[CMake] Add find module for Snappy

Add a find_package module for Snappy

CMake/FindSnappy.cmake

@@ -0,0 +1,17 @@
+# Find the Snappy libraries
+#
+# This module defines:
+# SNAPPY_FOUND
+# SNAPPY_INCLUDE_DIR
+# SNAPPY_LIBRARY
+
+find_path(SNAPPY_INCLUDE_DIR NAMES snappy.h)
+find_library(SNAPPY_LIBRARY NAMES snappy)
+
+include(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(
+    SNAPPY DEFAULT_MSG
+    SNAPPY_LIBRARY SNAPPY_INCLUDE_DIR
+)
+
+mark_as_advanced(SNAPPY_INCLUDE_DIR SNAPPY_LIBRARY)

CMake/folly-deps.cmake

@@ -105,16 +105,19 @@ if (LZ4_FOUND)
   list(APPEND FOLLY_LINK_LIBRARIES ${LZ4_LIBRARY})
 endif()
 
+find_package(Snappy MODULE)
+set(FOLLY_HAVE_LIBSNAPPY ${SNAPPY_FOUND})
+if (SNAPPY_FOUND)
+  list(APPEND FOLLY_INCLUDE_DIRECTORIES ${SNAPPY_INCLUDE_DIR})
+  list(APPEND FOLLY_LINK_LIBRARIES ${SNAPPY_LIBRARY})
+endif()
+
 # TODO: We should ideally build FindXXX modules for the following libraries,
 # rather than the simple checks we currently have here.
 CHECK_INCLUDE_FILE_CXX(zstd.h FOLLY_HAVE_LIBZSTD)
 if (FOLLY_HAVE_LIBZSTD)
   list(APPEND FOLLY_LINK_LIBRARIES zstd)
 endif()
-CHECK_INCLUDE_FILE_CXX(snappy.h FOLLY_HAVE_LIBSNAPPY)
-if (FOLLY_HAVE_LIBSNAPPY)
-  list(APPEND FOLLY_LINK_LIBRARIES snappy)
-endif()
 
 find_package(LibDwarf)
 list(APPEND FOLLY_LINK_LIBRARIES ${LIBDWARF_LIBRARIES})