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/*-
* Copyright (c) 2014-2016 MongoDB, Inc.
* Copyright (c) 2008-2014 WiredTiger, Inc.
* All rights reserved.
*
* See the file LICENSE for redistribution information.
*/
#include "wt_internal.h"
/*
* __wt_mmap --
* Map a file into memory.
*/
int
__wt_mmap(WT_SESSION_IMPL *session, WT_FH *fh, void *mapp, size_t *lenp,
void** mappingcookie)
{
void *map;
size_t orig_size;
/*
* Record the current size and only map and set that as the length, it
* could change between the map call and when we set the return length.
* For the same reason we could actually map past the end of the file;
* we don't read bytes past the end of the file though, so as long as
* the map call succeeds, it's all OK.
*/
orig_size = (size_t)fh->size;
*mappingcookie =
CreateFileMappingA(fh->filehandle, NULL, PAGE_READONLY, 0, 0, NULL);
if (*mappingcookie == NULL)
WT_RET_MSG(session, __wt_errno(),
"%s CreateFileMapping error: failed to map %"
WT_SIZET_FMT " bytes",
fh->name, orig_size);
if ((map = MapViewOfFile(
*mappingcookie, FILE_MAP_READ, 0, 0, orig_size)) == NULL) {
CloseHandle(*mappingcookie);
*mappingcookie = NULL;
WT_RET_MSG(session, __wt_errno(),
"%s map error: failed to map %" WT_SIZET_FMT " bytes",
fh->name, orig_size);
}
(void)__wt_verbose(session, WT_VERB_FILEOPS,
"%s: MapViewOfFile %p: %" WT_SIZET_FMT " bytes",
fh->name, map, orig_size);
*(void **)mapp = map;
*lenp = orig_size;
return (0);
}
/*
* __wt_mmap_preload --
* Cause a section of a memory map to be faulted in.
*/
int
__wt_mmap_preload(WT_SESSION_IMPL *session, const void *p, size_t size)
{
WT_UNUSED(session);
WT_UNUSED(p);
WT_UNUSED(size);
return (0);
}
/*
* __wt_mmap_discard --
* Discard a chunk of the memory map.
*/
int
__wt_mmap_discard(WT_SESSION_IMPL *session, void *p, size_t size)
{
WT_UNUSED(session);
WT_UNUSED(p);
WT_UNUSED(size);
return (0);
}
/*
* __wt_munmap --
* Remove a memory mapping.
*/
int
__wt_munmap(WT_SESSION_IMPL *session, WT_FH *fh, void *map, size_t len,
void** mappingcookie)
{
WT_RET(__wt_verbose(session, WT_VERB_FILEOPS,
"%s: UnmapViewOfFile %p: %" WT_SIZET_FMT " bytes",
fh->name, map, len));
if (UnmapViewOfFile(map) == 0) {
WT_RET_MSG(session, __wt_errno(),
"%s UnmapViewOfFile error: failed to unmap %" WT_SIZET_FMT
" bytes",
fh->name, len);
}
if (CloseHandle(*mappingcookie) == 0) {
WT_RET_MSG(session, __wt_errno(),
"CloseHandle: MapViewOfFile: %s", fh->name);
}
*mappingcookie = 0;
return (0);
}
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