Added support for gzip accepted_encoding in scgi headers.

src/utils/gzip.cc

@@ -0,0 +1,41 @@
+#include "config.h"
+
+#include "utils/gzip.h"
+
+#include <zlib.h>
+#include <torrent/exceptions.h>
+
+namespace utils {
+
+void
+gzip_compress_to_vector(const char* buffer, unsigned int length, std::vector<char>& output, unsigned int offset) {
+  z_stream zs{};
+  zs.zalloc = Z_NULL;
+  zs.zfree  = Z_NULL;
+  zs.opaque = Z_NULL;
+
+  constexpr int window_bits   = 15;
+  constexpr int gzip_encoding = 16;
+  constexpr int gzip_level    = 6;
+
+  if (deflateInit2(&zs, Z_DEFAULT_COMPRESSION, Z_DEFLATED, window_bits | gzip_encoding, gzip_level, Z_DEFAULT_STRATEGY) != Z_OK)
+    throw torrent::internal_error("gzip_compress_to_vector(...) could not initialize gzip deflate.");
+
+  auto max_response_size = deflateBound(&zs, length);
+
+  output.resize(offset + max_response_size);
+
+  zs.next_in  = (Bytef*)buffer;
+  zs.avail_in = length;
+  zs.next_out  = (Bytef*)(output.data() + offset);
+  zs.avail_out = max_response_size;
+
+  int ret = deflate(&zs, Z_FINISH);
+
+  if (ret != Z_STREAM_END)
+    throw torrent::internal_error("gzip_compress_to_vector(...) deflate did not return Z_STREAM_END: " + std::to_string(ret));
+
+  output.resize(offset + max_response_size - zs.avail_out);
+}
+
+} // namespace utils

src/utils/gzip.h

@@ -0,0 +1,12 @@
+#ifndef RTORRENT_UTILS_GZIP_H
+#define RTORRENT_UTILS_GZIP_H
+
+#include <functional>
+
+namespace utils {
+
+void gzip_compress_to_vector(const char* buffer, unsigned int length, std::vector<char>& output, unsigned int offset = 0);
+
+} // namespace utils
+
+#endif