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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_block_map --
* Map a segment of the file in, if possible.
*/
int
__wt_block_map(WT_SESSION_IMPL *session, WT_BLOCK *block,
void *mapped_regionp, size_t *lengthp, void *mapped_cookiep)
{
WT_DECL_RET;
WT_FILE_HANDLE *handle;
*(void **)mapped_regionp = NULL;
*lengthp = 0;
*(void **)mapped_cookiep = NULL;
/* Map support is configurable. */
if (!S2C(session)->mmap)
return (0);
/*
* Turn off mapping when verifying the file, because we can't perform
* checksum validation of mapped segments, and verify has to checksum
* pages.
*/
if (block->verify)
return (0);
/*
* Turn off mapping if the application configured a cache size maximum,
* we can't control how much of the cache size we use in that case.
*/
if (block->os_cache_max != 0)
return (0);
/*
* There may be no underlying functionality.
*/
handle = block->fh->handle;
if (handle->fh_map == NULL)
return (0);
/*
* Map the file into memory.
* Ignore not-supported errors, we'll read the file through the cache
* if map fails.
*/
ret = handle->fh_map(handle,
(WT_SESSION *)session, mapped_regionp, lengthp, mapped_cookiep);
if (ret == ENOTSUP) {
*(void **)mapped_regionp = NULL;
ret = 0;
}
return (ret);
}
/*
* __wt_block_unmap --
* Unmap any mapped-in segment of the file.
*/
int
__wt_block_unmap(WT_SESSION_IMPL *session,
WT_BLOCK *block, void *mapped_region, size_t length, void *mapped_cookie)
{
WT_FILE_HANDLE *handle;
/* Unmap the file from memory. */
handle = block->fh->handle;
return (handle->fh_unmap(handle,
(WT_SESSION *)session, mapped_region, length, mapped_cookie));
}
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