From: Howard Chu <hyc@symas.com>
Date: Tue, 6 Sep 2011 12:17:24 +0000 (-0700)
Subject: Change MDB_node to depend on 2-byte alignment
X-Git-Tag: OPENLDAP_REL_ENG_2_4_27~148^2~56
X-Git-Url: https://git.sur5r.net/?p=openldap;a=commitdiff_plain;h=293df78b2be77d6d153fd7052cc62d3377dc5501

Change MDB_node to depend on 2-byte alignment
---

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 01e2243af3..e8df3fc327 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -363,18 +363,19 @@ struct MDB_cursor {
 
 #define METADATA(p)	 ((void *)((char *)(p) + PAGEHDRSZ))
 
+/* We guarantee 2-byte alignment for nodes */
 typedef struct MDB_node {
-#define mn_pgno		 mn_p.np_pgno
-#define mn_dsize	 mn_p.np_dsize
-	union {
-		pgno_t		 np_pgno;	/* child page number */
-		uint32_t	 np_dsize;	/* leaf data size */
-	} mn_p;
-	unsigned int	mn_flags:4;
-	unsigned int	mn_ksize:12;			/* key size */
+	/* lo and hi are used for data size on leaf nodes and for
+	 * child pgno on branch nodes. On 64 bit platforms, flags
+	 * is also used for pgno. (branch nodes ignore flags)
+	 */
+	unsigned short	mn_lo;
+	unsigned short	mn_hi;
+	unsigned short	mn_flags;
 #define F_BIGDATA	 0x01			/* data put on overflow page */
 #define F_SUBDATA	 0x02			/* data is a sub-database */
 #define F_DUPDATA	 0x04			/* data has duplicates */
+	unsigned short	mn_ksize;				/* key size */
 	char		mn_data[1];
 } MDB_node;
 
@@ -455,8 +456,19 @@ struct MDB_env {
 #define NODEPTR(p, i)	 ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i]))
 #define NODEKEY(node)	 (void *)((node)->mn_data)
 #define NODEDATA(node)	 (void *)((char *)(node)->mn_data + (node)->mn_ksize)
-#define NODEPGNO(node)	 ((node)->mn_pgno)
-#define NODEDSZ(node)	 ((node)->mn_dsize)
+#if LONG_MAX == 0x7fffffff
+#define NODEPGNO(node)	 ((node)->mn_lo | ((node)->mn_hi << 16))
+#define SETPGNO(node,pgno)	do { \
+	(node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16;} while(0)
+#else
+#define NODEPGNO(node)	 ((node)->mn_lo | ((node)->mn_hi << 16) | ((unsigned long)(node)->mn_flags << 32))
+#define SETPGNO(node,pgno)	do { \
+	(node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
+	(node)->mn_flags = (pgno) >> 32; } while(0)
+#endif
+#define NODEDSZ(node)	 ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
+#define SETDSZ(node,size)	do { \
+	(node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
 #define NODEKSZ(node)	 ((node)->mn_ksize)
 #define LEAF2KEY(p, i, ks)	((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
 
@@ -486,10 +498,6 @@ static int  mdb_add_node(MDB_txn *txn, MDB_dbi dbi, MDB_page *mp,
 static void mdb_del_node(MDB_page *mp, indx_t indx, int ksize);
 static int mdb_del0(MDB_cursor *mc, unsigned int ki,
     MDB_pageparent *mpp, MDB_node *leaf);
-#if 0
-static int mdb_put0(MDB_txn *txn, MDB_dbi dbi,
-    MDB_val *key, MDB_val *data, unsigned int flags);
-#endif
 static int  mdb_read_data(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
 
 static int	mdb_rebalance(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *mp);
@@ -753,7 +761,7 @@ mdb_touch(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *pp)
 
 		/* Update the page number to new touched page. */
 		if (pp->mp_parent != NULL)
-			NODEPGNO(NODEPTR(pp->mp_parent, pp->mp_pi)) = mp->mp_pgno;
+			SETPGNO(NODEPTR(pp->mp_parent, pp->mp_pi), mp->mp_pgno);
 		pp->mp_page = mp;
 	}
 	return 0;
@@ -2267,14 +2275,14 @@ mdb_read_data(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
 	int rc;
 
 	if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
-		data->mv_size = leaf->mn_dsize;
+		data->mv_size = NODEDSZ(leaf);
 		data->mv_data = NODEDATA(leaf);
 		return MDB_SUCCESS;
 	}
 
 	/* Read overflow data.
 	 */
-	data->mv_size = leaf->mn_dsize;
+	data->mv_size = NODEDSZ(leaf);
 	memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
 	if ((rc = mdb_get_page(txn, pgno, &omp))) {
 		DPRINTF("read overflow page %lu failed", pgno);
@@ -3344,9 +3352,9 @@ mdb_add_node(MDB_txn *txn, MDB_dbi dbi, MDB_page *mp, indx_t indx,
 	node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
 	node->mn_flags = flags;
 	if (IS_LEAF(mp))
-		node->mn_dsize = data->mv_size;
+		SETDSZ(node,data->mv_size);
 	else
-		NODEPGNO(node) = pgno;
+		SETPGNO(node,pgno);
 
 	if (key)
 		memcpy(NODEKEY(node), key->mv_data, key->mv_size);
@@ -4199,7 +4207,7 @@ newsep:
 			rkey.mv_size = node->mn_ksize;
 			if (IS_LEAF(&mdp->p)) {
 				rdata.mv_data = NODEDATA(node);
-				rdata.mv_size = node->mn_dsize;
+				rdata.mv_size = NODEDSZ(node);
 			} else
 				pgno = NODEPGNO(node);
 			flags = node->mn_flags;
@@ -4226,164 +4234,6 @@ newsep:
 	return rc;
 }
 
-#if 0
-static int
-mdb_put0(MDB_txn *txn, MDB_dbi dbi,
-    MDB_val *key, MDB_val *data, unsigned int flags)
-{
-	int		 rc = MDB_SUCCESS, exact;
-	unsigned int	 ki;
-	MDB_node	*leaf;
-	MDB_pageparent	mpp;
-	MDB_val	xdata, *rdata, dkey;
-	MDB_db dummy;
-	char dbuf[PAGESIZE];
-	int do_sub = 0;
-	size_t nsize;
-	DKBUF;
-
-	DPRINTF("==> put db %u key [%s], size %zu, data size %zu",
-		dbi, DKEY(key), key->mv_size, data->mv_size);
-
-	dkey.mv_size = 0;
-	mpp.mp_parent = NULL;
-	mpp.mp_pi = 0;
-	rc = mdb_search_page(txn, dbi, key, NULL, 1, &mpp);
-	if (rc == MDB_SUCCESS) {
-		leaf = mdb_search_node(txn, dbi, mpp.mp_page, key, &exact, &ki);
-		if (leaf && exact) {
-			if (flags == MDB_NOOVERWRITE) {
-				DPRINTF("duplicate key [%s]", DKEY(key));
-				return MDB_KEYEXIST;
-			}
-			/* there's only a key anyway, so this is a no-op */
-			if (IS_LEAF2(mpp.mp_page))
-				return MDB_SUCCESS;
-
-			if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
-				/* Was a single item before, must convert now */
-				if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-					dkey.mv_size = NODEDSZ(leaf);
-					dkey.mv_data = dbuf;
-					memcpy(dbuf, NODEDATA(leaf), dkey.mv_size);
-					/* data matches, ignore it */
-					if (!mdb_dcmp(txn, dbi, data, &dkey))
-						return (flags == MDB_NODUPDATA) ? MDB_KEYEXIST : MDB_SUCCESS;
-					memset(&dummy, 0, sizeof(dummy));
-					if (txn->mt_dbs[dbi].md_flags & MDB_DUPFIXED) {
-						dummy.md_pad = data->mv_size;
-						dummy.md_flags = MDB_DUPFIXED;
-						if (txn->mt_dbs[dbi].md_flags & MDB_INTEGERDUP)
-							dummy.md_flags |= MDB_INTEGERKEY;
-					}
-					dummy.md_root = P_INVALID;
-					if (dkey.mv_size == sizeof(MDB_db)) {
-						memcpy(NODEDATA(leaf), &dummy, sizeof(dummy));
-						goto put_sub;
-					}
-					mdb_del_node(mpp.mp_page, ki, 0);
-					do_sub = 1;
-					rdata = &xdata;
-					xdata.mv_size = sizeof(MDB_db);
-					xdata.mv_data = &dummy;
-					goto new_sub;
-				}
-				goto put_sub;
-			}
-			/* same size, just replace it */
-			if (!F_ISSET(leaf->mn_flags, F_BIGDATA) &&
-				NODEDSZ(leaf) == data->mv_size) {
-				memcpy(NODEDATA(leaf), data->mv_data, data->mv_size);
-				goto done;
-			}
-			mdb_del_node(mpp.mp_page, ki, 0);
-		}
-		if (leaf == NULL) {		/* append if not found */
-			ki = NUMKEYS(mpp.mp_page);
-			DPRINTF("appending key at index %i", ki);
-		}
-	} else if (rc == MDB_NOTFOUND) {
-		MDB_dpage *dp;
-		/* new file, just write a root leaf page */
-		DPUTS("allocating new root leaf page");
-		if ((dp = mdb_new_page(txn, dbi, P_LEAF, 1)) == NULL) {
-			return ENOMEM;
-		}
-		mpp.mp_page = &dp->p;
-		txn->mt_dbs[dbi].md_root = mpp.mp_page->mp_pgno;
-		txn->mt_dbs[dbi].md_depth++;
-		txn->mt_dbxs[dbi].md_dirty = 1;
-		if ((txn->mt_dbs[dbi].md_flags & (MDB_DUPSORT|MDB_DUPFIXED)) == MDB_DUPFIXED)
-			mpp.mp_page->mp_flags |= P_LEAF2;
-		ki = 0;
-	}
-	else
-		goto done;
-
-	assert(IS_LEAF(mpp.mp_page));
-	DPRINTF("there are %u keys, should insert new key at index %i",
-		NUMKEYS(mpp.mp_page), ki);
-
-	rdata = data;
-
-new_sub:
-	nsize = IS_LEAF2(mpp.mp_page) ? key->mv_size : mdb_leaf_size(txn->mt_env, key, rdata);
-	if (SIZELEFT(mpp.mp_page) < nsize) {
-		rc = mdb_split(txn, dbi, &mpp.mp_page, &ki, key, rdata, P_INVALID);
-	} else {
-		/* There is room already in this leaf page. */
-		rc = mdb_add_node(txn, dbi, mpp.mp_page, ki, key, rdata, 0, 0);
-	}
-
-	if (rc != MDB_SUCCESS)
-		txn->mt_flags |= MDB_TXN_ERROR;
-	else {
-		/* Remember if we just added a subdatabase */
-		if (flags & F_SUBDATA) {
-			leaf = NODEPTR(mpp.mp_page, ki);
-			leaf->mn_flags |= F_SUBDATA;
-		}
-
-		/* Now store the actual data in the child DB. Note that we're
-		 * storing the user data in the keys field, so there are strict
-		 * size limits on dupdata. The actual data fields of the child
-		 * DB are all zero size.
-		 */
-		if (do_sub) {
-			MDB_cursor mc;
-			MDB_xcursor mx;
-
-			leaf = NODEPTR(mpp.mp_page, ki);
-put_sub:
-			mc.mc_txn = txn;
-			mc.mc_dbi = dbi;
-			mc.mc_flags = 0;
-			mc.mc_xcursor = &mx;
-			mdb_xcursor_init0(&mc);
-			mdb_xcursor_init1(txn, dbi, &mx, mpp.mp_page, leaf);
-			xdata.mv_size = 0;
-			xdata.mv_data = "";
-			if (flags == MDB_NODUPDATA)
-				flags = MDB_NOOVERWRITE;
-			/* converted, write the original data first */
-			if (dkey.mv_size) {
-				rc = mdb_put0(&mx.mx_txn, mx.mx_cursor.mc_dbi, &dkey, &xdata, flags);
-				if (rc) return rc;
-				leaf->mn_flags |= F_DUPDATA;
-			}
-			rc = mdb_put0(&mx.mx_txn, mx.mx_cursor.mc_dbi, data, &xdata, flags);
-			mdb_xcursor_fini(&mc);
-			memcpy(NODEDATA(leaf), &mx.mx_txn.mt_dbs[mx.mx_cursor.mc_dbi],
-				sizeof(MDB_db));
-		}
-		txn->mt_dbs[dbi].md_entries++;
-	}
-
-done:
-	return rc;
-}
-#endif
-
 int
 mdb_put(MDB_txn *txn, MDB_dbi dbi,
     MDB_val *key, MDB_val *data, unsigned int flags)