Initial commit of experimental zstd network compression

currently a bit buggy

1 files changed, 84 insertions, 0 deletions

diff --git a/source/core/StarZSTDCompression.cpp b/source/core/StarZSTDCompression.cpp
new file mode 100644
index 0000000..733b182
--- /dev/null
+++ b/source/core/StarZSTDCompression.cpp
@@ -0,0 +1,84 @@
+#include "StarZSTDCompression.hpp"
+#include <zstd.h>
+
+namespace Star {
+
+CompressionStream::CompressionStream() : m_cStream(ZSTD_createCStream()) {
+  ZSTD_CCtx_setParameter(m_cStream, ZSTD_c_enableLongDistanceMatching, 1);
+  ZSTD_CCtx_setParameter(m_cStream, ZSTD_c_windowLog, 24);
+  ZSTD_initCStream(m_cStream, 2);
+}
+
+CompressionStream::~CompressionStream() { ZSTD_freeCStream(m_cStream); }
+
+ByteArray CompressionStream::compress(const char* in, size_t inLen) {
+  size_t const cInSize  = ZSTD_CStreamInSize ();
+  size_t const cOutSize = ZSTD_CStreamOutSize();
+  ByteArray output(cOutSize, 0);
+  size_t written = 0, read = 0;
+  while (read < inLen) {
+    ZSTD_inBuffer inBuffer = {in + read, min(cInSize, inLen - read), 0};
+    ZSTD_outBuffer outBuffer = {output.ptr() + written, output.size() - written, 0};
+    bool finished = false;
+    do {
+      size_t ret = ZSTD_compressStream2(m_cStream, &outBuffer, &inBuffer, ZSTD_e_flush);
+      if (ZSTD_isError(ret)) {
+        throw IOException(strf("ZSTD compression error {}", ZSTD_getErrorName(ret)));
+        break;
+      }
+
+      if (outBuffer.pos == outBuffer.size) {
+        output.resize(output.size() * 2);
+        outBuffer.dst = output.ptr();
+        outBuffer.size = output.size();
+        continue;
+      }
+
+      finished = ret == 0 && inBuffer.pos == inBuffer.size;
+    } while (!finished);
+
+    read += inBuffer.pos;
+    written += outBuffer.pos;
+  }
+  output.resize(written);
+  return output;
+}
+
+DecompressionStream::DecompressionStream() : m_dStream(ZSTD_createDStream()) {
+  ZSTD_DCtx_setParameter(m_dStream, ZSTD_d_windowLogMax, 25);
+  ZSTD_initDStream(m_dStream);
+}
+
+DecompressionStream::~DecompressionStream() { ZSTD_freeDStream(m_dStream); }
+
+ByteArray DecompressionStream::decompress(const char* in, size_t inLen) {
+  size_t const dInSize  = ZSTD_DStreamInSize ();
+  size_t const dOutSize = ZSTD_DStreamOutSize();
+  ByteArray output(dOutSize, 0);
+  size_t written = 0, read = 0;
+  while (read < inLen) {
+    ZSTD_inBuffer inBuffer = {in + read, min(dInSize, inLen - read), 0};
+    ZSTD_outBuffer outBuffer = {output.ptr() + written, output.size() - written, 0};
+    do {
+      size_t ret = ZSTD_decompressStream(m_dStream, &outBuffer, &inBuffer);
+      if (ZSTD_isError(ret)) {
+        throw IOException(strf("ZSTD decompression error {}", ZSTD_getErrorName(ret)));
+        break;
+      }
+
+      if (outBuffer.pos == outBuffer.size) {
+        output.resize(output.size() * 2);
+        outBuffer.dst = output.ptr();
+        outBuffer.size = output.size();
+        continue;
+      }
+    } while (inBuffer.pos < inBuffer.size);
+
+    read += inBuffer.pos;
+    written += outBuffer.pos;
+  }
+  output.resize(written);
+  return output;
+}
+
+}
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