X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Ftraverse.c;h=f8a2504dcd61489eb23bf7b84c8e0a88ced07f43;hp=d30c24cdde5cc837dd849a4eec2662dc2ef75dee;hb=dc9da1e34fe6a9d113fd57e116ebbc6d5bd54819;hpb=ee6f11b307599200a574208372bc962eff81a9b1

diff --git a/ccan/tdb2/traverse.c b/ccan/tdb2/traverse.c
index d30c24cd..f8a2504d 100644
--- a/ccan/tdb2/traverse.c
+++ b/ccan/tdb2/traverse.c
@@ -1,7 +1,7 @@
- /* 
+ /*
    Trivial Database 2: traverse function.
    Copyright (C) Rusty Russell 2010
-   
+
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
@@ -18,108 +18,82 @@
 #include "private.h"
 #include <ccan/likely/likely.h>
 
-static int64_t traverse(struct tdb_context *tdb, int ltype,
-			tdb_traverse_func fn, void *p)
+int64_t tdb_traverse_(struct tdb_context *tdb,
+		      int (*fn)(struct tdb_context *,
+				TDB_DATA, TDB_DATA, void *),
+		      void *p)
 {
-	uint64_t i, num, count = 0;
-	tdb_off_t off, prev_bucket;
-	struct tdb_used_record rec;
+	enum TDB_ERROR ecode;
+	struct traverse_info tinfo;
 	struct tdb_data k, d;
-	bool finish = false;
-
-	/* FIXME: Do we need to start at 0? */
-	prev_bucket = tdb_lock_list(tdb, 0, ltype, TDB_LOCK_WAIT);
-	if (prev_bucket != 0)
-		return -1;
-
-	num = (1ULL << tdb->header.v.hash_bits);
+	int64_t count = 0;
 
-	for (i = tdb_find_nonzero_off(tdb, hash_off(tdb, 0), num);
-	     i != num && !finish;
-	     i += tdb_find_nonzero_off(tdb, hash_off(tdb, i), num - i)) {
-		if (tdb_lock_list(tdb, i, ltype, TDB_LOCK_WAIT) != i)
-			goto fail;
-
-		off = tdb_read_off(tdb, hash_off(tdb, i));
-		if (off == TDB_OFF_ERR) {
-			tdb_unlock_list(tdb, i, ltype);
-			goto fail;
-		}
-
-		/* This race can happen, but look again. */
-		if (off == 0) {
-			tdb_unlock_list(tdb, i, ltype);
-			continue;
-		}
-
-		/* Drop previous lock. */
-		tdb_unlock_list(tdb, prev_bucket, ltype);
-		prev_bucket = i;
-
-		if (tdb_read_convert(tdb, off, &rec, sizeof(rec)) != 0)
-			goto fail;
-
-		k.dsize = rec_key_length(&rec);
-		d.dsize = rec_data_length(&rec);
-		if (ltype == F_RDLCK) {
-			/* Read traverses can keep the lock. */
-			k.dptr = (void *)tdb_access_read(tdb,
-							 off + sizeof(rec),
-							 k.dsize + d.dsize,
-							 false);
-		} else {
-			k.dptr = tdb_alloc_read(tdb, off + sizeof(rec),
-						k.dsize + d.dsize);
-		}
-		if (!k.dptr)
-			goto fail;
+	k.dptr = NULL;
+	for (ecode = first_in_hash(tdb, &tinfo, &k, &d.dsize);
+	     ecode == TDB_SUCCESS;
+	     ecode = next_in_hash(tdb, &tinfo, &k, &d.dsize)) {
 		d.dptr = k.dptr + k.dsize;
+		
 		count++;
-
-		if (ltype == F_WRLCK) {
-			/* Drop lock before calling out. */
-			tdb_unlock_list(tdb, i, ltype);
-		}
-
-		if (fn && fn(tdb, k, d, p))
-			finish = true;
-
-		if (ltype == F_WRLCK) {
+		if (fn && fn(tdb, k, d, p)) {
 			free(k.dptr);
-			/* Regain lock.  FIXME: Is this necessary? */
-			if (tdb_lock_list(tdb, i, ltype, TDB_LOCK_WAIT) != i)
-				return -1;
-
-			/* This makes deleting under ourselves a bit nicer. */
-			if (tdb_read_off(tdb, hash_off(tdb, i)) == off)
-				i++;
-		} else {
-			tdb_access_release(tdb, k.dptr);
-			i++;
+			tdb->last_error = TDB_SUCCESS;
+			return count;
 		}
+		free(k.dptr);
 	}
 
-	/* Drop final lock. */
-	tdb_unlock_list(tdb, prev_bucket, ltype);
+	if (ecode != TDB_ERR_NOEXIST) {
+		return tdb->last_error = ecode;
+	}
+	tdb->last_error = TDB_SUCCESS;
 	return count;
+}
+	
+enum TDB_ERROR tdb_firstkey(struct tdb_context *tdb, struct tdb_data *key)
+{
+	struct traverse_info tinfo;
 
-fail:
-	tdb_unlock_list(tdb, prev_bucket, ltype);
-	return -1;
+	return tdb->last_error = first_in_hash(tdb, &tinfo, key, NULL);
 }
 
-int64_t tdb_traverse(struct tdb_context *tdb, tdb_traverse_func fn, void *p)
+/* We lock twice, not very efficient.  We could keep last key & tinfo cached. */
+enum TDB_ERROR tdb_nextkey(struct tdb_context *tdb, struct tdb_data *key)
 {
-	return traverse(tdb, F_WRLCK, fn, p);
+	struct traverse_info tinfo;
+	struct hash_info h;
+	struct tdb_used_record rec;
+
+	tinfo.prev = find_and_lock(tdb, *key, F_RDLCK, &h, &rec, &tinfo);
+	free(key->dptr);
+	if (TDB_OFF_IS_ERR(tinfo.prev)) {
+		return tdb->last_error = tinfo.prev;
+	}
+	tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
+
+	return tdb->last_error = next_in_hash(tdb, &tinfo, key, NULL);
 }
-	
-int64_t tdb_traverse_read(struct tdb_context *tdb,
-			  tdb_traverse_func fn, void *p)
+
+static int wipe_one(struct tdb_context *tdb,
+		    TDB_DATA key, TDB_DATA data, enum TDB_ERROR *ecode)
+{
+	*ecode = tdb_delete(tdb, key);
+	return (*ecode != TDB_SUCCESS);
+}
+
+enum TDB_ERROR tdb_wipe_all(struct tdb_context *tdb)
 {
-	int64_t ret;
-	bool was_ro = tdb->read_only;
-	tdb->read_only = true;
-	ret = traverse(tdb, F_RDLCK, fn, p);
-	tdb->read_only = was_ro;
-	return ret;
+	enum TDB_ERROR ecode;
+	int64_t count;
+
+	ecode = tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT, false);
+	if (ecode != TDB_SUCCESS)
+		return tdb->last_error = ecode;
+
+	/* FIXME: Be smarter. */
+	count = tdb_traverse(tdb, wipe_one, &ecode);
+	if (count < 0)
+		ecode = count;
+	tdb_allrecord_unlock(tdb, F_WRLCK);
+	return tdb->last_error = ecode;
 }