Class Deserializer

Helper function that primarily exists to support alternative syntax for deserialization. That is, if we have a const deserializer: new Deserializer(...), instead of having to use MyClass.deserialize(deserializer), we can call deserializer.deserialize(MyClass).

Example

const deserializer = new Deserializer(new Uint8Array([1, 2, 3]));
const value = deserializer.deserialize(MyClass); // where MyClass has a `deserialize` function
// value is now an instance of MyClass
// equivalent to `const value = MyClass.deserialize(deserializer)`
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Deserializes a boolean value.

BCS layout for "boolean": One byte. "0x01" for true and "0x00" for false.

Deserializes an array of bytes.

BCS layout for "bytes": bytes_length | bytes where bytes_length is a u32 integer encoded as a uleb128 integer, equal to the length of the bytes array.

Deserializes an array of bytes. The number of bytes to read is already known.

Deserializes a an optional deserializable class.

BCS layout for Optional: 0 if none, else 1 | bcs representation of class

Example

const deserializer = new Deserializer(new Uint8Array([1, 2, 3]));
const value = deserializer.deserializeOption(MyClass); // where MyClass has a `deserialize` function
// value is now an instance of MyClass

const deserializer = new Deserializer(new Uint8Array([0]));
const value = deserializer.deserializeOption(MyClass); // where MyClass has a `deserialize` function
// value is undefined
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Deserializes a an optional string.

BCS layout for Optional: 0 if none, else 1 | string_length | string_content

Example

const deserializer = new Deserializer(new Uint8Array([0x00]));
assert(deserializer.deserializeOptionStr() === undefined);
const deserializer = new Deserializer(new Uint8Array([1, 8, 49, 50, 51, 52, 97, 98, 99, 100]));
assert(deserializer.deserializeOptionStr() === "1234abcd");
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Deserializes a string. UTF8 string is supported. Reads the string's bytes length "l" first, and then reads "l" bytes of content. Decodes the byte array into a string.

BCS layout for "string": string_length | string_content where string_length is a u32 integer encoded as a uleb128 integer, equal to the number of bytes in string_content.

Example

const deserializer = new Deserializer(new Uint8Array([8, 49, 50, 51, 52, 97, 98, 99, 100]));
assert(deserializer.deserializeStr() === "1234abcd");
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Deserializes a uint128 number.

BCS layout for "uint128": Sixteen bytes. Binary format in little-endian representation.

Deserializes a uint16 number.

BCS layout for "uint16": Two bytes. Binary format in little-endian representation.

Example

const deserializer = new Deserializer(new Uint8Array([0x34, 0x12]));
assert(deserializer.deserializeU16() === 4660);
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Deserializes a uint256 number.

BCS layout for "uint256": Thirty-two bytes. Binary format in little-endian representation.

Deserializes a uint32 number.

BCS layout for "uint32": Four bytes. Binary format in little-endian representation.

Example

const deserializer = new Deserializer(new Uint8Array([0x78, 0x56, 0x34, 0x12]));
assert(deserializer.deserializeU32() === 305419896);
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Deserializes a uint64 number.

BCS layout for "uint64": Eight bytes. Binary format in little-endian representation.

Example

const deserializer = new Deserializer(new Uint8Array([0x00, 0xEF, 0xCD, 0xAB, 0x78, 0x56, 0x34, 0x12]));
assert(deserializer.deserializeU64() === 1311768467750121216);
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Deserializes a uint8 number.

BCS layout for "uint8": One byte. Binary format in little-endian representation.

Deserializes a uleb128 encoded uint32 number.

BCS use uleb128 encoding in two cases: (1) lengths of variable-length sequences and (2) tags of enum values

Deserializes an array of BCS Deserializable values given an existing Deserializer instance with a loaded byte buffer.

Example

// serialize a vector of addresses
const addresses = new Array<AccountAddress>(
  AccountAddress.from("0x1"),
  AccountAddress.from("0x2"),
  AccountAddress.from("0xa"),
  AccountAddress.from("0xb"),
);
const serializer = new Serializer();
serializer.serializeVector(addresses);
const serializedBytes = serializer.toUint8Array();

// deserialize the bytes into an array of addresses
const deserializer = new Deserializer(serializedBytes);
const deserializedAddresses = deserializer.deserializeVector(AccountAddress);
// deserializedAddresses is now an array of AccountAddress instances
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Returns the number of bytes remaining in the buffer.

Useful to tell if there's more data to be read.