BinData()

Definition

Creates a binary data object.

BinData has the following syntax:

BinData(<sub_type>,<buffer>)

Parameter	Type	Description
sub_type	integer	The binary type. Subtype Description 0 Generic binary subtype 1 Function 2 Byte Array 3 OLD UUID 4 UUID 5 MD5 128 User defined
buffer	string	The buffer object containing binary data, must be a base 64 encoded string value.

Returns:	A binary data object.

Behavior

The endianness of your system depends on the architecture of your machine. Numbers in BSON data are always stored as little-endian, if your system is big-endian this means that numeric data is converted between big and little endian.

In the context of the bit-test match expression operators:

• $bitsAnySet

• $bitsAnyClear

• $bitsAllSet

• $bitsAllClear

BinData values act as bitmasks and are interpreted as though they are arbitrary-length unsigned little-endian numbers. The lowest-addressable byte is always interpreted as the least significant byte. Similarly, the highest-addressable byte in the BinData is always interpreted as the most significant byte.

Examples

var bdata = BinData(0, "gf1UcxdHTJ2HQ/EGQrO7mQ==")

db.testbin.insertOne( { _id : 1, bin_data: bdata } )

db.testbin.find()

{
  _id: 1,
  bin_data: Binary(Buffer.from("81fd547317474c9d8743f10642b3bb99", "hex"), 0)
}

var bdata = BinData(0, "gf1UcxdHTJ2HQ/EGQrO7mQ==")

bdata.length()

16