Serge Bazanski | cc25bdf | 2018-10-25 14:02:58 +0200 | [diff] [blame] | 1 | // BSON library for Go |
| 2 | // |
| 3 | // Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net> |
| 4 | // |
| 5 | // All rights reserved. |
| 6 | // |
| 7 | // Redistribution and use in source and binary forms, with or without |
| 8 | // modification, are permitted provided that the following conditions are met: |
| 9 | // |
| 10 | // 1. Redistributions of source code must retain the above copyright notice, this |
| 11 | // list of conditions and the following disclaimer. |
| 12 | // 2. Redistributions in binary form must reproduce the above copyright notice, |
| 13 | // this list of conditions and the following disclaimer in the documentation |
| 14 | // and/or other materials provided with the distribution. |
| 15 | // |
| 16 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND |
| 17 | // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| 18 | // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| 19 | // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR |
| 20 | // ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| 21 | // (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 22 | // LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| 23 | // ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 24 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 25 | // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 26 | |
| 27 | // Package bson is an implementation of the BSON specification for Go: |
| 28 | // |
| 29 | // http://bsonspec.org |
| 30 | // |
| 31 | // It was created as part of the mgo MongoDB driver for Go, but is standalone |
| 32 | // and may be used on its own without the driver. |
| 33 | package bson |
| 34 | |
| 35 | import ( |
| 36 | "bytes" |
| 37 | "crypto/md5" |
| 38 | "crypto/rand" |
| 39 | "encoding/binary" |
| 40 | "encoding/hex" |
| 41 | "encoding/json" |
| 42 | "errors" |
| 43 | "fmt" |
| 44 | "io" |
| 45 | "math" |
| 46 | "os" |
| 47 | "reflect" |
| 48 | "runtime" |
| 49 | "strings" |
| 50 | "sync" |
| 51 | "sync/atomic" |
| 52 | "time" |
| 53 | ) |
| 54 | |
| 55 | //go:generate go run bson_corpus_spec_test_generator.go |
| 56 | |
| 57 | // -------------------------------------------------------------------------- |
| 58 | // The public API. |
| 59 | |
| 60 | // Element types constants from BSON specification. |
| 61 | const ( |
| 62 | ElementFloat64 byte = 0x01 |
| 63 | ElementString byte = 0x02 |
| 64 | ElementDocument byte = 0x03 |
| 65 | ElementArray byte = 0x04 |
| 66 | ElementBinary byte = 0x05 |
| 67 | Element06 byte = 0x06 |
| 68 | ElementObjectId byte = 0x07 |
| 69 | ElementBool byte = 0x08 |
| 70 | ElementDatetime byte = 0x09 |
| 71 | ElementNil byte = 0x0A |
| 72 | ElementRegEx byte = 0x0B |
| 73 | ElementDBPointer byte = 0x0C |
| 74 | ElementJavaScriptWithoutScope byte = 0x0D |
| 75 | ElementSymbol byte = 0x0E |
| 76 | ElementJavaScriptWithScope byte = 0x0F |
| 77 | ElementInt32 byte = 0x10 |
| 78 | ElementTimestamp byte = 0x11 |
| 79 | ElementInt64 byte = 0x12 |
| 80 | ElementDecimal128 byte = 0x13 |
| 81 | ElementMinKey byte = 0xFF |
| 82 | ElementMaxKey byte = 0x7F |
| 83 | |
| 84 | BinaryGeneric byte = 0x00 |
| 85 | BinaryFunction byte = 0x01 |
| 86 | BinaryBinaryOld byte = 0x02 |
| 87 | BinaryUUIDOld byte = 0x03 |
| 88 | BinaryUUID byte = 0x04 |
| 89 | BinaryMD5 byte = 0x05 |
| 90 | BinaryUserDefined byte = 0x80 |
| 91 | ) |
| 92 | |
| 93 | // Getter interface: a value implementing the bson.Getter interface will have its GetBSON |
| 94 | // method called when the given value has to be marshalled, and the result |
| 95 | // of this method will be marshaled in place of the actual object. |
| 96 | // |
| 97 | // If GetBSON returns return a non-nil error, the marshalling procedure |
| 98 | // will stop and error out with the provided value. |
| 99 | type Getter interface { |
| 100 | GetBSON() (interface{}, error) |
| 101 | } |
| 102 | |
| 103 | // Setter interface: a value implementing the bson.Setter interface will receive the BSON |
| 104 | // value via the SetBSON method during unmarshaling, and the object |
| 105 | // itself will not be changed as usual. |
| 106 | // |
| 107 | // If setting the value works, the method should return nil or alternatively |
| 108 | // bson.ErrSetZero to set the respective field to its zero value (nil for |
| 109 | // pointer types). If SetBSON returns a value of type bson.TypeError, the |
| 110 | // BSON value will be omitted from a map or slice being decoded and the |
| 111 | // unmarshalling will continue. If it returns any other non-nil error, the |
| 112 | // unmarshalling procedure will stop and error out with the provided value. |
| 113 | // |
| 114 | // This interface is generally useful in pointer receivers, since the method |
| 115 | // will want to change the receiver. A type field that implements the Setter |
| 116 | // interface doesn't have to be a pointer, though. |
| 117 | // |
| 118 | // Unlike the usual behavior, unmarshalling onto a value that implements a |
| 119 | // Setter interface will NOT reset the value to its zero state. This allows |
| 120 | // the value to decide by itself how to be unmarshalled. |
| 121 | // |
| 122 | // For example: |
| 123 | // |
| 124 | // type MyString string |
| 125 | // |
| 126 | // func (s *MyString) SetBSON(raw bson.Raw) error { |
| 127 | // return raw.Unmarshal(s) |
| 128 | // } |
| 129 | // |
| 130 | type Setter interface { |
| 131 | SetBSON(raw Raw) error |
| 132 | } |
| 133 | |
| 134 | // ErrSetZero may be returned from a SetBSON method to have the value set to |
| 135 | // its respective zero value. When used in pointer values, this will set the |
| 136 | // field to nil rather than to the pre-allocated value. |
| 137 | var ErrSetZero = errors.New("set to zero") |
| 138 | |
| 139 | // M is a convenient alias for a map[string]interface{} map, useful for |
| 140 | // dealing with BSON in a native way. For instance: |
| 141 | // |
| 142 | // bson.M{"a": 1, "b": true} |
| 143 | // |
| 144 | // There's no special handling for this type in addition to what's done anyway |
| 145 | // for an equivalent map type. Elements in the map will be dumped in an |
| 146 | // undefined ordered. See also the bson.D type for an ordered alternative. |
| 147 | type M map[string]interface{} |
| 148 | |
| 149 | // D represents a BSON document containing ordered elements. For example: |
| 150 | // |
| 151 | // bson.D{{"a", 1}, {"b", true}} |
| 152 | // |
| 153 | // In some situations, such as when creating indexes for MongoDB, the order in |
| 154 | // which the elements are defined is important. If the order is not important, |
| 155 | // using a map is generally more comfortable. See bson.M and bson.RawD. |
| 156 | type D []DocElem |
| 157 | |
| 158 | // DocElem is an element of the bson.D document representation. |
| 159 | type DocElem struct { |
| 160 | Name string |
| 161 | Value interface{} |
| 162 | } |
| 163 | |
| 164 | // Map returns a map out of the ordered element name/value pairs in d. |
| 165 | func (d D) Map() (m M) { |
| 166 | m = make(M, len(d)) |
| 167 | for _, item := range d { |
| 168 | m[item.Name] = item.Value |
| 169 | } |
| 170 | return m |
| 171 | } |
| 172 | |
| 173 | // The Raw type represents raw unprocessed BSON documents and elements. |
| 174 | // Kind is the kind of element as defined per the BSON specification, and |
| 175 | // Data is the raw unprocessed data for the respective element. |
| 176 | // Using this type it is possible to unmarshal or marshal values partially. |
| 177 | // |
| 178 | // Relevant documentation: |
| 179 | // |
| 180 | // http://bsonspec.org/#/specification |
| 181 | // |
| 182 | type Raw struct { |
| 183 | Kind byte |
| 184 | Data []byte |
| 185 | } |
| 186 | |
| 187 | // RawD represents a BSON document containing raw unprocessed elements. |
| 188 | // This low-level representation may be useful when lazily processing |
| 189 | // documents of uncertain content, or when manipulating the raw content |
| 190 | // documents in general. |
| 191 | type RawD []RawDocElem |
| 192 | |
| 193 | // RawDocElem elements of RawD type. |
| 194 | type RawDocElem struct { |
| 195 | Name string |
| 196 | Value Raw |
| 197 | } |
| 198 | |
| 199 | // ObjectId is a unique ID identifying a BSON value. It must be exactly 12 bytes |
| 200 | // long. MongoDB objects by default have such a property set in their "_id" |
| 201 | // property. |
| 202 | // |
| 203 | // http://www.mongodb.org/display/DOCS/Object+Ids |
| 204 | type ObjectId string |
| 205 | |
| 206 | // ObjectIdHex returns an ObjectId from the provided hex representation. |
| 207 | // Calling this function with an invalid hex representation will |
| 208 | // cause a runtime panic. See the IsObjectIdHex function. |
| 209 | func ObjectIdHex(s string) ObjectId { |
| 210 | d, err := hex.DecodeString(s) |
| 211 | if err != nil || len(d) != 12 { |
| 212 | panic(fmt.Sprintf("invalid input to ObjectIdHex: %q", s)) |
| 213 | } |
| 214 | return ObjectId(d) |
| 215 | } |
| 216 | |
| 217 | // IsObjectIdHex returns whether s is a valid hex representation of |
| 218 | // an ObjectId. See the ObjectIdHex function. |
| 219 | func IsObjectIdHex(s string) bool { |
| 220 | if len(s) != 24 { |
| 221 | return false |
| 222 | } |
| 223 | _, err := hex.DecodeString(s) |
| 224 | return err == nil |
| 225 | } |
| 226 | |
| 227 | // objectIdCounter is atomically incremented when generating a new ObjectId |
| 228 | // using NewObjectId() function. It's used as a counter part of an id. |
| 229 | var objectIdCounter = readRandomUint32() |
| 230 | |
| 231 | // readRandomUint32 returns a random objectIdCounter. |
| 232 | func readRandomUint32() uint32 { |
| 233 | var b [4]byte |
| 234 | _, err := io.ReadFull(rand.Reader, b[:]) |
| 235 | if err != nil { |
| 236 | panic(fmt.Errorf("cannot read random object id: %v", err)) |
| 237 | } |
| 238 | return uint32((uint32(b[0]) << 0) | (uint32(b[1]) << 8) | (uint32(b[2]) << 16) | (uint32(b[3]) << 24)) |
| 239 | } |
| 240 | |
| 241 | // machineId stores machine id generated once and used in subsequent calls |
| 242 | // to NewObjectId function. |
| 243 | var machineId = readMachineId() |
| 244 | var processId = os.Getpid() |
| 245 | |
| 246 | // readMachineId generates and returns a machine id. |
| 247 | // If this function fails to get the hostname it will cause a runtime error. |
| 248 | func readMachineId() []byte { |
| 249 | var sum [3]byte |
| 250 | id := sum[:] |
| 251 | hostname, err1 := os.Hostname() |
| 252 | if err1 != nil { |
| 253 | _, err2 := io.ReadFull(rand.Reader, id) |
| 254 | if err2 != nil { |
| 255 | panic(fmt.Errorf("cannot get hostname: %v; %v", err1, err2)) |
| 256 | } |
| 257 | return id |
| 258 | } |
| 259 | hw := md5.New() |
| 260 | hw.Write([]byte(hostname)) |
| 261 | copy(id, hw.Sum(nil)) |
| 262 | return id |
| 263 | } |
| 264 | |
| 265 | // NewObjectId returns a new unique ObjectId. |
| 266 | func NewObjectId() ObjectId { |
| 267 | var b [12]byte |
| 268 | // Timestamp, 4 bytes, big endian |
| 269 | binary.BigEndian.PutUint32(b[:], uint32(time.Now().Unix())) |
| 270 | // Machine, first 3 bytes of md5(hostname) |
| 271 | b[4] = machineId[0] |
| 272 | b[5] = machineId[1] |
| 273 | b[6] = machineId[2] |
| 274 | // Pid, 2 bytes, specs don't specify endianness, but we use big endian. |
| 275 | b[7] = byte(processId >> 8) |
| 276 | b[8] = byte(processId) |
| 277 | // Increment, 3 bytes, big endian |
| 278 | i := atomic.AddUint32(&objectIdCounter, 1) |
| 279 | b[9] = byte(i >> 16) |
| 280 | b[10] = byte(i >> 8) |
| 281 | b[11] = byte(i) |
| 282 | return ObjectId(b[:]) |
| 283 | } |
| 284 | |
| 285 | // NewObjectIdWithTime returns a dummy ObjectId with the timestamp part filled |
| 286 | // with the provided number of seconds from epoch UTC, and all other parts |
| 287 | // filled with zeroes. It's not safe to insert a document with an id generated |
| 288 | // by this method, it is useful only for queries to find documents with ids |
| 289 | // generated before or after the specified timestamp. |
| 290 | func NewObjectIdWithTime(t time.Time) ObjectId { |
| 291 | var b [12]byte |
| 292 | binary.BigEndian.PutUint32(b[:4], uint32(t.Unix())) |
| 293 | return ObjectId(string(b[:])) |
| 294 | } |
| 295 | |
| 296 | // String returns a hex string representation of the id. |
| 297 | // Example: ObjectIdHex("4d88e15b60f486e428412dc9"). |
| 298 | func (id ObjectId) String() string { |
| 299 | return fmt.Sprintf(`ObjectIdHex("%x")`, string(id)) |
| 300 | } |
| 301 | |
| 302 | // Hex returns a hex representation of the ObjectId. |
| 303 | func (id ObjectId) Hex() string { |
| 304 | return hex.EncodeToString([]byte(id)) |
| 305 | } |
| 306 | |
| 307 | // MarshalJSON turns a bson.ObjectId into a json.Marshaller. |
| 308 | func (id ObjectId) MarshalJSON() ([]byte, error) { |
| 309 | return []byte(fmt.Sprintf(`"%x"`, string(id))), nil |
| 310 | } |
| 311 | |
| 312 | var nullBytes = []byte("null") |
| 313 | |
| 314 | // UnmarshalJSON turns *bson.ObjectId into a json.Unmarshaller. |
| 315 | func (id *ObjectId) UnmarshalJSON(data []byte) error { |
| 316 | if len(data) > 0 && (data[0] == '{' || data[0] == 'O') { |
| 317 | var v struct { |
| 318 | Id json.RawMessage `json:"$oid"` |
| 319 | Func struct { |
| 320 | Id json.RawMessage |
| 321 | } `json:"$oidFunc"` |
| 322 | } |
| 323 | err := jdec(data, &v) |
| 324 | if err == nil { |
| 325 | if len(v.Id) > 0 { |
| 326 | data = []byte(v.Id) |
| 327 | } else { |
| 328 | data = []byte(v.Func.Id) |
| 329 | } |
| 330 | } |
| 331 | } |
| 332 | if len(data) == 2 && data[0] == '"' && data[1] == '"' || bytes.Equal(data, nullBytes) { |
| 333 | *id = "" |
| 334 | return nil |
| 335 | } |
| 336 | if len(data) != 26 || data[0] != '"' || data[25] != '"' { |
| 337 | return fmt.Errorf("invalid ObjectId in JSON: %s", string(data)) |
| 338 | } |
| 339 | var buf [12]byte |
| 340 | _, err := hex.Decode(buf[:], data[1:25]) |
| 341 | if err != nil { |
| 342 | return fmt.Errorf("invalid ObjectId in JSON: %s (%s)", string(data), err) |
| 343 | } |
| 344 | *id = ObjectId(string(buf[:])) |
| 345 | return nil |
| 346 | } |
| 347 | |
| 348 | // MarshalText turns bson.ObjectId into an encoding.TextMarshaler. |
| 349 | func (id ObjectId) MarshalText() ([]byte, error) { |
| 350 | return []byte(fmt.Sprintf("%x", string(id))), nil |
| 351 | } |
| 352 | |
| 353 | // UnmarshalText turns *bson.ObjectId into an encoding.TextUnmarshaler. |
| 354 | func (id *ObjectId) UnmarshalText(data []byte) error { |
| 355 | if len(data) == 1 && data[0] == ' ' || len(data) == 0 { |
| 356 | *id = "" |
| 357 | return nil |
| 358 | } |
| 359 | if len(data) != 24 { |
| 360 | return fmt.Errorf("invalid ObjectId: %s", data) |
| 361 | } |
| 362 | var buf [12]byte |
| 363 | _, err := hex.Decode(buf[:], data[:]) |
| 364 | if err != nil { |
| 365 | return fmt.Errorf("invalid ObjectId: %s (%s)", data, err) |
| 366 | } |
| 367 | *id = ObjectId(string(buf[:])) |
| 368 | return nil |
| 369 | } |
| 370 | |
| 371 | // Valid returns true if id is valid. A valid id must contain exactly 12 bytes. |
| 372 | func (id ObjectId) Valid() bool { |
| 373 | return len(id) == 12 |
| 374 | } |
| 375 | |
| 376 | // byteSlice returns byte slice of id from start to end. |
| 377 | // Calling this function with an invalid id will cause a runtime panic. |
| 378 | func (id ObjectId) byteSlice(start, end int) []byte { |
| 379 | if len(id) != 12 { |
| 380 | panic(fmt.Sprintf("invalid ObjectId: %q", string(id))) |
| 381 | } |
| 382 | return []byte(string(id)[start:end]) |
| 383 | } |
| 384 | |
| 385 | // Time returns the timestamp part of the id. |
| 386 | // It's a runtime error to call this method with an invalid id. |
| 387 | func (id ObjectId) Time() time.Time { |
| 388 | // First 4 bytes of ObjectId is 32-bit big-endian seconds from epoch. |
| 389 | secs := int64(binary.BigEndian.Uint32(id.byteSlice(0, 4))) |
| 390 | return time.Unix(secs, 0) |
| 391 | } |
| 392 | |
| 393 | // Machine returns the 3-byte machine id part of the id. |
| 394 | // It's a runtime error to call this method with an invalid id. |
| 395 | func (id ObjectId) Machine() []byte { |
| 396 | return id.byteSlice(4, 7) |
| 397 | } |
| 398 | |
| 399 | // Pid returns the process id part of the id. |
| 400 | // It's a runtime error to call this method with an invalid id. |
| 401 | func (id ObjectId) Pid() uint16 { |
| 402 | return binary.BigEndian.Uint16(id.byteSlice(7, 9)) |
| 403 | } |
| 404 | |
| 405 | // Counter returns the incrementing value part of the id. |
| 406 | // It's a runtime error to call this method with an invalid id. |
| 407 | func (id ObjectId) Counter() int32 { |
| 408 | b := id.byteSlice(9, 12) |
| 409 | // Counter is stored as big-endian 3-byte value |
| 410 | return int32(uint32(b[0])<<16 | uint32(b[1])<<8 | uint32(b[2])) |
| 411 | } |
| 412 | |
| 413 | // The Symbol type is similar to a string and is used in languages with a |
| 414 | // distinct symbol type. |
| 415 | type Symbol string |
| 416 | |
| 417 | // Now returns the current time with millisecond precision. MongoDB stores |
| 418 | // timestamps with the same precision, so a Time returned from this method |
| 419 | // will not change after a roundtrip to the database. That's the only reason |
| 420 | // why this function exists. Using the time.Now function also works fine |
| 421 | // otherwise. |
| 422 | func Now() time.Time { |
| 423 | return time.Unix(0, time.Now().UnixNano()/1e6*1e6) |
| 424 | } |
| 425 | |
| 426 | // MongoTimestamp is a special internal type used by MongoDB that for some |
| 427 | // strange reason has its own datatype defined in BSON. |
| 428 | type MongoTimestamp int64 |
| 429 | |
| 430 | // Time returns the time part of ts which is stored with second precision. |
| 431 | func (ts MongoTimestamp) Time() time.Time { |
| 432 | return time.Unix(int64(uint64(ts)>>32), 0) |
| 433 | } |
| 434 | |
| 435 | // Counter returns the counter part of ts. |
| 436 | func (ts MongoTimestamp) Counter() uint32 { |
| 437 | return uint32(ts) |
| 438 | } |
| 439 | |
| 440 | // NewMongoTimestamp creates a timestamp using the given |
| 441 | // date `t` (with second precision) and counter `c` (unique for `t`). |
| 442 | // |
| 443 | // Returns an error if time `t` is not between 1970-01-01T00:00:00Z |
| 444 | // and 2106-02-07T06:28:15Z (inclusive). |
| 445 | // |
| 446 | // Note that two MongoTimestamps should never have the same (time, counter) combination: |
| 447 | // the caller must ensure the counter `c` is increased if creating multiple MongoTimestamp |
| 448 | // values for the same time `t` (ignoring fractions of seconds). |
| 449 | func NewMongoTimestamp(t time.Time, c uint32) (MongoTimestamp, error) { |
| 450 | u := t.Unix() |
| 451 | if u < 0 || u > math.MaxUint32 { |
| 452 | return -1, errors.New("invalid value for time") |
| 453 | } |
| 454 | |
| 455 | i := int64(u<<32 | int64(c)) |
| 456 | |
| 457 | return MongoTimestamp(i), nil |
| 458 | } |
| 459 | |
| 460 | type orderKey int64 |
| 461 | |
| 462 | // MaxKey is a special value that compares higher than all other possible BSON |
| 463 | // values in a MongoDB database. |
| 464 | var MaxKey = orderKey(1<<63 - 1) |
| 465 | |
| 466 | // MinKey is a special value that compares lower than all other possible BSON |
| 467 | // values in a MongoDB database. |
| 468 | var MinKey = orderKey(-1 << 63) |
| 469 | |
| 470 | type undefined struct{} |
| 471 | |
| 472 | // Undefined represents the undefined BSON value. |
| 473 | var Undefined undefined |
| 474 | |
| 475 | // Binary is a representation for non-standard binary values. Any kind should |
| 476 | // work, but the following are known as of this writing: |
| 477 | // |
| 478 | // 0x00 - Generic. This is decoded as []byte(data), not Binary{0x00, data}. |
| 479 | // 0x01 - Function (!?) |
| 480 | // 0x02 - Obsolete generic. |
| 481 | // 0x03 - UUID |
| 482 | // 0x05 - MD5 |
| 483 | // 0x80 - User defined. |
| 484 | // |
| 485 | type Binary struct { |
| 486 | Kind byte |
| 487 | Data []byte |
| 488 | } |
| 489 | |
| 490 | // RegEx represents a regular expression. The Options field may contain |
| 491 | // individual characters defining the way in which the pattern should be |
| 492 | // applied, and must be sorted. Valid options as of this writing are 'i' for |
| 493 | // case insensitive matching, 'm' for multi-line matching, 'x' for verbose |
| 494 | // mode, 'l' to make \w, \W, and similar be locale-dependent, 's' for dot-all |
| 495 | // mode (a '.' matches everything), and 'u' to make \w, \W, and similar match |
| 496 | // unicode. The value of the Options parameter is not verified before being |
| 497 | // marshaled into the BSON format. |
| 498 | type RegEx struct { |
| 499 | Pattern string |
| 500 | Options string |
| 501 | } |
| 502 | |
| 503 | // JavaScript is a type that holds JavaScript code. If Scope is non-nil, it |
| 504 | // will be marshaled as a mapping from identifiers to values that may be |
| 505 | // used when evaluating the provided Code. |
| 506 | type JavaScript struct { |
| 507 | Code string |
| 508 | Scope interface{} |
| 509 | } |
| 510 | |
| 511 | // DBPointer refers to a document id in a namespace. |
| 512 | // |
| 513 | // This type is deprecated in the BSON specification and should not be used |
| 514 | // except for backwards compatibility with ancient applications. |
| 515 | type DBPointer struct { |
| 516 | Namespace string |
| 517 | Id ObjectId |
| 518 | } |
| 519 | |
| 520 | const initialBufferSize = 64 |
| 521 | |
| 522 | func handleErr(err *error) { |
| 523 | if r := recover(); r != nil { |
| 524 | if _, ok := r.(runtime.Error); ok { |
| 525 | panic(r) |
| 526 | } else if _, ok := r.(externalPanic); ok { |
| 527 | panic(r) |
| 528 | } else if s, ok := r.(string); ok { |
| 529 | *err = errors.New(s) |
| 530 | } else if e, ok := r.(error); ok { |
| 531 | *err = e |
| 532 | } else { |
| 533 | panic(r) |
| 534 | } |
| 535 | } |
| 536 | } |
| 537 | |
| 538 | // Marshal serializes the in value, which may be a map or a struct value. |
| 539 | // In the case of struct values, only exported fields will be serialized, |
| 540 | // and the order of serialized fields will match that of the struct itself. |
| 541 | // The lowercased field name is used as the key for each exported field, |
| 542 | // but this behavior may be changed using the respective field tag. |
| 543 | // The tag may also contain flags to tweak the marshalling behavior for |
| 544 | // the field. The tag formats accepted are: |
| 545 | // |
| 546 | // "[<key>][,<flag1>[,<flag2>]]" |
| 547 | // |
| 548 | // `(...) bson:"[<key>][,<flag1>[,<flag2>]]" (...)` |
| 549 | // |
| 550 | // The following flags are currently supported: |
| 551 | // |
| 552 | // omitempty Only include the field if it's not set to the zero |
| 553 | // value for the type or to empty slices or maps. |
| 554 | // |
| 555 | // minsize Marshal an int64 value as an int32, if that's feasible |
| 556 | // while preserving the numeric value. |
| 557 | // |
| 558 | // inline Inline the field, which must be a struct or a map, |
| 559 | // causing all of its fields or keys to be processed as if |
| 560 | // they were part of the outer struct. For maps, keys must |
| 561 | // not conflict with the bson keys of other struct fields. |
| 562 | // |
| 563 | // Some examples: |
| 564 | // |
| 565 | // type T struct { |
| 566 | // A bool |
| 567 | // B int "myb" |
| 568 | // C string "myc,omitempty" |
| 569 | // D string `bson:",omitempty" json:"jsonkey"` |
| 570 | // E int64 ",minsize" |
| 571 | // F int64 "myf,omitempty,minsize" |
| 572 | // } |
| 573 | // |
| 574 | func Marshal(in interface{}) (out []byte, err error) { |
| 575 | return MarshalBuffer(in, make([]byte, 0, initialBufferSize)) |
| 576 | } |
| 577 | |
| 578 | // MarshalBuffer behaves the same way as Marshal, except that instead of |
| 579 | // allocating a new byte slice it tries to use the received byte slice and |
| 580 | // only allocates more memory if necessary to fit the marshaled value. |
| 581 | func MarshalBuffer(in interface{}, buf []byte) (out []byte, err error) { |
| 582 | defer handleErr(&err) |
| 583 | e := &encoder{buf} |
| 584 | e.addDoc(reflect.ValueOf(in)) |
| 585 | return e.out, nil |
| 586 | } |
| 587 | |
| 588 | // Unmarshal deserializes data from in into the out value. The out value |
| 589 | // must be a map, a pointer to a struct, or a pointer to a bson.D value. |
| 590 | // In the case of struct values, only exported fields will be deserialized. |
| 591 | // The lowercased field name is used as the key for each exported field, |
| 592 | // but this behavior may be changed using the respective field tag. |
| 593 | // The tag may also contain flags to tweak the marshalling behavior for |
| 594 | // the field. The tag formats accepted are: |
| 595 | // |
| 596 | // "[<key>][,<flag1>[,<flag2>]]" |
| 597 | // |
| 598 | // `(...) bson:"[<key>][,<flag1>[,<flag2>]]" (...)` |
| 599 | // |
| 600 | // The following flags are currently supported during unmarshal (see the |
| 601 | // Marshal method for other flags): |
| 602 | // |
| 603 | // inline Inline the field, which must be a struct or a map. |
| 604 | // Inlined structs are handled as if its fields were part |
| 605 | // of the outer struct. An inlined map causes keys that do |
| 606 | // not match any other struct field to be inserted in the |
| 607 | // map rather than being discarded as usual. |
| 608 | // |
| 609 | // The target field or element types of out may not necessarily match |
| 610 | // the BSON values of the provided data. The following conversions are |
| 611 | // made automatically: |
| 612 | // |
| 613 | // - Numeric types are converted if at least the integer part of the |
| 614 | // value would be preserved correctly |
| 615 | // - Bools are converted to numeric types as 1 or 0 |
| 616 | // - Numeric types are converted to bools as true if not 0 or false otherwise |
| 617 | // - Binary and string BSON data is converted to a string, array or byte slice |
| 618 | // |
| 619 | // If the value would not fit the type and cannot be converted, it's |
| 620 | // silently skipped. |
| 621 | // |
| 622 | // Pointer values are initialized when necessary. |
| 623 | func Unmarshal(in []byte, out interface{}) (err error) { |
| 624 | if raw, ok := out.(*Raw); ok { |
| 625 | raw.Kind = 3 |
| 626 | raw.Data = in |
| 627 | return nil |
| 628 | } |
| 629 | defer handleErr(&err) |
| 630 | v := reflect.ValueOf(out) |
| 631 | switch v.Kind() { |
| 632 | case reflect.Ptr: |
| 633 | fallthrough |
| 634 | case reflect.Map: |
| 635 | d := newDecoder(in) |
| 636 | d.readDocTo(v) |
| 637 | if d.i < len(d.in) { |
| 638 | return errors.New("document is corrupted") |
| 639 | } |
| 640 | case reflect.Struct: |
| 641 | return errors.New("unmarshal can't deal with struct values. Use a pointer") |
| 642 | default: |
| 643 | return errors.New("unmarshal needs a map or a pointer to a struct") |
| 644 | } |
| 645 | return nil |
| 646 | } |
| 647 | |
| 648 | // Unmarshal deserializes raw into the out value. If the out value type |
| 649 | // is not compatible with raw, a *bson.TypeError is returned. |
| 650 | // |
| 651 | // See the Unmarshal function documentation for more details on the |
| 652 | // unmarshalling process. |
| 653 | func (raw Raw) Unmarshal(out interface{}) (err error) { |
| 654 | defer handleErr(&err) |
| 655 | v := reflect.ValueOf(out) |
| 656 | switch v.Kind() { |
| 657 | case reflect.Ptr: |
| 658 | v = v.Elem() |
| 659 | fallthrough |
| 660 | case reflect.Map: |
| 661 | d := newDecoder(raw.Data) |
| 662 | good := d.readElemTo(v, raw.Kind) |
| 663 | if !good { |
| 664 | return &TypeError{v.Type(), raw.Kind} |
| 665 | } |
| 666 | case reflect.Struct: |
| 667 | return errors.New("raw Unmarshal can't deal with struct values. Use a pointer") |
| 668 | default: |
| 669 | return errors.New("raw Unmarshal needs a map or a valid pointer") |
| 670 | } |
| 671 | return nil |
| 672 | } |
| 673 | |
| 674 | // TypeError store details for type error occuring |
| 675 | // during unmarshaling |
| 676 | type TypeError struct { |
| 677 | Type reflect.Type |
| 678 | Kind byte |
| 679 | } |
| 680 | |
| 681 | func (e *TypeError) Error() string { |
| 682 | return fmt.Sprintf("BSON kind 0x%02x isn't compatible with type %s", e.Kind, e.Type.String()) |
| 683 | } |
| 684 | |
| 685 | // -------------------------------------------------------------------------- |
| 686 | // Maintain a mapping of keys to structure field indexes |
| 687 | |
| 688 | type structInfo struct { |
| 689 | FieldsMap map[string]fieldInfo |
| 690 | FieldsList []fieldInfo |
| 691 | InlineMap int |
| 692 | Zero reflect.Value |
| 693 | } |
| 694 | |
| 695 | type fieldInfo struct { |
| 696 | Key string |
| 697 | Num int |
| 698 | OmitEmpty bool |
| 699 | MinSize bool |
| 700 | Inline []int |
| 701 | } |
| 702 | |
| 703 | var structMap = make(map[reflect.Type]*structInfo) |
| 704 | var structMapMutex sync.RWMutex |
| 705 | |
| 706 | type externalPanic string |
| 707 | |
| 708 | func (e externalPanic) String() string { |
| 709 | return string(e) |
| 710 | } |
| 711 | |
| 712 | func getStructInfo(st reflect.Type) (*structInfo, error) { |
| 713 | structMapMutex.RLock() |
| 714 | sinfo, found := structMap[st] |
| 715 | structMapMutex.RUnlock() |
| 716 | if found { |
| 717 | return sinfo, nil |
| 718 | } |
| 719 | n := st.NumField() |
| 720 | fieldsMap := make(map[string]fieldInfo) |
| 721 | fieldsList := make([]fieldInfo, 0, n) |
| 722 | inlineMap := -1 |
| 723 | for i := 0; i != n; i++ { |
| 724 | field := st.Field(i) |
| 725 | if field.PkgPath != "" && !field.Anonymous { |
| 726 | continue // Private field |
| 727 | } |
| 728 | |
| 729 | info := fieldInfo{Num: i} |
| 730 | |
| 731 | tag := field.Tag.Get("bson") |
| 732 | |
| 733 | // Fall-back to JSON struct tag, if feature flag is set. |
| 734 | if tag == "" && useJSONTagFallback { |
| 735 | tag = field.Tag.Get("json") |
| 736 | } |
| 737 | |
| 738 | // If there's no bson/json tag available. |
| 739 | if tag == "" { |
| 740 | // If there's no tag, and also no tag: value splits (i.e. no colon) |
| 741 | // then assume the entire tag is the value |
| 742 | if strings.Index(string(field.Tag), ":") < 0 { |
| 743 | tag = string(field.Tag) |
| 744 | } |
| 745 | } |
| 746 | |
| 747 | if tag == "-" { |
| 748 | continue |
| 749 | } |
| 750 | |
| 751 | inline := false |
| 752 | fields := strings.Split(tag, ",") |
| 753 | if len(fields) > 1 { |
| 754 | for _, flag := range fields[1:] { |
| 755 | switch flag { |
| 756 | case "omitempty": |
| 757 | info.OmitEmpty = true |
| 758 | case "minsize": |
| 759 | info.MinSize = true |
| 760 | case "inline": |
| 761 | inline = true |
| 762 | default: |
| 763 | msg := fmt.Sprintf("Unsupported flag %q in tag %q of type %s", flag, tag, st) |
| 764 | panic(externalPanic(msg)) |
| 765 | } |
| 766 | } |
| 767 | tag = fields[0] |
| 768 | } |
| 769 | |
| 770 | if inline { |
| 771 | switch field.Type.Kind() { |
| 772 | case reflect.Map: |
| 773 | if inlineMap >= 0 { |
| 774 | return nil, errors.New("Multiple ,inline maps in struct " + st.String()) |
| 775 | } |
| 776 | if field.Type.Key() != reflect.TypeOf("") { |
| 777 | return nil, errors.New("Option ,inline needs a map with string keys in struct " + st.String()) |
| 778 | } |
| 779 | inlineMap = info.Num |
| 780 | case reflect.Ptr: |
| 781 | // allow only pointer to struct |
| 782 | if kind := field.Type.Elem().Kind(); kind != reflect.Struct { |
| 783 | return nil, errors.New("Option ,inline allows a pointer only to a struct, was given pointer to " + kind.String()) |
| 784 | } |
| 785 | |
| 786 | field.Type = field.Type.Elem() |
| 787 | fallthrough |
| 788 | case reflect.Struct: |
| 789 | sinfo, err := getStructInfo(field.Type) |
| 790 | if err != nil { |
| 791 | return nil, err |
| 792 | } |
| 793 | for _, finfo := range sinfo.FieldsList { |
| 794 | if _, found := fieldsMap[finfo.Key]; found { |
| 795 | msg := "Duplicated key '" + finfo.Key + "' in struct " + st.String() |
| 796 | return nil, errors.New(msg) |
| 797 | } |
| 798 | if finfo.Inline == nil { |
| 799 | finfo.Inline = []int{i, finfo.Num} |
| 800 | } else { |
| 801 | finfo.Inline = append([]int{i}, finfo.Inline...) |
| 802 | } |
| 803 | fieldsMap[finfo.Key] = finfo |
| 804 | fieldsList = append(fieldsList, finfo) |
| 805 | } |
| 806 | default: |
| 807 | panic("Option ,inline needs a struct value or a pointer to a struct or map field") |
| 808 | } |
| 809 | continue |
| 810 | } |
| 811 | |
| 812 | if tag != "" { |
| 813 | info.Key = tag |
| 814 | } else { |
| 815 | info.Key = strings.ToLower(field.Name) |
| 816 | } |
| 817 | |
| 818 | if _, found = fieldsMap[info.Key]; found { |
| 819 | msg := "Duplicated key '" + info.Key + "' in struct " + st.String() |
| 820 | return nil, errors.New(msg) |
| 821 | } |
| 822 | |
| 823 | fieldsList = append(fieldsList, info) |
| 824 | fieldsMap[info.Key] = info |
| 825 | } |
| 826 | sinfo = &structInfo{ |
| 827 | fieldsMap, |
| 828 | fieldsList, |
| 829 | inlineMap, |
| 830 | reflect.New(st).Elem(), |
| 831 | } |
| 832 | structMapMutex.Lock() |
| 833 | structMap[st] = sinfo |
| 834 | structMapMutex.Unlock() |
| 835 | return sinfo, nil |
| 836 | } |