MDEV-13023 mariabackup does not preserve holes for page compressed ta…

…bles.

Changed "local" datasink logic to detect page compressed Innodb tables.

Whenever such table is detected, holes in the copied files are created by
skipping over binary zeros at the end of each compressed page.

extra/mariabackup/CMakeLists.txt

@@ -61,7 +61,7 @@ MYSQL_ADD_EXECUTABLE(mariabackup
   datasink.c
   ds_buffer.c
   ds_compress.c
-  ds_local.c
+  ds_local.cc
   ds_stdout.c
   ds_tmpfile.c
   ds_xbstream.c
@@ -98,7 +98,7 @@ ENDIF()
 ########################################################################
 MYSQL_ADD_EXECUTABLE(mbstream
   ds_buffer.c
-  ds_local.c
+  ds_local.cc
   ds_stdout.c
   datasink.c
   xbstream.c
@@ -112,6 +112,7 @@ TARGET_LINK_LIBRARIES(mbstream
   mysys
   crc
 )
+ADD_DEPENDENCIES(mbstream GenError)
 
 IF(MSVC)
   SET_TARGET_PROPERTIES(mbstream PROPERTIES LINK_FLAGS setargv.obj)

extra/mariabackup/datasink.c

@@ -108,7 +108,7 @@ Write to a datasink file.
 int
 ds_write(ds_file_t *file, const void *buf, size_t len)
 {
-	return file->datasink->write(file, buf, len);
+	return file->datasink->write(file, (const uchar *)buf, len);
 }
 
 /************************************************************************

extra/mariabackup/datasink.h

@@ -48,7 +48,7 @@ typedef struct {
 struct datasink_struct {
 	ds_ctxt_t *(*init)(const char *root);
 	ds_file_t *(*open)(ds_ctxt_t *ctxt, const char *path, MY_STAT *stat);
-	int (*write)(ds_file_t *file, const void *buf, size_t len);
+	int (*write)(ds_file_t *file, const unsigned char *buf, size_t len);
 	int (*close)(ds_file_t *file);
 	void (*deinit)(ds_ctxt_t *ctxt);
 };

extra/mariabackup/ds_buffer.c

@@ -45,7 +45,7 @@ typedef struct {
 static ds_ctxt_t *buffer_init(const char *root);
 static ds_file_t *buffer_open(ds_ctxt_t *ctxt, const char *path,
 			      MY_STAT *mystat);
-static int buffer_write(ds_file_t *file, const void *buf, size_t len);
+static int buffer_write(ds_file_t *file, const uchar *buf, size_t len);
 static int buffer_close(ds_file_t *file);
 static void buffer_deinit(ds_ctxt_t *ctxt);
 
@@ -119,7 +119,7 @@ buffer_open(ds_ctxt_t *ctxt, const char *path, MY_STAT *mystat)
 }
 
 static int
-buffer_write(ds_file_t *file, const void *buf, size_t len)
+buffer_write(ds_file_t *file, const uchar *buf, size_t len)
 {
 	ds_buffer_file_t	*buffer_file;
 

extra/mariabackup/ds_compress.c

@@ -65,7 +65,7 @@ extern ulonglong	xtrabackup_compress_chunk_size;
 static ds_ctxt_t *compress_init(const char *root);
 static ds_file_t *compress_open(ds_ctxt_t *ctxt, const char *path,
 				MY_STAT *mystat);
-static int compress_write(ds_file_t *file, const void *buf, size_t len);
+static int compress_write(ds_file_t *file, const uchar *buf, size_t len);
 static int compress_close(ds_file_t *file);
 static void compress_deinit(ds_ctxt_t *ctxt);
 
@@ -178,7 +178,7 @@ compress_open(ds_ctxt_t *ctxt, const char *path, MY_STAT *mystat)
 
 static
 int
-compress_write(ds_file_t *file, const void *buf, size_t len)
+compress_write(ds_file_t *file, const uchar *buf, size_t len)
 {
 	ds_compress_file_t	*comp_file;
 	ds_compress_ctxt_t	*comp_ctxt;