diff --git a/crates/xrpl-host-functions/src/lib.rs b/crates/xrpl-host-functions/src/lib.rs index d8602d8127..1b355b1127 100644 --- a/crates/xrpl-host-functions/src/lib.rs +++ b/crates/xrpl-host-functions/src/lib.rs @@ -199,6 +199,12 @@ host_functions! { #[wasm_name = "le_arr_len"] fn get_ledger_obj_array_len(&self, cache_idx: i32, field: i32) -> HostResult; + /// The number of elements in a nested array field of the transaction, reached by a + /// `locator`. Reads the locator region and answers the count directly. + #[gas = 70] + #[wasm_name = "tx_inner_arr_len"] + fn get_tx_nested_array_len(&self, locator: &[u8]) -> HostResult; + /// The XRPL `sha512Half` of `data`: the first [`HASH_LEN`] bytes of its SHA-512. #[gas = 2000] #[wasm_name = "sha512_half"] diff --git a/crates/xrpl-host-functions/tests/generated_abi.rs b/crates/xrpl-host-functions/tests/generated_abi.rs index 93ae0338ad..6b4c82e172 100644 --- a/crates/xrpl-host-functions/tests/generated_abi.rs +++ b/crates/xrpl-host-functions/tests/generated_abi.rs @@ -139,6 +139,14 @@ impl HostFunctions for FakeHost { Ok(cache_idx + field) } + /// A nested array-length getter, keyed by the locator bytes. + fn get_tx_nested_array_len(&self, locator: &[u8]) -> HostResult { + if locator.is_empty() { + return Err(HostError::LocatorMalformed); + } + Ok(locator.len() as i32) + } + fn sha512_half(&self, data: &[u8], out: &mut [u8]) -> HostResult { let mut digest = [0; HASH_LEN]; digest[0] = data.len() as u8; @@ -202,6 +210,11 @@ fn the_trait_is_implementable() { ); assert_eq!(host.get_ledger_obj_array_len(2, 3), Ok(5)); assert_eq!(host.get_ledger_obj_array_len(0, 3), Err(HostError::NoArray)); + assert_eq!(host.get_tx_nested_array_len(&[9, 0, 0, 0]), Ok(4)); + assert_eq!( + host.get_tx_nested_array_len(&[]), + 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(())); @@ -284,6 +297,7 @@ fn the_spec_table_matches_the_declarations() { ("tx_arr_len", 40), ("home_le_arr_len", 40), ("le_arr_len", 40), + ("tx_inner_arr_len", 70), ("sha512_half", 2000), ("trace", 500), ("trace_num", 500), diff --git a/crates/xrpl-wasm-vm-ffi/src/lib.rs b/crates/xrpl-wasm-vm-ffi/src/lib.rs index 7f5f96222e..571728198c 100644 --- a/crates/xrpl-wasm-vm-ffi/src/lib.rs +++ b/crates/xrpl-wasm-vm-ffi/src/lib.rs @@ -234,6 +234,10 @@ mod ffi { #[cxx_name = "getLedgerObjArrayLen"] fn get_ledger_obj_array_len(self: &HostContext, cache_idx: i32, field: i32) -> i32; + #[namespace = "xrpl"] + #[cxx_name = "getTxNestedArrayLen"] + fn get_tx_nested_array_len(self: &HostContext, locator: &[u8]) -> i32; + #[namespace = "xrpl"] #[cxx_name = "sha512Half"] fn sha512_half(self: &HostContext, data: &[u8], out: &mut [u8]) -> i32; @@ -365,6 +369,10 @@ impl HostFunctions for CxxHost<'_> { scalar(self.ctx.get_ledger_obj_array_len(cache_idx, field)) } + fn get_tx_nested_array_len(&self, locator: &[u8]) -> HostResult { + scalar(self.ctx.get_tx_nested_array_len(locator)) + } + fn sha512_half(&self, data: &[u8], out: &mut [u8]) -> HostResult { bytes_written(self.ctx.sha512_half(data, out)) } diff --git a/crates/xrpl-wasm-vm/src/abi.rs b/crates/xrpl-wasm-vm/src/abi.rs index 74894ea7c8..63b8459759 100644 --- a/crates/xrpl-wasm-vm/src/abi.rs +++ b/crates/xrpl-wasm-vm/src/abi.rs @@ -244,6 +244,9 @@ mod tests { fn get_ledger_obj_array_len(&self, _cache_idx: i32, _field: i32) -> HostResult { unreachable!("no unit test in this module calls the host") } + fn get_tx_nested_array_len(&self, _locator: &[u8]) -> HostResult { + unreachable!("no unit test in this module calls the host") + } fn sha512_half(&self, _data: &[u8], _out: &mut [u8]) -> HostResult { unreachable!("no unit test in this module calls the host") } diff --git a/crates/xrpl-wasm-vm/src/register.rs b/crates/xrpl-wasm-vm/src/register.rs index 7772194a3d..11be276a22 100644 --- a/crates/xrpl-wasm-vm/src/register.rs +++ b/crates/xrpl-wasm-vm/src/register.rs @@ -253,6 +253,20 @@ pub(crate) fn register_host_functions( }) }, ), + HostFunctionSpec::GetTxNestedArrayLen => linker.func_wrap( + HOST_MODULE, + op.wasm_name(), + |mut caller: Caller<'_, VmState<'_>>, + loc_ptr: i32, + loc_len: i32| + -> Result { + charged(&mut caller, HostFunctionSpec::GetTxNestedArrayLen, |c| { + let host = c.data().host; + let locator = read_borrowed(c, Region::new(loc_ptr, loc_len))?; + host.get_tx_nested_array_len(locator) + }) + }, + ), HostFunctionSpec::Sha512Half => linker.func_wrap( HOST_MODULE, op.wasm_name(), diff --git a/crates/xrpl-wasm-vm/tests/budgets.rs b/crates/xrpl-wasm-vm/tests/budgets.rs index 7ccf30ddc1..4ae9b2b7cf 100644 --- a/crates/xrpl-wasm-vm/tests/budgets.rs +++ b/crates/xrpl-wasm-vm/tests/budgets.rs @@ -124,6 +124,11 @@ fn call_for(op: HostFunctionSpec) -> Call { "(call $le_arr_len (i32.const 1) (i32.const 1))", 2, ), + HostFunctionSpec::GetTxNestedArrayLen => ( + import::TX_INNER_ARR_LEN, + "(call $tx_inner_arr_len (i32.const 0) (i32.const 4))", + 2, + ), HostFunctionSpec::Sha512Half => ( import::SHA512_HALF, "(call $sha512_half (i32.const 0) (i32.const 4) (i32.const 0) (i32.const 32))", diff --git a/crates/xrpl-wasm-vm/tests/host_calls.rs b/crates/xrpl-wasm-vm/tests/host_calls.rs index c5a72ac6cd..08d631797b 100644 --- a/crates/xrpl-wasm-vm/tests/host_calls.rs +++ b/crates/xrpl-wasm-vm/tests/host_calls.rs @@ -285,6 +285,22 @@ fn le_arr_len_passes_the_slot_and_selector_and_returns_the_count() { assert_eq!(*host.le_arr_lens_asked.borrow(), vec![(2, 17)]); } +/// A nested array-length getter: the locator is read from memory and the count comes +/// back as the status — read-input, scalar-out, no output buffer. +#[test] +fn tx_inner_arr_len_reads_the_locator_and_returns_the_count() { + let locator = vec![5u8, 0, 0, 0]; + let host = FakeHost::new().answering_tx_nested_arr_len(locator.clone(), 6); + + let wat = module( + &[import::TX_INNER_ARR_LEN, ONE_PAGE], + "(i32.store (i32.const 0) (i32.const 5)) + (call $tx_inner_arr_len (i32.const 0) (i32.const 4))", + ); + assert_eq!(status(&wat, &host), 6, "the array length"); + assert_eq!(*host.tx_nested_arr_lens_asked.borrow(), vec![locator]); +} + /// A leading scalar parameter reaches the host as declared. #[test] fn home_le_field_passes_the_field_selector_through() { diff --git a/crates/xrpl-wasm-vm/tests/preflight.rs b/crates/xrpl-wasm-vm/tests/preflight.rs index 19c39132f4..08578d172b 100644 --- a/crates/xrpl-wasm-vm/tests/preflight.rs +++ b/crates/xrpl-wasm-vm/tests/preflight.rs @@ -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; 18] = [ +const ALL_IMPORTS: [&str; 19] = [ import::LDGR_INDEX, import::PARENT_LDGR_TIME, import::PARENT_LDGR_HASH, @@ -114,6 +114,7 @@ const ALL_IMPORTS: [&str; 18] = [ import::TX_ARR_LEN, import::HOME_LE_ARR_LEN, import::LE_ARR_LEN, + import::TX_INNER_ARR_LEN, import::SHA512_HALF, import::TRACE, import::TRACE_NUM, diff --git a/crates/xrpl-wasm-vm/tests/support/mod.rs b/crates/xrpl-wasm-vm/tests/support/mod.rs index c4ce465631..2bfc049644 100644 --- a/crates/xrpl-wasm-vm/tests/support/mod.rs +++ b/crates/xrpl-wasm-vm/tests/support/mod.rs @@ -160,6 +160,11 @@ pub struct FakeHost { pub le_arr_lens: HashMap<(i32, i32), i32>, /// Every (cache slot, field selector) `get_ledger_obj_array_len` was asked for. pub le_arr_lens_asked: RefCell>, + /// What `get_tx_nested_array_len` answers, by locator bytes. An unlisted locator + /// answers `NoArray`. + pub tx_nested_arr_lens: HashMap, i32>, + /// Every locator `get_tx_nested_array_len` was asked for. + pub tx_nested_arr_lens_asked: RefCell>>, /// What `sha512_half` answers, whatever it is given. pub digest: Answer, /// Every field selector `get_current_ledger_obj_field` was asked for. @@ -205,6 +210,8 @@ impl Default for FakeHost { home_le_arr_lens_asked: RefCell::new(Vec::new()), le_arr_lens: HashMap::new(), le_arr_lens_asked: RefCell::new(Vec::new()), + tx_nested_arr_lens: HashMap::new(), + tx_nested_arr_lens_asked: RefCell::new(Vec::new()), digest: Answer::filler(32), fields_asked: RefCell::new(Vec::new()), digested: RefCell::new(Vec::new()), @@ -298,6 +305,11 @@ impl FakeHost { self } + pub fn answering_tx_nested_arr_len(mut self, locator: Vec, len: i32) -> FakeHost { + self.tx_nested_arr_lens.insert(locator, len); + self + } + pub fn answering_digest(mut self, answer: Answer) -> FakeHost { self.digest = answer; self @@ -425,6 +437,16 @@ impl HostFunctions for FakeHost { } } + fn get_tx_nested_array_len(&self, locator: &[u8]) -> HostResult { + self.tx_nested_arr_lens_asked + .borrow_mut() + .push(locator.to_vec()); + match self.tx_nested_arr_lens.get(locator) { + Some(&len) => Ok(len), + None => Err(HostError::NoArray), + } + } + fn sha512_half(&self, data: &[u8], out: &mut [u8]) -> HostResult { self.digested.borrow_mut().push(data.to_vec()); self.digest.fill(out) @@ -480,6 +502,7 @@ pub mod import { r#"(import "host_lib" "home_le_arr_len" (func $home_le_arr_len (param i32) (result i32)))"#; pub const LE_ARR_LEN: &str = 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 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)))"#; diff --git a/include/xrpl/tx/wasm/HostContext.h b/include/xrpl/tx/wasm/HostContext.h index 84580cef85..b691a2b249 100644 --- a/include/xrpl/tx/wasm/HostContext.h +++ b/include/xrpl/tx/wasm/HostContext.h @@ -103,6 +103,9 @@ public: [[nodiscard]] std::int32_t getLedgerObjArrayLen(std::int32_t cacheIdx, std::int32_t field) const noexcept; + [[nodiscard]] std::int32_t + getTxNestedArrayLen(rust::Slice locator) const noexcept; + [[nodiscard]] std::int32_t sha512Half(rust::Slice data, rust::Slice out) const noexcept; diff --git a/src/libxrpl/tx/wasm/HostContext.cpp b/src/libxrpl/tx/wasm/HostContext.cpp index 0b39e2bdc5..fff8a56f11 100644 --- a/src/libxrpl/tx/wasm/HostContext.cpp +++ b/src/libxrpl/tx/wasm/HostContext.cpp @@ -330,6 +330,26 @@ HostContext::getLedgerObjArrayLen(std::int32_t cacheIdx, std::int32_t field) con }); } +std::int32_t +HostContext::getTxNestedArrayLen(rust::Slice 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 locBuf(steps); + std::memcpy(locBuf.data(), locator.data(), locator.size()); + FieldLocator const fl(std::move(locBuf)); + + auto const len = hostFunctions_.getTxNestedArrayLen(fl); + if (!len) + return hfErrorToInt(len.error()); + + return *len; + }); +} + std::int32_t HostContext::sha512Half(rust::Slice data, rust::Slice out) const noexcept