NAME¶
MongoDB::BSON::Binary - Binary type
VERSION¶
version v0.705.0.0
SYNOPSIS¶
Creates an instance of binary data with a specific subtype.
NAME¶
MongoDB::BSON::Binary - A type that can be used to send binary data to the
database
EXAMPLE¶
For example, suppose we wanted to store a profile pic.
my $pic = MongoDB::BSON::Binary->new(data => $pic_bytes);
$collection->insert({name => "profile pic", pic => $pic});
You can also, optionally, specify a subtype:
my $pic = MongoDB::BSON::Binary->new(data => $pic_bytes,
subtype => MongoDB::BSON::Binary->SUBTYPE_GENERIC);
$collection->insert({name => "profile pic", pic => $pic});
SUBTYPES¶
MongoDB allows you to specify the "flavor" of binary data that you are
storing by providing a subtype. The subtypes are purely cosmetic: the database
treats them all the same.
There are several subtypes defined in the BSON spec:
- "SUBTYPE_GENERIC" (0x00) is the default used by the driver (as
of 0.46).
- "SUBTYPE_FUNCTION" (0x01) is for compiled byte code.
- "SUBTYPE_GENERIC_DEPRECATED" (0x02) is deprecated. It was used
by the driver prior to version 0.46, but this subtype wastes 4 bytes of
space so "SUBTYPE_GENERIC" is preferred. This is the only type
that is parsed differently based on type.
- "SUBTYPE_UUID_DEPRECATED" (0x03) is deprecated. It is for
UUIDs.
- "SUBTYPE_UUID" (0x04) is for UUIDs.
- "SUBTYPE_MD5" can be (0x05) is for MD5 hashes.
- "SUBTYPE_USER_DEFINED" (0x80) is for user-defined binary
types.
data¶
A string of binary data.
subtype¶
A subtype. Defaults to "SUBTYPE_GENERIC".
Why is "SUBTYPE_GENERIC_DEPRECATED" deprecated?¶
Binary data is stored with the length of the binary data, the subtype, and the
actually data. "SUBTYPE_GENERIC DEPRECATED" stores the length of the
data a second time, which just wastes four bytes.
If you have been using "SUBTYPE_GENERIC_DEPRECATED" for binary data,
moving to "SUBTYPE_GENERIC" should be painless: just use the driver
normally and all new/resaved data will be stored as
"SUBTYPE_GENERIC".
It gets a little trickier if you've been querying by binary data fields:
"SUBTYPE_GENERIC" won't match
"SUBTYPE_GENERIC_DEPRECATED", even if the data itself is the same.
Why is "SUBTYPE_UUID_DEPRECATED" deprecated?¶
Other languages were using the UUID type to deserialize into their languages'
native UUID type. They were doing this in different ways, so to standardize,
they decided on a deserialization format for everyone to use and changed the
subtype for UUID to the universal format.
This should not affect Perl users at all, as Perl does not deserialize it into
any native UUID type.
AUTHORS¶
- •
- David Golden <david.golden@mongodb.org>
- •
- Mike Friedman <friedo@mongodb.com>
- •
- Kristina Chodorow <kristina@mongodb.org>
- •
- Florian Ragwitz <rafl@debian.org>
COPYRIGHT AND LICENSE¶
This software is Copyright (c) 2014 by MongoDB, Inc..
This is free software, licensed under:
The Apache License, Version 2.0, January 2004