Delete PsiDeclarationProvider

And its two subclasses. Replace it by package-local MembersProvider, which is
used only in java scopes, and two factory methods (for package & for class)

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java

@@ -21,7 +21,7 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.resolve.DescriptorUtils;
-import org.jetbrains.jet.lang.resolve.java.provider.PsiDeclarationProvider;
+import org.jetbrains.jet.lang.resolve.java.provider.NamedMembers;
 import org.jetbrains.jet.lang.resolve.java.resolver.*;
 import org.jetbrains.jet.lang.resolve.name.FqName;
 import org.jetbrains.jet.lang.resolve.name.Name;
@@ -210,12 +210,8 @@ public class JavaDescriptorResolver implements DependencyClassByQualifiedNameRes
     }
 
     @NotNull
-    public Set<VariableDescriptor> resolveFieldGroupByName(
+    public Set<VariableDescriptor> resolveFieldGroup(@NotNull NamedMembers members, @NotNull ClassOrNamespaceDescriptor ownerDescriptor) {
-            @NotNull Name name,
+        return propertiesResolver.resolveFieldGroup(members, ownerDescriptor);
-            @NotNull PsiDeclarationProvider provider,
-            @NotNull ClassOrNamespaceDescriptor ownerDescriptor
-    ) {
-        return propertiesResolver.resolveFieldGroupByName(name, provider, ownerDescriptor);
     }
 
     @Nullable
@@ -245,21 +241,16 @@ public class JavaDescriptorResolver implements DependencyClassByQualifiedNameRes
 
     @NotNull
     public Set<FunctionDescriptor> resolveFunctionGroupForClass(
-            @NotNull Name methodName,
+            @NotNull NamedMembers members,
-            @NotNull PsiDeclarationProvider provider,
+            @NotNull ClassOrNamespaceDescriptor owner,
-            @NotNull ClassOrNamespaceDescriptor ownerDescriptor,
             @NotNull PsiClass psiClass
     ) {
-        return functionResolver.resolveFunctionGroupForClass(methodName, provider, ownerDescriptor, psiClass);
+        return functionResolver.resolveFunctionGroupForClass(members, owner, psiClass);
     }
 
     @NotNull
-    public Set<FunctionDescriptor> resolveFunctionGroupForPackage(
+    public Set<FunctionDescriptor> resolveFunctionGroupForPackage(@NotNull NamedMembers members, @NotNull NamespaceDescriptor owner) {
-            @NotNull Name methodName,
+        return functionResolver.resolveFunctionGroupForPackage(members, owner);
-            @NotNull PsiDeclarationProvider provider,
-            @NotNull NamespaceDescriptor ownerDescriptor
-    ) {
-        return functionResolver.resolveFunctionGroupForPackage(methodName, provider, ownerDescriptor);
     }
 
     @NotNull

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/provider/ClassPsiDeclarationProvider.java

@@ -1,40 +0,0 @@
-/*
- * Copyright 2010-2013 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jetbrains.jet.lang.resolve.java.provider;
-
-import com.intellij.psi.PsiClass;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.jet.lang.resolve.java.PsiClassFinder;
-
-public final class ClassPsiDeclarationProvider extends PsiDeclarationProvider {
-    @NotNull
-    private final PsiClass psiClass;
-
-    private final boolean staticMembers;
-
-    public ClassPsiDeclarationProvider(@NotNull PsiClass psiClass, boolean staticMembers, @NotNull PsiClassFinder psiClassFinder) {
-        super(psiClassFinder);
-        this.staticMembers = staticMembers;
-        this.psiClass = psiClass;
-    }
-
-    @Override
-    @NotNull
-    protected MembersCache buildMembersCache() {
-        return MembersCache.buildMembersByNameCache(psiClassFinder, psiClass, null, staticMembers);
-    }
-}

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/provider/PackagePsiDeclarationProvider.java

@@ -1,37 +0,0 @@
-/*
- * Copyright 2010-2013 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jetbrains.jet.lang.resolve.java.provider;
-
-import com.intellij.psi.PsiPackage;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.jet.lang.resolve.java.PsiClassFinder;
-
-public final class PackagePsiDeclarationProvider extends PsiDeclarationProvider {
-    @NotNull
-    private final PsiPackage psiPackage;
-
-    public PackagePsiDeclarationProvider(@NotNull PsiPackage psiPackage, @NotNull PsiClassFinder psiClassFinder) {
-        super(psiClassFinder);
-        this.psiPackage = psiPackage;
-    }
-
-    @NotNull
-    @Override
-    protected MembersCache buildMembersCache() {
-        return MembersCache.buildMembersByNameCache(psiClassFinder, null, psiPackage, true);
-    }
-}

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/provider/PsiDeclarationProvider.java

@@ -1,42 +0,0 @@
-/*
- * Copyright 2010-2013 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jetbrains.jet.lang.resolve.java.provider;
-
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.jet.lang.resolve.java.PsiClassFinder;
-
-public abstract class PsiDeclarationProvider {
-    @NotNull
-    protected final PsiClassFinder psiClassFinder;
-
-    private MembersCache membersCache;
-
-    protected PsiDeclarationProvider(@NotNull PsiClassFinder psiClassFinder) {
-        this.psiClassFinder = psiClassFinder;
-    }
-
-    @NotNull
-    public MembersCache getMembersCache() {
-        if (membersCache == null) {
-            membersCache = buildMembersCache();
-        }
-        return membersCache;
-    }
-
-    @NotNull
-    protected abstract MembersCache buildMembersCache();
-}

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/resolver/JavaFunctionResolver.java

@@ -35,7 +35,6 @@ import org.jetbrains.jet.lang.resolve.java.descriptor.ClassDescriptorFromJvmByte
 import org.jetbrains.jet.lang.resolve.java.kotlinSignature.AlternativeMethodSignatureData;
 import org.jetbrains.jet.lang.resolve.java.kotlinSignature.SignaturesPropagationData;
 import org.jetbrains.jet.lang.resolve.java.provider.NamedMembers;
-import org.jetbrains.jet.lang.resolve.java.provider.PsiDeclarationProvider;
 import org.jetbrains.jet.lang.resolve.java.wrapper.PsiMethodWrapper;
 import org.jetbrains.jet.lang.resolve.name.Name;
 import org.jetbrains.jet.lang.resolve.scopes.JetScope;
@@ -244,10 +243,12 @@ public final class JavaFunctionResolver {
     }
 
     @NotNull
-    private Set<FunctionDescriptor> resolveNamedGroupFunctions(
+    public Set<FunctionDescriptor> resolveFunctionGroupForClass(
-            @NotNull ClassOrNamespaceDescriptor owner, @NotNull PsiClass psiClass,
+            @NotNull NamedMembers namedMembers,
-            NamedMembers namedMembers, Name methodName
+            @NotNull ClassOrNamespaceDescriptor owner,
+            @NotNull PsiClass psiClass
     ) {
+        Name methodName = namedMembers.getName();
 
         Set<SimpleFunctionDescriptor> functionsFromSupertypes = null;
         if (owner instanceof ClassDescriptor) {
@@ -368,31 +369,10 @@ public final class JavaFunctionResolver {
     }
 
     @NotNull
-    public Set<FunctionDescriptor> resolveFunctionGroupForClass(
+    public Set<FunctionDescriptor> resolveFunctionGroupForPackage(@NotNull NamedMembers members, @NotNull NamespaceDescriptor owner) {
-            @NotNull Name methodName,
+        SimpleFunctionDescriptor samConstructor = resolveSamConstructor(owner, members);
-            @NotNull PsiDeclarationProvider provider,
+        if (samConstructor != null) {
-            @NotNull ClassOrNamespaceDescriptor ownerDescriptor,
+            return Collections.<FunctionDescriptor>singleton(samConstructor);
-            @NotNull PsiClass psiClass
-    ) {
-        NamedMembers namedMembers = provider.getMembersCache().get(methodName);
-        if (namedMembers == null) {
-            return Collections.emptySet();
-        }
-        return resolveNamedGroupFunctions(ownerDescriptor, psiClass, namedMembers, methodName);
-    }
-
-    @NotNull
-    public Set<FunctionDescriptor> resolveFunctionGroupForPackage(
-            @NotNull Name functionName,
-            @NotNull PsiDeclarationProvider provider,
-            @NotNull NamespaceDescriptor ownerDescriptor
-    ) {
-        NamedMembers namedMembers = provider.getMembersCache().get(functionName);
-        if (namedMembers != null) {
-            SimpleFunctionDescriptor samConstructor = resolveSamConstructor(ownerDescriptor, namedMembers);
-            if (samConstructor != null) {
-                return Collections.<FunctionDescriptor>singleton(samConstructor);
-            }
         }
         return Collections.emptySet();
     }

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/resolver/JavaPropertyResolver.java

@@ -31,7 +31,6 @@ import org.jetbrains.jet.lang.resolve.constants.CompileTimeConstant;
 import org.jetbrains.jet.lang.resolve.java.*;
 import org.jetbrains.jet.lang.resolve.java.kotlinSignature.AlternativeFieldSignatureData;
 import org.jetbrains.jet.lang.resolve.java.provider.NamedMembers;
-import org.jetbrains.jet.lang.resolve.java.provider.PsiDeclarationProvider;
 import org.jetbrains.jet.lang.resolve.java.wrapper.PsiFieldWrapper;
 import org.jetbrains.jet.lang.resolve.name.Name;
 import org.jetbrains.jet.lang.resolve.scopes.JetScope;
@@ -68,35 +67,18 @@ public final class JavaPropertyResolver {
     }
 
     @NotNull
-    public Set<VariableDescriptor> resolveFieldGroupByName(
+    public Set<VariableDescriptor> resolveFieldGroup(@NotNull NamedMembers members, @NotNull ClassOrNamespaceDescriptor ownerDescriptor) {
-            @NotNull Name fieldName,
+        Name propertyName = members.getName();
-            @NotNull PsiDeclarationProvider provider,
-            @NotNull ClassOrNamespaceDescriptor ownerDescriptor
-    ) {
-        NamedMembers namedMembers = provider.getMembersCache().get(fieldName);
-        if (namedMembers == null) {
-            return Collections.emptySet();
-        }
 
-        return resolveNamedGroupProperties(ownerDescriptor, namedMembers, fieldName,
+        List<PsiFieldWrapper> fields = members.getFields();
-                                           "class or namespace " + DescriptorUtils.getFQName(ownerDescriptor));
-    }
-
-    @NotNull
-    private Set<VariableDescriptor> resolveNamedGroupProperties(
-            @NotNull ClassOrNamespaceDescriptor ownerDescriptor,
-            @NotNull NamedMembers namedMembers,
-            @NotNull Name propertyName,
-            @NotNull String context
-    ) {
-        List<PsiFieldWrapper> fields = namedMembers.getFields();
 
         Set<PropertyDescriptor> propertiesFromCurrent = new HashSet<PropertyDescriptor>(1);
         assert fields.size() <= 1;
         if (fields.size() == 1) {
             PsiFieldWrapper field = fields.iterator().next();
             if (DescriptorResolverUtils.isCorrectOwnerForEnumMember(ownerDescriptor, field.getPsiField())) {
-                propertiesFromCurrent.add(resolveProperty(ownerDescriptor, propertyName, context, field));
+                propertiesFromCurrent.add(resolveProperty(ownerDescriptor, propertyName,
+                                                          "class or namespace " + DescriptorUtils.getFQName(ownerDescriptor), field));
             }
         }
 

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/scope/JavaBaseScope.java

@@ -28,7 +28,6 @@ import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.resolve.java.JavaDescriptorResolver;
 import org.jetbrains.jet.lang.resolve.java.provider.NamedMembers;
-import org.jetbrains.jet.lang.resolve.java.provider.PsiDeclarationProvider;
 import org.jetbrains.jet.lang.resolve.name.Name;
 import org.jetbrains.jet.lang.resolve.scopes.JetScopeImpl;
 
@@ -38,7 +37,7 @@ public abstract class JavaBaseScope extends JetScopeImpl {
     @NotNull
     protected final JavaDescriptorResolver javaDescriptorResolver;
     @NotNull
-    protected final PsiDeclarationProvider declarationProvider;
+    protected final MembersProvider membersProvider;
     @NotNull
     private final Map<Name, Set<FunctionDescriptor>> functionDescriptors = Maps.newHashMap();
     @NotNull
@@ -56,10 +55,10 @@ public abstract class JavaBaseScope extends JetScopeImpl {
     protected JavaBaseScope(
             @NotNull ClassOrNamespaceDescriptor descriptor,
             @NotNull JavaDescriptorResolver javaDescriptorResolver,
-            @NotNull PsiDeclarationProvider declarationProvider
+            @NotNull MembersProvider membersProvider
     ) {
         this.javaDescriptorResolver = javaDescriptorResolver;
-        this.declarationProvider = declarationProvider;
+        this.membersProvider = membersProvider;
         this.descriptor = descriptor;
     }
 
@@ -86,7 +85,11 @@ public abstract class JavaBaseScope extends JetScopeImpl {
 
     @NotNull
     private Set<VariableDescriptor> computePropertyDescriptors(@NotNull Name name) {
-        return javaDescriptorResolver.resolveFieldGroupByName(name, declarationProvider, descriptor);
+        NamedMembers members = membersProvider.get(name);
+        if (members == null) {
+            return Collections.emptySet();
+        }
+        return javaDescriptorResolver.resolveFieldGroup(members, descriptor);
     }
 
     @NotNull
@@ -146,7 +149,7 @@ public abstract class JavaBaseScope extends JetScopeImpl {
     @NotNull
     private Collection<DeclarationDescriptor> computeFieldAndFunctionDescriptors() {
         Collection<DeclarationDescriptor> result = Lists.newArrayList();
-        for (NamedMembers members : declarationProvider.getMembersCache().allMembers()) {
+        for (NamedMembers members : membersProvider.allMembers()) {
             Name name = members.getName();
             ProgressIndicatorProvider.checkCanceled();
             result.addAll(getFunctions(name));

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/scope/JavaClassMembersScope.java

@@ -20,18 +20,13 @@ import com.intellij.psi.PsiClass;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.resolve.java.JavaDescriptorResolver;
-import org.jetbrains.jet.lang.resolve.java.provider.ClassPsiDeclarationProvider;
+import org.jetbrains.jet.lang.resolve.java.provider.NamedMembers;
 import org.jetbrains.jet.lang.resolve.name.LabelName;
 import org.jetbrains.jet.lang.resolve.name.Name;
 
-import java.util.Collection;
+import java.util.*;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Set;
 
 public abstract class JavaClassMembersScope extends JavaBaseScope {
-    @NotNull
-    protected final ClassPsiDeclarationProvider declarationProvider;
     @NotNull
     protected final PsiClass psiClass;
 
@@ -40,11 +35,10 @@ public abstract class JavaClassMembersScope extends JavaBaseScope {
     protected JavaClassMembersScope(
             @NotNull ClassOrNamespaceDescriptor descriptor,
             @NotNull PsiClass psiClass,
-            @NotNull ClassPsiDeclarationProvider declarationProvider,
+            @NotNull MembersProvider membersProvider,
             @NotNull JavaDescriptorResolver javaDescriptorResolver
     ) {
-        super(descriptor, javaDescriptorResolver, declarationProvider);
+        super(descriptor, javaDescriptorResolver, membersProvider);
-        this.declarationProvider = declarationProvider;
         this.psiClass = psiClass;
     }
 
@@ -64,7 +58,11 @@ public abstract class JavaClassMembersScope extends JavaBaseScope {
     @NotNull
     @Override
     protected Set<FunctionDescriptor> computeFunctionDescriptor(@NotNull Name name) {
-        return javaDescriptorResolver.resolveFunctionGroupForClass(name, declarationProvider, descriptor, psiClass);
+        NamedMembers members = membersProvider.get(name);
+        if (members == null) {
+            return Collections.emptySet();
+        }
+        return javaDescriptorResolver.resolveFunctionGroupForClass(members, descriptor, psiClass);
     }
 
     @NotNull

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/scope/JavaClassNonStaticMembersScope.java

@@ -23,7 +23,6 @@ import org.jetbrains.jet.lang.descriptors.ClassDescriptor;
 import org.jetbrains.jet.lang.descriptors.ConstructorDescriptor;
 import org.jetbrains.jet.lang.resolve.java.JavaDescriptorResolver;
 import org.jetbrains.jet.lang.resolve.java.PsiClassFinder;
-import org.jetbrains.jet.lang.resolve.java.provider.ClassPsiDeclarationProvider;
 
 import java.util.Collection;
 import java.util.Collections;
@@ -45,10 +44,7 @@ public final class JavaClassNonStaticMembersScope extends JavaClassMembersScope
             @NotNull PsiClassFinder psiClassFinder,
             @NotNull JavaDescriptorResolver javaDescriptorResolver
     ) {
-        super(descriptor,
+        super(descriptor, psiClass, MembersProvider.forClass(psiClassFinder, psiClass, staticMembersOfPsiClass), javaDescriptorResolver);
-              psiClass,
-              new ClassPsiDeclarationProvider(psiClass, staticMembersOfPsiClass, psiClassFinder),
-              javaDescriptorResolver);
         this.descriptor = descriptor;
         this.psiClass = psiClass;
         this.staticMembersOfPsiClass = staticMembersOfPsiClass;

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/scope/JavaClassStaticMembersScope.java

@@ -25,7 +25,6 @@ import org.jetbrains.jet.lang.descriptors.NamespaceDescriptor;
 import org.jetbrains.jet.lang.resolve.java.DescriptorSearchRule;
 import org.jetbrains.jet.lang.resolve.java.JavaDescriptorResolver;
 import org.jetbrains.jet.lang.resolve.java.PsiClassFinder;
-import org.jetbrains.jet.lang.resolve.java.provider.ClassPsiDeclarationProvider;
 import org.jetbrains.jet.lang.resolve.name.FqName;
 import org.jetbrains.jet.lang.resolve.name.Name;
 
@@ -45,7 +44,7 @@ public final class JavaClassStaticMembersScope extends JavaClassMembersScope {
             @NotNull PsiClassFinder psiClassFinder,
             @NotNull JavaDescriptorResolver javaDescriptorResolver
     ) {
-        super(descriptor, psiClass, new ClassPsiDeclarationProvider(psiClass, true, psiClassFinder), javaDescriptorResolver);
+        super(descriptor, psiClass, MembersProvider.forClass(psiClassFinder, psiClass, true), javaDescriptorResolver);
         this.packageFQN = packageFQN;
         this.psiClass = psiClass;
     }

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/scope/JavaPackageScope.java

@@ -24,7 +24,7 @@ import com.intellij.psi.PsiPackage;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.resolve.java.*;
-import org.jetbrains.jet.lang.resolve.java.provider.PackagePsiDeclarationProvider;
+import org.jetbrains.jet.lang.resolve.java.provider.NamedMembers;
 import org.jetbrains.jet.lang.resolve.name.FqName;
 import org.jetbrains.jet.lang.resolve.name.Name;
 
@@ -47,7 +47,7 @@ public final class JavaPackageScope extends JavaBaseScope {
             @NotNull JavaDescriptorResolver javaDescriptorResolver,
             @NotNull PsiClassFinder psiClassFinder
     ) {
-        super(descriptor, javaDescriptorResolver, new PackagePsiDeclarationProvider(psiPackage, psiClassFinder));
+        super(descriptor, javaDescriptorResolver, MembersProvider.forPackage(psiClassFinder, psiPackage));
         this.psiPackage = psiPackage;
         this.packageFQN = packageFQN;
         this.psiClassFinder = psiClassFinder;
@@ -134,7 +134,11 @@ public final class JavaPackageScope extends JavaBaseScope {
     @Override
     @NotNull
     protected Set<FunctionDescriptor> computeFunctionDescriptor(@NotNull Name name) {
-        return javaDescriptorResolver.resolveFunctionGroupForPackage(name, declarationProvider, (NamespaceDescriptor) descriptor);
+        NamedMembers members = membersProvider.get(name);
+        if (members == null) {
+            return Collections.emptySet();
+        }
+        return javaDescriptorResolver.resolveFunctionGroupForPackage(members, (NamespaceDescriptor) descriptor);
     }
 
     @NotNull

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/scope/MembersProvider.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2010-2013 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.jet.lang.resolve.java.scope;
+
+import com.intellij.psi.PsiClass;
+import com.intellij.psi.PsiPackage;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.jet.lang.resolve.java.PsiClassFinder;
+import org.jetbrains.jet.lang.resolve.java.provider.MembersCache;
+import org.jetbrains.jet.lang.resolve.java.provider.NamedMembers;
+import org.jetbrains.jet.lang.resolve.name.Name;
+
+import java.util.Collection;
+
+/* package */ class MembersProvider {
+    @NotNull
+    private final PsiClassFinder psiClassFinder;
+    @Nullable
+    private final PsiClass psiClass;
+    @Nullable
+    private final PsiPackage psiPackage;
+    private final boolean staticMembers;
+
+    private MembersProvider(
+            @NotNull PsiClassFinder psiClassFinder,
+            @Nullable PsiClass psiClass,
+            @Nullable PsiPackage psiPackage,
+            boolean staticMembers
+    ) {
+        this.psiClassFinder = psiClassFinder;
+        this.psiClass = psiClass;
+        this.psiPackage = psiPackage;
+        this.staticMembers = staticMembers;
+    }
+
+    @NotNull
+    public static MembersProvider forPackage(@NotNull PsiClassFinder psiClassFinder, @NotNull PsiPackage psiPackage) {
+        return new MembersProvider(psiClassFinder, null, psiPackage, true);
+    }
+
+    @NotNull
+    public static MembersProvider forClass(@NotNull PsiClassFinder psiClassFinder, @NotNull PsiClass psiClass, boolean staticMembers) {
+        return new MembersProvider(psiClassFinder, psiClass, null, staticMembers);
+    }
+
+    @Nullable
+    public NamedMembers get(@NotNull Name name) {
+        return getMembersCache().get(name);
+    }
+
+    @NotNull
+    public Collection<NamedMembers> allMembers() {
+        return getMembersCache().allMembers();
+    }
+
+    private MembersCache membersCache;
+    @NotNull
+    private MembersCache getMembersCache() {
+        if (membersCache == null) {
+            membersCache = MembersCache.buildMembersByNameCache(psiClassFinder, psiClass, psiPackage, staticMembers);
+        }
+        return membersCache;
+    }
+}