org.kiji.schema.layout.KijiTableLayout.java Source code

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Here is the source code for org.kiji.schema.layout.KijiTableLayout.java

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/**
 * (c) Copyright 2012 WibiData, Inc.
 *
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * 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.kiji.schema.layout;

import java.io.IOException;
import java.io.InputStream;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import com.google.common.base.Joiner;
import com.google.common.base.Objects;
import com.google.common.base.Preconditions;
import com.google.common.collect.BiMap;
import com.google.common.collect.HashBiMap;
import com.google.common.collect.ImmutableBiMap;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import org.apache.avro.Schema;
import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.kiji.annotations.ApiAudience;
import org.kiji.annotations.ApiStability;
import org.kiji.schema.InternalKijiError;
import org.kiji.schema.KijiColumnName;
import org.kiji.schema.KijiSchemaTable;
import org.kiji.schema.NoSuchColumnException;
import org.kiji.schema.avro.CellSchema;
import org.kiji.schema.avro.ColumnDesc;
import org.kiji.schema.avro.ColumnNameTranslator;
import org.kiji.schema.avro.FamilyDesc;
import org.kiji.schema.avro.LocalityGroupDesc;
import org.kiji.schema.avro.RowKeyComponent;
import org.kiji.schema.avro.RowKeyEncoding;
import org.kiji.schema.avro.RowKeyFormat;
import org.kiji.schema.avro.RowKeyFormat2;
import org.kiji.schema.avro.SchemaStorage;
import org.kiji.schema.avro.SchemaType;
import org.kiji.schema.avro.TableLayoutDesc;
import org.kiji.schema.impl.Versions;
import org.kiji.schema.layout.KijiTableLayout.LocalityGroupLayout.FamilyLayout;
import org.kiji.schema.layout.KijiTableLayout.LocalityGroupLayout.FamilyLayout.ColumnLayout;
import org.kiji.schema.layout.impl.ColumnId;
import org.kiji.schema.util.FromJson;
import org.kiji.schema.util.Hasher;
import org.kiji.schema.util.KijiNameValidator;
import org.kiji.schema.util.ProtocolVersion;
import org.kiji.schema.util.ResourceUtils;
import org.kiji.schema.util.ToJson;

/**
 * Layout of a Kiji table.
 *
 * <p>
 *   Kiji uses the term <i>layout</i> to describe the structure of a table.
 *   Kiji does not use the term <i>schema</i> to avoid confusion with Avro schemas or XML schemas.
 * </p>
 *
 * <p>
 *   KijiTableLayout wraps a layout descriptor represented as a
 *   {@link org.kiji.schema.avro.TableLayoutDesc TableLayoutDesc} Avro record.
 *   KijiTableLayout provides strict validation and accessors to navigate through the layout.
 * </p>
 *
 * <p>
 *   KijiTableLayouts can be created via one of two methods: from a concrete layout with
 *   {@link #newLayout(TableLayoutDesc)}, or as a layout update from a preexisting
 *   KijiTableLayout, with {@link #createUpdatedLayout(TableLayoutDesc,KijiTableLayout)}.
 *   For the format requirements of layout descriptors for these methods, see the
 *   "Layout descriptors" section below.
 * </p>
 *
 * <h1>Overall structure</h1>
 * <p>At the top-level, a table contains:
 * <ul>
 *   <li>the table name and description;</li>
 *   <li>how row keys are encoded;</li>
 *   <li>the table locality groups.</li>
 * </ul>
 * </p>
 *
 * <p>Each locality group has:
 * <ul>
 *   <li>a primary name, unique within the table, a description and some name aliases;</li>
 *   <li>whether the data is to be stored in memory or on disk;</li>
 *   <li>data retention lifetime;</li>
 *   <li>maximum number of versions to keep;</li>
 *   <li>type of compression;</li>
 *   <li>column families stored in this locality group</li>
 * </ul>
 * </p>
 *
 * <p>Each column family has:
 * <ul>
 *   <li>a primary name, globally unique within the table,
 *       a description and some name aliases;</li>
 *   <li>for map-type families, the Avro schema of the cell values;</li>
 *   <li>for group-type families, the collection of columns in the group.</li>
 * </ul>
 * </p>
 *
 * <p>Each column in a group-type family has:
 * <ul>
 *   <li>a primary name, unique within the family, a description and some name aliases;</li>
 *   <li>an Avro schema.</li>
 * </ul>
 * </p>
 *
 * <h1>Layout descriptors</h1>
 *
 * Layout descriptors are represented using
 * {@link org.kiji.schema.avro.TableLayoutDesc TableLayoutDesc} Avro records.
 * Layout descriptors come in two flavors: <i>concrete layouts</i> and <i>layout updates</i>.
 *
 * <h2><i>Concrete layout descriptors</i></h2>
 * A concrete layout descriptors is an absolute, standalone description of a table layout, which
 * does not reference or build upon any previous version of the table layout. Column IDs have
 * been assigned to all locality groups, families and columns.
 *
 * <p> Names of tables, locality groups, families and column qualifiers must be valid identifiers.
 * Name validation occurs in {@link org.kiji.schema.util.KijiNameValidator KijiNameValidator}.
 *
 * <h3>Validation rules</h3>
 *
 * <ul>
 *   <li> Table names, locality group names, family names, and column names in a group-type family
 *        must be valid identifiers (no punctuation or symbols).
 *        Note: map-type family qualifiers are free-form, but do never appear in a table layout.
 *   <li> Locality group names and aliases must be unique within the table.
 *   <li> Family names and aliases must be unique within the table.
 *   <li> Group-type family qualifiers must be unique within the family.
 * </ul>
 *
 * <h2><i>Layout update descriptors</i></h2>
 * A table layout update descriptor builds on a reference table layout, and describes layout
 * modification to apply on the reference layout.
 * The reference table layout is specified by writing the ID of the reference layout
 * ({@link TableLayoutDesc#layout_id}) into the {@link TableLayoutDesc#reference_layout}.
 * This mechanism prevents race conditions when updating the layout of a table.
 * The first layout of a newly created table has no reference layout.
 *
 * <p>During a layout update, the user may delete or declare new locality groups, families and/or
 * columns, or modify existing entities, by specifying the new layout.  Update validation rules
 * are enforced to ensure compatibility (see Validation rules for updates below).
 *
 * <p>Entities may also be renamed, as long as uniqueness requirements are met.
 * Primary name updates must be explicitly annotated by setting the {@code renamedFrom} field of
 * the entity being renamed.
 * The name of a table cannot be changed.
 *
 * <p>For example, suppose the reference layout contained one family {@code Info}, containing a
 * column {@code Name}, and the user wishes to add a new {@code Address} column to the
 * {@code Info} family.
 * To perform this update, the user would create a layout update by starting with the existing
 * layout, setting the {@code reference_layout} field to the {@code layout_id} of the
 * current layout, and adding a new {@link ColumnDesc} record describing the {@code Address}
 * column to the the {@code columns} field of the {@link FamilyDesc} for the {@code Info} family.
 *
 * <p>The result of applying a layout update on top of a concrete reference layout is a new
 * concrete layout.
 *
 * <h3> Validation rules for updates </h3>
 *
 * <p> Updates are subject to the same restrictions as concrete layout descriptors.
 * In addition:</p>
 *
 * <ul>
 *   <li> The type of a family (map-type or group-type) cannot be changed.
 *   <li> A family cannot be moved into a different locality group.
 *   <li> The encoding of Kiji cells (hash, UID, final) cannot be modified.
 *   <li> The schema of a Kiji cell can only be changed to a schema that is compatible with
 *        all the former schemas of the column. Schema compatibility requires that the new schema
 *        allows decoding all former schemas associated to the column or the map-type family.
 * </ul>
 *
 * <h1>Row keys encoding</h1>
 *
 * A row in a Kiji table is identified by its Kiji row key. Kiji row keys are converted into HBase
 * row keys according to the row key encoding specified in the table layout:
 * <ul>
 *   <li> Raw encoding: the user has direct control over the encoding of row keys in the HBase
 *        table. In other words, the HBase row key is exactly the Kiji row key. These are used
 *        when the user would like to use arrays of bytes as row keys.
 *   </li>
 *   <li> Hashed: Deprecated! The HBase row key is computed as a hash of a single String or
 *   byte array component.
 *   </li>
 *   <li> Hash-prefixed: the HBase row key is computed as the concatenation of the hash of a
 *   single String or byte array component.
 *   </li>
 *   <li> Formatted: the row key is comprised of one or more components. Each component can be
 *        a string, a number or a hash of another component. The user will specify the size
 *        of this hash. The user also specifies the actual order of the components in the key.
 *   </li>
 * </ul>
 *
 * Hashing allows to spread the rows evenly across all the regions in the table. Specifying the size
 * of the hash gives the user fine grained control of how the data will be distributed.
 *
 * <h1>Cell schema</h1>
 *
 * Kiji cells are encoded according to a schema specified via
 * {@link org.kiji.schema.avro.CellSchema CellSchema} Avro records.
 * Kiji provides various cell encoding schemes:
 * <ul>
 *   <li> Hash: each Kiji cell is encoded as a hash of the Avro schema, followed by the binary
 *        encoding of the Avro value.
 *   </li>
 *   <li> UID: each Kiji cell is encoded as the unique ID of the Avro schema, followed by the
 *        binary encoding of the Avro value.
 *   </li>
 *   <li> Final: each Kiji cell is encoded as the binary encoding of the Avro value.
 *   </li>
 * </ul>
 * See {@link org.kiji.schema.impl.AvroCellEncoder KijiCellEncoder}
 * and {@link org.kiji.schema.impl.AvroCellDecoder KijiCellDecoder}
 * for more implementation details.
 *
 * <h1>Column IDs</h1>
 *
 * Kiji allows the column names to be represented on HBase in multiple modes via
 * {@link org.kiji.schema.avro.ColumnNameTranslator ColumnNameTranslator} Avro enumeration.
 * By default we use the shortened Kiji column name translation due to space efficiency.
 * Depending on compatability requirements with other HBase tools it may be desirable to use the
 * IDENTITY or HBASE_NATIVE column name translators.
 *
 * <h2>SHORT Kiji column name translation:</h2>
 * For storage efficiency purposes, Kiji family and column names are translated into short
 * HBase column names by default.
 * This translation happens in
 *   {@link org.kiji.schema.layout.impl.hbase.ShortColumnNameTranslator ShortColumnNameTranslator}
 * and relies on
 *   {@link org.kiji.schema.layout.impl.ColumnId ColumnId}.
 * Column IDs are assigned automatically by KijiTableLayout.
 * The user may specify column IDs manually. KijiTableLayout checks the consistency of column IDs.
 *
 * <p>Column IDs cannot be changed (a column ID change is equivalent to deleting the existing column
 * and then re-creating it as a new empty column).
 *
 * <h2>IDENTITY Kiji column name translation:</h2>
 * For compatibility with other HBase tools, Kiji family and column names can be written to HBase
 * directly.
 * This translation happens in
 *   {@link org.kiji.schema.layout.impl.hbase.IdentityColumnNameTranslator}
 * In this mode:
 * <ul>
 *   <li>Kiji locality groups are translated into HBase families.</li>
 *   <li>Kiji column families and qualifiers are combined to form the HBase
 *       qualifier("family:qualifier").</li>
 * </ul>
 *
 * <h2>HBASE_NATIVE Kiji column name translation:</h2>
 * For compatibility with existing HBase tables, the notion of a Kiji locality group can be
 * ignored, mapping Kiji family and column names directly to their HBase equivalents.
 * This translation happens in
 *   {@link org.kiji.schema.layout.impl.hbase.HBaseNativeColumnNameTranslator}
 * In this mode:
 * <ul>
 *   <li>Kiji locality groups and column families are translated into HBase families.</li>
 *   <li>Additionally, Kiji locality groups must match the Kiji column families.  This has the
 *   side effect of requiring a one to one mapping between the Kiji locality groups and column
 *   families.</li>
 *   <li>Kiji column qualifiers are combined to form the HBase qualifier.</li>
 * </ul>
 *
 */
@ApiAudience.Public
@ApiStability.Evolving
public final class KijiTableLayout {
    private static final Logger LOG = LoggerFactory.getLogger(KijiTableLayout.class);

    // ProtocolVersions specifying when different features were added to layout functionality.

    /** All layout versions must use the format 'kiji-x.y' to specify what version they use. */
    private static final String LAYOUT_PROTOCOL_NAME = "layout";

    /**
     * Returns the maximum layout version supported.
     *
     * @return the maximum layout version recognized by this version of Kiji.
     */
    public static ProtocolVersion getMaxSupportedLayoutVersion() {
        return Versions.MAX_LAYOUT_VERSION;
    }

    /**
     * Returns the minimum layout version supported.
     *
     * @return the minimum layout version recognized by this version of Kiji.
     */
    public static ProtocolVersion getMinSupportedLayoutVersion() {
        return Versions.MIN_LAYOUT_VERSION;
    }

    /** Concrete layout of a locality group. */
    @ApiAudience.Public
    public final class LocalityGroupLayout {

        /** Concrete layout of a family. */
        @ApiAudience.Public
        public final class FamilyLayout {

            /** Concrete layout of a column. */
            @ApiAudience.Public
            public final class ColumnLayout {
                /** Column layout descriptor. */
                private final ColumnDesc mDesc;

                /** Column name and aliases. */
                private final Set<String> mNames;

                /** Column ID. */
                private ColumnId mId = null;

                /**
                 * Builds a new column layout instance from a descriptor.
                 *
                 * @param desc Column descriptor.
                 * @param reference Optional reference layout, or null.
                 * @throws InvalidLayoutException if the layout is invalid or inconsistent.
                 */
                private ColumnLayout(ColumnDesc desc, ColumnLayout reference) throws InvalidLayoutException {
                    mDesc = Preconditions.checkNotNull(desc);

                    final Set<String> names = Sets.newHashSet();
                    names.add(desc.getName());
                    names.addAll(desc.getAliases());
                    mNames = ImmutableSet.copyOf(names);

                    if (!isValidName(desc.getName())) {
                        throw new InvalidLayoutException(
                                String.format("Invalid column name: '%s'.", desc.getName()));
                    }

                    for (String name : mNames) {
                        if (!isValidAlias(name)) {
                            throw new InvalidLayoutException(String.format("Invalid column alias: '%s'.", name));
                        }
                    }

                    if (desc.getId() > 0) {
                        mId = new ColumnId(desc.getId());
                    }

                    if (reference != null) {
                        if ((mId != null) && !mId.equals(reference.getId())) {
                            throw new InvalidLayoutException(
                                    String.format("Descriptor for column '%s' has ID %s but reference ID is %s.",
                                            getName(), mId, reference.getId()));
                        }
                        mId = reference.getId();
                        desc.setId(mId.getId());
                    }

                    // Force validation of schema:
                    final CellSchema referenceSchema = (null != reference) ? reference.getDesc().getColumnSchema()
                            : null;
                    validateCellSchema(mLayoutVersion, mDesc.getColumnSchema(), referenceSchema);
                }

                /** @return A copy of the Avro descriptor for this column. */
                public ColumnDesc getDesc() {
                    return ColumnDesc.newBuilder(mDesc).build();
                }

                /** @return the primary name for the column. */
                public String getName() {
                    return mDesc.getName();
                }

                /** @return the name and aliases for the column. */
                public Set<String> getNames() {
                    return mNames;
                }

                /** @return the ID associated to this column. */
                public ColumnId getId() {
                    return mId;
                }

                /**
                 * Assigns the ID of this column.
                 *
                 * @param cid the ID of the column.
                 * @return this column.
                 */
                private ColumnLayout setId(ColumnId cid) {
                    Preconditions.checkArgument(cid.getId() >= 1);
                    Preconditions.checkState(null == mId);
                    mId = cid;
                    mDesc.setId(cid.getId());
                    return this;
                }

                /** @return the family this column belongs to. */
                public FamilyLayout getFamily() {
                    return FamilyLayout.this;
                }
            } // class ColumnLayout

            // -------------------------------------------------------------------------------------------

            /** Family layout descriptor. */
            private final FamilyDesc mDesc;

            /** Family name and aliases. */
            private final Set<String> mNames;

            /** Columns in the family. */
            private final ImmutableList<ColumnLayout> mColumns;

            /** Map column qualifier name (no aliases) to column layout. */
            private final ImmutableMap<String, ColumnLayout> mColumnMap;

            /** Bidirectional mapping between column IDs and column names (no aliases). */
            private final BiMap<ColumnId, String> mColumnIdNameMap;

            /** Family ID. */
            private ColumnId mId = null;

            // CSOFF: MethodLengthCheck
            /**
             * Builds a new family layout instance.
             *
             * @param familyDesc Descriptor of the family.
             * @param reference Optional reference family layout, or null.
             * @throws InvalidLayoutException if the layout is invalid or inconsistent.
             */
            private FamilyLayout(FamilyDesc familyDesc, FamilyLayout reference) throws InvalidLayoutException {
                mDesc = Preconditions.checkNotNull(familyDesc);

                // Ensure the array of columns is mutable:
                mDesc.setColumns(Lists.newArrayList(mDesc.getColumns()));

                if (!mDesc.getColumns().isEmpty() && (null != mDesc.getMapSchema())) {
                    throw new InvalidLayoutException(
                            String.format("Invalid family '%s' with both map-type and columns", getName()));
                }

                final Set<String> familyNames = Sets.newHashSet();
                familyNames.add(familyDesc.getName());
                familyNames.addAll(familyDesc.getAliases());
                mNames = ImmutableSet.copyOf(familyNames);

                if (!isValidName(familyDesc.getName())) {
                    throw new InvalidLayoutException(
                            String.format("Invalid family name: '%s'.", familyDesc.getName()));
                }

                for (String name : mNames) {
                    if (!isValidAlias(name)) {
                        throw new InvalidLayoutException(String.format("Invalid family alias: '%s'.", name));
                    }
                }

                if (familyDesc.getId() > 0) {
                    mId = new ColumnId(familyDesc.getId());
                }

                if (reference != null) {
                    if ((mId != null) && !mId.equals(reference.getId())) {
                        throw new InvalidLayoutException(
                                String.format("Descriptor for family '%s' has ID %s but reference ID is %s.",
                                        getName(), mId, reference.getId()));
                    }
                    mId = reference.getId();
                    familyDesc.setId(mId.getId());

                    // Cannot change family type (group-type vs map-type):
                    if (reference.isMapType() != this.isMapType()) {
                        throw new InvalidLayoutException(String.format(
                                "Invalid layout update for family '%s' from reference type %s to type %s.",
                                getName(), reference.isMapType() ? "map" : "group",
                                this.isMapType() ? "map" : "group"));
                    }
                }

                if (this.isMapType()) {
                    // Force validation of schema:
                    final CellSchema referenceSchema = (null != reference) ? reference.getDesc().getMapSchema()
                            : null;
                    validateCellSchema(mLayoutVersion, mDesc.getMapSchema(), referenceSchema);
                }

                // Build columns:

                /**
                 * Map of columns from the reference layout.
                 * Entries are removed as they are processed and linked to column descriptors.
                 * At the end of the process, this map must be empty.
                 */
                final BiMap<String, ColumnId> refCIdMap = (reference != null)
                        ? HashBiMap.create(reference.getColumnIdNameMap().inverse())
                        : HashBiMap.<String, ColumnId>create();

                final List<ColumnLayout> columns = Lists.newArrayList();
                final Map<String, ColumnLayout> columnMap = Maps.newHashMap();

                /** Map of columns in the new layout. */
                final BiMap<ColumnId, String> idMap = HashBiMap.create();

                /** Columns with no ID assigned yet. */
                final List<ColumnLayout> unassigned = Lists.newArrayList();

                final Iterator<ColumnDesc> itColumnDesc = familyDesc.getColumns().iterator();
                while (itColumnDesc.hasNext()) {
                    final ColumnDesc columnDesc = itColumnDesc.next();
                    final boolean isRename = (columnDesc.getRenamedFrom() != null);
                    final String refCName = isRename ? columnDesc.getRenamedFrom() : columnDesc.getName();
                    columnDesc.setRenamedFrom(null);
                    if (isRename && (reference == null)) {
                        throw new InvalidLayoutException(
                                String.format("Invalid renaming: cannot find reference family for column '%s:%s'.",
                                        getName(), refCName));
                    }
                    final ColumnLayout refCLayout = (reference != null) ? reference.getColumnMap().get(refCName)
                            : null;
                    if (isRename && (refCLayout == null)) {
                        throw new InvalidLayoutException(
                                String.format("Invalid renaming: cannot find column '%s:%s' in reference family.",
                                        getName(), refCName));
                    }

                    final ColumnId refCId = refCIdMap.remove(refCName);

                    if (columnDesc.getDelete()) {
                        if (refCId == null) {
                            throw new InvalidLayoutException(
                                    String.format("Deleted column '%s:%s' does not exist in reference layout.",
                                            mDesc.getName(), refCName));
                        }
                        itColumnDesc.remove();
                        continue;
                    }

                    final ColumnLayout cLayout = new ColumnLayout(columnDesc, refCLayout);
                    columns.add(cLayout);
                    for (String columnName : cLayout.getNames()) {
                        if (null != columnMap.put(columnName, cLayout)) {
                            throw new InvalidLayoutException(
                                    String.format("Family '%s' contains duplicate column qualifier '%s'.",
                                            getName(), columnName));
                        }
                    }
                    if (cLayout.getId() != null) {
                        final String previous = idMap.put(cLayout.getId(), cLayout.getName());
                        Preconditions.checkState(previous == null,
                                String.format("Duplicate column ID '%s' associated to '%s' and '%s'.",
                                        cLayout.getId(), cLayout.getName(), previous));
                    } else {
                        unassigned.add(cLayout);
                    }
                }

                if (!refCIdMap.isEmpty()) {
                    throw new InvalidLayoutException(
                            String.format("Descriptor for family '%s' is missing columns: %s.", getName(),
                                    Joiner.on(",").join(refCIdMap.keySet())));
                }

                mColumns = ImmutableList.copyOf(columns);
                mColumnMap = ImmutableMap.copyOf(columnMap);

                // Assign IDs to columns, build ID maps
                int nextColumnId = 1;
                for (ColumnLayout column : unassigned) {
                    Preconditions.checkState(column.getId() == null);
                    while (true) {
                        final ColumnId columnId = new ColumnId(nextColumnId);
                        nextColumnId += 1;
                        if (!idMap.containsKey(columnId)) {
                            column.setId(columnId);
                            idMap.put(columnId, column.getName());
                            break;
                        }
                    }
                }

                mColumnIdNameMap = ImmutableBiMap.copyOf(idMap);
            }

            /** @return the Avro descriptor for this family. */
            public FamilyDesc getDesc() {
                return FamilyDesc.newBuilder(mDesc).build();
            }

            /** @return the primary name for the family. */
            public String getName() {
                return mDesc.getName();
            }

            /** @return the family name and aliases. */
            public Set<String> getNames() {
                return mNames;
            }

            /** @return the column ID assigned to this family. */
            public ColumnId getId() {
                return mId;
            }

            /**
             * Assigns the ID of this family.
             *
             * @param cid the ID of the family.
             * @return this column.
             */
            private FamilyLayout setId(ColumnId cid) {
                Preconditions.checkArgument(cid.getId() >= 1);
                Preconditions.checkState(null == mId);
                mId = cid;
                mDesc.setId(cid.getId());
                return this;
            }

            /** @return the columns in this family. */
            public Collection<ColumnLayout> getColumns() {
                return mColumns;
            }

            /** @return the mapping from column names (no aliases) to column layouts. */
            public Map<String, ColumnLayout> getColumnMap() {
                return mColumnMap;
            }

            /** @return the bidirectional mapping between column names (no aliases) and IDs. */
            public BiMap<ColumnId, String> getColumnIdNameMap() {
                return mColumnIdNameMap;
            }

            /** @return the locality group this family belongs to. */
            public LocalityGroupLayout getLocalityGroup() {
                return LocalityGroupLayout.this;
            }

            /** @return whether this is a group-type family. */
            public boolean isGroupType() {
                return mDesc.getMapSchema() == null;
            }

            /** @return whether this is a map-type family. */
            public boolean isMapType() {
                return !isGroupType();
            }
        } // class FamilyLayout

        // -------------------------------------------------------------------------------------------

        /** Locality group descriptor. */
        private final LocalityGroupDesc mDesc;

        /** Locality group name and aliases. */
        private final ImmutableSet<String> mNames;

        /** Families in the locality group. */
        private final ImmutableList<FamilyLayout> mFamilies;

        /** Map family name or alias to family layout. */
        private final ImmutableMap<String, FamilyLayout> mFamilyMap;

        /** Bidirectional mapping between family IDs and family names (no alias). */
        private final BiMap<ColumnId, String> mFamilyIdNameBiMap;

        /** Locality group ID. */
        private ColumnId mId = null;

        /**
         * Constructs a locality group layout.
         *
         * @param lgDesc Locality group descriptor.
         * @param reference Optional reference locality group, or null.
         * @throws InvalidLayoutException if the layout is invalid or inconsistent.
         */
        private LocalityGroupLayout(LocalityGroupDesc lgDesc, LocalityGroupLayout reference)
                throws InvalidLayoutException {
            mDesc = Preconditions.checkNotNull(lgDesc);

            // Ensure the array of families is mutable:
            mDesc.setFamilies(Lists.newArrayList(mDesc.getFamilies()));

            // All the recognized names for this locality group:
            final Set<String> names = Sets.newHashSet();
            names.add(lgDesc.getName());
            names.addAll(lgDesc.getAliases());
            mNames = ImmutableSet.copyOf(names);

            if (!isValidName(lgDesc.getName())) {
                throw new InvalidLayoutException(
                        String.format("Invalid locality group name: '%s'.", lgDesc.getName()));
            }

            for (String name : mNames) {
                if (!isValidAlias(name)) {
                    throw new InvalidLayoutException(String.format("Invalid locality group alias: '%s'.", name));
                }
            }

            if (lgDesc.getId() > 0) {
                mId = new ColumnId(lgDesc.getId());
            }

            if (mDesc.getTtlSeconds() <= 0) {
                throw new InvalidLayoutException(
                        String.format("Invalid TTL seconds for locality group '%s': TTL must be positive, got %d.",
                                getName(), mDesc.getTtlSeconds()));
            }
            if (mDesc.getMaxVersions() <= 0) {
                throw new InvalidLayoutException(String.format(
                        "Invalid max versions for locality group '%s': max versions must be positive, got %d.",
                        getName(), mDesc.getMaxVersions()));
            }

            if (reference != null) {
                if ((mId != null) && !mId.equals(reference.getId())) {
                    throw new InvalidLayoutException(
                            String.format("Descriptor for locality group '%s' has ID %s but reference ID is %s.",
                                    getName(), mId, reference.getId()));
                }
                mId = reference.getId();
                lgDesc.setId(mId.getId());
            }

            // Build families:

            /**
             * Map of the family IDs from the reference layout.
             * Entries are removed as they are linked to the families in the descriptor.
             * Eventually, this map must become empty.
             */
            final BiMap<String, ColumnId> refFIdMap = (reference != null)
                    ? HashBiMap.create(reference.getFamilyIdNameMap().inverse())
                    : HashBiMap.<String, ColumnId>create();

            final List<FamilyLayout> families = Lists.newArrayList();
            final Map<String, FamilyLayout> familyMap = Maps.newHashMap();

            /** Map of families in the new layout. */
            final BiMap<ColumnId, String> idMap = HashBiMap.create();

            /** Families with no ID assigned yet. */
            final List<FamilyLayout> unassigned = Lists.newArrayList();

            final Iterator<FamilyDesc> itFamilyDesc = lgDesc.getFamilies().iterator();
            while (itFamilyDesc.hasNext()) {
                final FamilyDesc familyDesc = itFamilyDesc.next();
                final boolean isRename = (familyDesc.getRenamedFrom() != null);
                final String refFName = isRename ? familyDesc.getRenamedFrom() : familyDesc.getName();
                familyDesc.setRenamedFrom(null);
                if (isRename && (reference == null)) {
                    throw new InvalidLayoutException(
                            String.format("Invalid rename: no reference locality group '%s' for family '%s'.",
                                    getName(), refFName));
                }
                final FamilyLayout refFLayout = (reference != null) ? reference.getFamilyMap().get(refFName) : null;
                if (isRename && (refFLayout == null)) {
                    throw new InvalidLayoutException(String.format(
                            "Invalid rename: cannot find reference family '%s' in locality group '%s'.", refFName,
                            getName()));
                }

                final ColumnId refFId = refFIdMap.remove(refFName);

                if (familyDesc.getDelete()) {
                    if (refFId == null) {
                        throw new InvalidLayoutException(
                                String.format("Deleted family '%s' unknown in reference locality group '%s'.",
                                        refFName, getName()));
                    }
                    itFamilyDesc.remove();
                    continue;
                }

                final FamilyLayout fLayout = new FamilyLayout(familyDesc, refFLayout);
                families.add(fLayout);
                for (String familyName : fLayout.getNames()) {
                    Preconditions.checkState(familyMap.put(familyName, fLayout) == null,
                            "Duplicate family name: " + familyName);
                }
                if (fLayout.getId() != null) {
                    final String previous = idMap.put(fLayout.getId(), fLayout.getName());
                    Preconditions.checkState(previous == null,
                            String.format("Duplicate family ID '%s' associated to '%s' and '%s'.", fLayout.getId(),
                                    fLayout.getName(), previous));
                } else {
                    unassigned.add(fLayout);
                }
            }

            if (!refFIdMap.isEmpty()) {
                throw new InvalidLayoutException(
                        String.format("Descriptor for locality group '%s' is missing families: %s",
                                lgDesc.getName(), Joiner.on(",").join(refFIdMap.keySet())));
            }

            mFamilies = ImmutableList.copyOf(families);
            mFamilyMap = ImmutableMap.copyOf(familyMap);

            // Assign IDs to families:
            int nextFamilyId = 1;
            for (FamilyLayout fLayout : unassigned) {
                Preconditions.checkState(fLayout.getId() == null);
                while (true) {
                    final ColumnId fId = new ColumnId(nextFamilyId);
                    nextFamilyId += 1;
                    if (!idMap.containsKey(fId)) {
                        fLayout.setId(fId);
                        idMap.put(fId, fLayout.getName());
                        break;
                    }
                }
            }

            mFamilyIdNameBiMap = ImmutableBiMap.copyOf(idMap);
        }

        /** @return the table layout this locality group belongs to. */
        public KijiTableLayout getTableLayout() {
            return KijiTableLayout.this;
        }

        /** @return the Avro descriptor for this locality group. */
        public LocalityGroupDesc getDesc() {
            return LocalityGroupDesc.newBuilder(mDesc).build();
        }

        /** @return the locality group primary name. */
        public String getName() {
            return mDesc.getName();
        }

        /** @return the locality group name and aliases. */
        public Set<String> getNames() {
            return mNames;
        }

        /** @return the ID associated to this locality group. */
        public ColumnId getId() {
            return mId;
        }

        /**
         * Assigns the ID of the locality group.
         *
         * @param cid the ID of the locality group.
         * @return this locality group.
         */
        private LocalityGroupLayout setId(ColumnId cid) {
            Preconditions.checkArgument(cid.getId() >= 1);
            Preconditions.checkState(null == mId);
            mId = cid;
            mDesc.setId(cid.getId());
            return this;
        }

        /** @return the families in this locality group, in no particular order. */
        public Collection<FamilyLayout> getFamilies() {
            return mFamilies;
        }

        /** @return the mapping from family names and aliases to family layouts. */
        public Map<String, FamilyLayout> getFamilyMap() {
            return mFamilyMap;
        }

        /** @return the bidirectional mapping between family names (no alias) and IDs. */
        public BiMap<ColumnId, String> getFamilyIdNameMap() {
            return mFamilyIdNameBiMap;
        }

    } // class LocalityGroupLayout

    // -----------------------------------------------------------------------------------------------

    /** Avro record describing the table layout absolutely (no reference layout required). */
    private final TableLayoutDesc mDesc;

    /** Version of this table layout. */
    private final ProtocolVersion mLayoutVersion;

    /** Locality groups in the table, in no particular order. */
    private final ImmutableList<LocalityGroupLayout> mLocalityGroups;

    /** Map locality group name or alias to locality group layout. */
    private final ImmutableMap<String, LocalityGroupLayout> mLocalityGroupMap;

    /** Families in the table, in no particular order. */
    private final ImmutableList<FamilyLayout> mFamilies;

    /** Map family names and aliases to family layout. */
    private final ImmutableMap<String, FamilyLayout> mFamilyMap;

    /** Bidirectional map between locality group names (no alias) and IDs. */
    private final ImmutableBiMap<ColumnId, String> mLocalityGroupIdNameMap;

    /** All primary column names in the table (including names for map-type families). */
    private final ImmutableSet<KijiColumnName> mColumnNames;

    /**
     * Optional schema table that allows resolution of Avro schemas.
     * The schema table is injected in the CellSpec instances created from this layout.
     */
    private KijiSchemaTable mSchemaTable;

    /**
     * Ensure a row key format (version 1) specified in a layout file is sane.
     * @param format The RowKeyFormat created from the layout file for a table.
     * @throws InvalidLayoutException If the format is invalid.
     */
    private void isValidRowKeyFormat1(RowKeyFormat format) throws InvalidLayoutException {
        RowKeyEncoding rowKeyEncoding = format.getEncoding();
        if (rowKeyEncoding != RowKeyEncoding.RAW && rowKeyEncoding != RowKeyEncoding.HASH
                && rowKeyEncoding != RowKeyEncoding.HASH_PREFIX) {
            throw new InvalidLayoutException("RowKeyFormat only supports encodings"
                    + "of type RAW, HASH and HASH_PREFIX. Use RowKeyFormat2 instead");
        }
        if (rowKeyEncoding == RowKeyEncoding.HASH || rowKeyEncoding == RowKeyEncoding.HASH_PREFIX) {
            if (format.getHashSize() < 0 || format.getHashSize() > Hasher.HASH_SIZE_BYTES) {
                throw new InvalidLayoutException("HASH or HASH_PREFIX row key formats require hash size"
                        + "to be between 1 and " + Hasher.HASH_SIZE_BYTES);
            }
        }
    }

    /**
     * Ensure a row key format (version 2) specified in a layout file is sane.
     * @param format The RowKeyFormat2 created from the layout file for a table.
     * @throws InvalidLayoutException If the format is invalid.
     */
    private void isValidRowKeyFormat2(RowKeyFormat2 format) throws InvalidLayoutException {
        // RowKeyFormat2 can only contain RAW or FORMATTED encoding types.
        if (format.getEncoding() != RowKeyEncoding.RAW && format.getEncoding() != RowKeyEncoding.FORMATTED) {
            throw new InvalidLayoutException("RowKeyFormat2 only supports RAW or FORMATTED encoding." + "Found "
                    + format.getEncoding().name());
        }

        // For RAW encoding, ignore the rest of the fields.
        if (format.getEncoding() == RowKeyEncoding.RAW) {
            return;
        }

        // At least one primitive component.
        if (format.getComponents().size() <= 0) {
            throw new InvalidLayoutException("At least 1 component is required in row key format.");
        }

        if (format.getSalt() == null) {
            // SCHEMA-489. The Avro decoder should replace this with a non-null HashSpec object,
            // but check here for paranoia.
            throw new InvalidLayoutException(
                    "Null values for RowKeyFormat2.salt are only allowed for RAW encoding.");
        }

        // Nullable index cannot be the first element or anything greater
        // than the components length (number of components).
        if (format.getNullableStartIndex() <= 0 || format.getNullableStartIndex() > format.getComponents().size()) {
            throw new InvalidLayoutException(
                    "Invalid index for nullable component. The second component" + " onwards can be set to null.");
        }

        // Range scan index cannot be the first element or anything greater
        // than the components length (number of components).
        if (format.getRangeScanStartIndex() <= 0
                || format.getRangeScanStartIndex() > format.getComponents().size()) {
            throw new InvalidLayoutException(
                    "Invalid range scan index. Range scans are supported " + "starting with the second component.");
        }

        // If suppress_key_materialization is true, range scans are impossible, as the
        // key components will not be stored.
        if (format.getSalt().getSuppressKeyMaterialization()
                && format.getRangeScanStartIndex() != format.getComponents().size()) {
            throw new InvalidLayoutException("Range scans are not supported if "
                    + "suppress_key_materialization is true. Please set range_scan_start_index "
                    + "to components.size");
        }

        Set<String> nameset = new HashSet<String>();
        for (RowKeyComponent component : format.getComponents()) {
            // ensure names are valid "[a-zA-Z_][a-zA-Z0-9_]*"
            if (!isValidName(component.getName())) {
                throw new InvalidLayoutException("Names should begin with a letter followed by a "
                        + "combination of letters, numbers and underscores.");
            }
            nameset.add(component.getName());
        }

        // repeated component names
        if (nameset.size() != format.getComponents().size()) {
            throw new InvalidLayoutException("Component name already used.");
        }

        // hash size invalid
        if (format.getSalt().getHashSize() <= 0 || format.getSalt().getHashSize() > Hasher.HASH_SIZE_BYTES) {
            throw new InvalidLayoutException("Valid hash sizes are between 1 and " + Hasher.HASH_SIZE_BYTES);
        }
    }

    /**
     * Computes the effective ProtocolVersion from a layout version string.
     *
     * <p> Normalizes kiji-1.0 into layout-1.0.0 </p>
     *
     * @param version Layout version string.
     * @return the effective layout ProtocolVersion.
     */
    private static ProtocolVersion computeLayoutVersion(String version) {
        final ProtocolVersion pversion = ProtocolVersion.parse(version);
        if (Objects.equal(pversion, Versions.LAYOUT_KIJI_1_0_0_DEPRECATED)) {
            // Deprecated "kiji-1.0" is compatible with "layout-1.0.0"
            return Versions.LAYOUT_1_0_0;
        } else {
            return pversion;
        }
    }

    // CSOFF: MethodLengthCheck
    /**
     * Constructs a KijiTableLayout from an Avro descriptor and an optional reference layout.
     *
     * @param desc Avro layout descriptor (relative to the reference layout).
     * @param reference Optional reference layout, or null.
     * @throws InvalidLayoutException if the descriptor is invalid or inconsistent wrt reference.
     */
    private KijiTableLayout(TableLayoutDesc desc, KijiTableLayout reference) throws InvalidLayoutException {
        // Deep-copy the descriptor to prevent mutating a parameter:
        mDesc = TableLayoutDesc.newBuilder(Preconditions.checkNotNull(desc)).build();

        // Ensure the array of locality groups is mutable:
        mDesc.setLocalityGroups(Lists.newArrayList(mDesc.getLocalityGroups()));

        // Check that the version specified in the layout matches the features used.
        // Any compatibility checks belong in this section.
        mLayoutVersion = computeLayoutVersion(mDesc.getVersion());

        if (!Objects.equal(LAYOUT_PROTOCOL_NAME, mLayoutVersion.getProtocolName())) {
            final String exceptionMessage;
            if (Objects.equal(Versions.LAYOUT_KIJI_1_0_0_DEPRECATED.getProtocolName(),
                    mLayoutVersion.getProtocolName())) {
                // Warn the user if they tried a version number like 'kiji-0.9' or 'kiji-1.1'.
                exceptionMessage = String.format(
                        "Deprecated layout version protocol '%s' only valid for version '%s',"
                                + " but received version '%s'. You should specify a layout version protocol"
                                + " as '%s-x.y', not '%s-x.y'.",
                        Versions.LAYOUT_KIJI_1_0_0_DEPRECATED.getProtocolName(),
                        Versions.LAYOUT_KIJI_1_0_0_DEPRECATED, mLayoutVersion, LAYOUT_PROTOCOL_NAME,
                        Versions.LAYOUT_KIJI_1_0_0_DEPRECATED.getProtocolName());
            } else {
                exceptionMessage = String.format("Invalid version protocol: '%s'. Expected '%s'.",
                        mLayoutVersion.getProtocolName(), LAYOUT_PROTOCOL_NAME);
            }
            throw new InvalidLayoutException(exceptionMessage);
        }

        if (Versions.MAX_LAYOUT_VERSION.compareTo(mLayoutVersion) < 0) {
            throw new InvalidLayoutException("The maximum layout version we support is "
                    + Versions.MAX_LAYOUT_VERSION + "; this layout requires " + mLayoutVersion);
        } else if (Versions.MIN_LAYOUT_VERSION.compareTo(mLayoutVersion) > 0) {
            throw new InvalidLayoutException("The minimum layout version we support is "
                    + Versions.MIN_LAYOUT_VERSION + "; this layout requires " + mLayoutVersion);
        }

        // max_filesize and memstore_flushsize were introduced in version 1.2.
        if (Versions.BLOCK_SIZE_LAYOUT_VERSION.compareTo(mLayoutVersion) > 0) {
            if (mDesc.getMaxFilesize() != null) {
                // Cannot use max_filesize if this is the case.
                throw new InvalidLayoutException("Support for specifying max_filesize begins with layout version "
                        + Versions.BLOCK_SIZE_LAYOUT_VERSION.toString());
            }

            if (mDesc.getMemstoreFlushsize() != null) {
                // Cannot use memstore_flushsize if this is the case.
                throw new InvalidLayoutException(
                        "Support for specifying memstore_flushsize begins with layout version "
                                + Versions.BLOCK_SIZE_LAYOUT_VERSION);
            }
        } else {
            if (mDesc.getMaxFilesize() != null && mDesc.getMaxFilesize() <= 0) {
                throw new InvalidLayoutException("max_filesize must be greater than 0");
            }

            if (mDesc.getMemstoreFlushsize() != null && mDesc.getMemstoreFlushsize() <= 0) {
                throw new InvalidLayoutException("memstore_flushsize must be greater than 0");
            }
        }

        // Ability to configure column name translation was introduced in version 1.5
        if (Versions.CONFIGURE_COLUMN_NAME_TRANSLATION_VERSION.compareTo(mLayoutVersion) > 0) {
            if (mDesc.getColumnNameTranslator() != ColumnNameTranslator.SHORT) {
                throw new InvalidLayoutException(
                        "Support for specifiying non-short column name translators begins with layout version "
                                + Versions.CONFIGURE_COLUMN_NAME_TRANSLATION_VERSION);
            }
        }

        // Composite keys and RowKeyFormat2 was introduced in version 1.1.
        if (Versions.RKF2_LAYOUT_VERSION.compareTo(mLayoutVersion) > 0
                && mDesc.getKeysFormat() instanceof RowKeyFormat2) {
            // Cannot use RowKeyFormat2 if this is the case.
            throw new InvalidLayoutException(
                    "Support for specifying keys_format as a RowKeyFormat2 begins with layout version "
                            + Versions.RKF2_LAYOUT_VERSION);
        }

        if (!isValidName(getName())) {
            throw new InvalidLayoutException(String.format("Invalid table name: '%s'.", getName()));
        }

        if (reference != null) {
            if (!getName().equals(reference.getName())) {
                throw new InvalidLayoutException(String.format(
                        "Invalid layout update: layout name '%s' does not match reference layout name '%s'.",
                        getName(), reference.getName()));
            }

            if (!mDesc.getKeysFormat().equals(reference.getDesc().getKeysFormat())) {
                throw new InvalidLayoutException(String.format(
                        "Invalid layout update from reference row keys format '%s' to row keys format '%s'.",
                        reference.getDesc().getKeysFormat(), mDesc.getKeysFormat()));
            }
        }

        // Layout ID:
        if (mDesc.getLayoutId() == null) {
            try {
                final long refLayoutId = (reference == null) ? 0
                        : Long.parseLong(reference.getDesc().getLayoutId());
                final long layoutId = refLayoutId + 1;
                mDesc.setLayoutId(Long.toString(layoutId));
            } catch (NumberFormatException nfe) {
                throw new InvalidLayoutException(
                        String.format("Reference layout for table '%s' has an invalid layout ID: '%s'", getName(),
                                reference.getDesc().getLayoutId()));
            }
        }

        if (mDesc.getKeysFormat() instanceof RowKeyFormat) {
            isValidRowKeyFormat1((RowKeyFormat) mDesc.getKeysFormat());
        } else if (mDesc.getKeysFormat() instanceof RowKeyFormat2) {
            // Check validity of row key format.
            isValidRowKeyFormat2((RowKeyFormat2) mDesc.getKeysFormat());
        }

        // Build localities:

        /**
         * Reference map from locality group name to locality group ID.
         * Entries are removed as we process locality group descriptors in the new layout.
         * At the end of the process, this map must be empty.
         */
        final BiMap<String, ColumnId> refLGIdMap = (reference == null) ? HashBiMap.<String, ColumnId>create()
                : HashBiMap.create(reference.mLocalityGroupIdNameMap.inverse());

        /** Map of locality groups in the new layout. */
        final List<LocalityGroupLayout> localityGroups = Lists.newArrayList();
        final Map<String, LocalityGroupLayout> lgMap = Maps.newHashMap();
        final BiMap<ColumnId, String> idMap = HashBiMap.create();

        /** Locality group with no ID assigned yet. */
        final List<LocalityGroupLayout> unassigned = Lists.newArrayList();

        /** All the families in the table. */
        final List<FamilyLayout> families = Lists.newArrayList();

        /** Map from family name or alias to family layout. */
        final Map<String, FamilyLayout> familyMap = Maps.newHashMap();

        /** All primary column names (including map-type families). */
        final Set<KijiColumnName> columnNames = Sets.newTreeSet();

        final Map<KijiColumnName, ColumnLayout> columnMap = Maps.newHashMap();

        final Iterator<LocalityGroupDesc> itLGDesc = mDesc.getLocalityGroups().iterator();
        while (itLGDesc.hasNext()) {
            final LocalityGroupDesc lgDesc = itLGDesc.next();
            final boolean isRename = (lgDesc.getRenamedFrom() != null);
            final String refLGName = isRename ? lgDesc.getRenamedFrom() : lgDesc.getName();
            lgDesc.setRenamedFrom(null);
            if (isRename && (reference == null)) {
                throw new InvalidLayoutException(String
                        .format("Invalid rename: no reference table layout for locality group '%s'.", refLGName));
            }
            final LocalityGroupLayout refLGLayout = (reference != null) ? reference.mLocalityGroupMap.get(refLGName)
                    : null;
            if (isRename && (refLGLayout == null)) {
                throw new InvalidLayoutException(
                        String.format("Invalid rename: cannot find reference locality group '%s'.", refLGName));
            }

            final ColumnId refLGId = refLGIdMap.remove(refLGName);

            if (lgDesc.getDelete()) {
                // This locality group is deleted:
                if (refLGId == null) {
                    throw new InvalidLayoutException(String.format(
                            "Attempting to delete locality group '%s' unknown in reference layout.", refLGName));
                }
                itLGDesc.remove();
                continue;
            }

            // BloomType, block_size were introduced in version 1.2.
            if (Versions.BLOCK_SIZE_LAYOUT_VERSION.compareTo(mLayoutVersion) > 0) {
                if (lgDesc.getBlockSize() != null) {
                    // Cannot use max_filesize if this is the case.
                    throw new InvalidLayoutException("Support for specifying block_size begins with layout version "
                            + Versions.BLOCK_SIZE_LAYOUT_VERSION);
                }
                if (lgDesc.getBloomType() != null) {
                    // Cannot use bloom_type if this is the case.
                    throw new InvalidLayoutException("Support for specifying bloom_type begins with layout version "
                            + Versions.BLOCK_SIZE_LAYOUT_VERSION);
                }
            } else {
                if (lgDesc.getBlockSize() != null && lgDesc.getBlockSize() <= 0) {
                    throw new InvalidLayoutException("block_size must be greater than 0");
                }
            }

            final LocalityGroupLayout lgLayout = new LocalityGroupLayout(lgDesc, refLGLayout);
            localityGroups.add(lgLayout);
            for (String lgName : lgLayout.getNames()) {
                Preconditions.checkState(lgMap.put(lgName, lgLayout) == null,
                        "Duplicate locality group name: " + lgName);
            }

            if (lgLayout.getId() != null) {
                final String previous = idMap.put(lgLayout.getId(), lgLayout.getName());
                Preconditions.checkState(previous == null,
                        String.format("Duplicate locality group ID '%s' associated to '%s' and '%s'.",
                                lgLayout.getId(), lgLayout.getName(), previous));
            } else {
                unassigned.add(lgLayout);
            }

            families.addAll(lgLayout.getFamilies());
            for (FamilyLayout familyLayout : lgLayout.getFamilies()) {
                for (String familyName : familyLayout.getNames()) {
                    if (null != familyMap.put(familyName, familyLayout)) {
                        throw new InvalidLayoutException(
                                String.format("Layout for table '%s' contains duplicate family name '%s'.",
                                        getName(), familyName));
                    }
                }

                if (familyLayout.isMapType()) {
                    Preconditions.checkState(columnNames.add(KijiColumnName.create(familyLayout.getName(), null)));
                }

                for (ColumnLayout columnLayout : familyLayout.getColumns()) {
                    for (String columnName : columnLayout.getNames()) {
                        final KijiColumnName column = KijiColumnName.create(familyLayout.getName(), columnName);
                        if (null != columnMap.put(column, columnLayout)) {
                            throw new InvalidLayoutException(String.format(
                                    "Layout for table '%s' contains duplicate column '%s'.", getName(), column));
                        }
                    }
                    Preconditions.checkState(
                            columnNames.add(KijiColumnName.create(familyLayout.getName(), columnLayout.getName())));
                }
            }
        }

        if (!refLGIdMap.isEmpty()) {
            throw new InvalidLayoutException(String.format("Missing descriptor(s) for locality group(s): %s.",
                    Joiner.on(",").join(refLGIdMap.keySet())));
        }

        mLocalityGroups = ImmutableList.copyOf(localityGroups);
        mLocalityGroupMap = ImmutableMap.copyOf(lgMap);

        mFamilies = ImmutableList.copyOf(families);
        mFamilyMap = ImmutableMap.copyOf(familyMap);

        mColumnNames = ImmutableSet.copyOf(columnNames);

        // Assign IDs to locality groups:
        int nextColumnId = 1;
        for (LocalityGroupLayout localityGroup : unassigned) {
            Preconditions.checkState(localityGroup.getId() == null);
            while (true) {
                final ColumnId columnId = new ColumnId(nextColumnId);
                nextColumnId += 1;
                if (!idMap.containsKey(columnId)) {
                    localityGroup.setId(columnId);
                    idMap.put(columnId, localityGroup.getName());
                    break;
                }
            }
        }

        mLocalityGroupIdNameMap = ImmutableBiMap.copyOf(idMap);
    }
    // CSON: MethodLengthCheck

    /**
     * Returns the Avro descriptor for this table layout.
     * @return the Avro descriptor for this table layout.
     */
    public TableLayoutDesc getDesc() {
        return TableLayoutDesc.newBuilder(mDesc).build();
    }

    /**
     * Returns the table name.
     * @return the table name.
     */
    public String getName() {
        return mDesc.getName();
    }

    /**
     * Returns the locality groups in the table, in no particular order.
     * @return the locality groups in the table, in no particular order.
     */
    public Collection<LocalityGroupLayout> getLocalityGroups() {
        return mLocalityGroups;
    }

    /**
     * Returns the bidirectional mapping between locality group names (no alias) and IDs.
     * @return the bidirectional mapping between locality group names (no alias) and IDs.
     */
    public BiMap<ColumnId, String> getLocalityGroupIdNameMap() {
        return mLocalityGroupIdNameMap;
    }

    /**
     * Returns the map from locality group names and aliases to layouts.
     * @return the map from locality group names and aliases to layouts.
     */
    public Map<String, LocalityGroupLayout> getLocalityGroupMap() {
        return mLocalityGroupMap;
    }

    /**
     * Returns the map from locality group names and aliases to layouts.
     * @return the map from locality group names and aliases to layouts.
     */
    public Map<String, FamilyLayout> getFamilyMap() {
        return mFamilyMap;
    }

    /**
     * Returns all the families in the table, in no particular order.
     * @return all the families in the table, in no particular order.
     */
    public Collection<FamilyLayout> getFamilies() {
        return mFamilies;
    }

    /**
     * Returns all the primary column names in the table, including map-type families.
     * @return all the primary column names in the table, including map-type families.
     */
    public Set<KijiColumnName> getColumnNames() {
        return mColumnNames;
    }

    /**
     * Reports the raw specification record for the specified column.
     *
     * <p> Note: in most cases, you should use {@link #getCellSpec(KijiColumnName)}. </p>
     *
     * @param columnName Column to reports the raw specification record of.
     * @return the raw specification record for the specified column.
     * @throws NoSuchColumnException if the column does not exist.
     */
    public CellSchema getCellSchema(KijiColumnName columnName) throws NoSuchColumnException {
        final FamilyLayout fLayout = mFamilyMap.get(columnName.getFamily());
        if (fLayout == null) {
            throw new NoSuchColumnException(
                    String.format("Table '%s' has no family '%s'.", getName(), columnName.getFamily()));
        }
        if (fLayout.isMapType()) {
            return CellSchema.newBuilder(fLayout.getDesc().getMapSchema()).build();
        }

        // Group-type family:
        Preconditions.checkArgument(columnName.isFullyQualified(),
                String.format("Cannot get CellFormat for entire group-type family: '%s'.", columnName));
        final FamilyLayout.ColumnLayout cLayout = fLayout.getColumnMap().get(columnName.getQualifier());
        if (cLayout == null) {
            throw new NoSuchColumnException(String.format("Table '%s' has no column '%s'.", getName(), columnName));
        }
        return CellSchema.newBuilder(cLayout.getDesc().getColumnSchema()).build();
    }

    /**
     * Reports the Avro schema of the specified column.
     *
     * <p> This method will return null in most cases on table with layout validation enabled. </p>
     *
     * @param columnName Column name.
     * @return the Avro schema of the column.
     * @throws InvalidLayoutException if the layout is invalid.
     * @throws NoSuchColumnException if the column does not exist.
     * @deprecated With schema validation and layout 1.3, there is no single Avro schema associated
     *     with a column anymore.
     *     Use {@link #getCellSpec(KijiColumnName)} to obtain further details about a column.
     */
    @Deprecated
    public Schema getSchema(KijiColumnName columnName) throws InvalidLayoutException, NoSuchColumnException {
        return CellSpec.readAvroSchema(getCellSchema(columnName));
    }

    /**
     * Reports the cell format for the specified column.
     *
     * @param column Column name.
     * @return the cell format for the column.
     * @throws NoSuchColumnException if the column does not exist.
     * @deprecated Use {@link #getCellSpec(KijiColumnName)} to obtain further details about a column.
     */
    @Deprecated
    public SchemaStorage getCellFormat(KijiColumnName column) throws NoSuchColumnException {
        return getCellSchema(column).getStorage();
    }

    /**
     * Reports the specification of the specified column.
     *
     * @param column Column to report the specification of.
     * @return the specification for the specified column.
     * @throws IOException on I/O error.
     */
    public CellSpec getCellSpec(KijiColumnName column) throws IOException {
        return CellSpec.fromCellSchema(getCellSchema(column)).setSchemaTable(mSchemaTable);
    }

    /**
     * Reports whether a column exists.
     *
     * @param column Column name.
     * @return whether the specified column exists.
     */
    public boolean exists(KijiColumnName column) {
        final FamilyLayout fLayout = mFamilyMap.get(column.getFamily());
        if (fLayout == null) {
            // Family does not exist:
            return false;
        }

        if (fLayout.isMapType()) {
            // This is a map-type family, we don't need to validate the qualifier:
            return true;
        }

        // This is a group-type family:
        if (!column.isFullyQualified()) {
            // No column qualifier, the group-type family exists:
            return true;
        }

        // Validate the qualifier:
        return fLayout.getColumnMap().containsKey(column.getQualifier());
    }

    /** {@inheritDoc} */
    @Override
    public boolean equals(Object other) {
        if (!(other instanceof KijiTableLayout)) {
            return false;
        }
        final KijiTableLayout otherLayout = (KijiTableLayout) other;
        return getDesc().equals(otherLayout.getDesc());
    }

    /** {@inheritDoc} */
    @Override
    public int hashCode() {
        return getDesc().hashCode();
    }

    /** {@inheritDoc} */
    @Override
    public String toString() {
        try {
            return ToJson.toJsonString(mDesc);
        } catch (IOException ioe) {
            throw new RuntimeException(ioe);
        }
    }

    /**
     * Binds this table layout to the specified schema table.
     *
     * <p> Once set, the schema table bound to a table layout cannot be modified. </p>
     *
     * @param schemaTable Avro schema table to bind this layout to.
     * @return this layout.
     */
    public KijiTableLayout setSchemaTable(KijiSchemaTable schemaTable) {
        Preconditions.checkState(mSchemaTable == null);
        mSchemaTable = schemaTable;
        return this;
    }

    /**
     * Returns the schema table bound to this table layout. Null means unbound.
     * @return the schema table bound to this table layout. Null means unbound.
     */
    public KijiSchemaTable getSchemaTable() {
        return mSchemaTable;
    }

    // -----------------------------------------------------------------------------------------------

    /**
     * Validates a name (table name, locality group name, family name, or column name).
     *
     * @param name The name to validate.
     * @return whether the name is valid.
     */
    private static boolean isValidName(String name) {
        return KijiNameValidator.isValidLayoutName(name);
    }

    /**
     * Validates an alias (table name, locality group name, family name, or column name).
     *
     * @param alias The alias to validate.
     * @return whether the alias is valid.
     */
    private static boolean isValidAlias(String alias) {
        return KijiNameValidator.isValidAlias(alias);
    }

    /**
     * Validates a cell schema descriptor.
     *
     * Ignores failures due to specific Avro record classes not being present on the classpath.
     *
     * @param layoutVersion Version of the new table layout.
     * @param schema New cell schema descriptor.
     * @param reference Reference cell schema descriptor, or null.
     * @throws InvalidLayoutException if the cell schema descriptor is invalid
     *     or incompatible with the reference cell schema.
     */
    private static void validateCellSchema(ProtocolVersion layoutVersion, CellSchema schema, CellSchema reference)
            throws InvalidLayoutException {

        switch (schema.getType()) {
        case INLINE:
        case CLASS:
        case COUNTER:
            // Nothing to validate
            break;
        case AVRO: {
            if (layoutVersion.compareTo(Versions.LAYOUT_VALIDATION_VERSION) < 0) {
                throw new InvalidLayoutException(String.format(
                        "Cell type %s requires table layout version >= %s, "
                                + "got version %s in cell specification %s.",
                        schema.getType(), Versions.LAYOUT_VALIDATION_VERSION, layoutVersion, schema));
            }
            break;
        }
        case RAW_BYTES: {
            if (layoutVersion.compareTo(Versions.RAW_BYTES_CELL_ENCODING_VERSION) < 0) {
                throw new InvalidLayoutException(String.format(
                        "Cell type %s requires table layout version >= %s, "
                                + "got version %s in cell specification %s.",
                        schema.getType(), Versions.RAW_BYTES_CELL_ENCODING_VERSION, layoutVersion, schema));
            }
            break;
        }
        case PROTOBUF: {
            if (layoutVersion.compareTo(Versions.PROTOBUF_CELL_ENCODING_VERSION) < 0) {
                throw new InvalidLayoutException(String.format(
                        "Cell type %s requires table layout version >= %s, "
                                + "got version %s in cell specification %s.",
                        schema.getType(), Versions.PROTOBUF_CELL_ENCODING_VERSION, layoutVersion, schema));
            }
            break;
        }
        default:
            throw new InternalKijiError("Unhandled cell type: " + schema);
        }

        // Validate Avro schema through loading and parsing:
        try {
            CellSpec.readAvroSchema(schema);
        } catch (SchemaClassNotFoundException scnfe) {
            LOG.debug(String.format("Avro schema class '%s' not found.", schema.getValue()));
        }

        // Final schema storage is only valid with counters and inline schema:
        if (schema.getStorage() == SchemaStorage.FINAL) {
            switch (schema.getType()) {
            case INLINE:
            case COUNTER:
                break;
            default:
                throw new InvalidLayoutException(String.format("Invalid final column schema: %s.", schema));
            }
        }

        // Counters require schema storage final:
        if (schema.getType() == SchemaType.COUNTER) {
            if (schema.getStorage() != SchemaStorage.FINAL) {
                throw new InvalidLayoutException(
                        String.format("Invalid counter schema, storage must be final: %s.", schema));
            }
        }

        if (null != reference) {
            // Schema storage cannot change:
            if (schema.getStorage() != reference.getStorage()) {
                throw new InvalidLayoutException(
                        String.format("Cell schema storage cannot be modified from %s to %s.", reference, schema));
            }

            // Final schema cannot change:
            if ((reference.getStorage() == SchemaStorage.FINAL)
                    && !Objects.equal(schema.getValue(), reference.getValue())) {
                throw new InvalidLayoutException(
                        String.format("Final column schema cannot be modified from %s to %s.", reference, schema));
            }

            // Counter is forever:
            if ((reference.getType() == SchemaType.COUNTER) ^ (schema.getType() == SchemaType.COUNTER)) {
                throw new InvalidLayoutException(
                        String.format("Column schema cannot be modified from %s to %s.", reference, schema));
            }
        }
    }

    /**
     * Loads a table layout from the specified resource as JSON.
     *
     * @param resource Path of the resource containing the JSON layout description.
     * @return the parsed table layout.
     * @throws IOException on I/O error.
     */
    public static KijiTableLayout createFromEffectiveJsonResource(String resource) throws IOException {
        return createFromEffectiveJson(KijiTableLayout.class.getResourceAsStream(resource));
    }

    /**
     * Loads a table layout from the specified JSON text.
     *
     * @param istream Input stream containing the JSON text.
     * @return the parsed table layout.
     * @throws IOException on I/O error.
     */
    public static KijiTableLayout createFromEffectiveJson(InputStream istream) throws IOException {
        try {
            final TableLayoutDesc desc = readTableLayoutDescFromJSON(istream);
            final KijiTableLayout layout = new KijiTableLayout(desc, null);
            return layout;
        } finally {
            ResourceUtils.closeOrLog(istream);
        }
    }

    /**
     * Creates and returns a new KijiTableLayout instance as specified by an Avro TableLayoutDesc
     * description record.
     *
     * @param layout The Avro TableLayoutDesc descriptor record that describes the actual layout.
     * of the table.
     * @return A new table layout.
     * @throws InvalidLayoutException If the descriptor is invalid.
     */
    public static KijiTableLayout newLayout(TableLayoutDesc layout) throws InvalidLayoutException {
        return new KijiTableLayout(layout, null);
    }

    /**
     * Creates and returns a new KijiTableLayout instance as specified by composing updates described
     * by a {@link org.kiji.schema.avro.TableLayoutDesc TableLayoutDesc} with the original
     * KijiTableLayout.  See {@link org.kiji.schema.layout.KijiTableLayout KijiTableLayout}
     * for what can and cannot be updated.
     *
     * @param updateLayoutDesc The Avro TableLayoutDesc descriptor record that describes
     * the layout update.
     * @param oldLayout The old table layout.
     * @return A new table layout.
     * @throws InvalidLayoutException If the descriptor is invalid or inconsistent wrt reference.
     */
    public static KijiTableLayout createUpdatedLayout(TableLayoutDesc updateLayoutDesc, KijiTableLayout oldLayout)
            throws InvalidLayoutException {
        return new KijiTableLayout(updateLayoutDesc, oldLayout);
    }

    /**
     * Reads a table layout descriptor from its JSON serialized form.
     *
     * @param istream JSON input stream.
     * @return the decoded table layout descriptor.
     * @throws IOException on I/O error.
     */
    public static TableLayoutDesc readTableLayoutDescFromJSON(InputStream istream) throws IOException {
        final String json = IOUtils.toString(istream);
        final TableLayoutDesc desc = (TableLayoutDesc) FromJson.fromJsonString(json, TableLayoutDesc.SCHEMA$);
        return desc;
    }

    /**
     * Find the encoding of the row key given the format.
     *
     * @param rowKeyFormat Format of row keys of type RowKeyFormat or RowKeyFormat2.
     * @return The specific row key encoding, e.g. RAW, HASH, etc.
     */
    public static RowKeyEncoding getEncoding(Object rowKeyFormat) {
        if (rowKeyFormat instanceof RowKeyFormat) {
            return ((RowKeyFormat) rowKeyFormat).getEncoding();
        } else if (rowKeyFormat instanceof RowKeyFormat2) {
            return ((RowKeyFormat2) rowKeyFormat).getEncoding();
        } else {
            throw new RuntimeException("Unsupported Row Key Format");
        }
    }

    /**
     * Get the hash size for a given row key format.
     *
     * @param rowKeyFormat Format of row keys of type RowKeyFormat or RowKeyFormat2.
     * @return The size of the hash prefix.
     */
    public static int getHashSize(Object rowKeyFormat) {
        if (rowKeyFormat instanceof RowKeyFormat) {
            return ((RowKeyFormat) rowKeyFormat).getHashSize();
        } else if (rowKeyFormat instanceof RowKeyFormat2) {
            RowKeyFormat2 format2 = (RowKeyFormat2) rowKeyFormat;
            if (null == format2.getSalt()) {
                throw new RuntimeException("This RowKeyFormat2 instance does not specify salt/hashing.");
            } else {
                return format2.getSalt().getHashSize();
            }
        } else {
            throw new RuntimeException("Unsupported Row Key Format");
        }
    }
}