hook_hash

Behaviour

C

• Look up the hash of the hook installed on hook account at position hook_no
• Write the 32 byte hash to write_ptr

JavaScript

• Look up the hash of the hook installed on the hook account at the specified position.
• The Namespace biased SHA512H of the currently executing Hook, or an error code if the lookup fails.

Definition

C

int64_t hook_hash (
    uint32_t write_ptr,
    uint32_t write_len,
    int32_t  hook_no
);

JavaScript

function hook_hash(hookno: number): ErrorCode | ByteArray

Example

C

uint8_t hash[32];
int64_t bytes_written =
    hook_hash(hash, 32, -1);

JavaScript

const hash = hook_hash(hookno)

Parameters

C

Name	Type	Description
write_ptr	uint32_t	Pointer to a buffer of a suitable size to store the output. Should be at least 32 bytes.
write_len	uint32_t	Length of the output buffer.
hook_no	int32_t	The position in the hook chain the hook is located at, or -1 for the currently executing hook.

JavaScript

Name	Type	Description
hook_no	number	The position in the hook chain the hook is located at, or -1 for the currently executing hook.

Return Code

C

Type	Description
int64_t	The number of bytes written If negative, an error: OUT_OF_BOUNDS - pointers/lengths specified outside of hook memory. DOESNT_EXIST - The specified hook sequence number doesn’t exist in the hook chain.

JavaScript

Type	Description
ByteArray or ErrorCode	Returns the Namespace biased SHA512H of the currently executing Hook, or an error code if the lookup fails.