BSON is a binary format in which zero or more ordered key/value -pairs are stored as a single entity. We call this entity -a document.
+BSON is a binary format in which zero or more ordered key/value + pairs are stored as a single entity. We call this entity + a document.
-The following grammar specifies version 1.1 of the
-BSON standard. We've written the grammar using a
-pseudo-BNF
-syntax. Valid BSON data is represented by
-the document non-terminal.
The following grammar specifies version 1.1 of the
+ BSON standard. We've written the grammar using a
+ pseudo-BNF
+ syntax. Valid BSON data is represented by
+ the document non-terminal.
The following basic types are used as terminals in - the rest of the grammar. Each type must be serialized in - little-endian format.
+The following basic types are used as terminals in + the rest of the grammar. Each type must be serialized in + little-endian format.
-| byte | -1 byte (8-bits) | -
| signed_byte(n) | -8-bit, two's complement signed integer for which the value is n |
-
| unsigned_byte(n) | -8-bit unsigned integer for which the value is n |
-
| int32 | -4 bytes (32-bit signed integer, two's complement) | -
| int64 | -8 bytes (64-bit signed integer, two's complement) | -
| uint64 | -8 bytes (64-bit unsigned integer) | -
| double | -8 bytes (64-bit IEEE 754-2008 binary floating point) | -
| decimal128 | -16 bytes (128-bit IEEE 754-2008 decimal floating point) | -
| byte | +1 byte (8-bits) | +
| signed_byte(n) | +8-bit, two's complement signed integer for which the value is n |
+
| unsigned_byte(n) | +8-bit unsigned integer for which the value is n |
+
| int32 | +4 bytes (32-bit signed integer, two's complement) | +
| int64 | +8 bytes (64-bit signed integer, two's complement) | +
| uint64 | +8 bytes (64-bit unsigned integer) | +
| double | +8 bytes (64-bit IEEE 754-2008 binary floating point) | +
| decimal128 | +16 bytes (128-bit IEEE 754-2008 decimal floating point) | +
The following specifies the rest of the BSON
- grammar. Note that we use the * operator as
- shorthand for repetition (e.g. (byte*2)
- is byte byte). When used as a unary
- operator, * means that the repetition can
- occur 0 or more times.
The following specifies the rest of the BSON
+ grammar. Note that we use the * operator as
+ shorthand for repetition (e.g. (byte*2)
+ is byte byte). When used as a unary
+ operator, * means that the repetition can
+ occur 0 or more times.
| document | -::= | -int32 e_list unsigned_byte(0) | -BSON Document. int32 is the total number of bytes comprising the document. | -
| e_list | -::= | -element e_list | -- |
| - | | | -"" | -- |
| element | -::= | -signed_byte(1) e_name double | -64-bit binary floating point | -
| - | | | -signed_byte(2) e_name string | -UTF-8 string | -
| - | | | -signed_byte(3) e_name document | -Embedded document | -
| - | | | -signed_byte(4) e_name document | -Array | -
| - | | | -signed_byte(5) e_name binary | -Binary data | -
| - | | | -signed_byte(6) e_name | -Undefined (value) — Deprecated | -
| - | | | -signed_byte(7) e_name (byte*12) | -ObjectId | -
| - | | | -signed_byte(8) e_name unsigned_byte(0) | -Boolean - false | -
| - | | | -signed_byte(8) e_name unsigned_byte(1) | -Boolean - true | -
| - | | | -signed_byte(9) e_name int64 | -UTC datetime | -
| - | | | -signed_byte(10) e_name | -Null value | -
| - | | | -signed_byte(11) e_name cstring cstring | -Regular expression - The first cstring is the regex pattern, the second is the regex options string. Options are identified by characters, which must be stored in alphabetical order. Valid options are 'i' for case insensitive matching, 'm' for multiline matching, 'x' for verbose mode, 'l' to make \w, \W, etc. locale dependent, 's' for dotall mode ('.' matches everything), and 'u' to make \w, \W, etc. match unicode. | -
| - | | | -signed_byte(12) e_name string (byte*12) | -DBPointer — Deprecated | -
| - | | | -signed_byte(13) e_name string | -JavaScript code | -
| - | | | -signed_byte(14) e_name string | -Symbol — Deprecated | -
| - | | | -signed_byte(15) e_name code_w_s | -JavaScript code with scope — Deprecated | -
| - | | | -signed_byte(16) e_name int32 | -32-bit integer | -
| - | | | -signed_byte(17) e_name uint64 | -Timestamp | -
| - | | | -signed_byte(18) e_name int64 | -64-bit integer | -
| - | | | -signed_byte(19) e_name decimal128 | -128-bit decimal floating point | -
| - | | | -signed_byte(-1) e_name | -Min key | -
| - | | | -signed_byte(127) e_name | -Max key | -
| e_name | -::= | -cstring | -Key name | -
| string | -::= | -int32 (byte*) unsigned_byte(0) | -String - The int32 is the number bytes in the - (byte*) plus one for the trailing null byte. The (byte*) is - zero or more UTF-8 encoded characters. | -
| cstring | -::= | -(byte*) unsigned_byte(0) | -Zero or more modified UTF-8 encoded characters
- followed by the null byte. The (byte*) MUST NOT contain
- unsigned_byte(0), hence it is not full UTF-8. |
-
| binary | -::= | -int32 subtype (byte*) | -Binary - The int32 is the number of bytes in the (byte*). | -
| subtype | -::= | -unsigned_byte(0) | -Generic binary subtype | -
| - | | | -unsigned_byte(1) | -Function | -
| - | | | -unsigned_byte(2) | -Binary (Old) | -
| - | | | -unsigned_byte(3) | -UUID (Old) | -
| - | | | -unsigned_byte(4) | -UUID | -
| - | | | -unsigned_byte(5) | -MD5 | -
| - | | | -unsigned_byte(6) | -Encrypted BSON value | -
| - | | | -unsigned_byte(7) | -Compressed BSON column | -
| - | | | -unsigned_byte(8) | -Sensitive | -
| - | | | -unsigned_byte(128)—unsigned_byte(255) | -User defined | -
| code_w_s | -::= | -int32 string document | -Code with scope — Deprecated | -
| document | +::= | +int32 e_list unsigned_byte(0) | +BSON Document. int32 is the total number of bytes comprising the document. | +
| e_list | +::= | +element e_list | ++ |
| + | | | +"" | ++ |
| element | +::= | +signed_byte(1) e_name double | +64-bit binary floating point | +
| + | | | +signed_byte(2) e_name string | +UTF-8 string | +
| + | | | +signed_byte(3) e_name document | +Embedded document | +
| + | | | +signed_byte(4) e_name document | +Array | +
| + | | | +signed_byte(5) e_name binary | +Binary data | +
| + | | | +signed_byte(6) e_name | +Undefined (value) — Deprecated | +
| + | | | +signed_byte(7) e_name (byte*12) | +ObjectId | +
| + | | | +signed_byte(8) e_name unsigned_byte(0) | +Boolean - false | +
| + | | | +signed_byte(8) e_name unsigned_byte(1) | +Boolean - true | +
| + | | | +signed_byte(9) e_name int64 | +UTC datetime | +
| + | | | +signed_byte(10) e_name | +Null value | +
| + | | | +signed_byte(11) e_name cstring cstring | +Regular expression - The first cstring is the regex pattern, the second is the regex options string. + Options are identified by characters, which must be stored in alphabetical order. Valid options are 'i' for + case insensitive matching, 'm' for multiline matching, 'x' for verbose mode, 'l' to make \w, \W, etc. locale + dependent, 's' for dotall mode ('.' matches everything), and 'u' to make \w, \W, etc. match unicode. | +
| + | | | +signed_byte(12) e_name string (byte*12) | +DBPointer — Deprecated | +
| + | | | +signed_byte(13) e_name string | +JavaScript code | +
| + | | | +signed_byte(14) e_name string | +Symbol — Deprecated | +
| + | | | +signed_byte(15) e_name code_w_s | +JavaScript code with scope — Deprecated | +
| + | | | +signed_byte(16) e_name int32 | +32-bit integer | +
| + | | | +signed_byte(17) e_name uint64 | +Timestamp | +
| + | | | +signed_byte(18) e_name int64 | +64-bit integer | +
| + | | | +signed_byte(19) e_name decimal128 | +128-bit + decimal floating point | +
| + | | | +signed_byte(-1) e_name | +Min key | +
| + | | | +signed_byte(127) e_name | +Max key | +
| e_name | +::= | +cstring | +Key name | +
| string | +::= | +int32 (byte*) unsigned_byte(0) | +String - The int32 is the number bytes in the + (byte*) plus one for the trailing null byte. The (byte*) is + zero or more UTF-8 encoded characters. | +
| cstring | +::= | +(byte*) unsigned_byte(0) | +Zero or more modified UTF-8 encoded characters
+ followed by the null byte. The (byte*) MUST NOT contain
+ unsigned_byte(0), hence it is not full UTF-8.
+ |
+
| binary | +::= | +int32 subtype (byte*) | +Binary - The int32 is the number of bytes in the (byte*). | +
| subtype | +::= | +unsigned_byte(0) | +Generic binary subtype | +
| + | | | +unsigned_byte(1) | +Function | +
| + | | | +unsigned_byte(2) | +Binary (Old) | +
| + | | | +unsigned_byte(3) | +UUID (Old) | +
| + | | | +unsigned_byte(4) | +UUID | +
| + | | | +unsigned_byte(5) | +MD5 | +
| + | | | +unsigned_byte(6) | +Encrypted + BSON value | +
| + | | | +unsigned_byte(7) | +Compressed BSON column | +
| + | | | +unsigned_byte(8) | +Sensitive | +
| + | | | +unsigned_byte(128)—unsigned_byte(255) | +User defined | +
| code_w_s | +::= | +int32 string document | +Code with scope — Deprecated | +
unsigned_byte(2) Binary (Old) - This used to be the default
- subtype, but was deprecated in favor of subtype 0.
- Drivers and tools should be sure to handle subtype 2
- appropriately. The structure of the binary data (the byte* array in
- the binary non-terminal) must be an int32 followed by a (byte*). The
- int32 is the number of bytes in the repetition.unsigned_byte(3) UUID (Old) - This used to be the UUID subtype,
- but was deprecated in favor of subtype 4. Drivers
- and tools for languages with a native UUID type should handle
- subtype 3 appropriately.unsigned_byte(128)—unsigned_byte(255) User defined subtypes. The binary data can be anything.unsigned_byte(2) Binary (Old) - This used to be the default
+ subtype, but was deprecated in favor of subtype 0.
+ Drivers and tools should be sure to handle subtype 2
+ appropriately. The structure of the binary data (the byte* array in
+ the binary non-terminal) must be an int32 followed by a (byte*). The
+ int32 is the number of bytes in the repetition.unsigned_byte(3) UUID (Old) - This used to be the UUID subtype,
+ but was deprecated in favor of subtype 4. Drivers
+ and tools for languages with a native UUID type should handle
+ subtype 3 appropriately.unsigned_byte(128)—unsigned_byte(255) User defined subtypes. The binary data can be
+ anything.