rust-workshop => backend-rust

backend-rust/step3-finished-app/src/ffi.rs

@@ -0,0 +1,26 @@
+// Description of inter-module communication
+//
+// Allows fluid module to call methods from sqlite module
+
+#[link(wasm_import_module = "sqlite")]
+extern "C" {
+    // Allocate chunk of SQLite memory, and return a pointer to that memory
+    #[link_name = "sqlite_allocate"]
+    pub fn allocate(size: usize) -> i32;
+
+    // Deallocate chunk of memory after it's not used anymore
+    #[link_name = "sqlite_deallocate"]
+    pub fn deallocate(ptr: i32, size: usize);
+
+    // Put 1 byte at ptr location in SQLite memory
+    #[link_name = "sqlite_store"]
+    pub fn store(ptr: i32, byte: u8);
+
+    // Read 1 byte from ptr location of SQLite memory
+    #[link_name = "sqlite_load"]
+    pub fn load(ptr: i32) -> u8;
+
+    // Call SQLite's invocation handler with data specified by pointer and size
+    #[link_name = "sqlite_invoke"]
+    pub fn invoke(ptr: i32, size: usize) -> i32;
+}