1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
// 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 ipc
import (
"io"
"github.com/apache/arrow-go/v18/arrow/internal/debug"
"github.com/apache/arrow-go/v18/arrow/internal/flatbuf"
"github.com/apache/arrow-go/v18/arrow/memory"
"github.com/klauspost/compress/zstd"
"github.com/pierrec/lz4/v4"
)
type compressor interface {
MaxCompressedLen(n int) int
Reset(io.Writer)
io.WriteCloser
Type() flatbuf.CompressionType
}
type lz4Compressor struct {
*lz4.Writer
}
func (lz4Compressor) MaxCompressedLen(n int) int {
return lz4.CompressBlockBound(n)
}
func (lz4Compressor) Type() flatbuf.CompressionType {
return flatbuf.CompressionTypeLZ4_FRAME
}
type zstdCompressor struct {
*zstd.Encoder
}
// from zstd.h, ZSTD_COMPRESSBOUND
func (zstdCompressor) MaxCompressedLen(len int) int {
debug.Assert(len >= 0, "MaxCompressedLen called with len less than 0")
extra := uint((uint(128<<10) - uint(len)) >> 11)
if len >= (128 << 10) {
extra = 0
}
return int(uint(len+(len>>8)) + extra)
}
func (zstdCompressor) Type() flatbuf.CompressionType {
return flatbuf.CompressionTypeZSTD
}
func getCompressor(codec flatbuf.CompressionType) compressor {
switch codec {
case flatbuf.CompressionTypeLZ4_FRAME:
w := lz4.NewWriter(nil)
// options here chosen in order to match the C++ implementation
w.Apply(lz4.ChecksumOption(false), lz4.BlockSizeOption(lz4.Block64Kb))
return &lz4Compressor{w}
case flatbuf.CompressionTypeZSTD:
enc, err := zstd.NewWriter(nil)
if err != nil {
panic(err)
}
return zstdCompressor{enc}
}
return nil
}
type decompressor interface {
io.Reader
Reset(io.Reader)
Close()
}
type zstdDecompressor struct {
*zstd.Decoder
}
func (z *zstdDecompressor) Reset(r io.Reader) {
if err := z.Decoder.Reset(r); err != nil {
panic(err)
}
}
func (z *zstdDecompressor) Close() {
z.Decoder.Close()
}
type lz4Decompressor struct {
*lz4.Reader
}
func (z *lz4Decompressor) Close() {
z.Reader.Reset(nil)
}
func getDecompressor(codec flatbuf.CompressionType) decompressor {
switch codec {
case flatbuf.CompressionTypeLZ4_FRAME:
return &lz4Decompressor{lz4.NewReader(nil)}
case flatbuf.CompressionTypeZSTD:
dec, err := zstd.NewReader(nil)
if err != nil {
panic(err)
}
return &zstdDecompressor{dec}
}
return nil
}
type bufferWriter struct {
buf *memory.Buffer
pos int
}
func (bw *bufferWriter) Write(p []byte) (n int, err error) {
if bw.pos+len(p) >= bw.buf.Cap() {
bw.buf.Reserve(bw.pos + len(p))
}
n = copy(bw.buf.Buf()[bw.pos:], p)
bw.pos += n
return
}
|
