Don Newton | 379ae25 | 2019-04-01 12:17:06 -0400 | [diff] [blame^] | 1 | // Copyright (C) MongoDB, Inc. 2017-present. |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); you may |
| 4 | // not use this file except in compliance with the License. You may obtain |
| 5 | // a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 |
| 6 | |
| 7 | package bsonrw |
| 8 | |
| 9 | import ( |
| 10 | "fmt" |
| 11 | "io" |
| 12 | "sync" |
| 13 | |
| 14 | "github.com/mongodb/mongo-go-driver/bson/bsontype" |
| 15 | "github.com/mongodb/mongo-go-driver/bson/primitive" |
| 16 | ) |
| 17 | |
| 18 | // ExtJSONValueReaderPool is a pool for ValueReaders that read ExtJSON. |
| 19 | type ExtJSONValueReaderPool struct { |
| 20 | pool sync.Pool |
| 21 | } |
| 22 | |
| 23 | // NewExtJSONValueReaderPool instantiates a new ExtJSONValueReaderPool. |
| 24 | func NewExtJSONValueReaderPool() *ExtJSONValueReaderPool { |
| 25 | return &ExtJSONValueReaderPool{ |
| 26 | pool: sync.Pool{ |
| 27 | New: func() interface{} { |
| 28 | return new(extJSONValueReader) |
| 29 | }, |
| 30 | }, |
| 31 | } |
| 32 | } |
| 33 | |
| 34 | // Get retrieves a ValueReader from the pool and uses src as the underlying ExtJSON. |
| 35 | func (bvrp *ExtJSONValueReaderPool) Get(r io.Reader, canonical bool) (ValueReader, error) { |
| 36 | vr := bvrp.pool.Get().(*extJSONValueReader) |
| 37 | return vr.reset(r, canonical) |
| 38 | } |
| 39 | |
| 40 | // Put inserts a ValueReader into the pool. If the ValueReader is not a ExtJSON ValueReader nothing |
| 41 | // is inserted into the pool and ok will be false. |
| 42 | func (bvrp *ExtJSONValueReaderPool) Put(vr ValueReader) (ok bool) { |
| 43 | bvr, ok := vr.(*extJSONValueReader) |
| 44 | if !ok { |
| 45 | return false |
| 46 | } |
| 47 | |
| 48 | bvr, _ = bvr.reset(nil, false) |
| 49 | bvrp.pool.Put(bvr) |
| 50 | return true |
| 51 | } |
| 52 | |
| 53 | type ejvrState struct { |
| 54 | mode mode |
| 55 | vType bsontype.Type |
| 56 | depth int |
| 57 | } |
| 58 | |
| 59 | // extJSONValueReader is for reading extended JSON. |
| 60 | type extJSONValueReader struct { |
| 61 | p *extJSONParser |
| 62 | |
| 63 | stack []ejvrState |
| 64 | frame int |
| 65 | } |
| 66 | |
| 67 | // NewExtJSONValueReader creates a new ValueReader from a given io.Reader |
| 68 | // It will interpret the JSON of r as canonical or relaxed according to the |
| 69 | // given canonical flag |
| 70 | func NewExtJSONValueReader(r io.Reader, canonical bool) (ValueReader, error) { |
| 71 | return newExtJSONValueReader(r, canonical) |
| 72 | } |
| 73 | |
| 74 | func newExtJSONValueReader(r io.Reader, canonical bool) (*extJSONValueReader, error) { |
| 75 | ejvr := new(extJSONValueReader) |
| 76 | return ejvr.reset(r, canonical) |
| 77 | } |
| 78 | |
| 79 | func (ejvr *extJSONValueReader) reset(r io.Reader, canonical bool) (*extJSONValueReader, error) { |
| 80 | p := newExtJSONParser(r, canonical) |
| 81 | typ, err := p.peekType() |
| 82 | |
| 83 | if err != nil { |
| 84 | return nil, ErrInvalidJSON |
| 85 | } |
| 86 | |
| 87 | var m mode |
| 88 | switch typ { |
| 89 | case bsontype.EmbeddedDocument: |
| 90 | m = mTopLevel |
| 91 | case bsontype.Array: |
| 92 | m = mArray |
| 93 | default: |
| 94 | m = mValue |
| 95 | } |
| 96 | |
| 97 | stack := make([]ejvrState, 1, 5) |
| 98 | stack[0] = ejvrState{ |
| 99 | mode: m, |
| 100 | vType: typ, |
| 101 | } |
| 102 | return &extJSONValueReader{ |
| 103 | p: p, |
| 104 | stack: stack, |
| 105 | }, nil |
| 106 | } |
| 107 | |
| 108 | func (ejvr *extJSONValueReader) advanceFrame() { |
| 109 | if ejvr.frame+1 >= len(ejvr.stack) { // We need to grow the stack |
| 110 | length := len(ejvr.stack) |
| 111 | if length+1 >= cap(ejvr.stack) { |
| 112 | // double it |
| 113 | buf := make([]ejvrState, 2*cap(ejvr.stack)+1) |
| 114 | copy(buf, ejvr.stack) |
| 115 | ejvr.stack = buf |
| 116 | } |
| 117 | ejvr.stack = ejvr.stack[:length+1] |
| 118 | } |
| 119 | ejvr.frame++ |
| 120 | |
| 121 | // Clean the stack |
| 122 | ejvr.stack[ejvr.frame].mode = 0 |
| 123 | ejvr.stack[ejvr.frame].vType = 0 |
| 124 | ejvr.stack[ejvr.frame].depth = 0 |
| 125 | } |
| 126 | |
| 127 | func (ejvr *extJSONValueReader) pushDocument() { |
| 128 | ejvr.advanceFrame() |
| 129 | |
| 130 | ejvr.stack[ejvr.frame].mode = mDocument |
| 131 | ejvr.stack[ejvr.frame].depth = ejvr.p.depth |
| 132 | } |
| 133 | |
| 134 | func (ejvr *extJSONValueReader) pushCodeWithScope() { |
| 135 | ejvr.advanceFrame() |
| 136 | |
| 137 | ejvr.stack[ejvr.frame].mode = mCodeWithScope |
| 138 | } |
| 139 | |
| 140 | func (ejvr *extJSONValueReader) pushArray() { |
| 141 | ejvr.advanceFrame() |
| 142 | |
| 143 | ejvr.stack[ejvr.frame].mode = mArray |
| 144 | } |
| 145 | |
| 146 | func (ejvr *extJSONValueReader) push(m mode, t bsontype.Type) { |
| 147 | ejvr.advanceFrame() |
| 148 | |
| 149 | ejvr.stack[ejvr.frame].mode = m |
| 150 | ejvr.stack[ejvr.frame].vType = t |
| 151 | } |
| 152 | |
| 153 | func (ejvr *extJSONValueReader) pop() { |
| 154 | switch ejvr.stack[ejvr.frame].mode { |
| 155 | case mElement, mValue: |
| 156 | ejvr.frame-- |
| 157 | case mDocument, mArray, mCodeWithScope: |
| 158 | ejvr.frame -= 2 // we pop twice to jump over the vrElement: vrDocument -> vrElement -> vrDocument/TopLevel/etc... |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | func (ejvr *extJSONValueReader) skipDocument() error { |
| 163 | // read entire document until ErrEOD (using readKey and readValue) |
| 164 | _, typ, err := ejvr.p.readKey() |
| 165 | for err == nil { |
| 166 | _, err = ejvr.p.readValue(typ) |
| 167 | if err != nil { |
| 168 | break |
| 169 | } |
| 170 | |
| 171 | _, typ, err = ejvr.p.readKey() |
| 172 | } |
| 173 | |
| 174 | return err |
| 175 | } |
| 176 | |
| 177 | func (ejvr *extJSONValueReader) skipArray() error { |
| 178 | // read entire array until ErrEOA (using peekType) |
| 179 | _, err := ejvr.p.peekType() |
| 180 | for err == nil { |
| 181 | _, err = ejvr.p.peekType() |
| 182 | } |
| 183 | |
| 184 | return err |
| 185 | } |
| 186 | |
| 187 | func (ejvr *extJSONValueReader) invalidTransitionErr(destination mode, name string, modes []mode) error { |
| 188 | te := TransitionError{ |
| 189 | name: name, |
| 190 | current: ejvr.stack[ejvr.frame].mode, |
| 191 | destination: destination, |
| 192 | modes: modes, |
| 193 | action: "read", |
| 194 | } |
| 195 | if ejvr.frame != 0 { |
| 196 | te.parent = ejvr.stack[ejvr.frame-1].mode |
| 197 | } |
| 198 | return te |
| 199 | } |
| 200 | |
| 201 | func (ejvr *extJSONValueReader) typeError(t bsontype.Type) error { |
| 202 | return fmt.Errorf("positioned on %s, but attempted to read %s", ejvr.stack[ejvr.frame].vType, t) |
| 203 | } |
| 204 | |
| 205 | func (ejvr *extJSONValueReader) ensureElementValue(t bsontype.Type, destination mode, callerName string, addModes ...mode) error { |
| 206 | switch ejvr.stack[ejvr.frame].mode { |
| 207 | case mElement, mValue: |
| 208 | if ejvr.stack[ejvr.frame].vType != t { |
| 209 | return ejvr.typeError(t) |
| 210 | } |
| 211 | default: |
| 212 | modes := []mode{mElement, mValue} |
| 213 | if addModes != nil { |
| 214 | modes = append(modes, addModes...) |
| 215 | } |
| 216 | return ejvr.invalidTransitionErr(destination, callerName, modes) |
| 217 | } |
| 218 | |
| 219 | return nil |
| 220 | } |
| 221 | |
| 222 | func (ejvr *extJSONValueReader) Type() bsontype.Type { |
| 223 | return ejvr.stack[ejvr.frame].vType |
| 224 | } |
| 225 | |
| 226 | func (ejvr *extJSONValueReader) Skip() error { |
| 227 | switch ejvr.stack[ejvr.frame].mode { |
| 228 | case mElement, mValue: |
| 229 | default: |
| 230 | return ejvr.invalidTransitionErr(0, "Skip", []mode{mElement, mValue}) |
| 231 | } |
| 232 | |
| 233 | defer ejvr.pop() |
| 234 | |
| 235 | t := ejvr.stack[ejvr.frame].vType |
| 236 | switch t { |
| 237 | case bsontype.Array: |
| 238 | // read entire array until ErrEOA |
| 239 | err := ejvr.skipArray() |
| 240 | if err != ErrEOA { |
| 241 | return err |
| 242 | } |
| 243 | case bsontype.EmbeddedDocument: |
| 244 | // read entire doc until ErrEOD |
| 245 | err := ejvr.skipDocument() |
| 246 | if err != ErrEOD { |
| 247 | return err |
| 248 | } |
| 249 | case bsontype.CodeWithScope: |
| 250 | // read the code portion and set up parser in document mode |
| 251 | _, err := ejvr.p.readValue(t) |
| 252 | if err != nil { |
| 253 | return err |
| 254 | } |
| 255 | |
| 256 | // read until ErrEOD |
| 257 | err = ejvr.skipDocument() |
| 258 | if err != ErrEOD { |
| 259 | return err |
| 260 | } |
| 261 | default: |
| 262 | _, err := ejvr.p.readValue(t) |
| 263 | if err != nil { |
| 264 | return err |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | return nil |
| 269 | } |
| 270 | |
| 271 | func (ejvr *extJSONValueReader) ReadArray() (ArrayReader, error) { |
| 272 | switch ejvr.stack[ejvr.frame].mode { |
| 273 | case mTopLevel: // allow reading array from top level |
| 274 | case mArray: |
| 275 | return ejvr, nil |
| 276 | default: |
| 277 | if err := ejvr.ensureElementValue(bsontype.Array, mArray, "ReadArray", mTopLevel, mArray); err != nil { |
| 278 | return nil, err |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | ejvr.pushArray() |
| 283 | |
| 284 | return ejvr, nil |
| 285 | } |
| 286 | |
| 287 | func (ejvr *extJSONValueReader) ReadBinary() (b []byte, btype byte, err error) { |
| 288 | if err := ejvr.ensureElementValue(bsontype.Binary, 0, "ReadBinary"); err != nil { |
| 289 | return nil, 0, err |
| 290 | } |
| 291 | |
| 292 | v, err := ejvr.p.readValue(bsontype.Binary) |
| 293 | if err != nil { |
| 294 | return nil, 0, err |
| 295 | } |
| 296 | |
| 297 | b, btype, err = v.parseBinary() |
| 298 | |
| 299 | ejvr.pop() |
| 300 | return b, btype, err |
| 301 | } |
| 302 | |
| 303 | func (ejvr *extJSONValueReader) ReadBoolean() (bool, error) { |
| 304 | if err := ejvr.ensureElementValue(bsontype.Boolean, 0, "ReadBoolean"); err != nil { |
| 305 | return false, err |
| 306 | } |
| 307 | |
| 308 | v, err := ejvr.p.readValue(bsontype.Boolean) |
| 309 | if err != nil { |
| 310 | return false, err |
| 311 | } |
| 312 | |
| 313 | if v.t != bsontype.Boolean { |
| 314 | return false, fmt.Errorf("expected type bool, but got type %s", v.t) |
| 315 | } |
| 316 | |
| 317 | ejvr.pop() |
| 318 | return v.v.(bool), nil |
| 319 | } |
| 320 | |
| 321 | func (ejvr *extJSONValueReader) ReadDocument() (DocumentReader, error) { |
| 322 | switch ejvr.stack[ejvr.frame].mode { |
| 323 | case mTopLevel: |
| 324 | return ejvr, nil |
| 325 | case mElement, mValue: |
| 326 | if ejvr.stack[ejvr.frame].vType != bsontype.EmbeddedDocument { |
| 327 | return nil, ejvr.typeError(bsontype.EmbeddedDocument) |
| 328 | } |
| 329 | |
| 330 | ejvr.pushDocument() |
| 331 | return ejvr, nil |
| 332 | default: |
| 333 | return nil, ejvr.invalidTransitionErr(mDocument, "ReadDocument", []mode{mTopLevel, mElement, mValue}) |
| 334 | } |
| 335 | } |
| 336 | |
| 337 | func (ejvr *extJSONValueReader) ReadCodeWithScope() (code string, dr DocumentReader, err error) { |
| 338 | if err = ejvr.ensureElementValue(bsontype.CodeWithScope, 0, "ReadCodeWithScope"); err != nil { |
| 339 | return "", nil, err |
| 340 | } |
| 341 | |
| 342 | v, err := ejvr.p.readValue(bsontype.CodeWithScope) |
| 343 | if err != nil { |
| 344 | return "", nil, err |
| 345 | } |
| 346 | |
| 347 | code, err = v.parseJavascript() |
| 348 | |
| 349 | ejvr.pushCodeWithScope() |
| 350 | return code, ejvr, err |
| 351 | } |
| 352 | |
| 353 | func (ejvr *extJSONValueReader) ReadDBPointer() (ns string, oid primitive.ObjectID, err error) { |
| 354 | if err = ejvr.ensureElementValue(bsontype.DBPointer, 0, "ReadDBPointer"); err != nil { |
| 355 | return "", primitive.NilObjectID, err |
| 356 | } |
| 357 | |
| 358 | v, err := ejvr.p.readValue(bsontype.DBPointer) |
| 359 | if err != nil { |
| 360 | return "", primitive.NilObjectID, err |
| 361 | } |
| 362 | |
| 363 | ns, oid, err = v.parseDBPointer() |
| 364 | |
| 365 | ejvr.pop() |
| 366 | return ns, oid, err |
| 367 | } |
| 368 | |
| 369 | func (ejvr *extJSONValueReader) ReadDateTime() (int64, error) { |
| 370 | if err := ejvr.ensureElementValue(bsontype.DateTime, 0, "ReadDateTime"); err != nil { |
| 371 | return 0, err |
| 372 | } |
| 373 | |
| 374 | v, err := ejvr.p.readValue(bsontype.DateTime) |
| 375 | if err != nil { |
| 376 | return 0, err |
| 377 | } |
| 378 | |
| 379 | d, err := v.parseDateTime() |
| 380 | |
| 381 | ejvr.pop() |
| 382 | return d, err |
| 383 | } |
| 384 | |
| 385 | func (ejvr *extJSONValueReader) ReadDecimal128() (primitive.Decimal128, error) { |
| 386 | if err := ejvr.ensureElementValue(bsontype.Decimal128, 0, "ReadDecimal128"); err != nil { |
| 387 | return primitive.Decimal128{}, err |
| 388 | } |
| 389 | |
| 390 | v, err := ejvr.p.readValue(bsontype.Decimal128) |
| 391 | if err != nil { |
| 392 | return primitive.Decimal128{}, err |
| 393 | } |
| 394 | |
| 395 | d, err := v.parseDecimal128() |
| 396 | |
| 397 | ejvr.pop() |
| 398 | return d, err |
| 399 | } |
| 400 | |
| 401 | func (ejvr *extJSONValueReader) ReadDouble() (float64, error) { |
| 402 | if err := ejvr.ensureElementValue(bsontype.Double, 0, "ReadDouble"); err != nil { |
| 403 | return 0, err |
| 404 | } |
| 405 | |
| 406 | v, err := ejvr.p.readValue(bsontype.Double) |
| 407 | if err != nil { |
| 408 | return 0, err |
| 409 | } |
| 410 | |
| 411 | d, err := v.parseDouble() |
| 412 | |
| 413 | ejvr.pop() |
| 414 | return d, err |
| 415 | } |
| 416 | |
| 417 | func (ejvr *extJSONValueReader) ReadInt32() (int32, error) { |
| 418 | if err := ejvr.ensureElementValue(bsontype.Int32, 0, "ReadInt32"); err != nil { |
| 419 | return 0, err |
| 420 | } |
| 421 | |
| 422 | v, err := ejvr.p.readValue(bsontype.Int32) |
| 423 | if err != nil { |
| 424 | return 0, err |
| 425 | } |
| 426 | |
| 427 | i, err := v.parseInt32() |
| 428 | |
| 429 | ejvr.pop() |
| 430 | return i, err |
| 431 | } |
| 432 | |
| 433 | func (ejvr *extJSONValueReader) ReadInt64() (int64, error) { |
| 434 | if err := ejvr.ensureElementValue(bsontype.Int64, 0, "ReadInt64"); err != nil { |
| 435 | return 0, err |
| 436 | } |
| 437 | |
| 438 | v, err := ejvr.p.readValue(bsontype.Int64) |
| 439 | if err != nil { |
| 440 | return 0, err |
| 441 | } |
| 442 | |
| 443 | i, err := v.parseInt64() |
| 444 | |
| 445 | ejvr.pop() |
| 446 | return i, err |
| 447 | } |
| 448 | |
| 449 | func (ejvr *extJSONValueReader) ReadJavascript() (code string, err error) { |
| 450 | if err = ejvr.ensureElementValue(bsontype.JavaScript, 0, "ReadJavascript"); err != nil { |
| 451 | return "", err |
| 452 | } |
| 453 | |
| 454 | v, err := ejvr.p.readValue(bsontype.JavaScript) |
| 455 | if err != nil { |
| 456 | return "", err |
| 457 | } |
| 458 | |
| 459 | code, err = v.parseJavascript() |
| 460 | |
| 461 | ejvr.pop() |
| 462 | return code, err |
| 463 | } |
| 464 | |
| 465 | func (ejvr *extJSONValueReader) ReadMaxKey() error { |
| 466 | if err := ejvr.ensureElementValue(bsontype.MaxKey, 0, "ReadMaxKey"); err != nil { |
| 467 | return err |
| 468 | } |
| 469 | |
| 470 | v, err := ejvr.p.readValue(bsontype.MaxKey) |
| 471 | if err != nil { |
| 472 | return err |
| 473 | } |
| 474 | |
| 475 | err = v.parseMinMaxKey("max") |
| 476 | |
| 477 | ejvr.pop() |
| 478 | return err |
| 479 | } |
| 480 | |
| 481 | func (ejvr *extJSONValueReader) ReadMinKey() error { |
| 482 | if err := ejvr.ensureElementValue(bsontype.MinKey, 0, "ReadMinKey"); err != nil { |
| 483 | return err |
| 484 | } |
| 485 | |
| 486 | v, err := ejvr.p.readValue(bsontype.MinKey) |
| 487 | if err != nil { |
| 488 | return err |
| 489 | } |
| 490 | |
| 491 | err = v.parseMinMaxKey("min") |
| 492 | |
| 493 | ejvr.pop() |
| 494 | return err |
| 495 | } |
| 496 | |
| 497 | func (ejvr *extJSONValueReader) ReadNull() error { |
| 498 | if err := ejvr.ensureElementValue(bsontype.Null, 0, "ReadNull"); err != nil { |
| 499 | return err |
| 500 | } |
| 501 | |
| 502 | v, err := ejvr.p.readValue(bsontype.Null) |
| 503 | if err != nil { |
| 504 | return err |
| 505 | } |
| 506 | |
| 507 | if v.t != bsontype.Null { |
| 508 | return fmt.Errorf("expected type null but got type %s", v.t) |
| 509 | } |
| 510 | |
| 511 | ejvr.pop() |
| 512 | return nil |
| 513 | } |
| 514 | |
| 515 | func (ejvr *extJSONValueReader) ReadObjectID() (primitive.ObjectID, error) { |
| 516 | if err := ejvr.ensureElementValue(bsontype.ObjectID, 0, "ReadObjectID"); err != nil { |
| 517 | return primitive.ObjectID{}, err |
| 518 | } |
| 519 | |
| 520 | v, err := ejvr.p.readValue(bsontype.ObjectID) |
| 521 | if err != nil { |
| 522 | return primitive.ObjectID{}, err |
| 523 | } |
| 524 | |
| 525 | oid, err := v.parseObjectID() |
| 526 | |
| 527 | ejvr.pop() |
| 528 | return oid, err |
| 529 | } |
| 530 | |
| 531 | func (ejvr *extJSONValueReader) ReadRegex() (pattern string, options string, err error) { |
| 532 | if err = ejvr.ensureElementValue(bsontype.Regex, 0, "ReadRegex"); err != nil { |
| 533 | return "", "", err |
| 534 | } |
| 535 | |
| 536 | v, err := ejvr.p.readValue(bsontype.Regex) |
| 537 | if err != nil { |
| 538 | return "", "", err |
| 539 | } |
| 540 | |
| 541 | pattern, options, err = v.parseRegex() |
| 542 | |
| 543 | ejvr.pop() |
| 544 | return pattern, options, err |
| 545 | } |
| 546 | |
| 547 | func (ejvr *extJSONValueReader) ReadString() (string, error) { |
| 548 | if err := ejvr.ensureElementValue(bsontype.String, 0, "ReadString"); err != nil { |
| 549 | return "", err |
| 550 | } |
| 551 | |
| 552 | v, err := ejvr.p.readValue(bsontype.String) |
| 553 | if err != nil { |
| 554 | return "", err |
| 555 | } |
| 556 | |
| 557 | if v.t != bsontype.String { |
| 558 | return "", fmt.Errorf("expected type string but got type %s", v.t) |
| 559 | } |
| 560 | |
| 561 | ejvr.pop() |
| 562 | return v.v.(string), nil |
| 563 | } |
| 564 | |
| 565 | func (ejvr *extJSONValueReader) ReadSymbol() (symbol string, err error) { |
| 566 | if err = ejvr.ensureElementValue(bsontype.Symbol, 0, "ReadSymbol"); err != nil { |
| 567 | return "", err |
| 568 | } |
| 569 | |
| 570 | v, err := ejvr.p.readValue(bsontype.Symbol) |
| 571 | if err != nil { |
| 572 | return "", err |
| 573 | } |
| 574 | |
| 575 | symbol, err = v.parseSymbol() |
| 576 | |
| 577 | ejvr.pop() |
| 578 | return symbol, err |
| 579 | } |
| 580 | |
| 581 | func (ejvr *extJSONValueReader) ReadTimestamp() (t uint32, i uint32, err error) { |
| 582 | if err = ejvr.ensureElementValue(bsontype.Timestamp, 0, "ReadTimestamp"); err != nil { |
| 583 | return 0, 0, err |
| 584 | } |
| 585 | |
| 586 | v, err := ejvr.p.readValue(bsontype.Timestamp) |
| 587 | if err != nil { |
| 588 | return 0, 0, err |
| 589 | } |
| 590 | |
| 591 | t, i, err = v.parseTimestamp() |
| 592 | |
| 593 | ejvr.pop() |
| 594 | return t, i, err |
| 595 | } |
| 596 | |
| 597 | func (ejvr *extJSONValueReader) ReadUndefined() error { |
| 598 | if err := ejvr.ensureElementValue(bsontype.Undefined, 0, "ReadUndefined"); err != nil { |
| 599 | return err |
| 600 | } |
| 601 | |
| 602 | v, err := ejvr.p.readValue(bsontype.Undefined) |
| 603 | if err != nil { |
| 604 | return err |
| 605 | } |
| 606 | |
| 607 | err = v.parseUndefined() |
| 608 | |
| 609 | ejvr.pop() |
| 610 | return err |
| 611 | } |
| 612 | |
| 613 | func (ejvr *extJSONValueReader) ReadElement() (string, ValueReader, error) { |
| 614 | switch ejvr.stack[ejvr.frame].mode { |
| 615 | case mTopLevel, mDocument, mCodeWithScope: |
| 616 | default: |
| 617 | return "", nil, ejvr.invalidTransitionErr(mElement, "ReadElement", []mode{mTopLevel, mDocument, mCodeWithScope}) |
| 618 | } |
| 619 | |
| 620 | name, t, err := ejvr.p.readKey() |
| 621 | |
| 622 | if err != nil { |
| 623 | if err == ErrEOD { |
| 624 | if ejvr.stack[ejvr.frame].mode == mCodeWithScope { |
| 625 | _, err := ejvr.p.peekType() |
| 626 | if err != nil { |
| 627 | return "", nil, err |
| 628 | } |
| 629 | } |
| 630 | |
| 631 | ejvr.pop() |
| 632 | } |
| 633 | |
| 634 | return "", nil, err |
| 635 | } |
| 636 | |
| 637 | ejvr.push(mElement, t) |
| 638 | return name, ejvr, nil |
| 639 | } |
| 640 | |
| 641 | func (ejvr *extJSONValueReader) ReadValue() (ValueReader, error) { |
| 642 | switch ejvr.stack[ejvr.frame].mode { |
| 643 | case mArray: |
| 644 | default: |
| 645 | return nil, ejvr.invalidTransitionErr(mValue, "ReadValue", []mode{mArray}) |
| 646 | } |
| 647 | |
| 648 | t, err := ejvr.p.peekType() |
| 649 | if err != nil { |
| 650 | if err == ErrEOA { |
| 651 | ejvr.pop() |
| 652 | } |
| 653 | |
| 654 | return nil, err |
| 655 | } |
| 656 | |
| 657 | ejvr.push(mValue, t) |
| 658 | return ejvr, nil |
| 659 | } |