Added new bdb_encode/bdb_decode functions, must #define BDB_USE_BINARY_RW

to activate. The bdb_decode works in-place on the db data. Add/Search are
OK, I think Modify needs to be tweaked. Don't use this yet unless you want
to help finish it.

servers/slapd/back-bdb/id2entry.c

@@ -12,6 +12,190 @@
 
 #include "back-bdb.h"
 
+#ifdef BDB_USE_BINARY_RW
+
+/* A cache of every AttributeDescription we ever see. We don't want
+ * to churn thru malloc/free on them all the time since most will be
+ * encountered repeatedly.
+ */
+static Avlnode *adcache;
+
+static int
+ad_type_cmp(
+	char *desc,
+	AttributeDescription *ad
+)
+{
+	return strcasecmp(desc, ad->ad_cname->bv_val);
+}
+
+static int
+ad_info_cmp(
+	AttributeDescription *a1,
+	AttributeDescription *a2
+)
+{
+	return strcasecmp(a1->ad_cname->bv_val, a2->ad_cname->bv_val);
+}
+
+AttributeDescription *
+bdb_str2ad(const char *desc)
+{
+	AttributeDescription *a;
+
+	a = (AttributeDescription *) avl_find(adcache, desc,
+		(AVL_CMP) ad_type_cmp);
+	if (!a) {
+		int rc;
+		const char *text;
+
+		rc = slap_str2ad(desc, &a, &text);
+		if (rc != LDAP_SUCCESS) {
+			return NULL;
+		}
+		rc = avl_insert(&adcache, (caddr_t)a, (AVL_CMP) ad_info_cmp,
+			(AVL_DUP) avl_dup_error);
+	}
+	return a;
+}
+
+/* Flatten an Entry into a buffer. The buffer contents become a direct
+ * copy of the entry, with all pointers converted to offsets from the
+ * beginning of the buffer. We do this by first walking through all
+ * the fields of the Entry, adding up their sizes. Then a single chunk
+ * of memory is malloc'd and the entry is copied. We differentiate between
+ * fixed size fields and variable-length content when tallying up the
+ * entry size, so that we can stick all of the variable-length stuff
+ * into the back half of the buffer.
+ */
+int bdb_encode(Entry *e, struct berval **bv)
+{
+	int siz = sizeof(Entry);
+	int len, dnlen;
+	int i, j;
+	Entry *f;
+	Attribute *a, *b;
+	struct berval **bvl, *bz;
+	char *ptr, *base, *data;
+
+	*bv = ch_malloc(sizeof(struct berval));
+	/* Compress any white space in the DN */
+	dn_validate(e->e_dn);
+	dnlen = strlen(e->e_dn);
+	/* The dn and ndn are always the same length */
+	len = dnlen + dnlen + 2;	/* two trailing NUL bytes */
+	for (a=e->e_attrs; a; a=a->a_next) {
+		/* For AttributeDesc, we only store the attr name */
+		siz += sizeof(Attribute);
+		len += a->a_desc->ad_cname->bv_len+1;
+		for (i=0; a->a_vals[i]; i++) {
+			siz += sizeof(struct berval *);
+			siz += sizeof(struct berval);
+			len += a->a_vals[i]->bv_len + 1;
+		}
+		siz += sizeof(struct berval *);	/* NULL pointer at end */
+	}
+	(*bv)->bv_len = siz + len;
+	(*bv)->bv_val = ch_malloc(siz+len);
+	base = (*bv)->bv_val;
+	ptr = base + siz;
+	f = (Entry *)base;
+	data = (char *)(f+1);
+	f->e_id = e->e_id;
+	f->e_dn = (char *)(ptr-base);
+	memcpy(ptr, e->e_dn, dnlen);
+	ptr += dnlen;
+	*ptr++ = '\0';
+	f->e_ndn = (char *)(ptr-base);
+	memcpy(ptr, e->e_ndn, dnlen);
+	ptr += dnlen;
+	*ptr++ = '\0';
+	f->e_attrs = e->e_attrs ? (Attribute *)sizeof(Entry) : NULL;
+	f->e_private = NULL;
+	for (a=e->e_attrs; a; a=a->a_next) {
+		b = (Attribute *)data;
+		data = (char *)(b+1);
+		b->a_desc = (AttributeDescription *)(ptr-base);
+		memcpy(ptr, a->a_desc->ad_cname->bv_val,
+			a->a_desc->ad_cname->bv_len);
+		ptr += a->a_desc->ad_cname->bv_len;
+		*ptr++ = '\0';
+		if (a->a_vals) {
+		    bvl = (struct berval **)data;
+		    b->a_vals = (struct berval **)(data-base);
+		    for (i=0; a->a_vals[i]; i++);
+		    data = (char *)(bvl+i+1);
+		    bz = (struct berval *)data;
+		    for (j=0; j<i; j++) {
+			    bz->bv_len = a->a_vals[j]->bv_len;
+			    if (a->a_vals[j]->bv_val) {
+				bz->bv_val = (char *)(ptr-base);
+				memcpy(ptr, a->a_vals[j]->bv_val, bz->bv_len);
+			    } else {
+			    	bz->bv_val = NULL;
+			    }
+			    ptr += bz->bv_len;
+			    *ptr++ = '\0';
+			    bvl[j] = (struct berval *)(data-base);
+			    bz++;
+			    data = (char *)bz;
+		    }
+		    bvl[j] = NULL;
+		} else {
+		    b->a_vals = NULL;
+		}
+
+		if (a->a_next)
+		    b->a_next = (Attribute *)(data-base);
+		else
+		    b->a_next = NULL;
+	}
+	return 0;
+}
+
+/* Retrieve an Entry that was stored using bdb_encode above.
+ * All we have to do is add the buffer address to all of the
+ * stored offsets. We also use the stored attribute names to
+ * pull AttributeDescriptions from our ad_cache.
+ */
+int bdb_decode(struct berval *bv, Entry **e)
+{
+	int i;
+	long base;
+	Attribute *a;
+	Entry *x = (Entry *)bv->bv_val;
+
+	base = (long)bv->bv_val;
+	x->e_dn += base;
+	x->e_ndn += base;
+	x->e_private = bv->bv_val + bv->bv_len;
+	if (x->e_attrs)
+		x->e_attrs = (Attribute *)((long)x->e_attrs+base);
+	for (a=x->e_attrs; a; a=a->a_next) {
+		if (a->a_next)
+			a->a_next = (Attribute *)((long)a->a_next+base);
+		a->a_desc=bdb_str2ad((char *)a->a_desc+base);
+		if (!a->a_desc) return -1;
+		if (a->a_vals) {
+			a->a_vals = (struct berval **)((long)a->a_vals+base);
+			for (i=0; a->a_vals[i]; i++) {
+				a->a_vals[i] = (struct berval *)
+					((long)a->a_vals[i]+base);
+				if (a->a_vals[i]->bv_val)
+				    a->a_vals[i]->bv_val += base;
+			}
+		}
+	}
+	*e = x;
+	return 0;
+}
+
+#define	entry_encode(a, b)	bdb_encode(a,b)
+#define	entry_decode(a, b)	bdb_decode(a,b)
+#define	entry_free(e)	ch_free(e)
+
+#endif	/* BDB_USE_BINARY_RW */
+
 int bdb_id2entry_add(
 	BackendDB *be,
 	DB_TXN *tid,
@@ -106,7 +290,9 @@ int bdb_id2entry(
 		(*e)->e_id = id;
 	}
 
+#ifndef BDB_USE_BINARY_RW
 	ch_free( data.data );
+#endif
 	return rc;
 }