pulsar/internal/compression/compression.go

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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 compression

import "io"

type Level int

const (
	Default Level = iota
	Faster
	Better
)

// Provider is a interface of compression providers
type Provider interface {
	// Return the max possible size for a compressed buffer given the uncompressed data size
	CompressMaxSize(originalSize int) int

	// Compress a []byte, the param is a []byte with the uncompressed content.
	// The reader/writer indexes will not be modified. The return is a []byte
	// with the compressed content.
	Compress(dst, src []byte) []byte

	// Decompress a []byte. The buffer needs to have been compressed with the matching Encoder.
	// The src is compressed content. If dst is passed, the decompressed data will be written there
	// The return were the result will be passed, if err is nil, the buffer was decompressed, no nil otherwise.
	Decompress(dst, src []byte, originalSize int) ([]byte, error)

	// Returns a new instance of the same provider, with the same exact configuration
	Clone() Provider

	// Close the compressor
	io.Closer
}