Begin to add node-addon-api for sherpa-onnx (#826)

scripts/node-addon-api/src/wave-reader.cc

@@ -0,0 +1,57 @@
+// scripts/node-addon-api/src/wave-reader.cc
+//
+// Copyright (c)  2024  Xiaomi Corporation
+
+#include <sstream>
+
+#include "napi.h"  // NOLINT
+#include "sherpa-onnx/c-api/c-api.h"
+
+static Napi::Object ReadWaveWrapper(const Napi::CallbackInfo &info) {
+  Napi::Env env = info.Env();
+  if (info.Length() != 1) {
+    std::ostringstream os;
+    os << "Expect only 1 argument. Given: " << info.Length();
+
+    Napi::TypeError::New(env, os.str()).ThrowAsJavaScriptException();
+
+    return {};
+  }
+  if (!info[0].IsString()) {
+    Napi::TypeError::New(env, "Argument should be a string")
+        .ThrowAsJavaScriptException();
+
+    return {};
+  }
+
+  std::string filename = info[0].As<Napi::String>().Utf8Value();
+
+  const SherpaOnnxWave *wave = SherpaOnnxReadWave(filename.c_str());
+  if (!wave) {
+    std::ostringstream os;
+    os << "Failed to read '" << filename << "'";
+    Napi::TypeError::New(env, os.str()).ThrowAsJavaScriptException();
+
+    return {};
+  }
+
+  Napi::ArrayBuffer arrayBuffer = Napi::ArrayBuffer::New(
+      env, const_cast<float *>(wave->samples),
+      sizeof(float) * wave->num_samples,
+      [](Napi::Env /*env*/, void * /*data*/, const SherpaOnnxWave *hint) {
+        SherpaOnnxFreeWave(hint);
+      },
+      wave);
+  Napi::Float32Array float32Array =
+      Napi::Float32Array::New(env, wave->num_samples, arrayBuffer, 0);
+
+  Napi::Object obj = Napi::Object::New(env);
+  obj.Set(Napi::String::New(env, "samples"), float32Array);
+  obj.Set(Napi::String::New(env, "sampleRate"), wave->sample_rate);
+  return obj;
+}
+
+void InitWaveReader(Napi::Env env, Napi::Object exports) {
+  exports.Set(Napi::String::New(env, "readWave"),
+              Napi::Function::New(env, ReadWaveWrapper));
+}