otxn_id

Output the canonical hash of the originating transaction

Behaviour

• Write the canonical hash of the originating transaction to the output buffer.
• If flags = 1 and the transaction is an EMIT_FAILURE transaction then write the canonical hash of the originating transaction that caused the emission.

Definition

C

int64_t otxn_id (
    uint32_t write_ptr,
    uint32_t write_len,
  	uint32_t flags
);

Example

C

uint8_t txn_id[32];
int64_t bytes_written = 
    otxn_id(txn_id, 32, 0);

Parameters

Name	Type	Description
write_ptr	uint32_t	Pointer to a buffer of to store the hash.
write_len	uint32_t	Length of the output buffer. Should be at least 32 bytes.
flags	uint32_t	If 0: Write the canonical hash of the originating transaction. If 1 AND the originating transaction is an EMIT_FAILURE: Write the canonical hash of the emitting transaction.

Return Code

Type	Description
int64_t	The number of bytes written If negative, an error: OUT_OF_BOUNDS - pointers/lengths specified outside of hook memory. TOO_SMALL - output buffer was not large enough to hold the serialized object