rust: initial api for Ndb and NdbConfig

This is the start of our rust library for nostrdb. Implement idiomatic
interfaces for Ndb and NdbConfig.

Changelog-Added: Add initial rust library

nostrdb.c

@@ -3147,7 +3147,7 @@ static int ndb_run_migrations(struct ndb *ndb)
 	return 1;
 }
 
-int ndb_init(struct ndb **pndb, const char *filename, struct ndb_config *config)
+int ndb_init(struct ndb **pndb, const char *filename, const struct ndb_config *config)
 {
 	struct ndb *ndb;
 	//MDB_dbi ind_id; // TODO: ind_pk, etc

nostrdb.h

@@ -295,7 +295,7 @@ int ndb_decode_key(const char *secstr, struct ndb_keypair *keypair);
 int ndb_note_verify(void *secp_ctx, unsigned char pubkey[32], unsigned char id[32], unsigned char signature[64]);
 
 // NDB
-int ndb_init(struct ndb **ndb, const char *dbdir, struct ndb_config *);
+int ndb_init(struct ndb **ndb, const char *dbdir, const struct ndb_config *);
 int ndb_db_version(struct ndb *ndb);
 int ndb_process_event(struct ndb *, const char *json, int len);
 int ndb_process_events(struct ndb *, const char *ldjson, size_t len);

rust/Cargo.toml

@@ -6,7 +6,9 @@ build = "build.rs"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
+[dependencies]
+libc = "0.2.151"
+
 [build-dependencies]
 bindgen = "0.69.1"
 cc = "1.0"
-

rust/src/config.rs

@@ -0,0 +1,43 @@
+use crate::bindings;
+
+// The Rust wrapper for ndb_config
+pub struct NdbConfig {
+    pub config: bindings::ndb_config,
+}
+
+impl NdbConfig {
+    // Constructor
+    pub fn new() -> Self {
+        let mut config = bindings::ndb_config {
+            filter_context: std::ptr::null_mut(),
+            ingest_filter: None,
+            flags: 0,
+            ingester_threads: 0,
+            mapsize: 0,
+        };
+
+        unsafe {
+            bindings::ndb_default_config(&mut config);
+        }
+
+        NdbConfig { config }
+    }
+
+    // Example setter methods
+    pub fn set_flags(&mut self, flags: i32) -> &mut Self {
+        self.config.flags = flags;
+        self
+    }
+
+    pub fn set_ingester_threads(&mut self, threads: i32) -> &mut Self {
+        self.config.ingester_threads = threads;
+        self
+    }
+
+    // Add other setter methods as needed
+
+    // Internal method to get a raw pointer to the config, used in Ndb
+    pub fn as_ptr(&self) -> *const bindings::ndb_config {
+        &self.config
+    }
+}

rust/src/error.rs

@@ -0,0 +1,3 @@
+pub enum Error {
+    DbOpenFailed,
+}

rust/src/lib.rs

@@ -4,31 +4,7 @@
 #[allow(unused)]
 mod bindings;
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use bindings as ndb;
-    use std::ffi::CString;
-
-    #[test]
-    fn ndb_init_works() {
-        unsafe {
-            // Initialize ndb
-            let mut ndb_ptr: *mut bindings::ndb = std::ptr::null_mut();
-            let mut config = ndb::ndb_config {
-                filter_context: std::ptr::null_mut(),
-                ingest_filter: None,
-                flags: 0,
-                ingester_threads: 0,
-                mapsize: 0,
-            };
-
-            let path = CString::new(".").expect("Failed to create CString");
-            ndb::ndb_default_config(&mut config);
-            ndb::ndb_init(&mut ndb_ptr, path.as_ptr(), &mut config);
-
-            // Clean up
-            bindings::ndb_destroy(ndb_ptr);
-        }
-    }
-}
+mod config;
+mod error;
+mod ndb;
+mod result;

rust/src/ndb.rs

@@ -0,0 +1,61 @@
+use std::ffi::CString;
+use std::ptr;
+
+use crate::bindings;
+use crate::config::NdbConfig;
+use crate::error::Error;
+use crate::result::Result;
+
+pub struct Ndb {
+    ndb: *mut bindings::ndb,
+}
+
+impl Ndb {
+    // Constructor
+    pub fn new(db_dir: &str, config: &NdbConfig) -> Result<Self> {
+        let db_dir_cstr = match CString::new(db_dir) {
+            Ok(cstr) => cstr,
+            Err(_) => return Err(Error::DbOpenFailed),
+        };
+        let mut ndb: *mut bindings::ndb = ptr::null_mut();
+        let result = unsafe { bindings::ndb_init(&mut ndb, db_dir_cstr.as_ptr(), config.as_ptr()) };
+
+        if result != 0 {
+            return Err(Error::DbOpenFailed);
+        }
+
+        Ok(Ndb { ndb })
+    }
+
+    // Add other methods to interact with the library here
+}
+
+impl Drop for Ndb {
+    fn drop(&mut self) {
+        unsafe {
+            bindings::ndb_destroy(self.ndb);
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::fs;
+
+    fn cleanup() {
+        let _ = fs::remove_file("data.mdb");
+        let _ = fs::remove_file("lock.mdb");
+    }
+
+    #[test]
+    fn ndb_init_works() {
+        // Initialize ndb
+        {
+            let cfg = NdbConfig::new();
+            let _ = Ndb::new(".", &cfg);
+        }
+
+        cleanup();
+    }
+}

rust/src/result.rs

@@ -0,0 +1,3 @@
+use crate::error::Error;
+
+pub type Result<T> = std::result::Result<T, Error>;