com.facebook.buck.core.cell.CellPathResolverView.java Source code

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Here is the source code for com.facebook.buck.core.cell.CellPathResolverView.java

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/*
 * Copyright 2017-present Facebook, Inc.
 *
 * 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 com.facebook.buck.core.cell;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import java.nio.file.Path;
import java.util.Objects;
import java.util.Optional;

/**
 * View of a subset of cells of a cell path resolver.
 *
 * <p>Views are used for non-root cells, to ensure that only the subset of cell names that the cell
 * declares are visible within that cell.
 */
public final class CellPathResolverView extends AbstractCellPathResolver {
    private final CellPathResolver delegate;
    private final ImmutableSet<String> declaredCellNames;
    private final Path cellPath;

    public CellPathResolverView(CellPathResolver delegate, ImmutableSet<String> declaredCellNames, Path cellPath) {
        this.delegate = delegate;
        Optional<String> thisName = delegate.getCanonicalCellName(cellPath);
        if (thisName.isPresent()) {
            // A cell should be able to view into itself even if it doesn't explicitly specify it.
            this.declaredCellNames = ImmutableSet
                    .copyOf(Sets.union(declaredCellNames, ImmutableSet.of(thisName.get())));
        } else {
            this.declaredCellNames = declaredCellNames;
        }
        this.cellPath = cellPath;
    }

    @Override
    public Optional<Path> getCellPath(Optional<String> cellName) {
        if (cellName.isPresent()) {
            if (declaredCellNames.contains(cellName.get())) {
                return delegate.getCellPath(cellName);
            } else {
                return Optional.empty();
            }
        } else {
            return Optional.of(cellPath);
        }
    }

    @Override
    public ImmutableMap<String, Path> getCellPaths() {
        return ImmutableMap.copyOf(Maps.filterKeys(delegate.getCellPaths(), declaredCellNames::contains));
    }

    @Override
    public Optional<String> getCanonicalCellName(Path cellPath) {
        // TODO(cjhopman): This should verify that this path is visible in this view.
        return delegate.getCanonicalCellName(cellPath);
    }

    @Override
    public boolean equals(Object another) {
        if (this == another)
            return true;
        return another instanceof CellPathResolverView && equalTo((CellPathResolverView) another);
    }

    private boolean equalTo(CellPathResolverView another) {
        return delegate.equals(another.delegate) && declaredCellNames.equals(another.declaredCellNames)
                && cellPath.equals(another.cellPath);
    }

    @Override
    public int hashCode() {
        return Objects.hash(delegate, declaredCellNames, cellPath);
    }
}