rust: Move history tree FFI logic into a module

src/rust/src/history_ffi.rs

@@ -0,0 +1,181 @@
+use std::slice;
+
+use libc::{c_uchar, size_t};
+use zcash_history::{Entry as MMREntry, NodeData as MMRNodeData, Tree as MMRTree};
+
+fn construct_mmr_tree(
+    // Consensus branch id
+    cbranch: u32,
+    // Length of tree in array representation
+    t_len: u32,
+
+    // Indices of provided tree nodes, length of p_len+e_len
+    ni_ptr: *const u32,
+    // Provided tree nodes data, length of p_len+e_len
+    n_ptr: *const [c_uchar; zcash_history::MAX_ENTRY_SIZE],
+
+    // Peaks count
+    p_len: size_t,
+    // Extra nodes loaded (for deletion) count
+    e_len: size_t,
+) -> Result<MMRTree, &'static str> {
+    let (indices, nodes) = unsafe {
+        (
+            slice::from_raw_parts(ni_ptr, p_len + e_len),
+            slice::from_raw_parts(n_ptr, p_len + e_len),
+        )
+    };
+
+    let mut peaks: Vec<_> = indices
+        .iter()
+        .zip(nodes.iter())
+        .map(
+            |(index, node)| match MMREntry::from_bytes(cbranch, &node[..]) {
+                Ok(entry) => Ok((*index, entry)),
+                Err(_) => Err("Invalid encoding"),
+            },
+        )
+        .collect::<Result<_, _>>()?;
+    let extra = peaks.split_off(p_len);
+
+    Ok(MMRTree::new(t_len, peaks, extra))
+}
+
+#[no_mangle]
+pub extern "system" fn librustzcash_mmr_append(
+    // Consensus branch id
+    cbranch: u32,
+    // Length of tree in array representation
+    t_len: u32,
+    // Indices of provided tree nodes, length of p_len
+    ni_ptr: *const u32,
+    // Provided tree nodes data, length of p_len
+    n_ptr: *const [c_uchar; zcash_history::MAX_ENTRY_SIZE],
+    // Peaks count
+    p_len: size_t,
+    // New node pointer
+    nn_ptr: *const [u8; zcash_history::MAX_NODE_DATA_SIZE],
+    // Return of root commitment
+    rt_ret: *mut [u8; 32],
+    // Return buffer for appended leaves, should be pre-allocated of ceiling(log2(t_len)) length
+    buf_ret: *mut [c_uchar; zcash_history::MAX_NODE_DATA_SIZE],
+) -> u32 {
+    let new_node_bytes: &[u8; zcash_history::MAX_NODE_DATA_SIZE] = unsafe {
+        match nn_ptr.as_ref() {
+            Some(r) => r,
+            None => {
+                return 0;
+            } // Null pointer passed, error
+        }
+    };
+
+    let mut tree = match construct_mmr_tree(cbranch, t_len, ni_ptr, n_ptr, p_len, 0) {
+        Ok(t) => t,
+        _ => {
+            return 0;
+        } // error
+    };
+
+    let node = match MMRNodeData::from_bytes(cbranch, &new_node_bytes[..]) {
+        Ok(node) => node,
+        _ => {
+            return 0;
+        } // error
+    };
+
+    let appended = match tree.append_leaf(node) {
+        Ok(appended) => appended,
+        _ => {
+            return 0;
+        }
+    };
+
+    let return_count = appended.len();
+
+    let root_node = tree
+        .root_node()
+        .expect("Just added, should resolve always; qed");
+    unsafe {
+        *rt_ret = root_node.data().hash();
+
+        for (idx, next_buf) in slice::from_raw_parts_mut(buf_ret, return_count as usize)
+            .iter_mut()
+            .enumerate()
+        {
+            tree.resolve_link(appended[idx])
+                .expect("This was generated by the tree and thus resolvable; qed")
+                .data()
+                .write(&mut &mut next_buf[..])
+                .expect("Write using cursor with enough buffer size cannot fail; qed");
+        }
+    }
+
+    return_count as u32
+}
+
+#[no_mangle]
+pub extern "system" fn librustzcash_mmr_delete(
+    // Consensus branch id
+    cbranch: u32,
+    // Length of tree in array representation
+    t_len: u32,
+    // Indices of provided tree nodes, length of p_len+e_len
+    ni_ptr: *const u32,
+    // Provided tree nodes data, length of p_len+e_len
+    n_ptr: *const [c_uchar; zcash_history::MAX_ENTRY_SIZE],
+    // Peaks count
+    p_len: size_t,
+    // Extra nodes loaded (for deletion) count
+    e_len: size_t,
+    // Return of root commitment
+    rt_ret: *mut [u8; 32],
+) -> u32 {
+    let mut tree = match construct_mmr_tree(cbranch, t_len, ni_ptr, n_ptr, p_len, e_len) {
+        Ok(t) => t,
+        _ => {
+            return 0;
+        } // error
+    };
+
+    let truncate_len = match tree.truncate_leaf() {
+        Ok(v) => v,
+        _ => {
+            return 0;
+        } // Error
+    };
+
+    unsafe {
+        *rt_ret = tree
+            .root_node()
+            .expect("Just generated without errors, root should be resolving")
+            .data()
+            .hash();
+    }
+
+    truncate_len
+}
+
+#[no_mangle]
+pub extern "system" fn librustzcash_mmr_hash_node(
+    cbranch: u32,
+    n_ptr: *const [u8; zcash_history::MAX_NODE_DATA_SIZE],
+    h_ret: *mut [u8; 32],
+) -> u32 {
+    let node_bytes: &[u8; zcash_history::MAX_NODE_DATA_SIZE] = unsafe {
+        match n_ptr.as_ref() {
+            Some(r) => r,
+            None => return 1,
+        }
+    };
+
+    let node = match MMRNodeData::from_bytes(cbranch, &node_bytes[..]) {
+        Ok(n) => n,
+        _ => return 1, // error
+    };
+
+    unsafe {
+        *h_ret = node.hash();
+    }
+
+    0
+}

src/rust/src/rustzcash.rs

@@ -61,14 +61,13 @@ use zcash_proofs::{
     sprout,
 };
 
-use zcash_history::{Entry as MMREntry, NodeData as MMRNodeData, Tree as MMRTree};
-
 mod blake2b;
 mod ed25519;
 mod metrics_ffi;
 mod streams_ffi;
 mod tracing_ffi;
 
+mod history_ffi;
 mod orchard_ffi;
 mod transaction_ffi;
 
@@ -1092,183 +1091,6 @@ pub extern "C" fn librustzcash_zip32_xfvk_address(
     true
 }
 
-fn construct_mmr_tree(
-    // Consensus branch id
-    cbranch: u32,
-    // Length of tree in array representation
-    t_len: u32,
-
-    // Indices of provided tree nodes, length of p_len+e_len
-    ni_ptr: *const u32,
-    // Provided tree nodes data, length of p_len+e_len
-    n_ptr: *const [c_uchar; zcash_history::MAX_ENTRY_SIZE],
-
-    // Peaks count
-    p_len: size_t,
-    // Extra nodes loaded (for deletion) count
-    e_len: size_t,
-) -> Result<MMRTree, &'static str> {
-    let (indices, nodes) = unsafe {
-        (
-            slice::from_raw_parts(ni_ptr, p_len + e_len),
-            slice::from_raw_parts(n_ptr, p_len + e_len),
-        )
-    };
-
-    let mut peaks: Vec<_> = indices
-        .iter()
-        .zip(nodes.iter())
-        .map(
-            |(index, node)| match MMREntry::from_bytes(cbranch, &node[..]) {
-                Ok(entry) => Ok((*index, entry)),
-                Err(_) => Err("Invalid encoding"),
-            },
-        )
-        .collect::<Result<_, _>>()?;
-    let extra = peaks.split_off(p_len);
-
-    Ok(MMRTree::new(t_len, peaks, extra))
-}
-
-#[no_mangle]
-pub extern "system" fn librustzcash_mmr_append(
-    // Consensus branch id
-    cbranch: u32,
-    // Length of tree in array representation
-    t_len: u32,
-    // Indices of provided tree nodes, length of p_len
-    ni_ptr: *const u32,
-    // Provided tree nodes data, length of p_len
-    n_ptr: *const [c_uchar; zcash_history::MAX_ENTRY_SIZE],
-    // Peaks count
-    p_len: size_t,
-    // New node pointer
-    nn_ptr: *const [u8; zcash_history::MAX_NODE_DATA_SIZE],
-    // Return of root commitment
-    rt_ret: *mut [u8; 32],
-    // Return buffer for appended leaves, should be pre-allocated of ceiling(log2(t_len)) length
-    buf_ret: *mut [c_uchar; zcash_history::MAX_NODE_DATA_SIZE],
-) -> u32 {
-    let new_node_bytes: &[u8; zcash_history::MAX_NODE_DATA_SIZE] = unsafe {
-        match nn_ptr.as_ref() {
-            Some(r) => r,
-            None => {
-                return 0;
-            } // Null pointer passed, error
-        }
-    };
-
-    let mut tree = match construct_mmr_tree(cbranch, t_len, ni_ptr, n_ptr, p_len, 0) {
-        Ok(t) => t,
-        _ => {
-            return 0;
-        } // error
-    };
-
-    let node = match MMRNodeData::from_bytes(cbranch, &new_node_bytes[..]) {
-        Ok(node) => node,
-        _ => {
-            return 0;
-        } // error
-    };
-
-    let appended = match tree.append_leaf(node) {
-        Ok(appended) => appended,
-        _ => {
-            return 0;
-        }
-    };
-
-    let return_count = appended.len();
-
-    let root_node = tree
-        .root_node()
-        .expect("Just added, should resolve always; qed");
-    unsafe {
-        *rt_ret = root_node.data().hash();
-
-        for (idx, next_buf) in slice::from_raw_parts_mut(buf_ret, return_count as usize)
-            .iter_mut()
-            .enumerate()
-        {
-            tree.resolve_link(appended[idx])
-                .expect("This was generated by the tree and thus resolvable; qed")
-                .data()
-                .write(&mut &mut next_buf[..])
-                .expect("Write using cursor with enough buffer size cannot fail; qed");
-        }
-    }
-
-    return_count as u32
-}
-
-#[no_mangle]
-pub extern "system" fn librustzcash_mmr_delete(
-    // Consensus branch id
-    cbranch: u32,
-    // Length of tree in array representation
-    t_len: u32,
-    // Indices of provided tree nodes, length of p_len+e_len
-    ni_ptr: *const u32,
-    // Provided tree nodes data, length of p_len+e_len
-    n_ptr: *const [c_uchar; zcash_history::MAX_ENTRY_SIZE],
-    // Peaks count
-    p_len: size_t,
-    // Extra nodes loaded (for deletion) count
-    e_len: size_t,
-    // Return of root commitment
-    rt_ret: *mut [u8; 32],
-) -> u32 {
-    let mut tree = match construct_mmr_tree(cbranch, t_len, ni_ptr, n_ptr, p_len, e_len) {
-        Ok(t) => t,
-        _ => {
-            return 0;
-        } // error
-    };
-
-    let truncate_len = match tree.truncate_leaf() {
-        Ok(v) => v,
-        _ => {
-            return 0;
-        } // Error
-    };
-
-    unsafe {
-        *rt_ret = tree
-            .root_node()
-            .expect("Just generated without errors, root should be resolving")
-            .data()
-            .hash();
-    }
-
-    truncate_len
-}
-
-#[no_mangle]
-pub extern "system" fn librustzcash_mmr_hash_node(
-    cbranch: u32,
-    n_ptr: *const [u8; zcash_history::MAX_NODE_DATA_SIZE],
-    h_ret: *mut [u8; 32],
-) -> u32 {
-    let node_bytes: &[u8; zcash_history::MAX_NODE_DATA_SIZE] = unsafe {
-        match n_ptr.as_ref() {
-            Some(r) => r,
-            None => return 1,
-        }
-    };
-
-    let node = match MMRNodeData::from_bytes(cbranch, &node_bytes[..]) {
-        Ok(n) => n,
-        _ => return 1, // error
-    };
-
-    unsafe {
-        *h_ret = node.hash();
-    }
-
-    0
-}
-
 #[no_mangle]
 pub extern "C" fn librustzcash_getrandom(buf: *mut u8, buf_len: usize) {
     let buf = unsafe { slice::from_raw_parts_mut(buf, buf_len) };

src/rust/src/tests/mmr.rs

@@ -1,6 +1,6 @@
 use zcash_history::{Entry, EntryLink, NodeData};
 
-use crate::{librustzcash_mmr_append, librustzcash_mmr_delete};
+use crate::history_ffi::{librustzcash_mmr_append, librustzcash_mmr_delete};
 
 const NODE_DATA_16L: &[u8] = include_bytes!("./res/tree16.dat");
 const NODE_DATA_1023L: &[u8] = include_bytes!("./res/tree1023.dat");