feat: Hook up le_inner_arr_len host function

This commit is contained in:
TimothyBanks
2026-08-10 17:30:57 -04:00
parent e23f8e266a
commit 229377abd9
11 changed files with 138 additions and 1 deletions

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@@ -211,6 +211,12 @@ host_functions! {
#[wasm_name = "home_le_inner_arr_len"]
fn get_current_ledger_obj_nested_array_len(&self, locator: &[u8]) -> HostResult<i32>;
/// The number of elements in a nested array field of a previously cached ledger
/// object, selected by its cache slot and reached by a `locator`.
#[gas = 70]
#[wasm_name = "le_inner_arr_len"]
fn get_ledger_obj_nested_array_len(&self, cache_idx: i32, locator: &[u8]) -> HostResult<i32>;
/// The XRPL `sha512Half` of `data`: the first [`HASH_LEN`] bytes of its SHA-512.
#[gas = 2000]
#[wasm_name = "sha512_half"]

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@@ -155,6 +155,14 @@ impl HostFunctions for FakeHost {
Ok(locator.len() as i32 + 1)
}
/// The same, over a cached object keyed by slot.
fn get_ledger_obj_nested_array_len(&self, cache_idx: i32, locator: &[u8]) -> HostResult<i32> {
if cache_idx <= 0 || locator.is_empty() {
return Err(HostError::LocatorMalformed);
}
Ok(cache_idx + locator.len() as i32)
}
fn sha512_half(&self, data: &[u8], out: &mut [u8]) -> HostResult<usize> {
let mut digest = [0; HASH_LEN];
digest[0] = data.len() as u8;
@@ -231,6 +239,14 @@ fn the_trait_is_implementable() {
host.get_current_ledger_obj_nested_array_len(&[]),
Err(HostError::LocatorMalformed)
);
assert_eq!(
host.get_ledger_obj_nested_array_len(2, &[9, 0, 0, 0]),
Ok(6)
);
assert_eq!(
host.get_ledger_obj_nested_array_len(0, &[9, 0, 0, 0]),
Err(HostError::LocatorMalformed)
);
assert_eq!(host.sha512_half(b"abc", &mut out), Ok(HASH_LEN));
assert_eq!(out[0], 3);
assert_eq!(host.trace("hello", b"xy", true), Ok(()));
@@ -315,6 +331,7 @@ fn the_spec_table_matches_the_declarations() {
("le_arr_len", 40),
("tx_inner_arr_len", 70),
("home_le_inner_arr_len", 70),
("le_inner_arr_len", 70),
("sha512_half", 2000),
("trace", 500),
("trace_num", 500),

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@@ -242,6 +242,14 @@ mod ffi {
#[cxx_name = "getCurrentLedgerObjNestedArrayLen"]
fn get_current_ledger_obj_nested_array_len(self: &HostContext, locator: &[u8]) -> i32;
#[namespace = "xrpl"]
#[cxx_name = "getLedgerObjNestedArrayLen"]
fn get_ledger_obj_nested_array_len(
self: &HostContext,
cache_idx: i32,
locator: &[u8],
) -> i32;
#[namespace = "xrpl"]
#[cxx_name = "sha512Half"]
fn sha512_half(self: &HostContext, data: &[u8], out: &mut [u8]) -> i32;
@@ -381,6 +389,10 @@ impl HostFunctions for CxxHost<'_> {
scalar(self.ctx.get_current_ledger_obj_nested_array_len(locator))
}
fn get_ledger_obj_nested_array_len(&self, cache_idx: i32, locator: &[u8]) -> HostResult<i32> {
scalar(self.ctx.get_ledger_obj_nested_array_len(cache_idx, locator))
}
fn sha512_half(&self, data: &[u8], out: &mut [u8]) -> HostResult<usize> {
bytes_written(self.ctx.sha512_half(data, out))
}

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@@ -250,6 +250,13 @@ mod tests {
fn get_current_ledger_obj_nested_array_len(&self, _locator: &[u8]) -> HostResult<i32> {
unreachable!("no unit test in this module calls the host")
}
fn get_ledger_obj_nested_array_len(
&self,
_cache_idx: i32,
_locator: &[u8],
) -> HostResult<i32> {
unreachable!("no unit test in this module calls the host")
}
fn sha512_half(&self, _data: &[u8], _out: &mut [u8]) -> HostResult<usize> {
unreachable!("no unit test in this module calls the host")
}

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@@ -285,6 +285,25 @@ pub(crate) fn register_host_functions(
)
},
),
HostFunctionSpec::GetLedgerObjNestedArrayLen => linker.func_wrap(
HOST_MODULE,
op.wasm_name(),
|mut caller: Caller<'_, VmState<'_>>,
cache_idx: i32,
loc_ptr: i32,
loc_len: i32|
-> Result<i32, wasmi::Error> {
charged(
&mut caller,
HostFunctionSpec::GetLedgerObjNestedArrayLen,
|c| {
let host = c.data().host;
let locator = read_borrowed(c, Region::new(loc_ptr, loc_len))?;
host.get_ledger_obj_nested_array_len(cache_idx, locator)
},
)
},
),
HostFunctionSpec::Sha512Half => linker.func_wrap(
HOST_MODULE,
op.wasm_name(),

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@@ -134,6 +134,11 @@ fn call_for(op: HostFunctionSpec) -> Call {
"(call $home_le_inner_arr_len (i32.const 0) (i32.const 4))",
2,
),
HostFunctionSpec::GetLedgerObjNestedArrayLen => (
import::LE_INNER_ARR_LEN,
"(call $le_inner_arr_len (i32.const 1) (i32.const 0) (i32.const 4))",
3,
),
HostFunctionSpec::Sha512Half => (
import::SHA512_HALF,
"(call $sha512_half (i32.const 0) (i32.const 4) (i32.const 0) (i32.const 32))",

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@@ -317,6 +317,22 @@ fn home_le_inner_arr_len_reads_the_locator_and_returns_the_count() {
assert_eq!(*host.home_le_nested_arr_lens_asked.borrow(), vec![locator]);
}
/// The nested array-length getter over a cached object: the slot leads, the locator
/// is read from memory, and the two reach the host keyed together.
#[test]
fn le_inner_arr_len_reads_the_slot_and_locator_and_returns_the_count() {
let locator = vec![5u8, 0, 0, 0];
let host = FakeHost::new().answering_le_nested_arr_len(3, locator.clone(), 8);
let wat = module(
&[import::LE_INNER_ARR_LEN, ONE_PAGE],
"(i32.store (i32.const 0) (i32.const 5))
(call $le_inner_arr_len (i32.const 3) (i32.const 0) (i32.const 4))",
);
assert_eq!(status(&wat, &host), 8, "the array length");
assert_eq!(*host.le_nested_arr_lens_asked.borrow(), vec![(3, locator)]);
}
/// A leading scalar parameter reaches the host as declared.
#[test]
fn home_le_field_passes_the_field_selector_through() {

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@@ -98,7 +98,7 @@ fn a_disabled_feature_does_not_pass() {
/// Every host function the ABI declares, spelled as a guest imports it. The count
/// is asserted against the ABI so a function added to it cannot be left out here.
const ALL_IMPORTS: [&str; 20] = [
const ALL_IMPORTS: [&str; 21] = [
import::LDGR_INDEX,
import::PARENT_LDGR_TIME,
import::PARENT_LDGR_HASH,
@@ -116,6 +116,7 @@ const ALL_IMPORTS: [&str; 20] = [
import::LE_ARR_LEN,
import::TX_INNER_ARR_LEN,
import::HOME_LE_INNER_ARR_LEN,
import::LE_INNER_ARR_LEN,
import::SHA512_HALF,
import::TRACE,
import::TRACE_NUM,

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@@ -170,6 +170,11 @@ pub struct FakeHost {
pub home_le_nested_arr_lens: HashMap<Vec<u8>, i32>,
/// Every locator `get_current_ledger_obj_nested_array_len` was asked for.
pub home_le_nested_arr_lens_asked: RefCell<Vec<Vec<u8>>>,
/// What `get_ledger_obj_nested_array_len` answers, by (cache slot, locator bytes).
/// An unlisted key answers `NoArray`.
pub le_nested_arr_lens: HashMap<(i32, Vec<u8>), i32>,
/// Every (cache slot, locator) `get_ledger_obj_nested_array_len` was asked for.
pub le_nested_arr_lens_asked: RefCell<Vec<(i32, Vec<u8>)>>,
/// What `sha512_half` answers, whatever it is given.
pub digest: Answer,
/// Every field selector `get_current_ledger_obj_field` was asked for.
@@ -219,6 +224,8 @@ impl Default for FakeHost {
tx_nested_arr_lens_asked: RefCell::new(Vec::new()),
home_le_nested_arr_lens: HashMap::new(),
home_le_nested_arr_lens_asked: RefCell::new(Vec::new()),
le_nested_arr_lens: HashMap::new(),
le_nested_arr_lens_asked: RefCell::new(Vec::new()),
digest: Answer::filler(32),
fields_asked: RefCell::new(Vec::new()),
digested: RefCell::new(Vec::new()),
@@ -322,6 +329,16 @@ impl FakeHost {
self
}
pub fn answering_le_nested_arr_len(
mut self,
cache_idx: i32,
locator: Vec<u8>,
len: i32,
) -> FakeHost {
self.le_nested_arr_lens.insert((cache_idx, locator), len);
self
}
pub fn answering_digest(mut self, answer: Answer) -> FakeHost {
self.digest = answer;
self
@@ -469,6 +486,16 @@ impl HostFunctions for FakeHost {
}
}
fn get_ledger_obj_nested_array_len(&self, cache_idx: i32, locator: &[u8]) -> HostResult<i32> {
self.le_nested_arr_lens_asked
.borrow_mut()
.push((cache_idx, locator.to_vec()));
match self.le_nested_arr_lens.get(&(cache_idx, locator.to_vec())) {
Some(&len) => Ok(len),
None => Err(HostError::NoArray),
}
}
fn sha512_half(&self, data: &[u8], out: &mut [u8]) -> HostResult<usize> {
self.digested.borrow_mut().push(data.to_vec());
self.digest.fill(out)
@@ -526,6 +553,7 @@ pub mod import {
r#"(import "host_lib" "le_arr_len" (func $le_arr_len (param i32 i32) (result i32)))"#;
pub const TX_INNER_ARR_LEN: &str = r#"(import "host_lib" "tx_inner_arr_len" (func $tx_inner_arr_len (param i32 i32) (result i32)))"#;
pub const HOME_LE_INNER_ARR_LEN: &str = r#"(import "host_lib" "home_le_inner_arr_len" (func $home_le_inner_arr_len (param i32 i32) (result i32)))"#;
pub const LE_INNER_ARR_LEN: &str = r#"(import "host_lib" "le_inner_arr_len" (func $le_inner_arr_len (param i32 i32 i32) (result i32)))"#;
pub const SHA512_HALF: &str = r#"(import "host_lib" "sha512_half" (func $sha512_half (param i32 i32 i32 i32) (result i32)))"#;
pub const TRACE: &str =
r#"(import "host_lib" "trace" (func $trace (param i32 i32 i32 i32 i32) (result i32)))"#;

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@@ -109,6 +109,10 @@ public:
[[nodiscard]] std::int32_t
getCurrentLedgerObjNestedArrayLen(rust::Slice<std::uint8_t const> locator) const noexcept;
[[nodiscard]] std::int32_t
getLedgerObjNestedArrayLen(std::int32_t cacheIdx, rust::Slice<std::uint8_t const> locator)
const noexcept;
[[nodiscard]] std::int32_t
sha512Half(rust::Slice<std::uint8_t const> data, rust::Slice<std::uint8_t> out) const noexcept;

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@@ -371,6 +371,28 @@ HostContext::getCurrentLedgerObjNestedArrayLen(
});
}
std::int32_t
HostContext::getLedgerObjNestedArrayLen(
std::int32_t cacheIdx,
rust::Slice<std::uint8_t const> locator) const noexcept
{
return guarded(hostFunctions_.getJournal(), kHostInternal, [&] {
if (locator.empty() || (locator.size() & 3) != 0)
return hfErrorToInt(HostFunctionError::LocatorMalformed);
std::uint32_t const steps = locator.size() / sizeof(std::int32_t);
std::vector<std::int32_t> locBuf(steps);
std::memcpy(locBuf.data(), locator.data(), locator.size());
FieldLocator const fl(std::move(locBuf));
auto const len = hostFunctions_.getLedgerObjNestedArrayLen(cacheIdx, fl);
if (!len)
return hfErrorToInt(len.error());
return *len;
});
}
std::int32_t
HostContext::sha512Half(rust::Slice<std::uint8_t const> data, rust::Slice<std::uint8_t> out)
const noexcept