initial code repo

[stor4nfv.git] / src / ceph / src / compressor / zstd / ZstdCompressor.h

diff --git a/src/ceph/src/compressor/zstd/ZstdCompressor.h b/src/ceph/src/compressor/zstd/ZstdCompressor.h
new file mode 100644 (file)
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--- /dev/null
+++ b/src/ceph/src/compressor/zstd/ZstdCompressor.h
@@ -0,0 +1,99 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2015 Haomai Wang <haomaiwang@gmail.com>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#ifndef CEPH_ZSTDCOMPRESSOR_H
+#define CEPH_ZSTDCOMPRESSOR_H
+
+#include "zstd/lib/zstd.h"
+#include "include/buffer.h"
+#include "include/encoding.h"
+#include "compressor/Compressor.h"
+
+#define COMPRESSION_LEVEL 5
+
+class ZstdCompressor : public Compressor {
+ public:
+  ZstdCompressor() : Compressor(COMP_ALG_ZSTD, "zstd") {}
+
+  int compress(const bufferlist &src, bufferlist &dst) override {
+    bufferptr outptr = buffer::create_page_aligned(
+      ZSTD_compressBound(src.length()));
+    ZSTD_outBuffer_s outbuf;
+    outbuf.dst = outptr.c_str();
+    outbuf.size = outptr.length();
+    outbuf.pos = 0;
+
+    ZSTD_CStream *s = ZSTD_createCStream();
+    ZSTD_initCStream(s, COMPRESSION_LEVEL);
+    auto p = src.begin();
+    size_t left = src.length();
+    while (left) {
+      assert(!p.end());
+      struct ZSTD_inBuffer_s inbuf;
+      inbuf.pos = 0;
+      inbuf.size = p.get_ptr_and_advance(left, (const char**)&inbuf.src);
+      ZSTD_compressStream(s, &outbuf, &inbuf);
+      left -= inbuf.size;
+    }
+    assert(p.end());
+    ZSTD_flushStream(s, &outbuf);
+    ZSTD_endStream(s, &outbuf);
+    ZSTD_freeCStream(s);
+
+    // prefix with decompressed length
+    ::encode((uint32_t)src.length(), dst);
+    dst.append(outptr, 0, outbuf.pos);
+    return 0;
+  }
+
+  int decompress(const bufferlist &src, bufferlist &dst) override {
+    bufferlist::iterator i = const_cast<bufferlist&>(src).begin();
+    return decompress(i, src.length(), dst);
+  }
+
+  int decompress(bufferlist::iterator &p,
+                size_t compressed_len,
+                bufferlist &dst) override {
+    if (compressed_len < 4) {
+      return -1;
+    }
+    compressed_len -= 4;
+    uint32_t dst_len;
+    ::decode(dst_len, p);
+
+    bufferptr dstptr(dst_len);
+    ZSTD_outBuffer_s outbuf;
+    outbuf.dst = dstptr.c_str();
+    outbuf.size = dstptr.length();
+    outbuf.pos = 0;
+    ZSTD_DStream *s = ZSTD_createDStream();
+    ZSTD_initDStream(s);
+    while (compressed_len > 0) {
+      if (p.end()) {
+       return -1;
+      }
+      ZSTD_inBuffer_s inbuf;
+      inbuf.pos = 0;
+      inbuf.size = p.get_ptr_and_advance(compressed_len, (const char**)&inbuf.src);
+      ZSTD_decompressStream(s, &outbuf, &inbuf);
+      compressed_len -= inbuf.size;
+    }
+    ZSTD_freeDStream(s);
+
+    dst.append(dstptr, 0, outbuf.pos);
+    return 0;
+  }
+};
+
+#endif