Map<String, Object> fieldValues = new ConcurrentHashMap<>(DEFAULT_HASH_TABLE_SIZE);
 
     private SchemaInstanceKey schemaInstanceKey;
 

src/main/java/com/nfl/dm/shield/dynamic/domain/schema/SchemaDescription.java

@@ -14,6 +14,7 @@
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
+import static com.nfl.dm.shield.dynamic.config.HashConfig.DEFAULT_HASH_TABLE_SIZE;
 import static com.nfl.dm.shield.dynamic.domain.schema.instancefield.SchemaInstanceField.MEMBER_TYPE_FIELD;
 import static graphql.Scalars.GraphQLID;
 import static graphql.Scalars.GraphQLLong;
@@ -63,13 +64,13 @@ public class SchemaDescription {
 
     private IdGeneration idGeneration = IdGeneration.SERVICE_GENERATED_GUID;
 
-    private List<SchemaInstanceField> domainFields = new ArrayList<>(89);
+    private List<SchemaInstanceField> domainFields = new ArrayList<>(DEFAULT_HASH_TABLE_SIZE);
 
-    private List<ValueObjectField> valueDefinitions = new ArrayList<>(89);
+    private List<ValueObjectField> valueDefinitions = new ArrayList<>(DEFAULT_HASH_TABLE_SIZE);
 
     private String memberConfiguration;
 
-    private List<FilterConfiguration> filterConfigurations = new ArrayList<>(89);
+    private List<FilterConfiguration> filterConfigurations = new ArrayList<>(DEFAULT_HASH_TABLE_SIZE);
 
     public SchemaDescription() {
     }
@@ -94,7 +95,7 @@ private void initMembers(Map<String, Object> initValues, InstanceOutputTypeServi
     }
 
     private void initValuesDefinitions(List<Map<String, Object>> valueDefinitions, InstanceOutputTypeService instanceOutputTypeService) {
-        setValueDefinitions(new ArrayList<>(89));
+        setValueDefinitions(new ArrayList<>(DEFAULT_HASH_TABLE_SIZE));
         valueDefinitions.forEach(valueDef -> addValueDefinition(new ValueObjectField(this, valueDef, instanceOutputTypeService)));
     }
 

src/main/java/com/nfl/dm/shield/dynamic/domain/schema/ValueObjectField.java

@@ -10,6 +10,7 @@
 import java.util.List;
 import java.util.Map;
 
+import static com.nfl.dm.shield.dynamic.config.HashConfig.DEFAULT_HASH_TABLE_SIZE;
 import static graphql.Scalars.GraphQLString;
 import static graphql.schema.GraphQLFieldDefinition.newFieldDefinition;
 import static graphql.schema.GraphQLInputObjectField.newInputObjectField;
@@ -24,7 +25,7 @@ public class ValueObjectField {
 
     private String name;
 
-    private List<SchemaInstanceField> valueFields = new ArrayList<>(89);
+    private List<SchemaInstanceField> valueFields = new ArrayList<>(DEFAULT_HASH_TABLE_SIZE);
 
     public ValueObjectField() {
         // For persistence

src/main/java/com/nfl/dm/shield/dynamic/domain/schema/instancefield/ExternalReferenceType.java

@@ -9,6 +9,7 @@
 import java.util.List;
 import java.util.Map;
 
+import static com.nfl.dm.shield.dynamic.config.HashConfig.DEFAULT_HASH_TABLE_SIZE;
 import static graphql.Scalars.GraphQLID;
 import static graphql.Scalars.GraphQLString;
 import static graphql.schema.GraphQLInputObjectField.newInputObjectField;
@@ -55,7 +56,7 @@ public GraphQLOutputType buildInstanceOutputType(InstanceFieldBuilderContext ins
 
     @Override
     Map<String, GraphQLObjectType> buildPossibleTypeMap(List<String> possibleTypes, InstanceFieldBuilderContext instanceFieldBuilderContext, InstanceOutputTypeService instanceOutputTypeService) {
-        Map<String, GraphQLObjectType> retMap = new HashMap<>(89);
+        Map<String, GraphQLObjectType> retMap = new HashMap<>(DEFAULT_HASH_TABLE_SIZE);
         possibleTypes.forEach(possible -> retMap.put(possible,
                 (GraphQLObjectType) instanceOutputTypeService.deriveFromExternalTypeName(possible)));
         return retMap;

src/main/java/com/nfl/dm/shield/dynamic/domain/schema/instancefield/MultiTypeDynamicReferenceType.java

@@ -20,6 +20,7 @@
 import java.util.List;
 import java.util.Map;
 
+import static com.nfl.dm.shield.dynamic.config.HashConfig.DEFAULT_HASH_TABLE_SIZE;
 import static com.nfl.dm.shield.dynamic.domain.BaseKey.SCHEMA_NAME_FIELD;
 import static com.nfl.dm.shield.dynamic.domain.instance.SchemaInstance.SCHEMA_INSTANCE_KEY_FIELD;
 import static graphql.Scalars.GraphQLID;
@@ -60,7 +61,7 @@ public GraphQLOutputType buildInstanceOutputType(InstanceFieldBuilderContext ins
     Map<String, GraphQLObjectType> buildPossibleTypeMap(List<String> possibleTypes,
                                                         InstanceFieldBuilderContext instanceFieldBuilderContext,
                                                         InstanceOutputTypeService instanceOutputTypeService) {
-        Map<String, GraphQLObjectType> retMap = new HashMap<>(89);
+        Map<String, GraphQLObjectType> retMap = new HashMap<>(DEFAULT_HASH_TABLE_SIZE);
         possibleTypes.forEach(possible -> {
             SchemaKey schemaKey = new SchemaKey(possible, instanceFieldBuilderContext.getSchemaNamespace());
             SchemaDescription schemaDescription = instanceOutputTypeService.findSchemaDescriptionByName(schemaKey);

src/main/java/com/nfl/dm/shield/dynamic/domain/schema/instancefield/SchemaInstanceField.java

@@ -13,6 +13,7 @@
 import java.util.*;
 import java.util.stream.Collectors;
 
+import static com.nfl.dm.shield.dynamic.config.HashConfig.DEFAULT_HASH_TABLE_SIZE;
 import static graphql.Scalars.GraphQLString;
 import static graphql.schema.GraphQLEnumType.newEnum;
 import static graphql.schema.GraphQLFieldDefinition.newFieldDefinition;
@@ -46,7 +47,7 @@ public class SchemaInstanceField {
 
     private String otherTypeName = "";
 
-    private List<EnumValueDef> enumValues = new ArrayList<>(89);
+    private List<EnumValueDef> enumValues = new ArrayList<>(DEFAULT_HASH_TABLE_SIZE);
 
     private String serviceKey;
 

src/main/java/com/nfl/dm/shield/dynamic/repository/InMemorySchemaRepository.java

@@ -16,6 +16,7 @@
 import java.util.stream.Stream;
 
 import static com.google.common.collect.Lists.transform;
+import static com.nfl.dm.shield.dynamic.config.HashConfig.DEFAULT_HASH_TABLE_SIZE;
 import static com.nfl.dm.shield.dynamic.domain.instance.SchemaInstance.UPDATE_DATE_FIELD;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.emptyMap;
@@ -25,10 +26,10 @@
 public class InMemorySchemaRepository extends BaseRepositoryImpl
         implements SchemaRepository, SchemaInstanceRepository {
 
-    private final Map<SchemaKey, InMemorySchemaDescriptionHolder> allTheSchemas = new ConcurrentHashMap<>(89);
+    private final Map<SchemaKey, InMemorySchemaDescriptionHolder> allTheSchemas = new ConcurrentHashMap<>(DEFAULT_HASH_TABLE_SIZE);
 
     private final Map<SchemaInstanceKey, Map<String, InMemorySchemaInstanceHolder>> instances
-            = new ConcurrentHashMap<>(89);
+            = new ConcurrentHashMap<>(DEFAULT_HASH_TABLE_SIZE);
 
     public InMemorySchemaRepository() {
     }
@@ -137,7 +138,7 @@ public SchemaInstance upsert(SchemaInstanceKey schemaInstanceKey, SchemaInstance
     }
 
     private Map<String, InMemorySchemaInstanceHolder> initInstance(SchemaInstanceKey schemaInstanceKey) {
-        Map<String, InMemorySchemaInstanceHolder> retMap = new ConcurrentHashMap<>(89);
+        Map<String, InMemorySchemaInstanceHolder> retMap = new ConcurrentHashMap<>(DEFAULT_HASH_TABLE_SIZE);
         instances.put(schemaInstanceKey, retMap);
         return retMap;
     }

src/main/java/com/nfl/dm/shield/dynamic/repository/StubbedExternalReferenceRepository.java

@@ -9,6 +9,7 @@
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 
+import static com.nfl.dm.shield.dynamic.config.HashConfig.DEFAULT_HASH_TABLE_SIZE;
 import static com.nfl.dm.shield.dynamic.domain.schema.instancefield.AbstractReferenceType.REFERENCE_ID;
 import static com.nfl.dm.shield.dynamic.domain.schema.instancefield.AbstractReferenceType.REFERENCE_TYPE;
 import static graphql.Scalars.GraphQLID;
@@ -21,7 +22,7 @@
 public class StubbedExternalReferenceRepository implements ExternalReferenceRepository {
 
     private final Map<String, Map<String, Map<String, Object>>> externalInstances
-            = new ConcurrentHashMap<>(89);
+            = new ConcurrentHashMap<>(DEFAULT_HASH_TABLE_SIZE);
 
     private final Map<String, GraphQLOutputType> outputTypeMap = new ConcurrentHashMap<>(89);
 
@@ -54,7 +55,7 @@ public Map<String, Object> findById(SelectionSet selections, Map<String, String>
 
     public void loadExternalInstance(String typeName, String id, Map<String, Object> instance) {
         if (!externalInstances.containsKey(typeName)) {
-            externalInstances.put(typeName, new HashMap<>(89));
+            externalInstances.put(typeName, new HashMap<>(DEFAULT_HASH_TABLE_SIZE));
         }
         externalInstances.get(typeName).put(id, instance);
 

src/main/java/com/nfl/dm/shield/dynamic/security/SchemaWriteAccess.java

@@ -4,6 +4,8 @@
 import java.util.Map;
 import java.util.Set;
 
+import static com.nfl.dm.shield.dynamic.config.HashConfig.DEFAULT_HASH_TABLE_SIZE;
+
 public class SchemaWriteAccess {
 
     public static final String SCHEMA_MODIFY = "SCHEMA_MODIFY";
@@ -13,7 +15,7 @@ public class SchemaWriteAccess {
 
     private final String authHeader;
 
-    private final Map<String, Set<String>> permissions = new HashMap<>(89);
+    private final Map<String, Set<String>> permissions = new HashMap<>(DEFAULT_HASH_TABLE_SIZE);
 
     public SchemaWriteAccess() {
         authHeader = "Testing only.";
@@ -27,7 +29,7 @@ public void addPermission(String namespace, String permissionName) {
 
         // Initialize
         if (!permissions.containsKey(namespace)) {
-            permissions.put(namespace, new HashSet<>(89));
+            permissions.put(namespace, new HashSet<>(DEFAULT_HASH_TABLE_SIZE));
         }
 
         permissions.get(namespace).add(permissionName);