DEFLATE = 1,

INFLATE,

GZIP,

GUNZIP,

DEFLATERAW,

INFLATERAW,

UNZIP

public:

ZCtx(node_zlib_mode mode) : ObjectWrap(), dictionary_(NULL), mode_(mode) {}

~ZCtx() {

if (mode_ == DEFLATE || mode_ == GZIP || mode_ == DEFLATERAW) {

(void)deflateEnd(&strm_);

} else if (mode_ == INFLATE || mode_ == GUNZIP || mode_ == INFLATERAW) {

(void)inflateEnd(&strm_);

}

if (dictionary_ != NULL) delete[] dictionary_;

}

// write(flush, in, in_off, in_len, out, out_off, out_len)

static Handle<Value> Write(const Arguments& args) {

HandleScope scope;

assert(args.Length() == 7);

ZCtx *ctx = ObjectWrap::Unwrap<ZCtx>(args.This());

assert(ctx->init_done_ && "write before init");

assert(!ctx->write_in_progress_ && "write already in progress");

ctx->write_in_progress_ = true;

unsigned int flush = args[0]->Uint32Value();

Bytef *in;

Bytef *out;

size_t in_off, in_len, out_off, out_len;

if (args[1]->IsNull()) {

// just a flush

Bytef nada[1] = { 0 };

in = nada;

in_len = 0;

in_off = 0;

} else {

assert(Buffer::HasInstance(args[1]));

Local<Object> in_buf;

in_buf = args[1]->ToObject();

in_off = args[2]->Uint32Value();

in_len = args[3]->Uint32Value();

assert(in_off + in_len <= Buffer::Length(in_buf));

in = reinterpret_cast<Bytef *>(Buffer::Data(in_buf) + in_off);

}

assert(Buffer::HasInstance(args[4]));

Local<Object> out_buf = args[4]->ToObject();

out_off = args[5]->Uint32Value();

out_len = args[6]->Uint32Value();

assert(out_off + out_len <= Buffer::Length(out_buf));

out = reinterpret_cast<Bytef *>(Buffer::Data(out_buf) + out_off);

// build up the work request

uv_work_t* work_req = &(ctx->work_req_);

ctx->strm_.avail_in = in_len;

ctx->strm_.next_in = in;

ctx->strm_.avail_out = out_len;

ctx->strm_.next_out = out;

ctx->flush_ = flush;

// set this so that later on, I can easily tell how much was written.

ctx->chunk_size_ = out_len;

uv_queue_work(uv_default_loop(),

work_req,

ZCtx::Process,

ZCtx::After);

ctx->Ref();

return ctx->handle_;

}

// thread pool!

// This function may be called multiple times on the uv_work pool

// for a single write() call, until all of the input bytes have

// been consumed.

static void Process(uv_work_t* work_req) {

ZCtx *ctx = container_of(work_req, ZCtx, work_req_);

// If the avail_out is left at 0, then it means that it ran out

// of room. If there was avail_out left over, then it means

// that all of the input was consumed.

switch (ctx->mode_) {

case DEFLATE:

case GZIP:

case DEFLATERAW:

ctx->err_ = deflate(&ctx->strm_, ctx->flush_);

break;

case UNZIP:

case INFLATE:

case GUNZIP:

case INFLATERAW:

ctx->err_ = inflate(&ctx->strm_, ctx->flush_);

// If data was encoded with dictionary

if (ctx->err_ == Z_NEED_DICT) {

assert(ctx->dictionary_ != NULL && "Stream has no dictionary");

if (ctx->dictionary_ != NULL) {

// Load it

ctx->err_ = inflateSetDictionary(&ctx->strm_,

ctx->dictionary_,

ctx->dictionary_len_);

assert(ctx->err_ == Z_OK && "Failed to set dictionary");

if (ctx->err_ == Z_OK) {

// And try to decode again

ctx->err_ = inflate(&ctx->strm_, ctx->flush_);

}

}

}

break;

default:

assert(0 && "wtf?");

}

// pass any errors back to the main thread to deal with.

// now After will emit the output, and

// either schedule another call to Process,

// or shift the queue and call Process.

}

// v8 land!

static void After(uv_work_t* work_req) {

HandleScope scope;

ZCtx *ctx = container_of(work_req, ZCtx, work_req_);

// Acceptable error states depend on the type of zlib stream.

switch (ctx->err_) {

case Z_OK:

case Z_STREAM_END:

case Z_BUF_ERROR:

// normal statuses, not fatal

break;

default:

// something else.

ZCtx::Error(ctx, "Zlib error");

return;

}

Local<Integer> avail_out = Integer::New(ctx->strm_.avail_out);

Local<Integer> avail_in = Integer::New(ctx->strm_.avail_in);

ctx->write_in_progress_ = false;

// call the write() cb

assert(ctx->handle_->Get(callback_sym)->IsFunction() &&

"Invalid callback");

Local<Value> args[2] = { avail_in, avail_out };

MakeCallback(ctx->handle_, callback_sym, ARRAY_SIZE(args), args);

ctx->Unref();

}

static void Error(ZCtx *ctx, const char *msg_) {

const char *msg;

if (ctx->strm_.msg != NULL) {

msg = ctx->strm_.msg;

} else {

msg = msg_;

}

assert(ctx->handle_->Get(onerror_sym)->IsFunction() &&

"Invalid error handler");

HandleScope scope;

Local<Value> args[2] = { String::New(msg),

Local<Value>::New(Number::New(ctx->err_)) };

MakeCallback(ctx->handle_, onerror_sym, ARRAY_SIZE(args), args);

// no hope of rescue.

ctx->Unref();

}

static Handle<Value> New(const Arguments& args) {

HandleScope scope;

if (args.Length() < 1 || !args[0]->IsInt32()) {

return ThrowException(Exception::TypeError(String::New("Bad argument")));

}

node_zlib_mode mode = (node_zlib_mode) args[0]->Int32Value();

if (mode < DEFLATE || mode > UNZIP) {

return ThrowException(Exception::TypeError(String::New("Bad argument")));

}

ZCtx *ctx = new ZCtx(mode);

ctx->Wrap(args.This());

return args.This();

}

// just pull the ints out of the args and call the other Init

static Handle<Value> Init(const Arguments& args) {

HandleScope scope;

assert((args.Length() == 4 || args.Length() == 5) &&

"init(windowBits, level, memLevel, strategy, [dictionary])");

ZCtx *ctx = ObjectWrap::Unwrap<ZCtx>(args.This());

int windowBits = args[0]->Uint32Value();

assert((windowBits >= 8 && windowBits <= 15) && "invalid windowBits");

int level = args[1]->Uint32Value();

assert((level >= -1 && level <= 9) && "invalid compression level");

int memLevel = args[2]->Uint32Value();

assert((memLevel >= 1 && memLevel <= 9) && "invalid memlevel");

int strategy = args[3]->Uint32Value();

assert((strategy == Z_FILTERED ||

strategy == Z_HUFFMAN_ONLY ||

strategy == Z_RLE ||

strategy == Z_FIXED ||

strategy == Z_DEFAULT_STRATEGY) && "invalid strategy");

char* dictionary = NULL;

size_t dictionary_len = 0;

if (args.Length() >= 5 && Buffer::HasInstance(args[4])) {

Local<Object> dictionary_ = args[4]->ToObject();

dictionary_len = Buffer::Length(dictionary_);

dictionary = new char[dictionary_len];

memcpy(dictionary, Buffer::Data(dictionary_), dictionary_len);

}

Init(ctx, level, windowBits, memLevel, strategy,

dictionary, dictionary_len);

SetDictionary(ctx);

return Undefined();

}

static Handle<Value> Reset(const Arguments &args) {

HandleScope scope;

ZCtx *ctx = ObjectWrap::Unwrap<ZCtx>(args.This());

Reset(ctx);

SetDictionary(ctx);

return Undefined();

}

static void Init(ZCtx *ctx, int level, int windowBits, int memLevel,

int strategy, char* dictionary, size_t dictionary_len) {

ctx->level_ = level;

ctx->windowBits_ = windowBits;

ctx->memLevel_ = memLevel;

ctx->strategy_ = strategy;

ctx->strm_.zalloc = Z_NULL;

ctx->strm_.zfree = Z_NULL;

ctx->strm_.opaque = Z_NULL;

ctx->flush_ = Z_NO_FLUSH;

ctx->err_ = Z_OK;

if (ctx->mode_ == GZIP || ctx->mode_ == GUNZIP) {

ctx->windowBits_ += 16;

}

if (ctx->mode_ == UNZIP) {

ctx->windowBits_ += 32;

}

if (ctx->mode_ == DEFLATERAW || ctx->mode_ == INFLATERAW) {

ctx->windowBits_ *= -1;

}

switch (ctx->mode_) {

case DEFLATE:

case GZIP:

case DEFLATERAW:

ctx->err_ = deflateInit2(&ctx->strm_,

ctx->level_,

Z_DEFLATED,

ctx->windowBits_,

ctx->memLevel_,

ctx->strategy_);

break;

case INFLATE:

case GUNZIP:

case INFLATERAW:

case UNZIP:

ctx->err_ = inflateInit2(&ctx->strm_, ctx->windowBits_);

break;

default:

assert(0 && "wtf?");

}

if (ctx->err_ != Z_OK) {

ZCtx::Error(ctx, "Init error");

}

ctx->dictionary_ = reinterpret_cast<Bytef *>(dictionary);

ctx->dictionary_len_ = dictionary_len;

ctx->write_in_progress_ = false;

ctx->init_done_ = true;

}

static void SetDictionary(ZCtx* ctx) {

if (ctx->dictionary_ == NULL) return;

ctx->err_ = Z_OK;

switch (ctx->mode_) {

case DEFLATE:

case DEFLATERAW:

ctx->err_ = deflateSetDictionary(&ctx->strm_,

ctx->dictionary_,

ctx->dictionary_len_);

break;

default:

break;

}

if (ctx->err_ != Z_OK) {

ZCtx::Error(ctx, "Failed to set dictionary");

}

}

static void Reset(ZCtx* ctx) {

ctx->err_ = Z_OK;

switch (ctx->mode_) {

case DEFLATE:

case DEFLATERAW:

ctx->err_ = deflateReset(&ctx->strm_);

break;

case INFLATE:

case INFLATERAW:

ctx->err_ = inflateReset(&ctx->strm_);

break;

default:

break;

}

if (ctx->err_ != Z_OK) {

ZCtx::Error(ctx, "Failed to reset stream");

}

}

private:

bool init_done_;

z_stream strm_;

int level_;

int windowBits_;

int memLevel_;

int strategy_;

int err_;

Bytef* dictionary_;

size_t dictionary_len_;

int flush_;

int chunk_size_;

bool write_in_progress_;

uv_work_t work_req_;

node_zlib_mode mode_;

HandleScope scope;

Local<FunctionTemplate> z = FunctionTemplate::New(ZCtx::New);

z->InstanceTemplate()->SetInternalFieldCount(1);

NODE_SET_PROTOTYPE_METHOD(z, "write", ZCtx::Write);

NODE_SET_PROTOTYPE_METHOD(z, "init", ZCtx::Init);

NODE_SET_PROTOTYPE_METHOD(z, "reset", ZCtx::Reset);

z->SetClassName(String::NewSymbol("Zlib"));

target->Set(String::NewSymbol("Zlib"), z->GetFunction());

callback_sym = NODE_PSYMBOL("callback");

onerror_sym = NODE_PSYMBOL("onerror");

NODE_DEFINE_CONSTANT(target, Z_NO_FLUSH);

NODE_DEFINE_CONSTANT(target, Z_PARTIAL_FLUSH);

NODE_DEFINE_CONSTANT(target, Z_SYNC_FLUSH);

NODE_DEFINE_CONSTANT(target, Z_FULL_FLUSH);

NODE_DEFINE_CONSTANT(target, Z_FINISH);

NODE_DEFINE_CONSTANT(target, Z_BLOCK);

// return/error codes

NODE_DEFINE_CONSTANT(target, Z_OK);

NODE_DEFINE_CONSTANT(target, Z_STREAM_END);

NODE_DEFINE_CONSTANT(target, Z_NEED_DICT);

NODE_DEFINE_CONSTANT(target, Z_ERRNO);

NODE_DEFINE_CONSTANT(target, Z_STREAM_ERROR);

NODE_DEFINE_CONSTANT(target, Z_DATA_ERROR);

NODE_DEFINE_CONSTANT(target, Z_MEM_ERROR);

NODE_DEFINE_CONSTANT(target, Z_BUF_ERROR);

NODE_DEFINE_CONSTANT(target, Z_VERSION_ERROR);

NODE_DEFINE_CONSTANT(target, Z_NO_COMPRESSION);

NODE_DEFINE_CONSTANT(target, Z_BEST_SPEED);

NODE_DEFINE_CONSTANT(target, Z_BEST_COMPRESSION);

NODE_DEFINE_CONSTANT(target, Z_DEFAULT_COMPRESSION);

NODE_DEFINE_CONSTANT(target, Z_FILTERED);

NODE_DEFINE_CONSTANT(target, Z_HUFFMAN_ONLY);

NODE_DEFINE_CONSTANT(target, Z_RLE);

NODE_DEFINE_CONSTANT(target, Z_FIXED);

NODE_DEFINE_CONSTANT(target, Z_DEFAULT_STRATEGY);

NODE_DEFINE_CONSTANT(target, ZLIB_VERNUM);

NODE_DEFINE_CONSTANT(target, DEFLATE);

NODE_DEFINE_CONSTANT(target, INFLATE);

NODE_DEFINE_CONSTANT(target, GZIP);

NODE_DEFINE_CONSTANT(target, GUNZIP);

NODE_DEFINE_CONSTANT(target, DEFLATERAW);

NODE_DEFINE_CONSTANT(target, INFLATERAW);

NODE_DEFINE_CONSTANT(target, UNZIP);

target->Set(String::NewSymbol("ZLIB_VERSION"), String::New(ZLIB_VERSION));