io.permazen.encoding.SimpleEncodingRegistry Maven / Gradle / Ivy
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/*
* Copyright (C) 2015 Archie L. Cobbs. All rights reserved.
*/
package io.permazen.encoding;
import com.google.common.base.Preconditions;
import com.google.common.reflect.TypeToken;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Optional;
import org.dellroad.stuff.java.Primitive;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A straightforward {@link EncodingRegistry} implementation that creates object array types on demand.
*
*
* The {@link #add add()} method only accepts non-array types and primitive array types. All other
* array types are automatically created on demand via {@link #buildArrayEncoding buildArrayEncoding()}.
*/
public class SimpleEncodingRegistry implements EncodingRegistry {
protected final Logger log = LoggerFactory.getLogger(this.getClass());
final HashMap> byId = new HashMap<>();
final HashMap, List>> byType = new HashMap<>();
// Public Methods
/**
* Add a new {@link Encoding} to this registry.
*
*
* The type's encoding ID must not contain any array dimensions except for single dimension primitive array types.
*
* @param encoding the {@link Encoding} to register
* @return true if it was added, false if it was already registered
* @throws IllegalArgumentException if {@code encoding} is null
* @throws IllegalArgumentException if {@code encoding}'s encoding ID is null (i.e., {@code encoding} is anonymous)
* @throws IllegalArgumentException if {@code encoding}'s encoding ID conflicts with an existing, but different, encoding
* @throws IllegalArgumentException if {@code encoding}'s encoding ID has one or more array dimensions
*/
public synchronized boolean add(Encoding encoding) {
Preconditions.checkArgument(encoding != null, "null encoding");
final EncodingId encodingId = encoding.getEncodingId();
Preconditions.checkArgument(encodingId != null, "encoding is anonymous");
final TypeToken elementTypeToken = encoding.getTypeToken().getComponentType();
Preconditions.checkArgument((elementTypeToken == null) == (encodingId.getArrayDimensions() == 0),
"inconsistent encoding ID \"" + encodingId + "\" for type " + encoding.getTypeToken());
Preconditions.checkArgument(elementTypeToken == null || elementTypeToken.getRawType().isPrimitive(),
"illegal array type \"" + encodingId + "\"");
final Encoding otherEncoding = this.byId.get(encodingId);
if (otherEncoding != null) {
if (!otherEncoding.equals(encoding)) {
throw new IllegalArgumentException(
String.format("encoding ID \"%s\" for encoding %s conflicts with existing encoding %s",
encodingId, encoding, otherEncoding));
}
return false;
}
this.register(encodingId, encoding);
return true;
}
/**
* Add a null-safe version of the given non-null supporting {@link Encoding} to this registry.
*
*
* The {@code encoding} is wrapped in a {@link NullSafeEncoding} to add null value support.
*
* @param encodingId the ID for the newly added encoding
* @param inner the inner non-null supporting {@link Encoding}
* @return true if it was added, false if it was already registered
* @throws IllegalArgumentException if {@code inner} or {@code encodingId} is null
* @throws IllegalArgumentException if {@code inner}'s encoding ID conflicts with an existing, but different, encoding
* @throws IllegalArgumentException if {@code inner}'s encoding ID has one or more array dimensions
* @throws IllegalArgumentException if {@code inner} already supports null values
*/
public boolean addNullSafe(EncodingId encodingId, Encoding inner) {
return this.add(new NullSafeEncoding<>(encodingId, inner));
}
/**
* Build an array encoding for the given element encoding using Permazen's default array encoding.
*
*
* The element encoding must represent a non-primitive type.
* This method uses the generic array encoding provided by {@link ObjectArrayEncoding}, wrapped via {@link NullSafeEncoding}.
*
*
* If {@code elementEncoding} is anonymous, so will be the returned encoding, otherwise the returned encoding's
* {@link EncodingId} will be equal to {@code elementEncoding.}{@link EncodingId#getArrayId getArrayId()}.
*
* @param elementEncoding element encoding
* @return corresponding array encoding
* @throws IllegalArgumentException if {@code elementEncoding} is null
* @throws IllegalArgumentException if {@code elementEncoding} encodes a primitive type
* @throws IllegalArgumentException if {@code elementEncoding} encodes an array type with 255 dimensions
*/
@SuppressWarnings("unchecked")
public static Encoding buildArrayEncoding(final Encoding elementEncoding) {
Preconditions.checkArgument(elementEncoding != null, "null elementEncoding");
Preconditions.checkArgument(Primitive.get(elementEncoding.getTypeToken().getRawType()) == null, "primitive element type");
final EncodingId encodingId = Optional.ofNullable(elementEncoding.getEncodingId()).map(EncodingId::getArrayId).orElse(null);
return new NullSafeEncoding<>(encodingId, new ObjectArrayEncoding<>(elementEncoding));
}
// EncodingRegistry
@Override
public synchronized Encoding getEncoding(EncodingId encodingId) {
// Sanity check
Preconditions.checkArgument(encodingId != null, "null encodingId");
// See if already registered
Encoding encoding = this.byId.get(encodingId);
if (encoding != null)
return encoding;
// Auto-register array encodings using element encoding
if (encodingId.getArrayDimensions() > 0) {
final Encoding elementEncoding = this.getEncoding(encodingId.getElementId());
if (elementEncoding != null) {
encoding = SimpleEncodingRegistry.buildArrayEncoding(elementEncoding);
this.register(encodingId, encoding);
}
}
// Done
return encoding;
}
@Override
@SuppressWarnings("unchecked")
public synchronized List> getEncodings(TypeToken typeToken) {
// Sanity check
Preconditions.checkArgument(typeToken != null, "null typeToken");
// See if already registered
List> encodingList = (List>)(Object)this.byType.get(typeToken);
// If not found, and type is an array type, find element type(s) and (as found) auto-register array type(s)
if (encodingList == null) {
final TypeToken elementTypeToken = typeToken.getComponentType();
if (elementTypeToken != null) {
this.getEncodings(elementTypeToken).stream()
.map(Encoding::getEncodingId)
.map(EncodingId::getArrayId)
.iterator()
.forEachRemaining(this::getEncoding);
encodingList = (List>)(Object)this.byType.get(typeToken);
}
}
// Return a copy of the list for safety
return encodingList != null ? new ArrayList<>(encodingList) : Collections.emptyList();
}
// Internal Methods
/**
* Register a new {@link Encoding}.
*
* @param encodingId encoding ID under which to register the new encoding
* @param encoding the new encoding to register
* @throws IllegalArgumentException if either parameter is null
* @throws IllegalArgumentException if there is already a encoding registered under {@code encodingId}
* @throws IllegalArgumentException if {@code encoding} is anonymous or has an encoding ID different from {@code encodingId}
*/
protected synchronized void register(EncodingId encodingId, Encoding encoding) {
Preconditions.checkArgument(encodingId != null, "null encodingId");
Preconditions.checkArgument(encoding != null, "null encoding");
Preconditions.checkArgument(encoding.getEncodingId() != null, "encoding is anonymous");
Preconditions.checkArgument(encoding.getEncodingId().equals(encodingId), "encoding ID mismatch");
Preconditions.checkArgument(!this.byId.containsKey(encodingId), "encoding ID is already registered");
this.log.debug("{}: registering encoding \"{}\" for type {}",
this.getClass().getSimpleName(), encodingId, encoding.getTypeToken());
this.byId.put(encodingId, encoding);
this.byType.computeIfAbsent(encoding.getTypeToken(), typeToken -> new ArrayList<>(1)).add(encoding);
}
}