1 files changed, 136 insertions, 0 deletions
diff --git a/src/third_party/wiredtiger/src/os_posix/os_map.c b/src/third_party/wiredtiger/src/os_posix/os_map.c
new file mode 100644
index 00000000000..be4d27e96a3
--- /dev/null
+++ b/src/third_party/wiredtiger/src/os_posix/os_map.c
@@ -0,0 +1,136 @@
+/*-
+ * 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;
+
+	WT_UNUSED(mappingcookie);
+
+	/*
+	 * 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;
+	if ((map = mmap(NULL, orig_size,
+	    PROT_READ,
+#ifdef MAP_NOCORE
+	    MAP_NOCORE |
+#endif
+	    MAP_PRIVATE,
+	    fh->fd, (wt_off_t)0)) == MAP_FAILED) {
+		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: map %p: %" WT_SIZET_FMT " bytes", fh->name, map, orig_size);
+
+	*(void **)mapp = map;
+	*lenp = orig_size;
+	return (0);
+}
+
+#define	WT_VM_PAGESIZE	4096
+
+/*
+ * __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)
+{
+#ifdef HAVE_POSIX_MADVISE
+	/* Linux requires the address be aligned to a 4KB boundary. */
+	WT_BM *bm = S2BT(session)->bm;
+	WT_DECL_RET;
+	void *blk = (void *)((uintptr_t)p & ~(uintptr_t)(WT_VM_PAGESIZE - 1));
+	size += WT_PTRDIFF(p, blk);
+
+	/* XXX proxy for "am I doing a scan?" -- manual read-ahead */
+	if (F_ISSET(session, WT_SESSION_NO_CACHE)) {
+		/* Read in 2MB blocks every 1MB of data. */
+		if (((uintptr_t)((uint8_t *)blk + size) &
+		    (uintptr_t)((1<<20) - 1)) < (uintptr_t)blk)
+			return (0);
+		size = WT_MIN(WT_MAX(20 * size, 2 << 20),
+		    WT_PTRDIFF((uint8_t *)bm->map + bm->maplen, blk));
+	}
+
+	/*
+	 * Manual pages aren't clear on whether alignment is required for the
+	 * size, so we will be conservative.
+	 */
+	size &= ~(size_t)(WT_VM_PAGESIZE - 1);
+
+	if (size > WT_VM_PAGESIZE &&
+	    (ret = posix_madvise(blk, size, POSIX_MADV_WILLNEED)) != 0)
+		WT_RET_MSG(session, ret, "posix_madvise will need");
+#else
+	WT_UNUSED(session);
+	WT_UNUSED(p);
+	WT_UNUSED(size);
+#endif
+
+	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)
+{
+#ifdef HAVE_POSIX_MADVISE
+	/* Linux requires the address be aligned to a 4KB boundary. */
+	WT_DECL_RET;
+	void *blk = (void *)((uintptr_t)p & ~(uintptr_t)(WT_VM_PAGESIZE - 1));
+	size += WT_PTRDIFF(p, blk);
+
+	if ((ret = posix_madvise(blk, size, POSIX_MADV_DONTNEED)) != 0)
+		WT_RET_MSG(session, ret, "posix_madvise don't need");
+#else
+	WT_UNUSED(session);
+	WT_UNUSED(p);
+	WT_UNUSED(size);
+#endif
+	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_UNUSED(mappingcookie);
+
+	WT_RET(__wt_verbose(session, WT_VERB_FILEOPS,
+	    "%s: unmap %p: %" WT_SIZET_FMT " bytes", fh->name, map, len));
+
+	if (munmap(map, len) == 0)
+		return (0);
+
+	WT_RET_MSG(session, __wt_errno(),
+	    "%s unmap error: failed to unmap %" WT_SIZET_FMT " bytes",
+	    fh->name, len);
+}