forked from pingcap/tidb
-
Notifications
You must be signed in to change notification settings - Fork 0
/
chunk.go
339 lines (301 loc) · 10.4 KB
/
chunk.go
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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
// Copyright 2017 PingCAP, Inc.
//
// 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,
// See the License for the specific language governing permissions and
// limitations under the License.
package chunk
import (
"encoding/binary"
"unsafe"
"github.com/pingcap/tidb/types"
"github.com/pingcap/tidb/types/json"
)
// Chunk stores multiple rows of data in Apache Arrow format.
// See https://arrow.apache.org/docs/memory_layout.html
// Values are appended in compact format and can be directly accessed without decoding.
// When the chunk is done processing, we can reuse the allocated memory by resetting it.
type Chunk struct {
columns []*column
// numVirtualRows indicates the number of virtual rows, which have zero column.
// It is used only when this Chunk doesn't hold any data, i.e. "len(columns)==0".
numVirtualRows int
}
// Capacity constants.
const (
InitialCapacity = 32
)
// NewChunkWithCapacity creates a new chunk with field types and capacity.
func NewChunkWithCapacity(fields []*types.FieldType, cap int) *Chunk {
chk := new(Chunk)
chk.columns = make([]*column, 0, len(fields))
chk.numVirtualRows = 0
for _, f := range fields {
chk.addColumnByFieldType(f, cap)
}
return chk
}
// MemoryUsage returns the total memory usage of a Chunk in B.
// We ignore the size of column.length and column.nullCount
// since they have little effect of the total memory usage.
func (c *Chunk) MemoryUsage() (sum int64) {
for _, col := range c.columns {
curColMemUsage := int64(unsafe.Sizeof(*col)) + int64(cap(col.nullBitmap)) + int64(cap(col.offsets)*4) + int64(cap(col.data)) + int64(cap(col.elemBuf))
sum += curColMemUsage
}
return
}
// addFixedLenColumn adds a fixed length column with elemLen and initial data capacity.
func (c *Chunk) addFixedLenColumn(elemLen, initCap int) {
c.columns = append(c.columns, &column{
elemBuf: make([]byte, elemLen),
data: make([]byte, 0, initCap*elemLen),
nullBitmap: make([]byte, 0, initCap>>3),
})
}
// addVarLenColumn adds a variable length column with initial data capacity.
func (c *Chunk) addVarLenColumn(initCap int) {
c.columns = append(c.columns, &column{
offsets: make([]int32, 1, initCap+1),
data: make([]byte, 0, initCap*4),
nullBitmap: make([]byte, 0, initCap>>3),
})
}
// addColumnByFieldType adds a column by field type.
func (c *Chunk) addColumnByFieldType(fieldTp *types.FieldType, initCap int) {
numFixedBytes := getFixedLen(fieldTp)
if numFixedBytes != -1 {
c.addFixedLenColumn(numFixedBytes, initCap)
return
}
c.addVarLenColumn(initCap)
}
// MakeRef makes column in "dstColIdx" reference to column in "srcColIdx".
func (c *Chunk) MakeRef(srcColIdx, dstColIdx int) {
c.columns[dstColIdx] = c.columns[srcColIdx]
}
// SwapColumn swaps column "c.columns[colIdx]" with column "other.columns[otherIdx]".
func (c *Chunk) SwapColumn(colIdx int, other *Chunk, otherIdx int) {
c.columns[colIdx], other.columns[otherIdx] = other.columns[otherIdx], c.columns[colIdx]
}
// SwapColumns swaps columns with another Chunk.
func (c *Chunk) SwapColumns(other *Chunk) {
c.columns, other.columns = other.columns, c.columns
c.numVirtualRows, other.numVirtualRows = other.numVirtualRows, c.numVirtualRows
}
// SetNumVirtualRows sets the virtual row number for a Chunk.
// It should only be used when there exists no column in the Chunk.
func (c *Chunk) SetNumVirtualRows(numVirtualRows int) {
c.numVirtualRows = numVirtualRows
}
// Reset resets the chunk, so the memory it allocated can be reused.
// Make sure all the data in the chunk is not used anymore before you reuse this chunk.
func (c *Chunk) Reset() {
for _, c := range c.columns {
c.reset()
}
c.numVirtualRows = 0
}
// NumCols returns the number of columns in the chunk.
func (c *Chunk) NumCols() int {
return len(c.columns)
}
// NumRows returns the number of rows in the chunk.
func (c *Chunk) NumRows() int {
if c.NumCols() == 0 {
return c.numVirtualRows
}
return c.columns[0].length
}
// GetRow gets the Row in the chunk with the row index.
func (c *Chunk) GetRow(idx int) Row {
return Row{c: c, idx: idx}
}
// AppendRow appends a row to the chunk.
func (c *Chunk) AppendRow(row Row) {
c.AppendPartialRow(0, row)
c.numVirtualRows++
}
// AppendPartialRow appends a row to the chunk.
func (c *Chunk) AppendPartialRow(colIdx int, row Row) {
for i, rowCol := range row.c.columns {
chkCol := c.columns[colIdx+i]
chkCol.appendNullBitmap(!rowCol.isNull(row.idx))
if rowCol.isFixed() {
elemLen := len(rowCol.elemBuf)
offset := row.idx * elemLen
chkCol.data = append(chkCol.data, rowCol.data[offset:offset+elemLen]...)
} else {
start, end := rowCol.offsets[row.idx], rowCol.offsets[row.idx+1]
chkCol.data = append(chkCol.data, rowCol.data[start:end]...)
chkCol.offsets = append(chkCol.offsets, int32(len(chkCol.data)))
}
chkCol.length++
}
}
// Append appends rows in [begin, end) in another Chunk to a Chunk.
func (c *Chunk) Append(other *Chunk, begin, end int) {
for colID, src := range other.columns {
dst := c.columns[colID]
if src.isFixed() {
elemLen := len(src.elemBuf)
dst.data = append(dst.data, src.data[begin*elemLen:end*elemLen]...)
} else {
beginOffset, endOffset := src.offsets[begin], src.offsets[end]
dst.data = append(dst.data, src.data[beginOffset:endOffset]...)
for i := begin; i < end; i++ {
dst.offsets = append(dst.offsets, dst.offsets[len(dst.offsets)-1]+src.offsets[i+1]-src.offsets[i])
}
}
for i := begin; i < end; i++ {
dst.appendNullBitmap(!src.isNull(i))
dst.length++
}
}
c.numVirtualRows += end - begin
}
// TruncateTo truncates rows from tail to head in a Chunk to "numRows" rows.
func (c *Chunk) TruncateTo(numRows int) {
for _, col := range c.columns {
if col.isFixed() {
elemLen := len(col.elemBuf)
col.data = col.data[:numRows*elemLen]
} else {
col.data = col.data[:col.offsets[numRows]]
col.offsets = col.offsets[:numRows+1]
}
for i := numRows; i < col.length; i++ {
if col.isNull(i) {
col.nullCount--
}
}
col.length = numRows
bitmapLen := (col.length + 7) / 8
col.nullBitmap = col.nullBitmap[:bitmapLen]
if col.length%8 != 0 {
// When we append null, we simply increment the nullCount,
// so we need to clear the unused bits in the last bitmap byte.
lastByte := col.nullBitmap[bitmapLen-1]
unusedBitsLen := 8 - uint(col.length%8)
lastByte <<= unusedBitsLen
lastByte >>= unusedBitsLen
col.nullBitmap[bitmapLen-1] = lastByte
}
}
c.numVirtualRows = numRows
}
// AppendNull appends a null value to the chunk.
func (c *Chunk) AppendNull(colIdx int) {
c.columns[colIdx].appendNull()
}
// AppendInt64 appends a int64 value to the chunk.
func (c *Chunk) AppendInt64(colIdx int, i int64) {
c.columns[colIdx].appendInt64(i)
}
// AppendUint64 appends a uint64 value to the chunk.
func (c *Chunk) AppendUint64(colIdx int, u uint64) {
c.columns[colIdx].appendUint64(u)
}
// AppendFloat32 appends a float32 value to the chunk.
func (c *Chunk) AppendFloat32(colIdx int, f float32) {
c.columns[colIdx].appendFloat32(f)
}
// AppendFloat64 appends a float64 value to the chunk.
func (c *Chunk) AppendFloat64(colIdx int, f float64) {
c.columns[colIdx].appendFloat64(f)
}
// AppendString appends a string value to the chunk.
func (c *Chunk) AppendString(colIdx int, str string) {
c.columns[colIdx].appendString(str)
}
// AppendBytes appends a bytes value to the chunk.
func (c *Chunk) AppendBytes(colIdx int, b []byte) {
c.columns[colIdx].appendBytes(b)
}
// AppendTime appends a Time value to the chunk.
// TODO: change the time structure so it can be directly written to memory.
func (c *Chunk) AppendTime(colIdx int, t types.Time) {
c.columns[colIdx].appendTime(t)
}
// AppendDuration appends a Duration value to the chunk.
func (c *Chunk) AppendDuration(colIdx int, dur types.Duration) {
c.columns[colIdx].appendDuration(dur)
}
// AppendMyDecimal appends a MyDecimal value to the chunk.
func (c *Chunk) AppendMyDecimal(colIdx int, dec *types.MyDecimal) {
c.columns[colIdx].appendMyDecimal(dec)
}
// AppendEnum appends an Enum value to the chunk.
func (c *Chunk) AppendEnum(colIdx int, enum types.Enum) {
c.columns[colIdx].appendNameValue(enum.Name, enum.Value)
}
// AppendSet appends a Set value to the chunk.
func (c *Chunk) AppendSet(colIdx int, set types.Set) {
c.columns[colIdx].appendNameValue(set.Name, set.Value)
}
// AppendJSON appends a JSON value to the chunk.
func (c *Chunk) AppendJSON(colIdx int, j json.BinaryJSON) {
c.columns[colIdx].appendJSON(j)
}
// AppendDatum appends a datum into the chunk.
func (c *Chunk) AppendDatum(colIdx int, d *types.Datum) {
switch d.Kind() {
case types.KindNull:
c.AppendNull(colIdx)
case types.KindInt64:
c.AppendInt64(colIdx, d.GetInt64())
case types.KindUint64:
c.AppendUint64(colIdx, d.GetUint64())
case types.KindFloat32:
c.AppendFloat32(colIdx, d.GetFloat32())
case types.KindFloat64:
c.AppendFloat64(colIdx, d.GetFloat64())
case types.KindString, types.KindBytes, types.KindBinaryLiteral, types.KindRaw, types.KindMysqlBit:
c.AppendBytes(colIdx, d.GetBytes())
case types.KindMysqlDecimal:
c.AppendMyDecimal(colIdx, d.GetMysqlDecimal())
case types.KindMysqlDuration:
c.AppendDuration(colIdx, d.GetMysqlDuration())
case types.KindMysqlEnum:
c.AppendEnum(colIdx, d.GetMysqlEnum())
case types.KindMysqlSet:
c.AppendSet(colIdx, d.GetMysqlSet())
case types.KindMysqlTime:
c.AppendTime(colIdx, d.GetMysqlTime())
case types.KindMysqlJSON:
c.AppendJSON(colIdx, d.GetMysqlJSON())
}
}
func writeTime(buf []byte, t types.Time) {
binary.BigEndian.PutUint16(buf, uint16(t.Time.Year()))
buf[2] = uint8(t.Time.Month())
buf[3] = uint8(t.Time.Day())
buf[4] = uint8(t.Time.Hour())
buf[5] = uint8(t.Time.Minute())
buf[6] = uint8(t.Time.Second())
binary.BigEndian.PutUint32(buf[8:], uint32(t.Time.Microsecond()))
buf[12] = t.Type
buf[13] = uint8(t.Fsp)
}
func readTime(buf []byte) types.Time {
year := int(binary.BigEndian.Uint16(buf))
month := int(buf[2])
day := int(buf[3])
hour := int(buf[4])
minute := int(buf[5])
second := int(buf[6])
microseconds := int(binary.BigEndian.Uint32(buf[8:]))
tp := buf[12]
fsp := int(buf[13])
return types.Time{
Time: types.FromDate(year, month, day, hour, minute, second, microseconds),
Type: tp,
Fsp: fsp,
}
}