CID class
Represents a Content Identifier (CID).
CIDs are self-describing content-addressed identifiers used in systems like IPFS. They uniquely identify a piece of content using a cryptographic hash and include metadata about the content's encoding and hash algorithm.
This class supports parsing CIDs from strings or bytes, creating new CIDs (including from raw data), and converting between CID versions.
See the CID specification for more details.
Examples
Creating a CID from data:
final data = utf8.encode('Hello World!');
final cid = CID.fromData(CID.V1, 'dag-pb', Uint8List.fromList(data));
print(cid.toString()); // e.g., bafybeid7qoywk77r7rj3slobqfekdvs57qwuwh5d2z3sqsw52iabe3mqne
Parsing a CID string:
final parsedCid = CID.fromString('QmWvQxTqbG2Z9HPJgG57jjwR154cKhbtJenbyYTWkjgF3e');
print('Version: ${parsedCid.version}, Codec: ${parsedCid.codecName}');
Constructors
- CID.new(int version, int codec, Uint8List multihash)
- Creates a new CID instance from its constituent parts.
- CID.create(int version, String codecName, Uint8List multihash)
-
Creates a CID instance from a version, codec name, and pre-computed multihash.
factory
- CID.fromBytes(Uint8List bytes)
-
Decodes a CID from its binary representation (
Uint8List).factory - CID.fromData(int version, String codecName, Uint8List data, [String multihashName = 'sha2-256'])
-
Creates a CID by hashing the input
data.factory - CID.fromString(String s)
-
Decodes a CID from its string representation.
factory
Properties
- codec → int
-
The multicodec code indicating the format of the content referenced by the CID.
final
- codecName → String
-
Returns the string name of the codec (e.g., "dag-pb", "raw").
no setter
- hashCode → int
-
The hash code for this object.
no setteroverride
- multihash → Uint8List
-
The full multihash bytes, including the hash algorithm code, digest length,
and the hash digest itself.
final
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- version → int
-
The version of the CID (either V0 or V1).
final
Methods
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
toBytes(
) → Uint8List -
Encodes this CID into its binary representation as a
Uint8List. -
toString(
) → String -
Returns the string representation of this CID.
override
-
toV0(
) → CID - Converts this CID to CIDv0, if possible.
-
toV1(
) → CID - Converts this CID to CIDv1.
Operators
-
operator ==(
Object other) → bool -
The equality operator.
override