allow lib to be loaded by consumer crates

and document the required placement

8 files changed, 437 insertions, 53 deletions

diff --git a/impls/monero_rust/Cargo.lock b/impls/monero_rust/Cargo.lock
index 2d20545..bf7f0e5 100644
--- a/impls/monero_rust/Cargo.lock
+++ b/impls/monero_rust/Cargo.lock
@@ -124,6 +124,7 @@ version = "0.0.1"
 dependencies = [
  "bindgen",
  "libc",
+ "libloading",
 ]
 
 [[package]]
diff --git a/impls/monero_rust/Cargo.toml b/impls/monero_rust/Cargo.toml
index 548823e..af37515 100644
--- a/impls/monero_rust/Cargo.toml
+++ b/impls/monero_rust/Cargo.toml
@@ -14,6 +14,7 @@ crate-type = ["lib", "cdylib"]
 
 [dependencies]
 libc = "0.2"
+libloading = "0.8.5"
 
 [build-dependencies]
 bindgen = "0.70.1"
diff --git a/impls/monero_rust/README.md b/impls/monero_rust/README.md
index 5affbd1..87d23a3 100644
--- a/impls/monero_rust/README.md
+++ b/impls/monero_rust/README.md
@@ -10,7 +10,7 @@ sudo apt-get install libhidapi-dev
 ```
 -->
 ### Build `monero_c`
-Build the monero_c Library for your architecture.  Follow the upstream docs at 
+Build the monero_c library for your architecture.  Follow the upstream docs at 
 https://github.com/MrCyjaneK/monero_c <!-- TODO: use example CMakeLists --> and 
 place the library at `monero_c/impls/monero_rust/lib/libwallet2_api_c.so` or use 
 the provided script:
@@ -35,8 +35,12 @@ mv release/monero/x86_64-linux-gnu_libwallet2_api_c.so ../lib/libwallet2_api_c.s
 # The library should be at monero_c/impls/monero_rust/lib/libwallet2_api_c.so.
 ```
 
-### Run `monero_rust` example
+### Run `monero_rust` demo
 From `monero_c/impls/monero_rust`:
 ```
 cargo run
 ```
+
+## Using `monero_rust` in your own crate
+Refer to the `example` folder.  `libwallet2_api_c.so` must be in the same 
+directory as the binary (*eg.* at `example/target/debug/libwallet2_api_c.so`).
diff --git a/impls/monero_rust/example/Cargo.lock b/impls/monero_rust/example/Cargo.lock
new file mode 100644
index 0000000..d921e0d
--- /dev/null
+++ b/impls/monero_rust/example/Cargo.lock
@@ -0,0 +1,295 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "aho-corasick"
+version = "1.1.3"
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+checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "bindgen"
+version = "0.70.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f49d8fed880d473ea71efb9bf597651e77201bdd4893efe54c9e5d65ae04ce6f"
+dependencies = [
+ "bitflags",
+ "cexpr",
+ "clang-sys",
+ "itertools",
+ "log",
+ "prettyplease",
+ "proc-macro2",
+ "quote",
+ "regex",
+ "rustc-hash",
+ "shlex",
+ "syn",
+]
+
+[[package]]
+name = "bitflags"
+version = "2.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b048fb63fd8b5923fc5aa7b340d8e156aec7ec02f0c78fa8a6ddc2613f6f71de"
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6fac387a98bb7c37292057cffc56d62ecb629900026402633ae9160df93a8766"
+dependencies = [
+ "nom",
+]
+
+[[package]]
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+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b023947811758c97c59bf9d1c188fd619ad4718dcaa767947df1cadb14f39f4"
+dependencies = [
+ "glob",
+ "libc",
+ "libloading",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
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+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d2fabcfbdc87f4758337ca535fb41a6d701b65693ce38287d856d1674551ec9b"
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "413ee7dfc52ee1a4949ceeb7dbc8a33f2d6c088194d9f922fb8318faf1f01186"
+dependencies = [
+ "either",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.159"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "561d97a539a36e26a9a5fad1ea11a3039a67714694aaa379433e580854bc3dc5"
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4979f22fdb869068da03c9f7528f8297c6fd2606bc3a4affe42e6a823fdb8da4"
+dependencies = [
+ "cfg-if",
+ "windows-targets",
+]
+
+[[package]]
+name = "log"
+version = "0.4.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"
+
+[[package]]
+name = "memchr"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "68354c5c6bd36d73ff3feceb05efa59b6acb7626617f4962be322a825e61f79a"
+
+[[package]]
+name = "monero_example"
+version = "0.0.1"
+dependencies = [
+ "monero_rust",
+]
+
+[[package]]
+name = "monero_rust"
+version = "0.0.1"
+dependencies = [
+ "bindgen",
+ "libc",
+ "libloading",
+]
+
+[[package]]
+name = "nom"
+version = "7.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d273983c5a657a70a3e8f2a01329822f3b8c8172b73826411a55751e404a0a4a"
+dependencies = [
+ "memchr",
+ "minimal-lexical",
+]
+
+[[package]]
+name = "prettyplease"
+version = "0.2.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "479cf940fbbb3426c32c5d5176f62ad57549a0bb84773423ba8be9d089f5faba"
+dependencies = [
+ "proc-macro2",
+ "syn",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.87"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b3e4daa0dcf6feba26f985457cdf104d4b4256fc5a09547140f3631bb076b19a"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5b9d34b8991d19d98081b46eacdd8eb58c6f2b201139f7c5f643cc155a633af"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "38200e5ee88914975b69f657f0801b6f6dccafd44fd9326302a4aaeecfacb1d8"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
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+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
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+
+[[package]]
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+
+[[package]]
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+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e91b56cd4cadaeb79bbf1a5645f6b4f8dc5bde8834ad5894a8db35fda9efa1fe"
+
+[[package]]
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+checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
+dependencies = [
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.6"
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+
+[[package]]
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+checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
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+
+[[package]]
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+checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
+
+[[package]]
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+version = "0.52.6"
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+
+[[package]]
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+checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
diff --git a/impls/monero_rust/example/Cargo.toml b/impls/monero_rust/example/Cargo.toml
new file mode 100644
index 0000000..e0b7823
--- /dev/null
+++ b/impls/monero_rust/example/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "monero_example"
+version = "0.0.1"
+edition = "2021"
+
+[dependencies]
+monero_rust = { path = ".." }
diff --git a/impls/monero_rust/example/src/main.rs b/impls/monero_rust/example/src/main.rs
new file mode 100644
index 0000000..aae688b
--- /dev/null
+++ b/impls/monero_rust/example/src/main.rs
@@ -0,0 +1,25 @@
+use monero_rust::{WalletError, WalletManager, NETWORK_TYPE_MAINNET};
+
+fn main() -> Result<(), WalletError> {
+    let wallet_manager = WalletManager::new(None)?;
+
+    let wallet = wallet_manager.create_wallet(
+        "wallet",
+        "password",
+        "English",
+        NETWORK_TYPE_MAINNET,
+    )?;
+
+    match wallet.get_seed("") {
+        Ok(seed) => println!("Seed: {}", seed),
+        Err(e) => {
+            eprintln!("Failed to get seed: {:?}", e);
+            return Err(e);
+        }
+    }
+
+    let address = wallet.get_address(0, 0)?;
+    println!("Wallet Address: {}", address);
+
+    Ok(())
+}
diff --git a/impls/monero_rust/src/lib.rs b/impls/monero_rust/src/lib.rs
index d576ea6..2175083 100644
--- a/impls/monero_rust/src/lib.rs
+++ b/impls/monero_rust/src/lib.rs
@@ -1,62 +1,69 @@
 use std::ffi::{CStr, CString};
 use std::os::raw::{c_char, c_int, c_void};
 use std::ptr::NonNull;
+use std::sync::Arc;
+
+use libloading::{Library, Symbol};
 
 pub const NETWORK_TYPE_MAINNET: c_int = 0;
 pub const NETWORK_TYPE_TESTNET: c_int = 1;
 pub const NETWORK_TYPE_STAGENET: c_int = 2;
 
-extern "C" {
-    pub fn MONERO_WalletManagerFactory_getWalletManager() -> *mut c_void;
-    pub fn MONERO_WalletManager_createWallet(
-        wm_ptr: *mut c_void,
-        path: *const c_char,
-        password: *const c_char,
-        language: *const c_char,
-        networkType: c_int,
-    ) -> *mut c_void;
-    pub fn MONERO_Wallet_seed(
-        wallet_ptr: *mut c_void,
-        seed_offset: *const c_char,
-    ) -> *const c_char;
-    pub fn MONERO_WalletManager_closeWallet(
-        wm_ptr: *mut c_void,
-        wallet_ptr: *mut c_void,
-        store: bool,
-    ) -> bool;
-    pub fn MONERO_Wallet_errorString(wallet_ptr: *mut c_void) -> *const c_char;
-    pub fn MONERO_Wallet_status(wallet_ptr: *mut c_void) -> c_int;
-    pub fn MONERO_Wallet_address(
-        wallet_ptr: *mut c_void,
-        account_index: u64,
-        address_index: u64,
-    ) -> *const c_char;
-    pub fn MONERO_Wallet_isDeterministic(wallet_ptr: *mut c_void) -> bool;
-    pub fn MONERO_WalletManager_walletExists(
-        wm_ptr: *mut c_void,
-        path: *const c_char,
-    ) -> bool;
-}
-
 #[derive(Debug)]
 pub enum WalletError {
     NullPointer,
     FfiError(String),
     WalletErrorCode(c_int, String),
+    LibraryLoadError(String),
 }
 
-type WalletResult<T> = Result<T, WalletError>;
+pub type WalletResult<T> = Result<T, WalletError>;
 
 pub struct WalletManager {
     ptr: NonNull<c_void>,
+    library: Arc<Library>,
 }
 
 impl WalletManager {
-    pub fn new() -> WalletResult<Self> {
+    /// Create a new WalletManager, optionally specifying the path to the shared library.
+    pub fn new(lib_path: Option<&str>) -> WalletResult<Self> {
+        let lib = match lib_path {
+            Some(path) => {
+                unsafe {
+                    Library::new(path).map_err(|e| WalletError::LibraryLoadError(e.to_string()))?
+                }
+            }
+            None => {
+                // Attempt to load from the same directory as the executable.
+                let exe_path = std::env::current_exe()
+                    .map_err(|e| WalletError::LibraryLoadError(e.to_string()))?;
+                let exe_dir = exe_path.parent().ok_or_else(|| {
+                    WalletError::LibraryLoadError("Failed to get executable directory".to_string())
+                })?;
+                let lib_path = exe_dir.join("libwallet2_api_c.so");
+
+                unsafe {
+                    if lib_path.exists() {
+                        Library::new(lib_path)
+                            .map_err(|e| WalletError::LibraryLoadError(e.to_string()))?
+                    } else {
+                        // Fallback to standard locations.
+                        Library::new("libwallet2_api_c.so")
+                            .map_err(|e| WalletError::LibraryLoadError(e.to_string()))?
+                    }
+                }
+            }
+        };
+
+        let library = Arc::new(lib);
+
         unsafe {
-            let ptr = MONERO_WalletManagerFactory_getWalletManager();
+            let func: Symbol<unsafe extern "C" fn() -> *mut c_void> =
+                library.get(b"MONERO_WalletManagerFactory_getWalletManager\0")
+                    .map_err(|e| WalletError::LibraryLoadError(e.to_string()))?;
+            let ptr = func();
             NonNull::new(ptr)
-                .map(|nn_ptr| WalletManager { ptr: nn_ptr })
+                .map(|nn_ptr| WalletManager { ptr: nn_ptr, library })
                 .ok_or(WalletError::NullPointer)
         }
     }
@@ -73,7 +80,19 @@ impl WalletManager {
         let c_language = CString::new(language).expect("CString::new failed");
 
         unsafe {
-            let wallet_ptr = MONERO_WalletManager_createWallet(
+            let func: Symbol<
+                unsafe extern "C" fn(
+                    *mut c_void,
+                    *const c_char,
+                    *const c_char,
+                    *const c_char,
+                    c_int,
+                ) -> *mut c_void,
+            > = self
+                .library
+                .get(b"MONERO_WalletManager_createWallet\0")
+                .map_err(|e| WalletError::LibraryLoadError(e.to_string()))?;
+            let wallet_ptr = func(
                 self.ptr.as_ptr(),
                 c_path.as_ptr(),
                 c_password.as_ptr(),
@@ -87,15 +106,24 @@ impl WalletManager {
                 Ok(Wallet {
                     ptr: NonNull::new_unchecked(wallet_ptr),
                     manager_ptr: self.ptr,
+                    library: Arc::clone(&self.library), // Keep the library alive.
                 })
             }
         }
     }
 }
 
+impl Drop for WalletManager {
+    fn drop(&mut self) {
+        // The library will be dropped automatically when all references are gone.
+    }
+}
+
+#[derive(Clone)]
 pub struct Wallet {
     ptr: NonNull<c_void>,
     manager_ptr: NonNull<c_void>,
+    library: Arc<Library>,
 }
 
 impl Wallet {
@@ -103,7 +131,11 @@ impl Wallet {
         let c_seed_offset = CString::new(seed_offset).expect("CString::new failed");
 
         unsafe {
-            let seed_ptr = MONERO_Wallet_seed(self.ptr.as_ptr(), c_seed_offset.as_ptr());
+            let func: Symbol<unsafe extern "C" fn(*mut c_void, *const c_char) -> *const c_char> =
+                self.library
+                    .get(b"MONERO_Wallet_seed\0")
+                    .map_err(|e| WalletError::LibraryLoadError(e.to_string()))?;
+            let seed_ptr = func(self.ptr.as_ptr(), c_seed_offset.as_ptr());
 
             if seed_ptr.is_null() {
                 Err(self.get_last_error())
@@ -122,11 +154,11 @@ impl Wallet {
 
     pub fn get_address(&self, account_index: u64, address_index: u64) -> WalletResult<String> {
         unsafe {
-            let address_ptr = MONERO_Wallet_address(
-                self.ptr.as_ptr(),
-                account_index,
-                address_index,
-            );
+            let func: Symbol<unsafe extern "C" fn(*mut c_void, u64, u64) -> *const c_char> =
+                self.library
+                    .get(b"MONERO_Wallet_address\0")
+                    .map_err(|e| WalletError::LibraryLoadError(e.to_string()))?;
+            let address_ptr = func(self.ptr.as_ptr(), account_index, address_index);
 
             if address_ptr.is_null() {
                 Err(self.get_last_error())
@@ -140,13 +172,28 @@ impl Wallet {
     }
 
     pub fn is_deterministic(&self) -> bool {
-        unsafe { MONERO_Wallet_isDeterministic(self.ptr.as_ptr()) }
+        unsafe {
+            let func: Symbol<unsafe extern "C" fn(*mut c_void) -> bool> = self
+                .library
+                .get(b"MONERO_Wallet_isDeterministic\0")
+                .expect("Failed to load MONERO_Wallet_isDeterministic");
+            func(self.ptr.as_ptr())
+        }
     }
 
     fn get_last_error(&self) -> WalletError {
         unsafe {
-            let error_ptr = MONERO_Wallet_errorString(self.ptr.as_ptr());
-            let status = MONERO_Wallet_status(self.ptr.as_ptr());
+            let error_func: Symbol<unsafe extern "C" fn(*mut c_void) -> *const c_char> = self
+                .library
+                .get(b"MONERO_Wallet_errorString\0")
+                .expect("Failed to load MONERO_Wallet_errorString");
+            let status_func: Symbol<unsafe extern "C" fn(*mut c_void) -> c_int> = self
+                .library
+                .get(b"MONERO_Wallet_status\0")
+                .expect("Failed to load MONERO_Wallet_status");
+
+            let error_ptr = error_func(self.ptr.as_ptr());
+            let status = status_func(self.ptr.as_ptr());
 
             let error_msg = if error_ptr.is_null() {
                 "Unknown error".to_string()
@@ -164,7 +211,13 @@ impl Wallet {
 impl Drop for Wallet {
     fn drop(&mut self) {
         unsafe {
-            MONERO_WalletManager_closeWallet(self.manager_ptr.as_ptr(), self.ptr.as_ptr(), false);
+            let func: Symbol<
+                unsafe extern "C" fn(*mut c_void, *mut c_void, bool) -> bool,
+            > = self
+                .library
+                .get(b"MONERO_WalletManager_closeWallet\0")
+                .expect("Failed to load MONERO_WalletManager_closeWallet");
+            func(self.manager_ptr.as_ptr(), self.ptr.as_ptr(), false);
         }
     }
 }
diff --git a/impls/monero_rust/src/main.rs b/impls/monero_rust/src/main.rs
index eb9e148..aae688b 100644
--- a/impls/monero_rust/src/main.rs
+++ b/impls/monero_rust/src/main.rs
@@ -1,9 +1,7 @@
-use monero_rust::{
-    WalletError, WalletManager, NETWORK_TYPE_MAINNET,
-};
+use monero_rust::{WalletError, WalletManager, NETWORK_TYPE_MAINNET};
 
 fn main() -> Result<(), WalletError> {
-    let wallet_manager = WalletManager::new()?;
+    let wallet_manager = WalletManager::new(None)?;
 
     let wallet = wallet_manager.create_wallet(
         "wallet",