io.atomix.catalyst.buffer.MappedBuffer Maven / Gradle / Ivy
/*
* Copyright 2015 the original author or authors.
*
* 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 io.atomix.catalyst.buffer;
import io.atomix.catalyst.buffer.util.MappedMemory;
import io.atomix.catalyst.buffer.util.MappedMemoryAllocator;
import io.atomix.catalyst.buffer.util.Memory;
import io.atomix.catalyst.util.reference.ReferenceManager;
import java.io.File;
import java.nio.channels.FileChannel;
/**
* Memory mapped file buffer.
*
* Mapped buffers provide direct access to memory from allocated by a {@link java.nio.MappedByteBuffer}. Memory is allocated
* by opening and expanding the given {@link java.io.File} to the desired {@code count} and mapping the file contents into memory
* via {@link java.nio.channels.FileChannel#map(java.nio.channels.FileChannel.MapMode, long, long)}.
*
* @author Jordan Halterman
*/
public class MappedBuffer extends NativeBuffer {
private static final long DEFAULT_INITIAL_CAPACITY = 1024 * 1024 * 16;
/**
* Allocates a dynamic capacity mapped buffer in {@link java.nio.channels.FileChannel.MapMode#READ_WRITE} mode with an initial capacity
* of {@code 16MiB} and a maximum capacity of {@link Integer#MAX_VALUE}.
*
* The resulting buffer will have a maximum capacity of {@link Integer#MAX_VALUE}. As bytes are written to the buffer
* its capacity will double in count each time the current capacity is reached. Memory will be mapped by opening and
* expanding the given {@link java.io.File} to the desired {@code capacity} and mapping the file contents into memory via
* {@link java.nio.channels.FileChannel#map(java.nio.channels.FileChannel.MapMode, long, long)}.
*
* @param file The file to map into memory.
* @return The mapped buffer.
* @throws NullPointerException If {@code file} is {@code null}
*
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode)
* @see MappedBuffer#allocate(java.io.File, long)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode, long)
* @see MappedBuffer#allocate(java.io.File, long, long)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode, long, long)
*/
public static MappedBuffer allocate(File file) {
return allocate(file, MappedMemoryAllocator.DEFAULT_MAP_MODE, DEFAULT_INITIAL_CAPACITY, Long.MAX_VALUE);
}
/**
* Allocates a dynamic capacity mapped buffer in {@link java.nio.channels.FileChannel.MapMode#READ_WRITE} mode with an initial capacity
* of {@code 16MiB} and a maximum capacity of {@link Integer#MAX_VALUE}.
*
* The resulting buffer will be initialized to a capacity of {@code 4096} and have a maximum capacity of
* {@link Integer#MAX_VALUE}. As bytes are written to the buffer its capacity will double in count each time the current
* capacity is reached. Memory will be mapped by opening and expanding the given {@link java.io.File} to the desired
* {@code capacity} and mapping the file contents into memory via
* {@link java.nio.channels.FileChannel#map(java.nio.channels.FileChannel.MapMode, long, long)}.
*
* @param file The file to map into memory.
* @param mode The mode with which to map the file.
* @return The mapped buffer.
* @throws NullPointerException If {@code file} is {@code null}
*
* @see MappedBuffer#allocate(java.io.File)
* @see MappedBuffer#allocate(java.io.File, long)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode, long)
* @see MappedBuffer#allocate(java.io.File, long, long)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode, long, long)
*/
public static MappedBuffer allocate(File file, FileChannel.MapMode mode) {
return allocate(file, mode, DEFAULT_INITIAL_CAPACITY, Long.MAX_VALUE);
}
/**
* Allocates a fixed capacity mapped buffer in {@link java.nio.channels.FileChannel.MapMode#READ_WRITE} mode.
*
* Memory will be mapped by opening and expanding the given {@link java.io.File} to the desired {@code capacity} and mapping the
* file contents into memory via {@link java.nio.channels.FileChannel#map(java.nio.channels.FileChannel.MapMode, long, long)}.
*
* The resulting buffer will have a capacity of {@code capacity}. The underlying {@link MappedBytes} will be
* initialized to the next power of {@code 2}.
*
* @param file The file to map into memory.
* @param capacity The fixed capacity of the buffer to allocate (in bytes).
* @return The mapped buffer.
* @throws NullPointerException If {@code file} is {@code null}
* @throws IllegalArgumentException If the {@code capacity} is greater than {@link Integer#MAX_VALUE}.
*
* @see MappedBuffer#allocate(java.io.File)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode, long)
* @see MappedBuffer#allocate(java.io.File, long, long)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode, long, long)
*/
public static MappedBuffer allocate(File file, long capacity) {
return allocate(file, MappedMemoryAllocator.DEFAULT_MAP_MODE, capacity, capacity);
}
/**
* Allocates a fixed capacity mapped buffer in the given {@link java.nio.channels.FileChannel.MapMode}.
*
* Memory will be mapped by opening and expanding the given {@link java.io.File} to the desired {@code capacity} and mapping the
* file contents into memory via {@link java.nio.channels.FileChannel#map(java.nio.channels.FileChannel.MapMode, long, long)}.
*
* The resulting buffer will have a capacity of {@code capacity}. The underlying {@link MappedBytes} will be
* initialized to the next power of {@code 2}.
*
* @param file The file to map into memory.
* @param mode The mode with which to map the file.
* @param capacity The fixed capacity of the buffer to allocate (in bytes).
* @return The mapped buffer.
* @throws NullPointerException If {@code file} is {@code null}
* @throws IllegalArgumentException If the {@code capacity} is greater than {@link Integer#MAX_VALUE}.
*
* @see MappedBuffer#allocate(java.io.File)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode)
* @see MappedBuffer#allocate(java.io.File, long)
* @see MappedBuffer#allocate(java.io.File, long, long)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode, long, long)
*/
public static MappedBuffer allocate(File file, FileChannel.MapMode mode, long capacity) {
return allocate(file, mode, capacity, capacity);
}
/**
* Allocates a mapped buffer.
*
* Memory will be mapped by opening and expanding the given {@link java.io.File} to the desired {@code count} and mapping the
* file contents into memory via {@link java.nio.channels.FileChannel#map(java.nio.channels.FileChannel.MapMode, long, long)}.
*
* The resulting buffer will have a capacity of {@code initialCapacity}. The underlying {@link MappedBytes} will be
* initialized to the next power of {@code 2}. As bytes are written to the buffer, the buffer's capacity will double
* as long as {@code maxCapacity > capacity}.
*
* @param file The file to map into memory. If the file doesn't exist it will be automatically created.
* @param initialCapacity The initial capacity of the buffer.
* @param maxCapacity The maximum capacity of the buffer.
* @return The mapped buffer.
* @throws NullPointerException If {@code file} is {@code null}
* @throws IllegalArgumentException If the {@code capacity} or {@code maxCapacity} is greater than
* {@link Integer#MAX_VALUE}.
*
* @see MappedBuffer#allocate(java.io.File)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode)
* @see MappedBuffer#allocate(java.io.File, long)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode, long)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode, long, long)
*/
public static MappedBuffer allocate(File file, long initialCapacity, long maxCapacity) {
return allocate(file, MappedMemoryAllocator.DEFAULT_MAP_MODE, initialCapacity, maxCapacity);
}
/**
* Allocates a mapped buffer.
*
* Memory will be mapped by opening and expanding the given {@link java.io.File} to the desired {@code count} and mapping the
* file contents into memory via {@link java.nio.channels.FileChannel#map(java.nio.channels.FileChannel.MapMode, long, long)}.
*
* The resulting buffer will have a capacity of {@code initialCapacity}. The underlying {@link MappedBytes} will be
* initialized to the next power of {@code 2}. As bytes are written to the buffer, the buffer's capacity will double
* as long as {@code maxCapacity > capacity}.
*
* @param file The file to map into memory. If the file doesn't exist it will be automatically created.
* @param mode The mode with which to map the file.
* @param initialCapacity The initial capacity of the buffer.
* @param maxCapacity The maximum capacity of the buffer.
* @return The mapped buffer.
* @throws NullPointerException If {@code file} is {@code null}
* @throws IllegalArgumentException If the {@code capacity} or {@code maxCapacity} is greater than
* {@link Integer#MAX_VALUE}.
*
* @see MappedBuffer#allocate(java.io.File)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode)
* @see MappedBuffer#allocate(java.io.File, long)
* @see MappedBuffer#allocate(java.io.File, java.nio.channels.FileChannel.MapMode, long)
* @see MappedBuffer#allocate(java.io.File, long, long)
*/
public static MappedBuffer allocate(File file, FileChannel.MapMode mode, long initialCapacity, long maxCapacity) {
if (file == null)
throw new NullPointerException("file cannot be null");
if (mode == null)
mode = MappedMemoryAllocator.DEFAULT_MAP_MODE;
if (initialCapacity > maxCapacity)
throw new IllegalArgumentException("initial capacity cannot be greater than maximum capacity");
if (initialCapacity > MappedMemory.MAX_SIZE)
throw new IllegalArgumentException("initial capacity for MappedBuffer cannot be greater than " + MappedMemory.MAX_SIZE);
if (maxCapacity > MappedMemory.MAX_SIZE)
throw new IllegalArgumentException("maximum capacity for MappedBuffer cannot be greater than " + MappedMemory.MAX_SIZE);
return new MappedBuffer(new MappedBytes(file, MappedMemory.allocate(file, mode, Memory.Util.toPow2(initialCapacity))), 0, initialCapacity, maxCapacity);
}
protected MappedBuffer(MappedBytes bytes, ReferenceManager referenceManager) {
super(bytes, referenceManager);
}
MappedBuffer(MappedBytes bytes, long offset, long initialCapacity, long maxCapacity) {
super(bytes, offset, initialCapacity, maxCapacity);
}
/**
* Deletes the underlying file.
*/
public void delete() {
((MappedBytes) bytes).delete();
}
}