util_keylet

Concepts

Behaviour

Compute a keylet of the specified keylet_type according to the parameters a through f depending on type.
Write the serialized 34 byte keylet into write_ptr

Definition

C
JavaScript

int64_t util_keylet (
    uint32_t write_ptr,
    uint32_t write_len,
    uint32_t keylet_type,
    uint32_t a,
    uint32_t b,
    uint32_t c,
    uint32_t d,
    uint32_t e,
    uint32_t f
);

function util_keylet(
    keylet_type: number,
    accountid: ByteArray | HexString,
    statekey: ByteArray | HexString,
    namespace: ByteArray | HexString
  ): ErrorCode | ByteArray

Example

C
JavaScript

uint8_t keylet[34];
if (util_keylet(keylet, 34, KEYLET_LINE,
              hook_accid, 20,
              account_field, 20,
              currency_code, 20) != 34)
  rollback("Keylet Failed.", 14, 1);

if (util_keylet(
        KEYLET_LINE, hook_accid, account_field, currency_code
        ).length < 34)
    rollback("Keylet Failed.", 1)

Parameters

C
JavaScript

Name	Type	Description
write_ptr	uint32_t	Pointer to a buffer the serialized keylet will be written to
write_len	uint32_t	Length of output buffer, should be at least 34.
keylet_type	uint32_t	One of the keylet types as defined in `hookapi.h` e.g. `KEYLET_LINE` for a trustline.
a	uint32_t	See keylet table below
b	uint32_t	See keylet table below
c	uint32_t	See keylet table below
d	uint32_t	See keylet table below
e	uint32_t	See keylet table below
f	uint32_t	See keylet table below

Name	Type	Description
keylet_type		The type of the keylet to create
accountid		(Optional) First piece of data for the keylet, can be an array of numbers, a string, or a number.
statekey		(Optional) Second piece of data for the keylet, can be an array of numbers, a string, or a number.
namespace		(Optional) Third piece of data for the keylet, can be an array of numbers, a string, or a number.

Keylet Type	Parameters
KEYLET_HOOK_STATE	`a` points to an Account ID `b` is the length of the Account ID (should be 20) `c` points to a hook state key `d` is the length of the key (should be 32) `e` points to a hook state namespace `f` is the length of the namespace (should be 32)
KEYLET_AMENDMENTS KEYLET_FEES KEYLET_NEGATIVE_UNL KEYLET_EMITTED_DIR	`a`, `b`, `c`, `d`, `e`, `f` must all be zero
KEYLET_SKIP	Either: `a`, `b`, `c`, `d`, `e`, `f` all zero Or: `a` is a `LedgerIndex` `b` is 1 `c`, `d`, `e`, `f` must all be zero
KEYLET_LINE	`a` points to the High Account ID `b` is the length of the above (should be 20) `c` points to the Low Account ID `d` is the length of the above (should be 20) `e` points to the Currency Code `f` is the length of the above (should be 20)
KEYLET_QUALITY	`a` points to a serialized keylet `b` is the length of the above (should be 34) `c` is the high 32 bits of the uint64 to pass `d` is the low 32 bits of the uint64 to pass `e`, `f` must all be zero
KEYLET_DEPOSIT_PREAUTH	`a` points to an Account ID `b` is the length (should be 20) `c` points to an Account ID `d` is the length (should be 20) `e`, `f` must all be zero
KEYLET_UNCHECKED KEYLET_CHILD KEYLET_EMITTED_TXN	`a` points to a key. `b` is the length of the key (should be 32.) `c`, `d`, `e`, `f` must both be zero
KEYLET_OWNER_DIR KEYLET_SIGNERS KEYLET_ACCOUNT KEYLET_HOOK	`a` points to an Account ID. `b` is the length (should be 20.) `c`, `d`, `e`, `f` must all be zero.
KEYLET_PAGE	`a` points to a key. `b` is the length of the key (should be 32.) `c` is the high 32 bits of the uint64 to pass `d` is the low 32 bits of the uint64 to pass `e`, `f` must both be zero
KEYLET_OFFER KEYLET_CHECK KEYLET_ESCROW KEYLET_NFT_OFFER	`a` points to an Account ID. `b` is the length (should be 20.) And Either: `c` is a 32bit unsigned integer (sequence) `d` is 0 Or: `c` points to a 32 byte key `d` is the length of the key (32). In both cases: `e` and `f` must be 0.
KEYLET_PAYCHAN	`a` points to an Account ID `b` is the length (should be 20) `c` points to an Account ID `d` is the length (should be 20) And Either: `e` 32bit unsigned int to pass `f` is zero Or: `e` points to a 32 byte key `f` is the length of the key (32)

Return Code

C
JavaScript

Type	Description
int64_t	The number of bytes written, should always be 34. If negative, an error: `OUT_OF_BOUNDS` - pointers/lengths specified outside of hook memory. `INVALID_ARGUMENT` - Call didn’t comply with the above table. `TOO_SMALL` - Writing buffer was smaller than 34 bytes.