net.openhft.chronicle.bytes.util.UTF8StringInterner Maven / Gradle / Ivy
/*
* Copyright (c) 2016-2022 chronicle.software
*
* https://chronicle.software
*
* 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 net.openhft.chronicle.bytes.util;
import net.openhft.chronicle.bytes.AppendableUtil;
import net.openhft.chronicle.bytes.BytesStore;
import net.openhft.chronicle.bytes.UTFDataFormatRuntimeException;
import net.openhft.chronicle.core.annotation.NonNegative;
import net.openhft.chronicle.core.io.ClosedIllegalStateException;
import net.openhft.chronicle.core.io.ThreadingIllegalStateException;
import net.openhft.chronicle.core.pool.StringBuilderPool;
import net.openhft.chronicle.core.scoped.ScopedResource;
import net.openhft.chronicle.core.scoped.ScopedResourcePool;
import org.jetbrains.annotations.NotNull;
import java.nio.BufferUnderflowException;
/**
* A specialized interner for interning strings encoded in UTF-8.
*
* This class extends {@link AbstractInterner} and overrides its getValue method to intern
* strings encoded in UTF-8 format represented in {@link BytesStore}.
*/
public class UTF8StringInterner extends AbstractInterner {
/**
* A pool of {@link StringBuilder} instances, used for efficient string construction.
*/
private static final ScopedResourcePool SBP = StringBuilderPool.createThreadLocal(1);
/**
* Constructs a new UTF8StringInterner with the specified capacity.
*
* @param capacity the maximum number of items that the interner can hold.
*/
public UTF8StringInterner(@NonNegative int capacity) {
super(capacity);
}
/**
* Converts the bytes from a {@link BytesStore} into a UTF-8 encoded string.
* The bytes are assumed to be in UTF-8 format and are decoded accordingly.
*
* @param cs the {@link BytesStore} containing the bytes to be converted
* @param length the number of bytes to read from the {@link BytesStore}
* @return the resulting UTF-8 encoded string
* @throws UTFDataFormatRuntimeException If the bytes are not valid UTF-8 encoded characters
* @throws BufferUnderflowException If the buffer's limits are exceeded
* @throws ClosedIllegalStateException If the resource has been released or closed.
* @throws ThreadingIllegalStateException If this resource was accessed by multiple threads in an unsafe way
*/
@SuppressWarnings("rawtypes")
@Override
@NotNull
protected String getValue(@NotNull BytesStore cs, @NonNegative int length)
throws UTFDataFormatRuntimeException, IllegalStateException, BufferUnderflowException {
try (final ScopedResource sbTl = SBP.get()) {
// Acquire a StringBuilder from the pool for efficient string construction
StringBuilder sb = sbTl.get();
// Parse the bytes as UTF-8 and append them to the StringBuilder
AppendableUtil.parseUtf8(cs, sb, true, length);
// Convert the StringBuilder to a string and return it
return sb.toString();
}
}
}