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-rw-r--r--api/logic/GZip.cpp115
1 files changed, 115 insertions, 0 deletions
diff --git a/api/logic/GZip.cpp b/api/logic/GZip.cpp
new file mode 100644
index 00000000..38605df6
--- /dev/null
+++ b/api/logic/GZip.cpp
@@ -0,0 +1,115 @@
+#include "GZip.h"
+#include <zlib.h>
+#include <QByteArray>
+
+bool GZip::unzip(const QByteArray &compressedBytes, QByteArray &uncompressedBytes)
+{
+ if (compressedBytes.size() == 0)
+ {
+ uncompressedBytes = compressedBytes;
+ return true;
+ }
+
+ unsigned uncompLength = compressedBytes.size();
+ uncompressedBytes.clear();
+ uncompressedBytes.resize(uncompLength);
+
+ z_stream strm;
+ memset(&strm, 0, sizeof(strm));
+ strm.next_in = (Bytef *)compressedBytes.data();
+ strm.avail_in = compressedBytes.size();
+
+ bool done = false;
+
+ if (inflateInit2(&strm, (16 + MAX_WBITS)) != Z_OK)
+ {
+ return false;
+ }
+
+ int err = Z_OK;
+
+ while (!done)
+ {
+ // If our output buffer is too small
+ if (strm.total_out >= uncompLength)
+ {
+ uncompressedBytes.resize(uncompLength * 2);
+ uncompLength *= 2;
+ }
+
+ strm.next_out = (Bytef *)(uncompressedBytes.data() + strm.total_out);
+ strm.avail_out = uncompLength - strm.total_out;
+
+ // Inflate another chunk.
+ err = inflate(&strm, Z_SYNC_FLUSH);
+ if (err == Z_STREAM_END)
+ done = true;
+ else if (err != Z_OK)
+ {
+ break;
+ }
+ }
+
+ if (inflateEnd(&strm) != Z_OK || !done)
+ {
+ return false;
+ }
+
+ uncompressedBytes.resize(strm.total_out);
+ return true;
+}
+
+bool GZip::zip(const QByteArray &uncompressedBytes, QByteArray &compressedBytes)
+{
+ if (uncompressedBytes.size() == 0)
+ {
+ compressedBytes = uncompressedBytes;
+ return true;
+ }
+
+ unsigned compLength = std::min(uncompressedBytes.size(), 16);
+ compressedBytes.clear();
+ compressedBytes.resize(compLength);
+
+ z_stream zs;
+ memset(&zs, 0, sizeof(zs));
+
+ if (deflateInit2(&zs, Z_DEFAULT_COMPRESSION, Z_DEFLATED, (16 + MAX_WBITS), 8, Z_DEFAULT_STRATEGY) != Z_OK)
+ {
+ return false;
+ }
+
+ zs.next_in = (Bytef*)uncompressedBytes.data();
+ zs.avail_in = uncompressedBytes.size();
+
+ int ret;
+ compressedBytes.resize(uncompressedBytes.size());
+
+ unsigned offset = 0;
+ unsigned temp = 0;
+ do
+ {
+ auto remaining = compressedBytes.size() - offset;
+ if(remaining < 1)
+ {
+ compressedBytes.resize(compressedBytes.size() * 2);
+ }
+ zs.next_out = (Bytef *) (compressedBytes.data() + offset);
+ temp = zs.avail_out = compressedBytes.size() - offset;
+ ret = deflate(&zs, Z_FINISH);
+ offset += temp - zs.avail_out;
+ } while (ret == Z_OK);
+
+ compressedBytes.resize(offset);
+
+ if (deflateEnd(&zs) != Z_OK)
+ {
+ return false;
+ }
+
+ if (ret != Z_STREAM_END)
+ {
+ return false;
+ }
+ return true;
+} \ No newline at end of file