rust: Move history tree FFI declarations into a separate header

src/rust/include/librustzcash.h

@@ -11,25 +11,6 @@
   #include <stdalign.h>
 #endif
 
-#define NODE_SERIALIZED_LENGTH 171
-#define ENTRY_SERIALIZED_LENGTH (NODE_SERIALIZED_LENGTH + 9)
-
-typedef struct HistoryNode {
-    unsigned char bytes[NODE_SERIALIZED_LENGTH];
-}  HistoryNode;
-static_assert(
-    sizeof(HistoryNode) == NODE_SERIALIZED_LENGTH,
-    "HistoryNode struct is not the same size as the underlying byte array");
-static_assert(alignof(HistoryNode) == 1, "HistoryNode struct alignment is not 1");
-
-typedef struct HistoryEntry {
-    unsigned char bytes[ENTRY_SERIALIZED_LENGTH];
-}  HistoryEntry;
-static_assert(
-    sizeof(HistoryEntry) == ENTRY_SERIALIZED_LENGTH,
-    "HistoryEntry struct is not the same size as the underlying byte array");
-static_assert(alignof(HistoryEntry) == 1, "HistoryEntry struct alignment is not 1");
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -333,33 +314,6 @@ extern "C" {
         unsigned char *addr_ret
     );
 
-    uint32_t librustzcash_mmr_append(
-        uint32_t cbranch,
-        uint32_t t_len,
-        const uint32_t *ni_ptr,
-        const HistoryEntry *n_ptr,
-        size_t p_len,
-        const HistoryNode *nn_ptr,
-        unsigned char *rt_ret,
-        HistoryNode *buf_ret
-    );
-
-    uint32_t librustzcash_mmr_delete(
-        uint32_t cbranch,
-        uint32_t t_len,
-        const uint32_t *ni_ptr,
-        const HistoryEntry *n_ptr,
-        size_t p_len,
-        size_t e_len,
-        unsigned char *rt_ret
-    );
-
-    uint32_t librustzcash_mmr_hash_node(
-        uint32_t cbranch,
-        const HistoryNode *n_ptr,
-        unsigned char *h_ret
-    );
-
     /// Fills the provided buffer with random bytes. This is intended to
     /// be a cryptographically secure RNG; it uses Rust's `OsRng`, which
     /// is implemented in terms of the `getrandom` crate. The first call

src/rust/include/rust/history.h

@@ -0,0 +1,60 @@
+// Copyright (c) 2020 The Zcash developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or https://www.opensource.org/licenses/mit-license.php .
+
+#ifndef ZCASH_RUST_INCLUDE_RUST_HISTORY_H
+#define ZCASH_RUST_INCLUDE_RUST_HISTORY_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#define NODE_SERIALIZED_LENGTH 171
+#define ENTRY_SERIALIZED_LENGTH (NODE_SERIALIZED_LENGTH + 9)
+
+typedef struct HistoryNode {
+    unsigned char bytes[NODE_SERIALIZED_LENGTH];
+}  HistoryNode;
+static_assert(
+    sizeof(HistoryNode) == NODE_SERIALIZED_LENGTH,
+    "HistoryNode struct is not the same size as the underlying byte array");
+static_assert(alignof(HistoryNode) == 1, "HistoryNode struct alignment is not 1");
+
+typedef struct HistoryEntry {
+    unsigned char bytes[ENTRY_SERIALIZED_LENGTH];
+}  HistoryEntry;
+static_assert(
+    sizeof(HistoryEntry) == ENTRY_SERIALIZED_LENGTH,
+    "HistoryEntry struct is not the same size as the underlying byte array");
+static_assert(alignof(HistoryEntry) == 1, "HistoryEntry struct alignment is not 1");
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+uint32_t librustzcash_mmr_append(
+    uint32_t cbranch,
+    uint32_t t_len,
+    const uint32_t* ni_ptr,
+    const HistoryEntry* n_ptr,
+    size_t p_len,
+    const HistoryNode* nn_ptr,
+    unsigned char* rt_ret,
+    HistoryNode* buf_ret);
+
+uint32_t librustzcash_mmr_delete(
+    uint32_t cbranch,
+    uint32_t t_len,
+    const uint32_t* ni_ptr,
+    const HistoryEntry* n_ptr,
+    size_t p_len,
+    size_t e_len,
+    unsigned char* rt_ret);
+
+uint32_t librustzcash_mmr_hash_node(
+    uint32_t cbranch,
+    const HistoryNode* n_ptr,
+    unsigned char* h_ret);
+#ifdef __cplusplus
+}
+#endif
+
+#endif // ZCASH_RUST_INCLUDE_RUST_HISTORY_H

src/zcash/History.hpp

@@ -9,6 +9,8 @@
 #include "streams.h"
 #include "uint256.h"
 
+#include <rust/history.h>
+
 #include "librustzcash.h"
 
 namespace libzcash {