1+ #pragma once
2+ #include " generic_compression.h"
3+ #include " zlib-ng/zlib-ng.h"
4+ #include < array>
5+ #include < queue>
6+
7+ namespace SleepyDiscord {
8+ class ZLibCompression : public GenericCompression {
9+ public:
10+ bool uncompress (const std::string& compressed, std::string& uncompressedOut) override {
11+ auto stream = zng_stream{};
12+ memset (&stream, 0 , sizeof (stream));
13+ int output = zng_inflateInit (&stream);
14+ if (output != Z_OK) {
15+ zng_inflateEnd (&stream);
16+ return false ;
17+ }
18+
19+ stream.next_in = reinterpret_cast <const uint8_t *>(compressed.data ());
20+ stream.avail_in = static_cast <uint32_t >(compressed.length ());
21+
22+ constexpr size_t chunkSize = 16 * 1024 ;
23+ using Data = std::array<char , chunkSize>;
24+ using Buffer = std::pair<Data, std::size_t >;
25+ std::list<Buffer> outputQueue;
26+
27+ bool makeNewBuffer = true ;
28+ std::size_t totalSize = 0 ;
29+ output = Z_BUF_ERROR;
30+ do {
31+ if (makeNewBuffer == true ) {
32+ outputQueue.emplace_back (); // make a new output buffer
33+ makeNewBuffer = false ;
34+ }
35+ Buffer& buffer = outputQueue.back ();
36+ Data& data = buffer.first ;
37+ std::size_t size = buffer.second ;
38+
39+ stream.next_out = reinterpret_cast <uint8_t *>(&data[size]);
40+ stream.avail_out = static_cast <uint32_t >(data.max_size () - size);
41+
42+ output = zng_inflate (&stream, Z_SYNC_FLUSH);
43+
44+ auto oldSize = size;
45+ size = data.max_size () - stream.avail_out ;
46+ buffer.second = size;
47+ auto deltaSize = size - oldSize;
48+ totalSize += deltaSize;
49+
50+ if (output == Z_STREAM_END) {
51+ output = zng_inflateEnd (&stream);
52+ break ;
53+ } else if (deltaSize == 0 ) {
54+ makeNewBuffer = true ;
55+ }
56+ } while (output == Z_OK || output == Z_BUF_ERROR);
57+
58+ uncompressedOut.clear ();
59+ uncompressedOut.reserve (totalSize);
60+ for (; 0 < outputQueue.size (); outputQueue.pop_front ()) {
61+ Buffer& buffer = outputQueue.front ();
62+ Data& data = buffer.first ;
63+ std::size_t size = buffer.second ;
64+
65+ uncompressedOut.append (data.data (), size);
66+ }
67+
68+ return true ;
69+ }
70+ };
71+
72+ using DefaultCompression = ZLibCompression;
73+ #define SLEEPY_DEFAULT_COMPRESSION ZLibCompression
74+ }
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