1#include <node.h>
2#include <node_buffer.h>
3#include <zlib.h>
4#include <assert.h>
5
6namespace {
7
8inline void CompressBytes(const v8::FunctionCallbackInfo<v8::Value>& info) {
9  assert(info[0]->IsArrayBufferView());
10  auto view = info[0].As<v8::ArrayBufferView>();
11  auto byte_offset = view->ByteOffset();
12  auto byte_length = view->ByteLength();
13  assert(view->HasBuffer());
14  auto buffer = view->Buffer();
15  auto contents = buffer->GetBackingStore();
16  auto data = static_cast<unsigned char*>(contents->Data()) + byte_offset;
17
18  Bytef buf[1024];
19
20  z_stream stream;
21  stream.zalloc = nullptr;
22  stream.zfree = nullptr;
23
24  int err = deflateInit2(&stream, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
25                         -15, MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
26  assert(err == Z_OK);
27
28  stream.avail_in = byte_length;
29  stream.next_in = data;
30  stream.avail_out = sizeof(buf);
31  stream.next_out = buf;
32  err = deflate(&stream, Z_FINISH);
33  assert(err == Z_STREAM_END);
34
35  auto result = node::Buffer::Copy(info.GetIsolate(),
36                                   reinterpret_cast<const char*>(buf),
37                                   sizeof(buf) - stream.avail_out);
38
39  deflateEnd(&stream);
40
41  info.GetReturnValue().Set(result.ToLocalChecked());
42}
43
44inline void Initialize(v8::Local<v8::Object> exports,
45                       v8::Local<v8::Value> module,
46                       v8::Local<v8::Context> context) {
47  auto isolate = context->GetIsolate();
48  auto key = v8::String::NewFromUtf8(
49      isolate, "compressBytes").ToLocalChecked();
50  auto value = v8::FunctionTemplate::New(isolate, CompressBytes)
51                   ->GetFunction(context)
52                   .ToLocalChecked();
53  assert(exports->Set(context, key, value).IsJust());
54}
55
56}  // anonymous namespace
57
58NODE_MODULE_CONTEXT_AWARE(NODE_GYP_MODULE_NAME, Initialize)
59