Holger Hildebrandt | fa07499 | 2020-03-27 15:42:06 +0000 | [diff] [blame^] | 1 | package sarama |
| 2 | |
| 3 | import ( |
| 4 | "encoding/binary" |
| 5 | "math" |
| 6 | ) |
| 7 | |
| 8 | var errInvalidArrayLength = PacketDecodingError{"invalid array length"} |
| 9 | var errInvalidByteSliceLength = PacketDecodingError{"invalid byteslice length"} |
| 10 | var errInvalidByteSliceLengthType = PacketDecodingError{"invalid byteslice length type"} |
| 11 | var errInvalidStringLength = PacketDecodingError{"invalid string length"} |
| 12 | var errInvalidSubsetSize = PacketDecodingError{"invalid subset size"} |
| 13 | var errVarintOverflow = PacketDecodingError{"varint overflow"} |
| 14 | var errInvalidBool = PacketDecodingError{"invalid bool"} |
| 15 | |
| 16 | type realDecoder struct { |
| 17 | raw []byte |
| 18 | off int |
| 19 | stack []pushDecoder |
| 20 | } |
| 21 | |
| 22 | // primitives |
| 23 | |
| 24 | func (rd *realDecoder) getInt8() (int8, error) { |
| 25 | if rd.remaining() < 1 { |
| 26 | rd.off = len(rd.raw) |
| 27 | return -1, ErrInsufficientData |
| 28 | } |
| 29 | tmp := int8(rd.raw[rd.off]) |
| 30 | rd.off++ |
| 31 | return tmp, nil |
| 32 | } |
| 33 | |
| 34 | func (rd *realDecoder) getInt16() (int16, error) { |
| 35 | if rd.remaining() < 2 { |
| 36 | rd.off = len(rd.raw) |
| 37 | return -1, ErrInsufficientData |
| 38 | } |
| 39 | tmp := int16(binary.BigEndian.Uint16(rd.raw[rd.off:])) |
| 40 | rd.off += 2 |
| 41 | return tmp, nil |
| 42 | } |
| 43 | |
| 44 | func (rd *realDecoder) getInt32() (int32, error) { |
| 45 | if rd.remaining() < 4 { |
| 46 | rd.off = len(rd.raw) |
| 47 | return -1, ErrInsufficientData |
| 48 | } |
| 49 | tmp := int32(binary.BigEndian.Uint32(rd.raw[rd.off:])) |
| 50 | rd.off += 4 |
| 51 | return tmp, nil |
| 52 | } |
| 53 | |
| 54 | func (rd *realDecoder) getInt64() (int64, error) { |
| 55 | if rd.remaining() < 8 { |
| 56 | rd.off = len(rd.raw) |
| 57 | return -1, ErrInsufficientData |
| 58 | } |
| 59 | tmp := int64(binary.BigEndian.Uint64(rd.raw[rd.off:])) |
| 60 | rd.off += 8 |
| 61 | return tmp, nil |
| 62 | } |
| 63 | |
| 64 | func (rd *realDecoder) getVarint() (int64, error) { |
| 65 | tmp, n := binary.Varint(rd.raw[rd.off:]) |
| 66 | if n == 0 { |
| 67 | rd.off = len(rd.raw) |
| 68 | return -1, ErrInsufficientData |
| 69 | } |
| 70 | if n < 0 { |
| 71 | rd.off -= n |
| 72 | return -1, errVarintOverflow |
| 73 | } |
| 74 | rd.off += n |
| 75 | return tmp, nil |
| 76 | } |
| 77 | |
| 78 | func (rd *realDecoder) getArrayLength() (int, error) { |
| 79 | if rd.remaining() < 4 { |
| 80 | rd.off = len(rd.raw) |
| 81 | return -1, ErrInsufficientData |
| 82 | } |
| 83 | tmp := int(int32(binary.BigEndian.Uint32(rd.raw[rd.off:]))) |
| 84 | rd.off += 4 |
| 85 | if tmp > rd.remaining() { |
| 86 | rd.off = len(rd.raw) |
| 87 | return -1, ErrInsufficientData |
| 88 | } else if tmp > 2*math.MaxUint16 { |
| 89 | return -1, errInvalidArrayLength |
| 90 | } |
| 91 | return tmp, nil |
| 92 | } |
| 93 | |
| 94 | func (rd *realDecoder) getBool() (bool, error) { |
| 95 | b, err := rd.getInt8() |
| 96 | if err != nil || b == 0 { |
| 97 | return false, err |
| 98 | } |
| 99 | if b != 1 { |
| 100 | return false, errInvalidBool |
| 101 | } |
| 102 | return true, nil |
| 103 | } |
| 104 | |
| 105 | // collections |
| 106 | |
| 107 | func (rd *realDecoder) getBytes() ([]byte, error) { |
| 108 | tmp, err := rd.getInt32() |
| 109 | if err != nil { |
| 110 | return nil, err |
| 111 | } |
| 112 | if tmp == -1 { |
| 113 | return nil, nil |
| 114 | } |
| 115 | |
| 116 | return rd.getRawBytes(int(tmp)) |
| 117 | } |
| 118 | |
| 119 | func (rd *realDecoder) getVarintBytes() ([]byte, error) { |
| 120 | tmp, err := rd.getVarint() |
| 121 | if err != nil { |
| 122 | return nil, err |
| 123 | } |
| 124 | if tmp == -1 { |
| 125 | return nil, nil |
| 126 | } |
| 127 | |
| 128 | return rd.getRawBytes(int(tmp)) |
| 129 | } |
| 130 | |
| 131 | func (rd *realDecoder) getStringLength() (int, error) { |
| 132 | length, err := rd.getInt16() |
| 133 | if err != nil { |
| 134 | return 0, err |
| 135 | } |
| 136 | |
| 137 | n := int(length) |
| 138 | |
| 139 | switch { |
| 140 | case n < -1: |
| 141 | return 0, errInvalidStringLength |
| 142 | case n > rd.remaining(): |
| 143 | rd.off = len(rd.raw) |
| 144 | return 0, ErrInsufficientData |
| 145 | } |
| 146 | |
| 147 | return n, nil |
| 148 | } |
| 149 | |
| 150 | func (rd *realDecoder) getString() (string, error) { |
| 151 | n, err := rd.getStringLength() |
| 152 | if err != nil || n == -1 { |
| 153 | return "", err |
| 154 | } |
| 155 | |
| 156 | tmpStr := string(rd.raw[rd.off : rd.off+n]) |
| 157 | rd.off += n |
| 158 | return tmpStr, nil |
| 159 | } |
| 160 | |
| 161 | func (rd *realDecoder) getNullableString() (*string, error) { |
| 162 | n, err := rd.getStringLength() |
| 163 | if err != nil || n == -1 { |
| 164 | return nil, err |
| 165 | } |
| 166 | |
| 167 | tmpStr := string(rd.raw[rd.off : rd.off+n]) |
| 168 | rd.off += n |
| 169 | return &tmpStr, err |
| 170 | } |
| 171 | |
| 172 | func (rd *realDecoder) getInt32Array() ([]int32, error) { |
| 173 | if rd.remaining() < 4 { |
| 174 | rd.off = len(rd.raw) |
| 175 | return nil, ErrInsufficientData |
| 176 | } |
| 177 | n := int(binary.BigEndian.Uint32(rd.raw[rd.off:])) |
| 178 | rd.off += 4 |
| 179 | |
| 180 | if rd.remaining() < 4*n { |
| 181 | rd.off = len(rd.raw) |
| 182 | return nil, ErrInsufficientData |
| 183 | } |
| 184 | |
| 185 | if n == 0 { |
| 186 | return nil, nil |
| 187 | } |
| 188 | |
| 189 | if n < 0 { |
| 190 | return nil, errInvalidArrayLength |
| 191 | } |
| 192 | |
| 193 | ret := make([]int32, n) |
| 194 | for i := range ret { |
| 195 | ret[i] = int32(binary.BigEndian.Uint32(rd.raw[rd.off:])) |
| 196 | rd.off += 4 |
| 197 | } |
| 198 | return ret, nil |
| 199 | } |
| 200 | |
| 201 | func (rd *realDecoder) getInt64Array() ([]int64, error) { |
| 202 | if rd.remaining() < 4 { |
| 203 | rd.off = len(rd.raw) |
| 204 | return nil, ErrInsufficientData |
| 205 | } |
| 206 | n := int(binary.BigEndian.Uint32(rd.raw[rd.off:])) |
| 207 | rd.off += 4 |
| 208 | |
| 209 | if rd.remaining() < 8*n { |
| 210 | rd.off = len(rd.raw) |
| 211 | return nil, ErrInsufficientData |
| 212 | } |
| 213 | |
| 214 | if n == 0 { |
| 215 | return nil, nil |
| 216 | } |
| 217 | |
| 218 | if n < 0 { |
| 219 | return nil, errInvalidArrayLength |
| 220 | } |
| 221 | |
| 222 | ret := make([]int64, n) |
| 223 | for i := range ret { |
| 224 | ret[i] = int64(binary.BigEndian.Uint64(rd.raw[rd.off:])) |
| 225 | rd.off += 8 |
| 226 | } |
| 227 | return ret, nil |
| 228 | } |
| 229 | |
| 230 | func (rd *realDecoder) getStringArray() ([]string, error) { |
| 231 | if rd.remaining() < 4 { |
| 232 | rd.off = len(rd.raw) |
| 233 | return nil, ErrInsufficientData |
| 234 | } |
| 235 | n := int(binary.BigEndian.Uint32(rd.raw[rd.off:])) |
| 236 | rd.off += 4 |
| 237 | |
| 238 | if n == 0 { |
| 239 | return nil, nil |
| 240 | } |
| 241 | |
| 242 | if n < 0 { |
| 243 | return nil, errInvalidArrayLength |
| 244 | } |
| 245 | |
| 246 | ret := make([]string, n) |
| 247 | for i := range ret { |
| 248 | str, err := rd.getString() |
| 249 | if err != nil { |
| 250 | return nil, err |
| 251 | } |
| 252 | |
| 253 | ret[i] = str |
| 254 | } |
| 255 | return ret, nil |
| 256 | } |
| 257 | |
| 258 | // subsets |
| 259 | |
| 260 | func (rd *realDecoder) remaining() int { |
| 261 | return len(rd.raw) - rd.off |
| 262 | } |
| 263 | |
| 264 | func (rd *realDecoder) getSubset(length int) (packetDecoder, error) { |
| 265 | buf, err := rd.getRawBytes(length) |
| 266 | if err != nil { |
| 267 | return nil, err |
| 268 | } |
| 269 | return &realDecoder{raw: buf}, nil |
| 270 | } |
| 271 | |
| 272 | func (rd *realDecoder) getRawBytes(length int) ([]byte, error) { |
| 273 | if length < 0 { |
| 274 | return nil, errInvalidByteSliceLength |
| 275 | } else if length > rd.remaining() { |
| 276 | rd.off = len(rd.raw) |
| 277 | return nil, ErrInsufficientData |
| 278 | } |
| 279 | |
| 280 | start := rd.off |
| 281 | rd.off += length |
| 282 | return rd.raw[start:rd.off], nil |
| 283 | } |
| 284 | |
| 285 | func (rd *realDecoder) peek(offset, length int) (packetDecoder, error) { |
| 286 | if rd.remaining() < offset+length { |
| 287 | return nil, ErrInsufficientData |
| 288 | } |
| 289 | off := rd.off + offset |
| 290 | return &realDecoder{raw: rd.raw[off : off+length]}, nil |
| 291 | } |
| 292 | |
| 293 | func (rd *realDecoder) peekInt8(offset int) (int8, error) { |
| 294 | const byteLen = 1 |
| 295 | if rd.remaining() < offset+byteLen { |
| 296 | return -1, ErrInsufficientData |
| 297 | } |
| 298 | return int8(rd.raw[rd.off+offset]), nil |
| 299 | } |
| 300 | |
| 301 | // stacks |
| 302 | |
| 303 | func (rd *realDecoder) push(in pushDecoder) error { |
| 304 | in.saveOffset(rd.off) |
| 305 | |
| 306 | var reserve int |
| 307 | if dpd, ok := in.(dynamicPushDecoder); ok { |
| 308 | if err := dpd.decode(rd); err != nil { |
| 309 | return err |
| 310 | } |
| 311 | } else { |
| 312 | reserve = in.reserveLength() |
| 313 | if rd.remaining() < reserve { |
| 314 | rd.off = len(rd.raw) |
| 315 | return ErrInsufficientData |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | rd.stack = append(rd.stack, in) |
| 320 | |
| 321 | rd.off += reserve |
| 322 | |
| 323 | return nil |
| 324 | } |
| 325 | |
| 326 | func (rd *realDecoder) pop() error { |
| 327 | // this is go's ugly pop pattern (the inverse of append) |
| 328 | in := rd.stack[len(rd.stack)-1] |
| 329 | rd.stack = rd.stack[:len(rd.stack)-1] |
| 330 | |
| 331 | return in.check(rd.off, rd.raw) |
| 332 | } |