From 616b8229b68e609c9252e24f8bc4d499497613ab Mon Sep 17 00:00:00 2001
From: Snappy Team <no-reply@google.com>
Date: Wed, 18 Nov 2020 21:10:24 +0000
Subject: [PATCH] Add LZ4 as a benchmark option. Snappy is starting to look
 really good compared to LZ4. LZ4 is considered the fastest solution by many
 on internet. We now see that Snappy is actually becoming very competitive
 with compression a little faster and decompression slower but certainly not
 terribly slower.

PiperOrigin-RevId: 343140860
---
 CMakeLists.txt     |  4 ++++
 snappy-test.h      |  4 ++++
 snappy_unittest.cc | 46 +++++++++++++++++++++++++++++++++++++---------
 3 files changed, 45 insertions(+), 9 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7d9f542..4bd15f8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -108,6 +108,7 @@ check_include_file("windows.h" HAVE_WINDOWS_H)
 include(CheckLibraryExists)
 check_library_exists(z zlibVersion "" HAVE_LIBZ)
 check_library_exists(lzo2 lzo1x_1_15_compress "" HAVE_LIBLZO2)
+check_library_exists(lz4 LZ4_compress_default "" HAVE_LIBLZ4)
 
 include(CheckCXXCompilerFlag)
 CHECK_CXX_COMPILER_FLAG("/arch:AVX" HAVE_VISUAL_STUDIO_ARCH_AVX)
@@ -268,6 +269,9 @@ if(SNAPPY_BUILD_TESTS)
   if(HAVE_LIBLZO2)
     target_link_libraries(snappy_unittest lzo2)
   endif(HAVE_LIBLZO2)
+  if(HAVE_LIBLZ4)
+    target_link_libraries(snappy_unittest lz4)
+  endif(HAVE_LIBLZ4)
 
   target_include_directories(snappy_unittest
     BEFORE PRIVATE
diff --git a/snappy-test.h b/snappy-test.h
index b5a53b5..09d5bde 100644
--- a/snappy-test.h
+++ b/snappy-test.h
@@ -107,6 +107,10 @@
 #include "lzo/lzo1x.h"
 #endif
 
+#ifdef HAVE_LIBLZ4
+#include "lz4.h"
+#endif
+
 namespace {
 
 namespace file {
diff --git a/snappy_unittest.cc b/snappy_unittest.cc
index 0e207db..3b1b43f 100644
--- a/snappy_unittest.cc
+++ b/snappy_unittest.cc
@@ -51,6 +51,7 @@ DEFINE_bool(zlib, false,
             "Run zlib compression (http://www.zlib.net)");
 DEFINE_bool(lzo, false,
             "Run LZO compression (http://www.oberhumer.com/opensource/lzo/)");
+DEFINE_bool(lz4, false, "Run LZ4 compression (https://github.com/lz4/lz4)");
 DEFINE_bool(snappy, true, "Run snappy compression");
 
 DEFINE_bool(write_compressed, false,
@@ -116,13 +117,9 @@ using DataEndingAtUnreadablePage = std::string;
 
 #endif
 
-enum CompressorType {
-  ZLIB, LZO, SNAPPY
-};
+enum CompressorType { ZLIB, LZO, LZ4, SNAPPY };
 
-const char* names[] = {
-  "ZLIB", "LZO", "SNAPPY"
-};
+const char* names[] = {"ZLIB", "LZO", "LZ4", "SNAPPY"};
 
 static size_t MinimumRequiredOutputSpace(size_t input_size,
                                          CompressorType comp) {
@@ -137,6 +134,11 @@ static size_t MinimumRequiredOutputSpace(size_t input_size,
       return input_size + input_size/64 + 16 + 3;
 #endif  // LZO_VERSION
 
+#ifdef LZ4_VERSION_NUMBER
+    case LZ4:
+      return LZ4_compressBound(input_size);
+#endif  // LZ4_VERSION_NUMBER
+
     case SNAPPY:
       return snappy::MaxCompressedLength(input_size);
 
@@ -196,6 +198,19 @@ static bool Compress(const char* input, size_t input_size, CompressorType comp,
     }
 #endif  // LZO_VERSION
 
+#ifdef LZ4_VERSION_NUMBER
+    case LZ4: {
+      lzo_uint destlen = compressed->size();
+      destlen = LZ4_compress_default(input, string_as_array(compressed),
+                                     input_size, destlen);
+      CHECK(destlen != 0);
+      if (!compressed_is_preallocated) {
+        compressed->resize(destlen);
+      }
+      break;
+    }
+#endif  // LZ4_VERSION_NUMBER
+
     case SNAPPY: {
       size_t destlen;
       snappy::RawCompress(input, input_size,
@@ -250,6 +265,18 @@ static bool Uncompress(const std::string& compressed, CompressorType comp,
     }
 #endif  // LZO_VERSION
 
+#ifdef LZ4_VERSION_NUMBER
+    case LZ4: {
+      output->resize(size);
+      ZLib zlib;
+      uLongf destlen = output->size();
+      destlen = LZ4_decompress_safe(compressed.data(), string_as_array(output),
+                                    compressed.size(), destlen);
+      CHECK(destlen != 0);
+      CHECK_EQ(size, destlen);
+      break;
+    }
+#endif  // LZ4_VERSION_NUMBER
     case SNAPPY: {
       snappy::RawUncompress(compressed.data(), compressed.size(),
                             string_as_array(output));
@@ -1223,9 +1250,10 @@ static void MeasureFile(const char* fname) {
   for (int len = start_len; len <= end_len; ++len) {
     const char* const input = fullinput.data();
     int repeats = (FLAGS_bytes + len) / (len + 1);
-    if (FLAGS_zlib)     Measure(input, len, ZLIB, repeats, 1024<<10);
-    if (FLAGS_lzo)      Measure(input, len, LZO, repeats, 1024<<10);
-    if (FLAGS_snappy)    Measure(input, len, SNAPPY, repeats, 4096<<10);
+    if (FLAGS_zlib) Measure(input, len, ZLIB, repeats, 1024 << 10);
+    if (FLAGS_lzo) Measure(input, len, LZO, repeats, 1024 << 10);
+    if (FLAGS_lz4) Measure(input, len, LZ4, repeats, 1024 << 10);
+    if (FLAGS_snappy) Measure(input, len, SNAPPY, repeats, 4096 << 10);
 
     // For block-size based measurements
     if (0 && FLAGS_snappy) {