BSON NIF for Elixir/Erlang language http://bsonspec.org
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README.md

elixir-cbson

BSON NIF for Elixir language http://bsonspec.org

THANKS

This library has taken many great ideas and codes from Jiffy to make it fasting and flexible.

The API of elixir-cbson is the same as elixir-bson which I always used in my projects.

WARNING

  • At this moment, elixir-cbson only supports Little-endian machine and I will improve it sometime.
  • Only support Elixir 1.1.0+

MongoDB Driver

The MongodB driver using this project is here, being changed from elixir-mongo.

Usage

CBson.decode/1,2

  • CBson.decode(iodata)
  • CBson.decode(iodata, options)

The options for decode are:

  • :return_lists - Return objects using the lists data(keywrods) type.
  • :return_atom - Return objects using atom keys instead of string. The internal implementation is using String.to_existing_atom/1, if convertion failed, the string key returned.
  • {:nil_term, term} - Returns the specified term instead of nil when decoding BSON. This is for people that wish to use undefined instead of nil.
  • :use_null - Returns the atom null instead of nil when decoding BSON. This is a short hand for {nil_term, null}.
  • :return_trailer - If any data is found after the first BSON term is decoded the return value of decode/2 becomes {:has_trailer, first_term, rest_data::iodata()}. This is useful to decode multiple terms in a single binary.
  • {:bytes_per_red, n} where n >= 0 - This controls the number of bytes that elixir-cbson will process as an equivalent to a reduction. Each 20 reductions we consume 1% of our allocated time slice for the current process. When the Erlang VM indicates we need to return from the NIF.

CBson.encode/1,2

  • CBson.encode(bson_doc)
  • CBson.encode(bson_doc, options)

The options for encode are:

  • force_utf8 - Force strings to encode as UTF-8 by fixing broken surrogate pairs and/or using the replacement character to remove broken UTF-8 sequences in data.
  • {:nil_term, term} - Returns the specified term instead of nil when decoding BSON. This is for people that wish to use undefined instead of nil.
  • :use_null - Returns the atom null instead of nil when decoding BSON. This is a short hand for {nil_term, null}.
  • {:bytes_per_red, n} - Refer to the decode options

Types

BSON Type Elixir Type Notes
double double
string string
doc map or keywords :return_lists
array list
binary %Bson.Bin{}
bool atom: true/false
datetime %Bson.UTC{}
Null nil :use_null/:nil_term
Regex %Bson.Regex{}
JavaScript not supported
int32 integer
Timestamp %Bson.Timestamp{}
int64 integer
Min key atom: min_key
Max key atom: max_key

Benchmarking

There're some benchmark cases vs mongodb & elixir-bson

MIX_ENV=bench mix bench