112 lines
2.9 KiB
Go
112 lines
2.9 KiB
Go
|
// Copyright (C) MongoDB, Inc. 2017-present.
|
||
|
|
//
|
||
|
|
// 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
|
||
|
|
|
||
|
|
package driver
|
||
|
|
|
||
|
|
import (
|
||
|
|
"bytes"
|
||
|
|
"compress/zlib"
|
||
|
|
"fmt"
|
||
|
|
"io"
|
||
|
|
"sync"
|
||
|
|
|
||
|
|
"github.com/golang/snappy"
|
||
|
|
"github.com/klauspost/compress/zstd"
|
||
|
|
"go.mongodb.org/mongo-driver/x/mongo/driver/wiremessage"
|
||
|
|
)
|
||
|
|
|
||
|
|
// CompressionOpts holds settings for how to compress a payload
|
||
|
|
type CompressionOpts struct {
|
||
|
|
Compressor wiremessage.CompressorID
|
||
|
|
ZlibLevel int
|
||
|
|
ZstdLevel int
|
||
|
|
UncompressedSize int32
|
||
|
|
}
|
||
|
|
|
||
|
|
var zstdEncoders = &sync.Map{}
|
||
|
|
|
||
|
|
func getZstdEncoder(l zstd.EncoderLevel) (*zstd.Encoder, error) {
|
||
|
|
v, ok := zstdEncoders.Load(l)
|
||
|
|
if ok {
|
||
|
|
return v.(*zstd.Encoder), nil
|
||
|
|
}
|
||
|
|
encoder, err := zstd.NewWriter(nil, zstd.WithEncoderLevel(l))
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
zstdEncoders.Store(l, encoder)
|
||
|
|
return encoder, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// CompressPayload takes a byte slice and compresses it according to the options passed
|
||
|
|
func CompressPayload(in []byte, opts CompressionOpts) ([]byte, error) {
|
||
|
|
switch opts.Compressor {
|
||
|
|
case wiremessage.CompressorNoOp:
|
||
|
|
return in, nil
|
||
|
|
case wiremessage.CompressorSnappy:
|
||
|
|
return snappy.Encode(nil, in), nil
|
||
|
|
case wiremessage.CompressorZLib:
|
||
|
|
var b bytes.Buffer
|
||
|
|
w, err := zlib.NewWriterLevel(&b, opts.ZlibLevel)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
_, err = w.Write(in)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
err = w.Close()
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
return b.Bytes(), nil
|
||
|
|
case wiremessage.CompressorZstd:
|
||
|
|
encoder, err := getZstdEncoder(zstd.EncoderLevelFromZstd(opts.ZstdLevel))
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
return encoder.EncodeAll(in, nil), nil
|
||
|
|
default:
|
||
|
|
return nil, fmt.Errorf("unknown compressor ID %v", opts.Compressor)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// DecompressPayload takes a byte slice that has been compressed and undoes it according to the options passed
|
||
|
|
func DecompressPayload(in []byte, opts CompressionOpts) ([]byte, error) {
|
||
|
|
switch opts.Compressor {
|
||
|
|
case wiremessage.CompressorNoOp:
|
||
|
|
return in, nil
|
||
|
|
case wiremessage.CompressorSnappy:
|
||
|
|
uncompressed := make([]byte, opts.UncompressedSize)
|
||
|
|
return snappy.Decode(uncompressed, in)
|
||
|
|
case wiremessage.CompressorZLib:
|
||
|
|
decompressor, err := zlib.NewReader(bytes.NewReader(in))
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
uncompressed := make([]byte, opts.UncompressedSize)
|
||
|
|
_, err = io.ReadFull(decompressor, uncompressed)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
return uncompressed, nil
|
||
|
|
case wiremessage.CompressorZstd:
|
||
|
|
w, err := zstd.NewReader(bytes.NewBuffer(in))
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
defer w.Close()
|
||
|
|
var b bytes.Buffer
|
||
|
|
_, err = io.Copy(&b, w)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
return b.Bytes(), nil
|
||
|
|
default:
|
||
|
|
return nil, fmt.Errorf("unknown compressor ID %v", opts.Compressor)
|
||
|
|
}
|
||
|
|
}
|