|
| 1 | +package kafka |
| 2 | + |
| 3 | +import ( |
| 4 | + "bytes" |
| 5 | + "fmt" |
| 6 | + "io" |
| 7 | + "time" |
| 8 | + |
| 9 | + "github.com/segmentio/kafka-go/compress" |
| 10 | +) |
| 11 | + |
| 12 | +// This file defines builders to assist in creating kafka payloads for unit testing. |
| 13 | + |
| 14 | +// fetchResponseBuilder builds v10 fetch responses. The version of the v10 fetch |
| 15 | +// responses are not as important as the message sets contained within, as this |
| 16 | +// type is ultimately used to unit test the message set reader that consumes the |
| 17 | +// rest of the response once the header has been parsed. |
| 18 | +type fetchResponseBuilder struct { |
| 19 | + header fetchResponseHeader |
| 20 | + msgSets []messageSetBuilder |
| 21 | + rendered []byte |
| 22 | +} |
| 23 | + |
| 24 | +type fetchResponseHeader struct { |
| 25 | + throttle int32 |
| 26 | + errorCode int16 |
| 27 | + sessionID int32 |
| 28 | + topic string |
| 29 | + partition int32 |
| 30 | + partitionErrorCode int16 |
| 31 | + highWatermarkOffset int64 |
| 32 | + lastStableOffset int64 |
| 33 | + logStartOffset int64 |
| 34 | +} |
| 35 | + |
| 36 | +func (b *fetchResponseBuilder) messages() (res []Message) { |
| 37 | + for _, set := range b.msgSets { |
| 38 | + res = append(res, set.messages()...) |
| 39 | + } |
| 40 | + return |
| 41 | +} |
| 42 | + |
| 43 | +func (b *fetchResponseBuilder) bytes() []byte { |
| 44 | + if b.rendered == nil { |
| 45 | + b.rendered = newWB().call(func(wb *kafkaWriteBuffer) { |
| 46 | + wb.writeInt32(b.header.throttle) |
| 47 | + wb.writeInt16(b.header.errorCode) |
| 48 | + wb.writeInt32(b.header.sessionID) |
| 49 | + wb.writeInt32(1) // num topics |
| 50 | + wb.writeString(b.header.topic) |
| 51 | + wb.writeInt32(1) // how many partitions |
| 52 | + wb.writeInt32(b.header.partition) |
| 53 | + wb.writeInt16(b.header.partitionErrorCode) |
| 54 | + wb.writeInt64(b.header.highWatermarkOffset) |
| 55 | + wb.writeInt64(b.header.lastStableOffset) |
| 56 | + wb.writeInt64(b.header.logStartOffset) |
| 57 | + wb.writeInt32(-1) // num aborted tx |
| 58 | + wb.writeBytes(newWB().call(func(wb *kafkaWriteBuffer) { |
| 59 | + for _, msgSet := range b.msgSets { |
| 60 | + wb.Write(msgSet.bytes()) |
| 61 | + } |
| 62 | + })) |
| 63 | + }) |
| 64 | + } |
| 65 | + return b.rendered |
| 66 | +} |
| 67 | + |
| 68 | +func (b *fetchResponseBuilder) Len() int { |
| 69 | + return len(b.bytes()) |
| 70 | +} |
| 71 | + |
| 72 | +type messageSetBuilder interface { |
| 73 | + bytes() []byte |
| 74 | + messages() []Message |
| 75 | +} |
| 76 | + |
| 77 | +type v0MessageSetBuilder struct { |
| 78 | + msgs []Message |
| 79 | + codec CompressionCodec |
| 80 | +} |
| 81 | + |
| 82 | +func (f v0MessageSetBuilder) messages() []Message { |
| 83 | + return f.msgs |
| 84 | +} |
| 85 | + |
| 86 | +func (f v0MessageSetBuilder) bytes() []byte { |
| 87 | + bs := newWB().call(func(wb *kafkaWriteBuffer) { |
| 88 | + for _, msg := range f.msgs { |
| 89 | + bs := newWB().call(func(wb *kafkaWriteBuffer) { |
| 90 | + wb.writeInt64(msg.Offset) // offset |
| 91 | + wb.writeBytes(newWB().call(func(wb *kafkaWriteBuffer) { |
| 92 | + wb.writeInt32(-1) // crc, unused |
| 93 | + wb.writeInt8(0) // magic |
| 94 | + wb.writeInt8(0) // attributes -- zero, no compression for the inner message |
| 95 | + wb.writeBytes(msg.Key) |
| 96 | + wb.writeBytes(msg.Value) |
| 97 | + })) |
| 98 | + }) |
| 99 | + wb.Write(bs) |
| 100 | + } |
| 101 | + }) |
| 102 | + if f.codec != nil { |
| 103 | + bs = newWB().call(func(wb *kafkaWriteBuffer) { |
| 104 | + wb.writeInt64(f.msgs[0].Offset) // offset |
| 105 | + wb.writeBytes(newWB().call(func(wb *kafkaWriteBuffer) { |
| 106 | + compressed := mustCompress(bs, f.codec) |
| 107 | + wb.writeInt32(-1) // crc, unused |
| 108 | + wb.writeInt8(0) // magic |
| 109 | + wb.writeInt8(f.codec.Code()) // attributes |
| 110 | + wb.writeBytes(nil) // key is always nil for compressed |
| 111 | + wb.writeBytes(compressed) // the value is the compressed message |
| 112 | + })) |
| 113 | + }) |
| 114 | + } |
| 115 | + return bs |
| 116 | +} |
| 117 | + |
| 118 | +type v1MessageSetBuilder struct { |
| 119 | + msgs []Message |
| 120 | + codec CompressionCodec |
| 121 | +} |
| 122 | + |
| 123 | +func (f v1MessageSetBuilder) messages() []Message { |
| 124 | + return f.msgs |
| 125 | +} |
| 126 | + |
| 127 | +func (f v1MessageSetBuilder) bytes() []byte { |
| 128 | + bs := newWB().call(func(wb *kafkaWriteBuffer) { |
| 129 | + for i, msg := range f.msgs { |
| 130 | + bs := newWB().call(func(wb *kafkaWriteBuffer) { |
| 131 | + if f.codec != nil { |
| 132 | + wb.writeInt64(int64(i)) // compressed inner message offsets are relative |
| 133 | + } else { |
| 134 | + wb.writeInt64(msg.Offset) // offset |
| 135 | + } |
| 136 | + wb.writeBytes(newWB().call(func(wb *kafkaWriteBuffer) { |
| 137 | + wb.writeInt32(-1) // crc, unused |
| 138 | + wb.writeInt8(1) // magic |
| 139 | + wb.writeInt8(0) // attributes -- zero, no compression for the inner message |
| 140 | + wb.writeInt64(msg.Time.UnixMilli()) // timestamp |
| 141 | + wb.writeBytes(msg.Key) |
| 142 | + wb.writeBytes(msg.Value) |
| 143 | + })) |
| 144 | + }) |
| 145 | + wb.Write(bs) |
| 146 | + } |
| 147 | + }) |
| 148 | + if f.codec != nil { |
| 149 | + bs = newWB().call(func(wb *kafkaWriteBuffer) { |
| 150 | + wb.writeInt64(f.msgs[len(f.msgs)-1].Offset) // offset of the wrapper message is the last offset of the inner messages |
| 151 | + wb.writeBytes(newWB().call(func(wb *kafkaWriteBuffer) { |
| 152 | + bs := mustCompress(bs, f.codec) |
| 153 | + wb.writeInt32(-1) // crc, unused |
| 154 | + wb.writeInt8(1) // magic |
| 155 | + wb.writeInt8(f.codec.Code()) // attributes |
| 156 | + wb.writeInt64(f.msgs[0].Time.UnixMilli()) // timestamp |
| 157 | + wb.writeBytes(nil) // key is always nil for compressed |
| 158 | + wb.writeBytes(bs) // the value is the compressed message |
| 159 | + })) |
| 160 | + }) |
| 161 | + } |
| 162 | + return bs |
| 163 | +} |
| 164 | + |
| 165 | +type v2MessageSetBuilder struct { |
| 166 | + msgs []Message |
| 167 | + codec CompressionCodec |
| 168 | +} |
| 169 | + |
| 170 | +func (f v2MessageSetBuilder) messages() []Message { |
| 171 | + return f.msgs |
| 172 | +} |
| 173 | + |
| 174 | +func (f v2MessageSetBuilder) bytes() []byte { |
| 175 | + attributes := int16(0) |
| 176 | + if f.codec != nil { |
| 177 | + attributes = int16(f.codec.Code()) // set codec code on attributes |
| 178 | + } |
| 179 | + return newWB().call(func(wb *kafkaWriteBuffer) { |
| 180 | + wb.writeInt64(f.msgs[0].Offset) |
| 181 | + wb.writeBytes(newWB().call(func(wb *kafkaWriteBuffer) { |
| 182 | + wb.writeInt32(0) // leader epoch |
| 183 | + wb.writeInt8(2) // magic = 2 |
| 184 | + wb.writeInt32(0) // crc, unused |
| 185 | + wb.writeInt16(attributes) // record set attributes |
| 186 | + wb.writeInt32(0) // record set last offset delta |
| 187 | + wb.writeInt64(f.msgs[0].Time.UnixMilli()) // record set first timestamp |
| 188 | + wb.writeInt64(f.msgs[0].Time.UnixMilli()) // record set last timestamp |
| 189 | + wb.writeInt64(0) // record set producer id |
| 190 | + wb.writeInt16(0) // record set producer epoch |
| 191 | + wb.writeInt32(0) // record set base sequence |
| 192 | + wb.writeInt32(int32(len(f.msgs))) // record set count |
| 193 | + bs := newWB().call(func(wb *kafkaWriteBuffer) { |
| 194 | + for i, msg := range f.msgs { |
| 195 | + wb.Write(newWB().call(func(wb *kafkaWriteBuffer) { |
| 196 | + bs := newWB().call(func(wb *kafkaWriteBuffer) { |
| 197 | + wb.writeInt8(0) // record attributes, not used here |
| 198 | + wb.writeVarInt(time.Now().UnixMilli() - msg.Time.UnixMilli()) // timestamp |
| 199 | + wb.writeVarInt(int64(i)) // offset delta |
| 200 | + wb.writeVarInt(int64(len(msg.Key))) // key len |
| 201 | + wb.Write(msg.Key) // key bytes |
| 202 | + wb.writeVarInt(int64(len(msg.Value))) // value len |
| 203 | + wb.Write(msg.Value) // value bytes |
| 204 | + wb.writeVarInt(int64(len(msg.Headers))) // number of headers |
| 205 | + for _, header := range msg.Headers { |
| 206 | + wb.writeVarInt(int64(len(header.Key))) |
| 207 | + wb.Write([]byte(header.Key)) |
| 208 | + wb.writeVarInt(int64(len(header.Value))) |
| 209 | + wb.Write(header.Value) |
| 210 | + } |
| 211 | + }) |
| 212 | + wb.writeVarInt(int64(len(bs))) |
| 213 | + wb.Write(bs) |
| 214 | + })) |
| 215 | + } |
| 216 | + }) |
| 217 | + if f.codec != nil { |
| 218 | + bs = mustCompress(bs, f.codec) |
| 219 | + } |
| 220 | + wb.Write(bs) |
| 221 | + })) |
| 222 | + }) |
| 223 | +} |
| 224 | + |
| 225 | +// kafkaWriteBuffer is a write buffer that helps writing fetch responses |
| 226 | +type kafkaWriteBuffer struct { |
| 227 | + writeBuffer |
| 228 | + buf bytes.Buffer |
| 229 | +} |
| 230 | + |
| 231 | +func newWB() *kafkaWriteBuffer { |
| 232 | + res := kafkaWriteBuffer{} |
| 233 | + res.writeBuffer.w = &res.buf |
| 234 | + return &res |
| 235 | +} |
| 236 | + |
| 237 | +func (f *kafkaWriteBuffer) Bytes() []byte { |
| 238 | + return f.buf.Bytes() |
| 239 | +} |
| 240 | + |
| 241 | +// call is a convenience method that allows the kafkaWriteBuffer to be used |
| 242 | +// in a functional manner. This is helpful when building |
| 243 | +// nested structures, as the return value can be fed into |
| 244 | +// other fwWB APIs. |
| 245 | +func (f *kafkaWriteBuffer) call(cb func(wb *kafkaWriteBuffer)) []byte { |
| 246 | + cb(f) |
| 247 | + bs := f.Bytes() |
| 248 | + if bs == nil { |
| 249 | + bs = []byte{} |
| 250 | + } |
| 251 | + return bs |
| 252 | +} |
| 253 | + |
| 254 | +func mustCompress(bs []byte, codec compress.Codec) (res []byte) { |
| 255 | + buf := bytes.Buffer{} |
| 256 | + codecWriter := codec.NewWriter(&buf) |
| 257 | + _, err := io.Copy(codecWriter, bytes.NewReader(bs)) |
| 258 | + if err != nil { |
| 259 | + panic(fmt.Errorf("compress: %w", err)) |
| 260 | + } |
| 261 | + err = codecWriter.Close() |
| 262 | + if err != nil { |
| 263 | + panic(fmt.Errorf("close codec writer: %w", err)) |
| 264 | + } |
| 265 | + res = buf.Bytes() |
| 266 | + return |
| 267 | +} |
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