1 files changed, 359 insertions, 0 deletions
diff --git a/contrib/lmdb/midl.c b/contrib/lmdb/midl.c
new file mode 100644
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--- /dev/null
+++ b/contrib/lmdb/midl.c
@@ -0,0 +1,359 @@
+/**	@file midl.c
+ *	@brief ldap bdb back-end ID List functions */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 2000-2016 The OpenLDAP Foundation.
+ * Portions Copyright 2001-2017 Howard Chu, Symas Corp.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+
+#include <limits.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/types.h>
+#include "midl.h"
+
+/** @defgroup internal	LMDB Internals
+ *	@{
+ */
+/** @defgroup idls	ID List Management
+ *	@{
+ */
+#define CMP(x,y)	 ( (x) < (y) ? -1 : (x) > (y) )
+
+unsigned mdb_midl_search( MDB_IDL ids, MDB_ID id )
+{
+	/*
+	 * binary search of id in ids
+	 * if found, returns position of id
+	 * if not found, returns first position greater than id
+	 */
+	unsigned base = 0;
+	unsigned cursor = 1;
+	int val = 0;
+	unsigned n = ids[0];
+
+	while( 0 < n ) {
+		unsigned pivot = n >> 1;
+		cursor = base + pivot + 1;
+		val = CMP( ids[cursor], id );
+
+		if( val < 0 ) {
+			n = pivot;
+
+		} else if ( val > 0 ) {
+			base = cursor;
+			n -= pivot + 1;
+
+		} else {
+			return cursor;
+		}
+	}
+
+	if( val > 0 ) {
+		++cursor;
+	}
+	return cursor;
+}
+
+#if 0	/* superseded by append/sort */
+int mdb_midl_insert( MDB_IDL ids, MDB_ID id )
+{
+	unsigned x, i;
+
+	x = mdb_midl_search( ids, id );
+	assert( x > 0 );
+
+	if( x < 1 ) {
+		/* internal error */
+		return -2;
+	}
+
+	if ( x <= ids[0] && ids[x] == id ) {
+		/* duplicate */
+		assert(0);
+		return -1;
+	}
+
+	if ( ++ids[0] >= MDB_IDL_DB_MAX ) {
+		/* no room */
+		--ids[0];
+		return -2;
+
+	} else {
+		/* insert id */
+		for (i=ids[0]; i>x; i--)
+			ids[i] = ids[i-1];
+		ids[x] = id;
+	}
+
+	return 0;
+}
+#endif
+
+MDB_IDL mdb_midl_alloc(int num)
+{
+	MDB_IDL ids = malloc((num+2) * sizeof(MDB_ID));
+	if (ids) {
+		*ids++ = num;
+		*ids = 0;
+	}
+	return ids;
+}
+
+void mdb_midl_free(MDB_IDL ids)
+{
+	if (ids)
+		free(ids-1);
+}
+
+void mdb_midl_shrink( MDB_IDL *idp )
+{
+	MDB_IDL ids = *idp;
+	if (*(--ids) > MDB_IDL_UM_MAX &&
+		(ids = realloc(ids, (MDB_IDL_UM_MAX+2) * sizeof(MDB_ID))))
+	{
+		*ids++ = MDB_IDL_UM_MAX;
+		*idp = ids;
+	}
+}
+
+static int mdb_midl_grow( MDB_IDL *idp, int num )
+{
+	MDB_IDL idn = *idp-1;
+	/* grow it */
+	idn = realloc(idn, (*idn + num + 2) * sizeof(MDB_ID));
+	if (!idn)
+		return ENOMEM;
+	*idn++ += num;
+	*idp = idn;
+	return 0;
+}
+
+int mdb_midl_need( MDB_IDL *idp, unsigned num )
+{
+	MDB_IDL ids = *idp;
+	num += ids[0];
+	if (num > ids[-1]) {
+		num = (num + num/4 + (256 + 2)) & -256;
+		if (!(ids = realloc(ids-1, num * sizeof(MDB_ID))))
+			return ENOMEM;
+		*ids++ = num - 2;
+		*idp = ids;
+	}
+	return 0;
+}
+
+int mdb_midl_append( MDB_IDL *idp, MDB_ID id )
+{
+	MDB_IDL ids = *idp;
+	/* Too big? */
+	if (ids[0] >= ids[-1]) {
+		if (mdb_midl_grow(idp, MDB_IDL_UM_MAX))
+			return ENOMEM;
+		ids = *idp;
+	}
+	ids[0]++;
+	ids[ids[0]] = id;
+	return 0;
+}
+
+int mdb_midl_append_list( MDB_IDL *idp, MDB_IDL app )
+{
+	MDB_IDL ids = *idp;
+	/* Too big? */
+	if (ids[0] + app[0] >= ids[-1]) {
+		if (mdb_midl_grow(idp, app[0]))
+			return ENOMEM;
+		ids = *idp;
+	}
+	memcpy(&ids[ids[0]+1], &app[1], app[0] * sizeof(MDB_ID));
+	ids[0] += app[0];
+	return 0;
+}
+
+int mdb_midl_append_range( MDB_IDL *idp, MDB_ID id, unsigned n )
+{
+	MDB_ID *ids = *idp, len = ids[0];
+	/* Too big? */
+	if (len + n > ids[-1]) {
+		if (mdb_midl_grow(idp, n | MDB_IDL_UM_MAX))
+			return ENOMEM;
+		ids = *idp;
+	}
+	ids[0] = len + n;
+	ids += len;
+	while (n)
+		ids[n--] = id++;
+	return 0;
+}
+
+void mdb_midl_xmerge( MDB_IDL idl, MDB_IDL merge )
+{
+	MDB_ID old_id, merge_id, i = merge[0], j = idl[0], k = i+j, total = k;
+	idl[0] = (MDB_ID)-1;		/* delimiter for idl scan below */
+	old_id = idl[j];
+	while (i) {
+		merge_id = merge[i--];
+		for (; old_id < merge_id; old_id = idl[--j])
+			idl[k--] = old_id;
+		idl[k--] = merge_id;
+	}
+	idl[0] = total;
+}
+
+/* Quicksort + Insertion sort for small arrays */
+
+#define SMALL	8
+#define	MIDL_SWAP(a,b)	{ itmp=(a); (a)=(b); (b)=itmp; }
+
+void
+mdb_midl_sort( MDB_IDL ids )
+{
+	/* Max possible depth of int-indexed tree * 2 items/level */
+	int istack[sizeof(int)*CHAR_BIT * 2];
+	int i,j,k,l,ir,jstack;
+	MDB_ID a, itmp;
+
+	ir = (int)ids[0];
+	l = 1;
+	jstack = 0;
+	for(;;) {
+		if (ir - l < SMALL) {	/* Insertion sort */
+			for (j=l+1;j<=ir;j++) {
+				a = ids[j];
+				for (i=j-1;i>=1;i--) {
+					if (ids[i] >= a) break;
+					ids[i+1] = ids[i];
+				}
+				ids[i+1] = a;
+			}
+			if (jstack == 0) break;
+			ir = istack[jstack--];
+			l = istack[jstack--];
+		} else {
+			k = (l + ir) >> 1;	/* Choose median of left, center, right */
+			MIDL_SWAP(ids[k], ids[l+1]);
+			if (ids[l] < ids[ir]) {
+				MIDL_SWAP(ids[l], ids[ir]);
+			}
+			if (ids[l+1] < ids[ir]) {
+				MIDL_SWAP(ids[l+1], ids[ir]);
+			}
+			if (ids[l] < ids[l+1]) {
+				MIDL_SWAP(ids[l], ids[l+1]);
+			}
+			i = l+1;
+			j = ir;
+			a = ids[l+1];
+			for(;;) {
+				do i++; while(ids[i] > a);
+				do j--; while(ids[j] < a);
+				if (j < i) break;
+				MIDL_SWAP(ids[i],ids[j]);
+			}
+			ids[l+1] = ids[j];
+			ids[j] = a;
+			jstack += 2;
+			if (ir-i+1 >= j-l) {
+				istack[jstack] = ir;
+				istack[jstack-1] = i;
+				ir = j-1;
+			} else {
+				istack[jstack] = j-1;
+				istack[jstack-1] = l;
+				l = i;
+			}
+		}
+	}
+}
+
+unsigned mdb_mid2l_search( MDB_ID2L ids, MDB_ID id )
+{
+	/*
+	 * binary search of id in ids
+	 * if found, returns position of id
+	 * if not found, returns first position greater than id
+	 */
+	unsigned base = 0;
+	unsigned cursor = 1;
+	int val = 0;
+	unsigned n = (unsigned)ids[0].mid;
+
+	while( 0 < n ) {
+		unsigned pivot = n >> 1;
+		cursor = base + pivot + 1;
+		val = CMP( id, ids[cursor].mid );
+
+		if( val < 0 ) {
+			n = pivot;
+
+		} else if ( val > 0 ) {
+			base = cursor;
+			n -= pivot + 1;
+
+		} else {
+			return cursor;
+		}
+	}
+
+	if( val > 0 ) {
+		++cursor;
+	}
+	return cursor;
+}
+
+int mdb_mid2l_insert( MDB_ID2L ids, MDB_ID2 *id )
+{
+	unsigned x, i;
+
+	x = mdb_mid2l_search( ids, id->mid );
+
+	if( x < 1 ) {
+		/* internal error */
+		return -2;
+	}
+
+	if ( x <= ids[0].mid && ids[x].mid == id->mid ) {
+		/* duplicate */
+		return -1;
+	}
+
+	if ( ids[0].mid >= MDB_IDL_UM_MAX ) {
+		/* too big */
+		return -2;
+
+	} else {
+		/* insert id */
+		ids[0].mid++;
+		for (i=(unsigned)ids[0].mid; i>x; i--)
+			ids[i] = ids[i-1];
+		ids[x] = *id;
+	}
+
+	return 0;
+}
+
+int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id )
+{
+	/* Too big? */
+	if (ids[0].mid >= MDB_IDL_UM_MAX) {
+		return -2;
+	}
+	ids[0].mid++;
+	ids[ids[0].mid] = *id;
+	return 0;
+}
+
+/** @} */
+/** @} */