Decoding Responses

Decoding request responses

Results of an oracle request are returned by calling dest_method method of the smart contract specified in dest_id. The method gets passed the following two arguments:

• type: uint32 - response type; currently is always 1.

• body: byte[] - encoded body of the response (details below).

The body argument contains an ABI-encoded tuple of the following structure:

• byte[] - request ID. Currently the same as Algorand transaction ID of the request smart contract call that initiated the request.

• address - address of the account making the request

• byte[] - The value of the data requested by the caller, more details below.

• byte[] - data specified in userData field of the request

• uint32 - error code if a request handling error occured in GoraNetwork software, 0 otherwise. Currently there is a single error code of 1, meaning that node runners could not correctly decode the request spec.

• uint64 - bit field with bits corresponding to the request sources; if n'th bit is set, the n'th source has failed to yield a valid value.

Numeric oracle return values

When returned oracle value is a number, it is encoded into a 17-byte array. 0's byte encodes value type:

• 0 - empty value (not-a-number, NaN)

• 1 - positive number

• 2 - negative number

Bytes 1 - 8 contain the integer part, 9 - 17 - the decimal fraction part, as big endian uint64's.

For example, 0x021000000000000000ff00000000000000 in memory order (first byte has 0 offset) decodes as -16.255