use ENUM not ULONG for innodb-compression-algorithm command-line option

storage/innobase/handler/ha_innodb.cc

@@ -16804,14 +16804,17 @@ static MYSQL_SYSVAR_BOOL(use_trim, srv_use_trim,
 #else
 #define default_compression_algorithm PAGE_ZLIB_ALGORITHM
 #endif
-static MYSQL_SYSVAR_LONG(compression_algorithm, innodb_compression_algorithm,
+static const char *page_compression_algorithms[]= { "none", "zlib", "lz4", "lzo", 0 };
+static TYPELIB page_compression_algorithms_typelib=
+{
+  array_elements(page_compression_algorithms) - 1, 0,
+  page_compression_algorithms, 0
+};
+static MYSQL_SYSVAR_ENUM(compression_algorithm, innodb_compression_algorithm,
   PLUGIN_VAR_OPCMDARG,
-  "Compression algorithm used on page compression. 1 for zlib, 2 for lz3, 3 for lzo",
-  NULL, NULL,
-  PAGE_ZLIB_ALGORITHM,
-  0,
-  default_compression_algorithm,
-  0);
+  "Compression algorithm used on page compression. One of: none, zlib, lz4, or lzo",
+  NULL, NULL, default_compression_algorithm,
+  &page_compression_algorithms_typelib);
 
 static MYSQL_SYSVAR_LONG(mtflush_threads, srv_mtflush_threads,
   PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,

storage/innobase/include/srv0srv.h

@@ -252,7 +252,7 @@ extern my_bool srv_use_posix_fallocate;
 extern my_bool srv_use_atomic_writes;
 
 /* Compression algorithm*/
-extern long innodb_compression_algorithm;
+extern ulong innodb_compression_algorithm;
 
 /* Number of flush threads */
 #define MTFLUSH_MAX_WORKER       64

storage/innobase/srv/srv0srv.cc

@@ -155,7 +155,7 @@ UNIV_INTERN my_bool	srv_use_posix_fallocate = FALSE;
 /* If this flag is TRUE, then we disable doublewrite buffer */
 UNIV_INTERN my_bool	srv_use_atomic_writes = FALSE;
 /* If this flag IS TRUE, then we use lz4 to compress/decompress pages */
-UNIV_INTERN long	innodb_compression_algorithm = PAGE_ZLIB_ALGORITHM;
+UNIV_INTERN ulong	innodb_compression_algorithm = PAGE_ZLIB_ALGORITHM;
 /* Number of threads used for multi-threaded flush */
 UNIV_INTERN long srv_mtflush_threads = MTFLUSH_DEFAULT_WORKER;
 /* If this flag is TRUE, then we will use multi threaded flush. */

storage/xtradb/handler/ha_innodb.cc

@@ -17961,14 +17961,17 @@ static MYSQL_SYSVAR_BOOL(use_trim, srv_use_trim,
 #else
 #define default_compression_algorithm PAGE_ZLIB_ALGORITHM
 #endif
-static MYSQL_SYSVAR_LONG(compression_algorithm, innodb_compression_algorithm,
+static const char *page_compression_algorithms[]= { "none", "zlib", "lz4", "lzo", 0 };
+static TYPELIB page_compression_algorithms_typelib=
+{
+  array_elements(page_compression_algorithms) - 1, 0,
+  page_compression_algorithms, 0
+};
+static MYSQL_SYSVAR_ENUM(compression_algorithm, innodb_compression_algorithm,
   PLUGIN_VAR_OPCMDARG,
-  "Compression algorithm used on page compression. 1 for zlib, 2 for lz3, 3 for lzo",
-  NULL, NULL,
-  PAGE_ZLIB_ALGORITHM,
-  0,
-  default_compression_algorithm,
-  0);
+  "Compression algorithm used on page compression. One of: none, zlib, lz4, or lzo",
+  NULL, NULL, default_compression_algorithm,
+  &page_compression_algorithms_typelib);
 
 static MYSQL_SYSVAR_LONG(mtflush_threads, srv_mtflush_threads,
   PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,

storage/xtradb/include/srv0srv.h

@@ -270,7 +270,7 @@ extern my_bool srv_use_posix_fallocate;
 extern my_bool srv_use_atomic_writes;
 
 /* Compression algorithm*/
-extern long innodb_compression_algorithm;
+extern ulong innodb_compression_algorithm;
 
 /* Number of flush threads */
 #define MTFLUSH_MAX_WORKER       64

storage/xtradb/srv/srv0srv.cc

@@ -173,7 +173,7 @@ UNIV_INTERN my_bool     srv_use_posix_fallocate         = FALSE;
 /* If this flag is TRUE, then we disable doublewrite buffer */
 UNIV_INTERN my_bool     srv_use_atomic_writes           = FALSE;
 /* If this flag IS TRUE, then we use lz4 to compress/decompress pages */
-UNIV_INTERN long	innodb_compression_algorithm = PAGE_ZLIB_ALGORITHM;
+UNIV_INTERN ulong	innodb_compression_algorithm = PAGE_ZLIB_ALGORITHM;
 /* Number of threads used for multi-threaded flush */
 UNIV_INTERN long srv_mtflush_threads = MTFLUSH_DEFAULT_WORKER;
 /* If this flag is TRUE, then we will use multi threaded flush. */