sqlite: avoid extra copy for large text binds

When binding UTF-8 strings to prepared statements, transfer ownership of the
malloc-backed Utf8Value buffer to SQLite to avoid an extra copy. Also use
sqlite3_bind_blob64() when binding BLOB parameters.

Author: thisalihassan

src/node_sqlite.cc

@@ -2260,20 +2260,41 @@ bool StatementSync::BindValue(const Local<Value>& value, const int index) {
   // Dates could be supported by converting them to numbers. However, there
   // would not be a good way to read the values back from SQLite with the
   // original type.
+  Isolate* isolate = env()->isolate();
   int r;
   if (value->IsNumber()) {
-    double val = value.As<Number>()->Value();
+    const double val = value.As<Number>()->Value();
     r = sqlite3_bind_double(statement_, index, val);
   } else if (value->IsString()) {
-    Utf8Value val(env()->isolate(), value.As<String>());
-    r = sqlite3_bind_text(
-        statement_, index, *val, val.length(), SQLITE_TRANSIENT);
+    Utf8Value val(isolate, value.As<String>());
+    if (val.IsAllocated()) {
+      // Avoid an extra SQLite copy for large strings by transferring ownership
+      // of the malloc()'d buffer to SQLite.
+      char* data = *val;
+      const sqlite3_uint64 length =
+          static_cast<sqlite3_uint64>(val.length());
+      val.Release();
+      r = sqlite3_bind_text64(
+          statement_, index, data, length, std::free, SQLITE_UTF8);
+    } else {
+      // Stack-backed buffer: SQLite must make its own copy.
+      r = sqlite3_bind_text64(statement_,
+                              index,
+                              *val,
+                              static_cast<sqlite3_uint64>(val.length()),
+                              SQLITE_TRANSIENT,
+                              SQLITE_UTF8);
+    }
   } else if (value->IsNull()) {
     r = sqlite3_bind_null(statement_, index);
   } else if (value->IsArrayBufferView()) {
     ArrayBufferViewContents<uint8_t> buf(value);
-    r = sqlite3_bind_blob(
-        statement_, index, buf.data(), buf.length(), SQLITE_TRANSIENT);
+    r = sqlite3_bind_blob64(
+        statement_,
+        index,
+        buf.data(),
+        static_cast<sqlite3_uint64>(buf.length()),
+        SQLITE_TRANSIENT);
   } else if (value->IsBigInt()) {
     bool lossless;
     int64_t as_int = value.As<BigInt>()->Int64Value(&lossless);
@@ -2284,13 +2305,13 @@ bool StatementSync::BindValue(const Local<Value>& value, const int index) {
     r = sqlite3_bind_int64(statement_, index, as_int);
   } else {
     THROW_ERR_INVALID_ARG_TYPE(
-        env()->isolate(),
+        isolate,
         "Provided value cannot be bound to SQLite parameter %d.",
         index);
     return false;
   }
 
-  CHECK_ERROR_OR_THROW(env()->isolate(), db_.get(), r, SQLITE_OK, false);
+  CHECK_ERROR_OR_THROW(isolate, db_.get(), r, SQLITE_OK, false);
   return true;
 }