ObjectId

Blazing fast, cross-platform ObjectId implementation for the dart language!

Dart tests pub package License: MIT style: effective dart codecov

Why this package?

Getting started.

  1. Depend on it.
dependencies:
  objectid: 2.0.0
  1. Play with it!
final id = ObjectId(); // That's all 🔥😮!
print(id);   // it's working! => 5f52c805df41c9df948e6135

Documentation

ObjectId()

Creates ObjectId instance based on current timestamp, process unique and counter. For more information take a look at ObjectId specification.

/// Creates ObjectId instance.
final id = ObjectId();
print(id.hexString); // => 5f52c805df41c9df948e6135

ObjectId.fromHexString(String hexString)

Creates ObjectId from hex string.

TIP 💡:
Can be helpful for mapping hex strings returned from API / mongodb.

/// Create ObjectId instance.
final id = ObjectId.fromHexString('5f52c805df41c9df948e6135');
print(id.hexString); // => 5f52c805df41c9df948e6135

final id2 = ObjectId.fromHexString(id.hexString);
print(id == id2); // => true

ObjectId.fromBytes(List

Creates ObjectId from bytes.

TIP 💡:
Sometimes we may want to save ObjectId representation to file, binary format is the best way to do so.

/// Create ObjectId instance.
final id = ObjectId.fromBytes([95, 82, 205, 121, 180, 195, 28, 88, 32, 47, 183, 78]);
print(id.hexString); // => 5f52cd79b4c31c58202fb74e

/// To retrive ObjectId bytes as [Uint8list] you can use `bytes` property.
print(id.bytes); // => [95, 82, 205, 121, 180, 195, 28, 88, 32, 47, 183, 78]

final id2 = ObjectId.fromBytes(id.bytes);
print(id == id2); // => true

ObjectId.fromValues(int millisecondsSinceEpoch, int processUnique, int counter)

Creates an ObjectId from the provided integer values.

/// Create ObjectId instance.
/// `hexString = 000000000000000000000000`
final zeroed = ObjectId.fromValues(0, 0, 0);

/// `hexString = ffffffff0000000000000000`
final withTimestamp = ObjectId.fromValues(0x3e7fffffc18, 0, 0); 

/// `hexString = 00000000ffffffffff000000`
final withProcessUnique = ObjectId.fromValues(0, 0xffffffffff, 0); 

/// `hexString = 000000000000000000ffffff`
final withCounter = ObjectId.fromValues(0, 0, 0xffffff);

/// `hexString = ffffffffffffffffffffffff`
final filled = ObjectId.fromValues(0x3e7fffffc18, 0xffffffffff, 0xffffff);

ObjectId.fromTimestamp(DateTime timestamp)

Creates ObjectId from provided timestamp.
Propably you do not want to use this constructor. It is mostly used for ObjectId comparisons or sorting.

Warning ⚠️:
Only timestamp segment is set while the rest of the ObjectId is zeroed out.

/// Create ObjectId instance.
final id = ObjectId.fromTimestamp(DateTime.now());
print(id.hexString); // => 5f52d05e0000000000000000

bool operator ==

It is possible to compare ObjectIds instances by equality operator ==.
Comparison is based on ObjectId runtimeType and bytes.

int hashCode

Hashcode is calculated by dart implementation of Austin Appleby, MurmurHash2 algorithm; wich is for ObjectId almost 2 times faster 🚀 than the commonly used Jenkins algorithm.

Property value will be generated only once (with the first read) and cached, what's strongly improves performance.

String hexString

Returns a 24-bit hex string representation of the ObjectId.

Property value will be generated only once (with the first read) and cached, what's strongly improves performance.

DateTime timestamp

Returns an accurate up to the second ObjectId generation time (timestamp).

Property value will be generated only once (with the first read) and cached, what's strongly improves performance.

Uint8List bytes

Returns a ObjectId bytes.

static bool isValid(String hexString)

Helper method that checks whether the provided hexString is a valid ObjectId.

Benchmark:

Benchmark hardware/software:
UNIT: MacBook Pro (13-inch, M2, 2022)
CPU: Apple M2, 16GB RAM
RAM: 16 GB
OS: macOS Monterey 12.6.1 (Build 21G217)
Dart SDK version: 3.0.5

Constructors:
ObjectId() → (RunTime): 0.29132956069161253 us.
ObjectId.fromHexString() → (RunTime): 0.75057425 us.
ObjectId.fromBytes() → (RunTime): 0.14730780908787755 us.
ObjectId.fromValues() → (RunTime): 0.07130824418248206 us.
ObjectId.fromTimestamp() → (RunTime): 0.044412125467054496 us.
Properties:
ObjectId.hexString → (RunTime): 0.039307475449695345 us.
ObjectId.timestamp → (RunTime): 0.050248475 us.
ObjectId.hashCode → (RunTime): 0.03570540247334531 us.
Operators:
ObjectId == ObjectId → (RunTime): 0.12478619550684174 us.

Benchmark is available in the example app.

Libraries

objectid