Create prepared to pass strings via malloc

Author: carlopi

lib/CMakeLists.txt

@@ -327,6 +327,7 @@ if(EMSCRIPTEN)
           _duckdb_web_pending_query_start_buffer, \
           _duckdb_web_prepared_close, \
           _duckdb_web_prepared_create, \
+          _duckdb_web_prepared_create_buffer, \
           _duckdb_web_prepared_run, \
           _duckdb_web_prepared_send, \
           _duckdb_web_query_fetch_results, \

lib/src/webdb_api.cc

@@ -170,6 +170,13 @@ void duckdb_web_prepared_create(WASMResponse* packed, ConnectionHdl connHdl, con
     auto r = c->CreatePreparedStatement(script);
     WASMResponseBuffer::Get().Store(*packed, std::move(r));
 }
+/// Prepare a query statement
+void duckdb_web_prepared_create_buffer(WASMResponse* packed, ConnectionHdl connHdl, const uint8_t* buffer, size_t buffer_length) {
+    auto c = reinterpret_cast<WebDB::Connection*>(connHdl);
+    std::string_view script(reinterpret_cast<const char*>(buffer), buffer_length);
+    auto r = c->CreatePreparedStatement(script);
+    WASMResponseBuffer::Get().Store(*packed, std::move(r));
+}
 /// Close a prepared statement
 void duckdb_web_prepared_close(WASMResponse* packed, ConnectionHdl connHdl, size_t statement_id) {
     auto c = reinterpret_cast<WebDB::Connection*>(connHdl);

packages/duckdb-wasm/src/bindings/bindings_base.ts

@@ -288,7 +288,12 @@ export abstract class DuckDBBindingsBase implements DuckDBBindings {
 
     /** Prepare a statement and return its identifier */
     public createPrepared(conn: number, text: string): number {
-        const [s, d, n] = callSRet(this.mod, 'duckdb_web_prepared_create', ['number', 'string'], [conn, text]);
+        const BUF = TEXT_ENCODER.encode(text);
+        const bufferPtr = this.mod._malloc(BUF.length);
+        const bufferOfs = this.mod.HEAPU8.subarray(bufferPtr, bufferPtr + BUF.length);
+        bufferOfs.set(BUF);
+        const [s, d, n] = callSRet(this.mod, 'duckdb_web_prepared_create_buffer', ['number', 'number', 'number'], [conn, bufferPtr, BUF.length]);
+        this.mod._free(bufferPtr);
         if (s !== StatusCode.SUCCESS) {
             throw new Error(readString(this.mod, d, n));
         }