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-rw-r--r--mysys/my_mmap.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/mysys/my_mmap.c b/mysys/my_mmap.c
new file mode 100644
index 00000000..e04f4add
--- /dev/null
+++ b/mysys/my_mmap.c
@@ -0,0 +1,105 @@
+/* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
+
+#include "mysys_priv.h"
+
+#ifdef HAVE_SYS_MMAN_H
+
+/*
+ system msync() only syncs mmap'ed area to fs cache.
+ fsync() is required to really sync to disc
+*/
+int my_msync(int fd, void *addr, size_t len, int flags)
+{
+ msync(addr, len, flags);
+ return my_sync(fd, MYF(0));
+}
+
+#elif defined(_WIN32)
+
+#ifndef FILE_DAX_VOLUME
+#define FILE_DAX_VOLUME 0x20000000
+#endif
+
+static SECURITY_ATTRIBUTES mmap_security_attributes=
+ {sizeof(SECURITY_ATTRIBUTES), 0, TRUE};
+
+void *my_mmap(void *addr, size_t len, int prot,
+ int flags, File fd, my_off_t offset)
+{
+ HANDLE hFileMap;
+ LPVOID ptr;
+ HANDLE hFile= (HANDLE)my_get_osfhandle(fd);
+ DBUG_ENTER("my_mmap");
+ DBUG_PRINT("mysys", ("map fd: %d", fd));
+
+ if (hFile == INVALID_HANDLE_VALUE)
+ DBUG_RETURN(MAP_FAILED);
+
+ hFileMap=CreateFileMapping(hFile, &mmap_security_attributes,
+ PAGE_READWRITE, 0, (DWORD) len, NULL);
+ if (hFileMap == 0)
+ DBUG_RETURN(MAP_FAILED);
+
+ ptr=MapViewOfFile(hFileMap,
+ prot & PROT_WRITE ? FILE_MAP_WRITE : FILE_MAP_READ,
+ (DWORD)(offset >> 32), (DWORD)offset, len);
+
+ /*
+ MSDN explicitly states that it's possible to close File Mapping Object
+ even when a view is not unmapped - then the object will be held open
+ implicitly until unmap, as every view stores internally a handler of
+ a corresponding File Mapping Object
+ */
+ CloseHandle(hFileMap);
+
+ if (flags & MAP_SYNC)
+ {
+ DWORD filesystemFlags;
+ if (!GetVolumeInformationByHandleW(hFile, NULL, 0, NULL, NULL,
+ &filesystemFlags, NULL, 0) ||
+ !(filesystemFlags & FILE_DAX_VOLUME))
+ {
+ UnmapViewOfFile(ptr);
+ ptr= NULL;
+ }
+ }
+
+ if (ptr)
+ {
+ DBUG_PRINT("mysys", ("mapped addr: %p", ptr));
+ DBUG_RETURN(ptr);
+ }
+
+ DBUG_RETURN(MAP_FAILED);
+}
+
+int my_munmap(void *addr, size_t len)
+{
+ DBUG_ENTER("my_munmap");
+ DBUG_PRINT("mysys", ("unmap addr: %p", addr));
+ DBUG_RETURN(UnmapViewOfFile(addr) ? 0 : -1);
+}
+
+int my_msync(int fd, void *addr, size_t len, int flags)
+{
+ return FlushViewOfFile(addr, len) &&
+ FlushFileBuffers(my_get_osfhandle(fd)) ? 0 : -1;
+}
+
+#else
+#warning "no mmap!"
+#endif
+