MDEV-39092 BACKUP SERVER of ENGINE=Aria to the local file system

Incorporate changes from code review.

Author: mariadb-andrzejjarzabek

include/my_backup.h

@@ -17,38 +17,64 @@ this program; if not, write to the Free Software Foundation, Inc.,
 
 #pragma once
 
-#include <cstdint>
+#include <stdint.h>
 
-namespace backup
-{
+#ifndef _WIN32
+#include <sys/types.h>
+#endif // _WIN32
 
-using target_dir_t= IF_WIN(const char*,int);
 
-inline void* to_void_ptr(target_dir_t tgt) noexcept
-{
-  return IF_WIN(const_cast<char*>, reinterpret_cast<void*>)(tgt);
-}
+#ifdef __cplusplus
+extern "C" {
+#endif
 
-inline target_dir_t to_target_dir(void* ptr) noexcept
-{
-  return IF_WIN(static_cast<const char*>(ptr), 
-                int(reinterpret_cast<uintptr_t>(ptr)));
-}
+typedef IF_WIN(const char*,int) Backup_target;
 
 #ifndef _WIN32
-/** Copy a file.
+/** Copy a file in its entirety.
 @param src  source file descriptor
 @param dst  target to append src to
 @return error code (negative)
 @retval 0   on success */
-int copy_file(int src, int dst) noexcept;
+int my_copy_file_fd(int src, int dst);
 
-/** Copy the entire file.
+/** Copy a file given a known length to be copied.
 @param src  source file descriptor
 @param dst  target to append src to
 @param size amount of data to be copied
 @return error code (negative)
 @retval 0   on success */
-int copy_file(int src, int dst, off_t size) noexcept;
+int my_copy_file_length_fd(int src, int dst, off_t size);
+
 #endif // _WIN32
+
+#ifdef __cplusplus
 }
+namespace backup
+{
+
+using Target= Backup_target;
+
+inline void* to_void_ptr(const Target &tgt) noexcept
+{
+  return IF_WIN(const_cast<char*>, reinterpret_cast<void*>)(tgt);
+}
+
+inline Target to_target(void* ptr) noexcept
+{
+  return IF_WIN(static_cast<const char*>(ptr), 
+                int(reinterpret_cast<uintptr_t>(ptr)));
+}
+
+# ifndef _WIN32
+
+/* Same as my_copy_file_fd but for C++ code. */
+int copy_file(int src, int dst) noexcept;
+
+/* Same as for my_copy_file_length_fd but for C++ code. */
+int copy_file(int src, int dst, off_t size) noexcept;
+
+# endif // _WIN32
+}
+
+#endif // __cplusplus

mysys/my_backup.cc

@@ -11,6 +11,29 @@
 # include <sys/mman.h>
 #endif
 
+#ifndef _WIN32
+/** Copy a file in its entirety.
+@param src  source file descriptor
+@param dst  target to append src to
+@return error code (negative)
+@retval 0   on success */
+int my_copy_file_fd(int src, int dst)
+{
+  return backup::copy_file(src, dst);
+}
+
+/** Copy a file given a known length to be copied.
+@param src  source file descriptor
+@param dst  target to append src to
+@param size amount of data to be copied
+@return error code (negative)
+@retval 0   on success */
+int my_copy_file_length_fd(int src, int dst, off_t size)
+{
+  return backup::copy_file(src, dst, size);
+}
+
+#endif
 namespace
 {
 #if !(defined __APPLE__ || defined _WIN32)
@@ -44,7 +67,7 @@ copy_step(int in_fd, int out_fd, size_t count, off_t *offset) noexcept
   return copy_file_range(in_fd, offset, out_fd, nullptr, count, 0);
 }
 #  define cfr(src,dst,size) copy<copy_step>(src, dst, size)
-# endif
+# endif // defined __linux__ || defined __FreeBSD__
 # ifdef __linux__
 /* Copy a file to a stream or to a regular file. */
 static inline ssize_t
@@ -62,10 +85,10 @@ send_step(int in_fd, int out_fd, size_t count, off_t *offset) noexcept
 @retval 1  if a memory mapping failed */
 static ssize_t mmap_copy(int in_fd, int out_fd, off_t count)
 {
-#if SIZEOF_SIZE_T < 8
+#  if SIZEOF_SIZE_T < 8
   if (count != ssize_t(count))
     return 1;
-#endif
+#  endif // SIZEOF_SIZE_T < 8
   void *p= mmap(nullptr, count, PROT_READ, MAP_SHARED, in_fd, 0);
   if (p == MAP_FAILED)
     return 1;
@@ -121,56 +144,46 @@ static ssize_t pread_write(int in_fd, int out_fd, off_t count) noexcept
   aligned_free(b);
   return ret;
 }
-# endif
-#endif
+# endif //  __linux__
+#endif // !(defined __APPLE__ || defined _WIN32)
 }
 
 namespace backup
 {
 
 #ifndef _WIN32
-/** Copy a file.
-@param src  source file descriptor
-@param dst  target to append src to
-@return error code (negative)
-@retval 0   on success */
+
 int copy_file(int src, int dst) noexcept
 {
-#ifdef __APPLE__
+# ifdef __APPLE__
   return fcopyfile(src, dst, nullptr, COPYFILE_ALL | COPYFILE_CLONE);
-#else
+# else
   return copy_file(src, dst, lseek(src, 0, SEEK_END));
-#endif
+# endif // __APPLE__
 }
 
-/** Copy a file.
-@param src  source file descriptor
-@param dst  target to append src to
-@param size amount of data to be copied
-@return error code (negative)
-@retval 0   on success */
 int copy_file(int src, int dst, off_t size) noexcept
 {
-#ifdef __APPLE__
+# ifdef __APPLE__
   return fcopyfile(src, dst, nullptr, COPYFILE_ALL | COPYFILE_CLONE);
-#else
+# else
   ssize_t ret;
-# ifdef cfr
+#  ifdef cfr
   if (!(ret= cfr(src, dst, size)))
     return int(ret);
-#  ifdef __linux__
+#   ifdef __linux__
   if (errno == EOPNOTSUPP)
-#  endif
-# endif
-# ifdef __linux__ // starting with Linux 2.6.33, we can rely on sendfile(2)
+#   endif // __linux__
+#  endif // cfr
+#  ifdef __linux__ // starting with Linux 2.6.33, we can rely on sendfile(2)
     ret= copy<send_step>(src, dst, size);
-# else
+#  else
   if ((ret= mmap_copy(src, dst, size)) == 1)
     ret= pread_write(src, dst, size);
-# endif
+#  endif // __linux__
   DBUG_ASSERT(ret <= 0);
   return int(ret);
-#endif
+# endif // __APPLE__
+}
+#endif // _WIN32
 }
-#endif
-}

sql/handler.h

@@ -1906,7 +1906,7 @@ struct handlerton : public transaction_participant
      @return error code
      @retval 0 on success
   */
-  int (*backup_start)(THD *thd, backup::target_dir_t target);
+  int (*backup_start)(THD *thd, Backup_target target);
   /**
      Process a file that was collected in backup_start().
      @param thd   current session
@@ -1929,7 +1929,7 @@ struct handlerton : public transaction_participant
      @return error code
      @retval 0 on success
   */
-  int (*backup_finalize)(THD *thd, backup::target_dir_t target);
+  int (*backup_finalize)(THD *thd, Backup_target target);
 
   /**********************************************************************
    WSREP specific

sql/sql_backup.cc

@@ -27,7 +27,7 @@ static my_bool backup_start(THD *thd, plugin_ref plugin, void *dst) noexcept
 {
   handlerton *hton= plugin_hton(plugin);
   if (hton->backup_start)
-    return hton->backup_start(thd, to_target_dir(dst));
+    return hton->backup_start(thd, to_target(dst));
   return false;
 }
 
@@ -54,7 +54,7 @@ static my_bool backup_finalize(THD *thd, plugin_ref plugin, void *dst) noexcept
 {
   handlerton *hton= plugin_hton(plugin);
   if (hton->backup_finalize)
-    return hton->backup_finalize(thd, to_target_dir(dst));
+    return hton->backup_finalize(thd, to_target(dst));
   return 0;
 }
 

storage/innobase/handler/backup_innodb.cc

@@ -51,7 +51,7 @@ class InnoDB_backup
   std::vector<lsn_t> logs;
 
   /** target directory name or handle */
-  target_dir_t target;
+  Target target;
 
   /** the checkpoint from which the backup starts */
   lsn_t checkpoint;
@@ -65,7 +65,7 @@ class InnoDB_backup
      @return error code
      @retval 0 on success
   */
-  int init(THD *thd, target_dir_t target) noexcept
+  int init(THD *thd, Target target) noexcept
   {
     trx_t *trx= check_trx_exists(thd);
     if (trx->id || trx->state != TRX_STATE_NOT_STARTED)
@@ -269,7 +269,7 @@ class InnoDB_backup
      @return error code
      @retval 0 on success
   */
-  int fini(THD *thd, target_dir_t target) noexcept
+  int fini(THD *thd, Target target) noexcept
   {
     int fail= 0;
     log_sys.latch.wr_lock();
@@ -650,7 +650,7 @@ void log_t::backup_stop(uint64_t old_size, THD *thd) noexcept
     resize_finish(thd);
 }
 
-int innodb_backup_start(THD *thd, target_dir_t target) noexcept
+int innodb_backup_start(THD *thd, Backup_target target) noexcept
 {
   return innodb_backup.init(thd, target);
 }
@@ -665,7 +665,7 @@ int innodb_backup_end(THD *thd, bool abort) noexcept
   return innodb_backup.end(thd, abort);
 }
 
-int innodb_backup_finalize(THD *thd, target_dir_t target) noexcept
+int innodb_backup_finalize(THD *thd, Backup_target target) noexcept
 {
   return innodb_backup.fini(thd, target);
 }

storage/innobase/handler/backup_innodb.h

@@ -22,7 +22,7 @@
    @return error code
    @retval 0 on success
 */
-int innodb_backup_start(THD *thd, backup::target_dir_t target) noexcept;
+int innodb_backup_start(THD *thd, Backup_target target) noexcept;
 
 /**
    Process a file that was collected in backup_start().
@@ -48,7 +48,7 @@ int innodb_backup_end(THD *thd, bool abort) noexcept;
    @return error code
    @retval 0 on success
 */
-int innodb_backup_finalize(THD *thd, backup::target_dir_t target) noexcept;
+int innodb_backup_finalize(THD *thd, Backup_target target) noexcept;
 
 /**
    Complete the first checkpoint in a new archive log file.