First cut at DUPFIXED support

Also in cursor_set, check the current page (if already set from
before) before starting over again from the root.

libraries/libmdb/Makefile

@@ -24,6 +24,7 @@ mdb_stat: mdb_stat.o libmdb.a
 mtest:    mtest.o    libmdb.a
 mtest2:	mtest2.o libmdb.a
 mtest3:	mtest3.o libmdb.a
+mtest4:	mtest4.o libmdb.a
 
 mdb.o: mdb.c mdb.h midl.h
 	$(CC) $(CFLAGS) -fPIC $(CPPFLAGS) -c mdb.c

libraries/libmdb/mdb.h

@@ -70,9 +70,11 @@ typedef enum MDB_cursor_op {		/* cursor operations */
 	MDB_FIRST,
 	MDB_GET_BOTH,			/* position at key/data */
 	MDB_GET_BOTH_RANGE,		/* position at key, nearest data */
+	MDB_GET_MULTIPLE,		/* only for MDB_DUPFIXED */
 	MDB_LAST,
 	MDB_NEXT,
 	MDB_NEXT_DUP,
+	MDB_NEXT_MULTIPLE,		/* only for MDB_DUPFIXED */
 	MDB_NEXT_NODUP,
 	MDB_PREV,
 	MDB_PREV_DUP,
@@ -95,6 +97,8 @@ typedef enum MDB_cursor_op {		/* cursor operations */
 #define MDB_REVERSEKEY	0x02		/* use reverse string keys */
 #define MDB_DUPSORT		0x04		/* use sorted duplicates */
 #define MDB_INTEGERKEY	0x08		/* numeric keys in native byte order */
+#define MDB_DUPFIXED	0x10		/* sorted dup items have fixed size */
+#define MDB_INTEGERDUP	0x20		/* numeric dups in native byte order */
 
 /* environment flags */
 #define MDB_FIXEDMAP	0x01		/* mmap at a fixed address */

libraries/libmdb/mtest4.c

+/* mtest4.c - memory-mapped database tester/toy */
+/*
+ * Copyright 2011 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>.
+ */
+
+/* Tests for sorted duplicate DBs with fixed-size keys */
+#define _XOPEN_SOURCE 500		/* srandom(), random() */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include "mdb.h"
+
+int main(int argc,char * argv[])
+{
+	int i = 0, j = 0, rc;
+	MDB_env *env;
+	MDB_dbi dbi;
+	MDB_val key, data;
+	MDB_txn *txn;
+	MDB_stat mst;
+	MDB_cursor *cursor;
+	int count;
+	int *values;
+	char sval[8];
+	char kval[sizeof(int)];
+
+	memset(sval, 0, sizeof(sval));
+
+	count = 510;
+	values = (int *)malloc(count*sizeof(int));
+
+	for(i = 0;i<count;i++) {
+		values[i] = i*5;
+	}
+
+	rc = mdb_env_create(&env);
+	rc = mdb_env_set_mapsize(env, 10485760);
+	rc = mdb_env_set_maxdbs(env, 4);
+	rc = mdb_env_open(env, "./testdb", MDB_FIXEDMAP|MDB_NOSYNC, 0664);
+	rc = mdb_txn_begin(env, 0, &txn);
+	rc = mdb_open(txn, "id2", MDB_CREATE|MDB_DUPSORT|MDB_DUPFIXED, &dbi);
+
+	key.mv_size = sizeof(int);
+	key.mv_data = kval;
+	data.mv_size = sizeof(sval);
+	data.mv_data = sval;
+
+	printf("Adding %d values\n", count);
+	strcpy(kval, "001");
+	for (i=0;i<count;i++) {
+		sprintf(sval, "%07x", values[i]);
+		rc = mdb_put(txn, dbi, &key, &data, MDB_NODUPDATA);
+		if (rc) j++;
+	}
+	if (j) printf("%d duplicates skipped\n", j);
+	rc = mdb_txn_commit(txn);
+	rc = mdb_env_stat(env, &mst);
+
+	/* there should be one full page of dups now.
+	 */
+	rc = mdb_txn_begin(env, 1, &txn);
+	rc = mdb_cursor_open(txn, dbi, &cursor);
+	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
+		printf("key: %p %.*s, data: %p %.*s\n",
+			key.mv_data,  (int) key.mv_size,  (char *) key.mv_data,
+			data.mv_data, (int) data.mv_size, (char *) data.mv_data);
+	}
+	mdb_cursor_close(cursor);
+	mdb_txn_abort(txn);
+
+	/* test all 3 branches of split code:
+	 * 1: new key in lower half
+	 * 2: new key at split point
+	 * 3: new key in upper half
+	 */
+
+	key.mv_size = sizeof(int);
+	key.mv_data = kval;
+	data.mv_size = sizeof(sval);
+	data.mv_data = sval;
+
+	sprintf(sval, "%07x", values[3]+1);
+	rc = mdb_txn_begin(env, 0, &txn);
+	rc = mdb_put(txn, dbi, &key, &data, MDB_NODUPDATA);
+	mdb_txn_abort(txn);
+
+	sprintf(sval, "%07x", values[255]+1);
+	rc = mdb_txn_begin(env, 0, &txn);
+	rc = mdb_put(txn, dbi, &key, &data, MDB_NODUPDATA);
+	mdb_txn_abort(txn);
+
+	sprintf(sval, "%07x", values[500]+1);
+	rc = mdb_txn_begin(env, 0, &txn);
+	rc = mdb_put(txn, dbi, &key, &data, MDB_NODUPDATA);
+	rc = mdb_txn_commit(txn);
+
+	/* Try MDB_NEXT_MULTIPLE */
+	rc = mdb_txn_begin(env, 0, &txn);
+	rc = mdb_cursor_open(txn, dbi, &cursor);
+	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT_MULTIPLE)) == 0) {
+		printf("key: %.*s, data: %.*s\n",
+			(int) key.mv_size,  (char *) key.mv_data,
+			(int) data.mv_size, (char *) data.mv_data);
+	}
+	mdb_cursor_close(cursor);
+	mdb_txn_abort(txn);
+	j=0;
+
+	for (i= count - 1; i > -1; i-= (random()%3)) {
+		j++;
+		txn=NULL;
+		rc = mdb_txn_begin(env, 0, &txn);
+		sprintf(sval, "%07x", values[i]);
+		key.mv_size = sizeof(int);
+		key.mv_data = kval;
+		data.mv_size = sizeof(sval);
+		data.mv_data = sval;
+		rc = mdb_del(txn, dbi, &key, &data, MDB_DEL_DUP);
+		if (rc) {
+			j--;
+			mdb_txn_abort(txn);
+		} else {
+			rc = mdb_txn_commit(txn);
+		}
+	}
+	free(values);
+	printf("Deleted %d values\n", j);
+
+	rc = mdb_env_stat(env, &mst);
+	rc = mdb_txn_begin(env, 1, &txn);
+	rc = mdb_cursor_open(txn, dbi, &cursor);
+	printf("Cursor next\n");
+	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
+		printf("key: %.*s, data: %.*s\n",
+			(int) key.mv_size,  (char *) key.mv_data,
+			(int) data.mv_size, (char *) data.mv_data);
+	}
+	printf("Cursor prev\n");
+	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_PREV)) == 0) {
+		printf("key: %.*s, data: %.*s\n",
+			(int) key.mv_size,  (char *) key.mv_data,
+			(int) data.mv_size, (char *) data.mv_data);
+	}
+	mdb_cursor_close(cursor);
+	mdb_close(txn, dbi);
+
+	mdb_txn_abort(txn);
+	mdb_env_close(env);
+
+	return 0;
+}