Source code upload

eoe/cmd/sss/ssdb/ssdbserver/sql/sql_map.cc

@@ -0,0 +1,144 @@
+/* Copyright (C) 1979-1996 TcX AB & Monty Program KB & Detron HB
+
+   This software is distributed with NO WARRANTY OF ANY KIND.  No author or
+   distributor accepts any responsibility for the consequences of using it, or
+   for whether it serves any particular purpose or works at all, unless he or
+   she says so in writing.  Refer to the Free Public License (the "License")
+   for full details.
+
+   Every copy of this file must include a copy of the License, normally in a
+   plain ASCII text file named PUBLIC.	The License grants you the right to
+   copy, modify and redistribute this file, but only under certain conditions
+   described in the License.  Among other things, the License requires that
+   the copyright notice and this notice be preserved on all copies. */
+
+#ifdef __GNUC__
+#pragma implementation				// gcc: Class implementation
+#endif
+
+#include "mysql_priv.h"
+#ifdef HAVE_MMAP
+#include <sys/mman.h>
+#include <sys/stat.h>
+#endif
+
+#ifndef MAP_NORESERVE
+#define MAP_NORESERVE 0				// For IRIX
+#endif
+
+mapped_files::mapped_files(const my_string filename,byte *magic,uint magic_length)
+{
+#ifdef HAVE_MMAP
+  name=my_strdup(filename,MYF(0));
+  use_count=1;
+  error=0;
+  map=0;
+  size=0;
+  if ((file=my_open(name,O_RDONLY,MYF(MY_WME))) >= 0)
+  {
+    struct stat stat_buf;
+    if (!fstat(file,&stat_buf))
+    {
+      if (!(map=(byte*) mmap(0,(size=(ulong) stat_buf.st_size),PROT_READ,
+			     MAP_SHARED | MAP_NORESERVE,file,
+			     0L)))
+      {
+	error=errno;
+	my_printf_error(0,"Can't map file: %s, errno: %d",MYF(0),
+			(my_string) name,error);
+      }
+    }
+    if (map && memcmp(map,magic,magic_length))
+    {
+      my_printf_error(0,"Wrong magic in %s",MYF(0),name);
+      VOID(munmap(map,size));
+      map=0;
+    }
+    if (!map)
+    {
+      VOID(my_close(file,MYF(0)));
+      file= -1;
+    }
+  }
+#endif
+}
+
+
+mapped_files::~mapped_files()
+{
+#ifdef HAVE_MMAP
+  if (file >= 0)
+  {
+    VOID(munmap((caddr_t) map,size));
+    VOID(my_close(file,MYF(0)));
+    file= -1; map=0;
+  }
+  my_free(name,MYF(0));
+#endif
+}
+
+
+static I_List<mapped_files> maps_in_use;
+
+/*
+**  Check if a file is mapped. If it is, then return pointer to old map,
+**  else alloc new object
+*/
+
+mapped_files *map_file(const my_string name,byte *magic,uint magic_length)
+{
+#ifdef HAVE_MMAP
+  VOID(pthread_mutex_lock(&LOCK_mapped_file));
+  I_List_iterator<mapped_files> list(maps_in_use);
+  mapped_files *map;
+  char path[FN_REFLEN];
+  sprintf(path,"%s/%s/%s.uniq",mysql_data_home,current_thd->db,name);
+  (void) unpack_filename(path,path);
+
+  while ((map=list++))
+  {
+    if (!strcmp(path,map->name))
+      break;
+  }
+  if (!map)
+  {
+    map=new mapped_files(path,magic,magic_length);
+    maps_in_use.append(map);
+  }
+  else
+  {
+    map->use_count++;
+    if (!map->map)
+      my_printf_error(0,"Can't map file: %s, error: %d",MYF(0),path,
+		      map->error);
+  }
+  VOID(pthread_mutex_unlock(&LOCK_mapped_file));
+  return map;
+#else
+  return NULL;
+#endif
+}
+
+/*
+** free the map if there are no more users for it
+*/
+
+void unmap_file(mapped_files *map)
+{
+#ifdef HAVE_MMAP
+  VOID(pthread_mutex_lock(&LOCK_mapped_file));
+  if (!map->use_count--)
+    delete map;
+  VOID(pthread_mutex_unlock(&LOCK_mapped_file));
+#endif
+}
+
+/*****************************************************************************
+** Instansiate templates
+*****************************************************************************/
+
+#ifdef __GNUC__
+/* Used templates */
+template class I_List<mapped_files>;
+template class I_List_iterator<mapped_files>;
+#endif