Add wasm32-unknown-unknown target support

diesel/Cargo.toml

@@ -24,7 +24,6 @@ include = [
 byteorder = { version = "1.0", optional = true }
 chrono = { version = "0.4.20", optional = true, default-features = false, features = ["clock", "std"] }
 libc = { version = "0.2.0", optional = true }
-libsqlite3-sys = { version = ">=0.17.2, <0.31.0", optional = true, features = ["bundled_bindings"] }
 mysqlclient-sys = { version = ">=0.2.5, <0.5.0",  optional = true }
 mysqlclient-src = { version = "0.1.0", optional = true }
 pq-sys = { version = ">=0.4.0, <0.7.0", optional = true }
@@ -50,6 +49,12 @@ downcast-rs = "1.2.1"
 version = "~2.2.0"
 path = "../diesel_derives"
 
+[target.'cfg(not(all(target_family = "wasm", not(target_os = "wasi"))))'.dependencies]
+libsqlite3-sys = { version = ">=0.17.2, <0.31.0", optional = true, features = ["bundled_bindings"] }
+
+[target.'cfg(all(target_family = "wasm", not(target_os = "wasi")))'.dependencies]
+sqlite-wasm-rs = { version = "0.1.0", optional = true }
+
 [dev-dependencies]
 cfg-if = "1"
 dotenvy = "0.15"
@@ -67,7 +72,7 @@ huge-tables = ["64-column-tables"]
 64-column-tables = ["32-column-tables", "diesel_derives/64-column-tables"]
 128-column-tables = ["64-column-tables", "diesel_derives/128-column-tables"]
 postgres = ["dep:pq-sys", "postgres_backend"]
-sqlite = ["dep:libsqlite3-sys", "diesel_derives/sqlite", "time?/formatting", "time?/parsing"]
+sqlite = ["dep:libsqlite3-sys", "dep:sqlite-wasm-rs", "diesel_derives/sqlite", "time?/formatting", "time?/parsing"]
 mysql = ["dep:mysqlclient-sys", "dep:url", "dep:percent-encoding", "dep:bitflags", "mysql_backend"]
 without-deprecated = ["diesel_derives/without-deprecated"]
 with-deprecated = ["diesel_derives/with-deprecated"]

diesel/src/lib.rs

@@ -768,6 +768,13 @@ pub mod prelude {
     #[cfg(feature = "sqlite")]
     #[doc(inline)]
     pub use crate::sqlite::SqliteConnection;
+    // Before using C-API, you must initialize sqlite.
+    //
+    // Initializing the database is a one-time operation during
+    // the life of the program.
+    #[cfg(feature = "sqlite")]
+    #[cfg(all(target_family = "wasm", not(target_os = "wasi")))]
+    pub use sqlite_wasm_rs::init_sqlite;
 }
 
 #[doc(inline)]

diesel/src/sqlite/connection/bind_collector.rs

@@ -3,6 +3,10 @@ use crate::serialize::{IsNull, Output};
 use crate::sql_types::HasSqlType;
 use crate::sqlite::{Sqlite, SqliteType};
 use crate::QueryResult;
+#[cfg(not(all(target_family = "wasm", not(target_os = "wasi"))))]
+use libsqlite3_sys as ffi;
+#[cfg(all(target_family = "wasm", not(target_os = "wasi")))]
+use sqlite_wasm_rs::c as ffi;
 
 #[derive(Debug, Default)]
 pub struct SqliteBindCollector<'a> {
@@ -127,9 +131,8 @@ impl InternalSqliteBindValue<'_> {
     #[allow(unsafe_code)] // ffi function calls
     pub(in crate::sqlite) fn result_of(
         self,
-        ctx: &mut libsqlite3_sys::sqlite3_context,
+        ctx: &mut ffi::sqlite3_context,
     ) -> Result<(), std::num::TryFromIntError> {
-        use libsqlite3_sys as ffi;
         use std::os::raw as libc;
         // This unsafe block assumes the following invariants:
         //

diesel/src/sqlite/connection/functions.rs

@@ -1,5 +1,9 @@
+#[cfg(not(all(target_family = "wasm", not(target_os = "wasi"))))]
 extern crate libsqlite3_sys as ffi;
 
+#[cfg(all(target_family = "wasm", not(target_os = "wasi")))]
+use sqlite_wasm_rs::c as ffi;
+
 use super::raw::RawConnection;
 use super::row::PrivateSqliteRow;
 use super::{Sqlite, SqliteAggregateFunction, SqliteBindValue};

diesel/src/sqlite/connection/mod.rs

@@ -1,5 +1,9 @@
+#[cfg(not(all(target_family = "wasm", not(target_os = "wasi"))))]
 extern crate libsqlite3_sys as ffi;
 
+#[cfg(all(target_family = "wasm", not(target_os = "wasi")))]
+use sqlite_wasm_rs::c as ffi;
+
 mod bind_collector;
 mod functions;
 mod owned_row;

diesel/src/sqlite/connection/raw.rs

@@ -1,6 +1,10 @@
 #![allow(unsafe_code)] // ffi calls
+#[cfg(not(all(target_family = "wasm", not(target_os = "wasi"))))]
 extern crate libsqlite3_sys as ffi;
 
+#[cfg(all(target_family = "wasm", not(target_os = "wasi")))]
+use sqlite_wasm_rs::c as ffi;
+
 use std::ffi::{CString, NulError};
 use std::io::{stderr, Write};
 use std::os::raw as libc;
@@ -45,8 +49,23 @@ impl RawConnection {
             CString::new(database_url)?
         };
         let flags = ffi::SQLITE_OPEN_READWRITE | ffi::SQLITE_OPEN_CREATE | ffi::SQLITE_OPEN_URI;
+        // Persistent Storage is supported, use opfs vfs.
+        // This support is only available when sqlite is loaded from a
+        // Worker thread, whether it's loaded in its own dedicated worker
+        // or in a worker together with client code.
+        #[cfg(all(target_family = "wasm", not(target_os = "wasi")))]
+        let vfs = CString::new("opfs")?;
+
         let connection_status = unsafe {
-            ffi::sqlite3_open_v2(database_url.as_ptr(), &mut conn_pointer, flags, ptr::null())
+            ffi::sqlite3_open_v2(
+                database_url.as_ptr(),
+                &mut conn_pointer,
+                flags,
+                #[cfg(not(all(target_family = "wasm", not(target_os = "wasi"))))]
+                ptr::null(),
+                #[cfg(all(target_family = "wasm", not(target_os = "wasi")))]
+                vfs.as_ptr(),
+            )
         };
 
         match connection_status {

diesel/src/sqlite/connection/serialized_database.rs

@@ -1,6 +1,10 @@
 #![allow(unsafe_code)]
+#[cfg(not(all(target_family = "wasm", not(target_os = "wasi"))))]
 extern crate libsqlite3_sys as ffi;
 
+#[cfg(all(target_family = "wasm", not(target_os = "wasi")))]
+use sqlite_wasm_rs::c as ffi;
+
 use std::ops::Deref;
 
 /// `SerializedDatabase` is a wrapper for a serialized database that is dynamically allocated by calling `sqlite3_serialize`.

diesel/src/sqlite/connection/sqlite_value.rs

@@ -1,6 +1,10 @@
 #![allow(unsafe_code)] // ffi calls
+#[cfg(not(all(target_family = "wasm", not(target_os = "wasi"))))]
 extern crate libsqlite3_sys as ffi;
 
+#[cfg(all(target_family = "wasm", not(target_os = "wasi")))]
+use sqlite_wasm_rs::c as ffi;
+
 use std::cell::Ref;
 use std::ptr::NonNull;
 use std::{slice, str};

diesel/src/sqlite/connection/stmt.rs

@@ -8,7 +8,10 @@ use crate::query_builder::{QueryFragment, QueryId};
 use crate::result::Error::DatabaseError;
 use crate::result::*;
 use crate::sqlite::{Sqlite, SqliteType};
+#[cfg(not(all(target_family = "wasm", not(target_os = "wasi"))))]
 use libsqlite3_sys as ffi;
+#[cfg(all(target_family = "wasm", not(target_os = "wasi")))]
+use sqlite_wasm_rs::c as ffi;
 use std::cell::OnceCell;
 use std::ffi::{CStr, CString};
 use std::io::{stderr, Write};