initial commit

backend-rust/step2-database-only/src/database.rs

@@ -1,64 +0,0 @@
-use log;
-
-use crate::errors::AppResult;
-
-use crate::errors::err_msg;
-use crate::ffi;
-
-// Execute query on SQLite
-pub fn query(query: String) -> AppResult<String> {
-    log::debug!("executing query: '{}'", query);
-
-    unsafe {
-        // Convert query string to bytes
-        let query_bytes = query.as_bytes();
-        // Allocate memory for query in SQLite module
-        let query_ptr = ffi::allocate(query_bytes.len());
-
-        // Store query in SQLite's memory
-        for (i, byte) in query_bytes.iter().enumerate() {
-            let ptr = query_ptr + i as i32;
-            ffi::store(ptr, *byte);
-        }
-
-        // Execute the query, and get pointer to the result
-        let result_ptr = ffi::invoke(query_ptr, query_bytes.len());
-
-        // First 4 bytes at result_ptr location encode result size, read that first
-        let mut result_size: usize = 0;
-        for i in 0..3 {
-            let ptr = result_ptr + i as i32;
-            let b = ffi::load(ptr) as usize;
-            result_size = result_size + (b << (8 * i));
-        }
-        // Now we know exact size of the query execution result
-
-        // Read query execution result byte-by-byte
-        let mut result_bytes = vec![0; result_size as usize];
-        for i in 4..(result_size + 4) {
-            let ptr = result_ptr + i as i32;
-            let b = ffi::load(ptr);
-            result_bytes[i as usize - 4] = b;
-        }
-
-        // Deallocate query result
-        ffi::deallocate(result_ptr, result_size + 4);
-
-        // Decode query result to a utf8 string
-        let result_str = std::str::from_utf8(result_bytes.as_slice());
-
-        // Log if there's an error
-        if result_str.is_err() {
-            log::error!("unable to decode result from bytes: {:#x?}", result_bytes);
-        }
-        // Wrap error with a better message, and return Result
-        result_str
-            .map_err(|e| {
-                err_msg(&format!(
-                    "unable to decode result from bytes {:#x?}: {}",
-                    result_bytes, e
-                ))
-            })
-            .map(|s| s.to_string())
-    }
-}

backend-rust/step2-database-only/src/ffi.rs

@@ -1,26 +0,0 @@
-// 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;
-}

backend-rust/step2-database-only/src/lib.rs

@@ -1,37 +1,39 @@
 use fluence::sdk::*;
 
-pub mod database;
 pub mod errors;
-pub mod ffi;
+pub mod utils;
+
+use crate::utils::sqlite_call_wrapper;
 
 fn init() {
     logger::WasmLogger::init_with_level(log::Level::Info).unwrap();
 }
 
-#[invocation_handler(init_fn = init)]
+#[invocation_handler(init_fn = init, side_modules = sqlite)]
 fn run(nickname: String) -> String {
     // Create table for messages storage
-    database::query("CREATE TABLE messages(message text, username text)".to_string())
+    sqlite_call_wrapper("CREATE TABLE messages(message text, username text)")
         .expect("error on CREATE TABLE");
 
     // Insert message 'Hello, username!' using `nickname` as author's username
-    database::query(format!(
-        r#"INSERT INTO messages VALUES("{}","{}")"#,
-        "Hello, username!", nickname
-    ))
+    sqlite_call_wrapper(
+        format!(
+            r#"INSERT INTO messages VALUES("{}","{}")"#,
+            "Hello, username!", nickname
+        )
+        .as_str(),
+    )
     .expect("error on INSERT INTO");
 
     // Get all messages
-    let messages =
-        database::query("SELECT * FROM messages".to_string()).expect("error on SELECT *");
+    let messages = sqlite_call_wrapper("SELECT * FROM messages").expect("error on SELECT *");
     log::info!("messages: {:?}", messages);
 
     // Get all messages as JSON via SQLite's JSON extension
-    database::query(
+    sqlite_call_wrapper(
         "SELECT json_group_array(
             json_object('message', message, 'username', username)
-        ) AS json_result FROM (SELECT * FROM messages)"
-            .to_string(),
+        ) AS json_result FROM (SELECT * FROM messages)",
     )
     .expect("error on SELECT as json")
 }

backend-rust/step2-database-only/src/utils.rs

@@ -0,0 +1,24 @@
+use crate::errors::{err_msg, AppResult};
+use crate::sqlite;
+
+pub fn sqlite_call_wrapper(bytes: &str) -> AppResult<String> {
+    let response = sqlite::call(bytes.as_bytes());
+
+    // Decode query result to a utf8 string
+    let result_str = std::str::from_utf8(&response);
+
+    // Log if there's an error
+    if result_str.is_err() {
+        log::error!("unable to decode result from bytes: {:#x?}", bytes);
+    }
+
+    // Wrap error with a better message, and return Result
+    result_str
+        .map_err(|e| {
+            err_msg(&format!(
+                "unable to decode result from bytes {:#x?}: {}",
+                bytes, e
+            ))
+        })
+        .map(|s| s.to_string())
+}