From: Adam Kupczyk <akupczyk@mirantis.com>
Date: Fri, 30 Sep 2016 09:26:29 +0000 (+0200)
Subject: Fixed problem with snappy compressor when data size <=3.
X-Git-Tag: v11.1.0~429^2~11
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=262f6683c0c6a0a908964f1eed97ee2361eef74d;p=ceph.git

Fixed problem with snappy compressor when data size <=3.

Signed-off-by: Adam Kupczyk <akupczyk@mirantis.com>
---

diff --git a/src/compressor/snappy/SnappyCompressor.h b/src/compressor/snappy/SnappyCompressor.h
index dadd17902b8b..aa377b510ac3 100644
--- a/src/compressor/snappy/SnappyCompressor.h
+++ b/src/compressor/snappy/SnappyCompressor.h
@@ -76,23 +76,15 @@ class SnappyCompressor : public Compressor {
   int decompress(bufferlist::iterator &p,
 		 size_t compressed_len,
 		 bufferlist &dst) override {
-    size_t res_len = 0;
-    // Trick, decompress only need first few bytes of buffer.  note
-    // that 4 bytes is *not* enough.. it works for small buffers (a
-    // few MB), but not large ones (~260 MB), because the 32-bit value
-    // is encoded as a varint.  From snappy.cc:
-    //     if (Varint::Parse32WithLimit(start, limit, &v) != NULL) {
-    // 8 bytes is enough.
-    bufferlist::const_iterator ptmp = p;
-    bufferlist tmp;
-    ptmp.copy(std::min(8lu, compressed_len), tmp);
-    if (!snappy::GetUncompressedLength(tmp.c_str(), tmp.length(), &res_len)) {
+    snappy::uint32 res_len = 0;
+    BufferlistSource source_1(p, compressed_len);
+    if (!snappy::GetUncompressedLength(&source_1, &res_len)) {
       return -1;
     }
-    BufferlistSource source(p, compressed_len);
+    BufferlistSource source_2(p, compressed_len);
     bufferptr ptr(res_len);
-    if (snappy::RawUncompress(&source, ptr.c_str())) {
-      p = source.get_pos();
+    if (snappy::RawUncompress(&source_2, ptr.c_str())) {
+      p = source_2.get_pos();
       dst.append(ptr);
       return 0;
     }