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authorRusty Russell <rusty@rustcorp.com.au>2011-06-20 16:58:15 +0930
committerRusty Russell <rusty@rustcorp.com.au>2011-06-20 11:18:34 +0200
commit61bf43f5d17c9ac3fc9a36cab74a81f26ac97ccb (patch)
treefaa7f5e9176338f3d9e236860c57cd26132a7864 /lib/tdb_compat
parenteb8cb4f5486ec8648527e78c110b9167887ee479 (diff)
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lib/tdb_compat: header for tdb1 vs tdb2.
TDB2's API is slightly different from TDB1. In particular, all functions return 0 (TDB_SUCCESS) or a negative error number, rather than -1 or tdb_null and storing the error in tdb_error() (though TDB2 does that as well). The simplest fix is to replace all the different functions with a wrapper, and that is done here. Compatibility functions: tdb_null: not used as an error return, so not defined by tdb2. tdb_fetch_compat: TDB1-style data-returning tdb_fetch. tdb_firstkey_compat: TDB1-style data-returning tdb_firstkey tdb_nextkey_compat: TDB1-style data-returning tdb_nextkey, with TDB2-style free of old key. tdb_errorstr_compat: TDB1-style tdb_errorstr() which takes TDB instead of ecode. TDB_CONTEXT: TDB1-style typedef for struct tdb_context. tdb_open_compat: Simplified open routine which takes log function, sets TDB_ALLOW_NESTING as Samba expects, and adds TDB_CLEAR_IF_FIRST support. Things defined away in TDB2 wrappers: tdb_traverse_read: TDB2's tdb_traverse only uses read-locks anyway. tdb_reopen/tdb_reopen_all: TDB2 detects this error itself. TDB_INCOMPATIBLE_HASH: TDB2 uses the Jenkins hash already. TDB_VOLATILE: TDB2 shouldn't have freelist scaling issues. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'lib/tdb_compat')
-rw-r--r--lib/tdb_compat/tdb_compat.c96
-rw-r--r--lib/tdb_compat/tdb_compat.h136
-rw-r--r--lib/tdb_compat/wscript7
3 files changed, 239 insertions, 0 deletions
diff --git a/lib/tdb_compat/tdb_compat.c b/lib/tdb_compat/tdb_compat.c
new file mode 100644
index 0000000000..f432296a40
--- /dev/null
+++ b/lib/tdb_compat/tdb_compat.c
@@ -0,0 +1,96 @@
+#include <tdb_compat.h>
+
+/* Note: for the moment, we only need this file for TDB2, so we can
+ * assume waf. */
+#if BUILD_TDB2
+TDB_DATA tdb_null = { NULL, 0 };
+
+/* Proxy which sets waitflag to false so we never block. */
+static int lock_nonblock(int fd, int rw, off_t off, off_t len, bool waitflag,
+ void *_orig)
+{
+ struct tdb_attribute_flock *orig = _orig;
+
+ return orig->lock(fd, rw, off, len, false, orig->data);
+}
+
+enum TDB_ERROR tdb_transaction_start_nonblock(struct tdb_context *tdb)
+{
+ union tdb_attribute locking, orig;
+ enum TDB_ERROR ecode;
+
+ orig.base.attr = TDB_ATTRIBUTE_FLOCK;
+ ecode = tdb_get_attribute(tdb, &orig);
+ if (ecode != TDB_SUCCESS)
+ return ecode;
+
+ /* Replace locking function with our own. */
+ locking = orig;
+ locking.flock.data = &orig;
+ locking.flock.lock = lock_nonblock;
+
+ ecode = tdb_set_attribute(tdb, &locking);
+ if (ecode != TDB_SUCCESS)
+ return ecode;
+
+ ecode = tdb_transaction_start(tdb);
+ tdb_unset_attribute(tdb, TDB_ATTRIBUTE_FLOCK);
+ return ecode;
+}
+
+/*
+ * This handles TDB_CLEAR_IF_FIRST.
+ */
+static enum TDB_ERROR clear_if_first(int fd, void *unused)
+{
+ /* We hold a lock offset 63 always, so we can tell if anyone else is. */
+ struct flock fl;
+
+ fl.l_type = F_WRLCK;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = 63;
+ fl.l_len = 1;
+
+ if (fcntl(fd, F_SETLK, &fl) == 0) {
+ /* We must be first ones to open it w/ TDB_CLEAR_IF_FIRST! */
+ if (ftruncate(fd, 0) != 0) {
+ return TDB_ERR_IO;
+ }
+ }
+ fl.l_type = F_RDLCK;
+ if (fcntl(fd, F_SETLKW, &fl) != 0) {
+ return TDB_ERR_IO;
+ }
+ return TDB_SUCCESS;
+}
+
+struct tdb_context *
+tdb_open_compat_(const char *name, int hash_size_unused,
+ int tdb_flags, int open_flags, mode_t mode,
+ void (*log_fn)(struct tdb_context *,
+ enum tdb_log_level,
+ const char *message,
+ void *data),
+ void *log_data)
+{
+ union tdb_attribute cif, log, *attr = NULL;
+
+ if (log_fn) {
+ log.log.base.attr = TDB_ATTRIBUTE_LOG;
+ log.log.base.next = NULL;
+ log.log.fn = log_fn;
+ log.log.data = log_data;
+ attr = &log;
+ }
+
+ if (tdb_flags & TDB_CLEAR_IF_FIRST) {
+ cif.openhook.base.attr = TDB_ATTRIBUTE_OPENHOOK;
+ cif.openhook.base.next = attr;
+ cif.openhook.fn = clear_if_first;
+ attr = &cif;
+ tdb_flags &= ~TDB_CLEAR_IF_FIRST;
+ }
+ return tdb_open(name, tdb_flags|TDB_ALLOW_NESTING, open_flags, mode,
+ attr);
+}
+#endif
diff --git a/lib/tdb_compat/tdb_compat.h b/lib/tdb_compat/tdb_compat.h
new file mode 100644
index 0000000000..ea401cba49
--- /dev/null
+++ b/lib/tdb_compat/tdb_compat.h
@@ -0,0 +1,136 @@
+/*
+ Unix SMB/CIFS implementation.
+
+ Compatibility layer for TDB1 vs TDB2.
+
+ Copyright (C) Rusty Russell 2011
+
+ ** NOTE! The following LGPL license applies to the tdb_compat
+ ** library. This does NOT imply that all of Samba is released
+ ** under the LGPL
+
+ 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
+ version 3 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+#ifndef TDB_COMPAT_H
+#define TDB_COMPAT_H
+
+#include "replace.h"
+#include <ccan/typesafe_cb/typesafe_cb.h>
+#if BUILD_TDB2
+#include <tdb2.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+extern TDB_DATA tdb_null;
+
+/* Old-style tdb_fetch. */
+static inline TDB_DATA tdb_fetch_compat(struct tdb_context *tdb, TDB_DATA k)
+{
+ TDB_DATA dbuf;
+ if (tdb_fetch(tdb, k, &dbuf) != TDB_SUCCESS) {
+ return tdb_null;
+ }
+ return dbuf;
+}
+
+static inline TDB_DATA tdb_firstkey_compat(struct tdb_context *tdb)
+{
+ TDB_DATA k;
+ if (tdb_firstkey(tdb, &k) != TDB_SUCCESS) {
+ return tdb_null;
+ }
+ return k;
+}
+
+/* Note: this frees the old key.dptr. */
+static inline TDB_DATA tdb_nextkey_compat(struct tdb_context *tdb, TDB_DATA k)
+{
+ if (tdb_nextkey(tdb, &k) != TDB_SUCCESS) {
+ return tdb_null;
+ }
+ return k;
+}
+
+/* tdb_traverse_read and tdb_traverse are equal: both only take read locks. */
+#define tdb_traverse_read tdb_traverse
+
+/* Old-style tdb_errorstr */
+#define tdb_errorstr_compat(tdb) tdb_errorstr(tdb_error(tdb))
+
+/* This typedef doesn't exist in TDB2. */
+typedef struct tdb_context TDB_CONTEXT;
+
+/* We don't need these any more. */
+#define tdb_reopen_all(flag) 0
+#define tdb_reopen(tdb) 0
+
+/* These no longer exist in tdb2. */
+#define TDB_CLEAR_IF_FIRST 1048576
+#define TDB_INCOMPATIBLE_HASH 0
+#define TDB_VOLATILE 0
+
+/* tdb2 does nonblocking functions via attibutes. */
+enum TDB_ERROR tdb_transaction_start_nonblock(struct tdb_context *tdb);
+
+/* Convenient (typesafe) wrapper for tdb open with logging */
+#define tdb_open_compat(name, hsize, tdb_fl, open_fl, mode, log_fn, log_data) \
+ tdb_open_compat_((name), (hsize), (tdb_fl), (open_fl), (mode), \
+ typesafe_cb_preargs(void, void *, \
+ (log_fn), (log_data), \
+ struct tdb_context *, \
+ enum tdb_log_level, \
+ const char *), \
+ (log_data))
+
+struct tdb_context *
+tdb_open_compat_(const char *name, int hash_size_unused,
+ int tdb_flags, int open_flags, mode_t mode,
+ void (*log_fn)(struct tdb_context *,
+ enum tdb_log_level,
+ const char *message,
+ void *data),
+ void *log_data);
+#else
+#include <tdb.h>
+
+/* FIXME: Inlining this is a bit lazy, but eases S3 build. */
+static inline struct tdb_context *
+tdb_open_compat(const char *name, int hash_size,
+ int tdb_flags, int open_flags, mode_t mode,
+ tdb_log_func log_fn, void *log_private)
+{
+ struct tdb_logging_context lctx;
+ lctx.log_fn = log_fn;
+ lctx.log_private = log_private;
+
+ if (log_fn)
+ return tdb_open_ex(name, hash_size, tdb_flags, open_flags,
+ mode, &lctx, NULL);
+ else
+ return tdb_open(name, hash_size, tdb_flags, open_flags, mode);
+}
+
+#define tdb_firstkey_compat tdb_firstkey
+/* Note: this frees the old key.dptr. */
+static inline TDB_DATA tdb_nextkey_compat(struct tdb_context *tdb, TDB_DATA k)
+{
+ TDB_DATA next = tdb_nextkey(tdb, k);
+ free(k.dptr);
+ return next;
+}
+#define tdb_errorstr_compat(tdb) tdb_errorstr(tdb)
+#define tdb_fetch_compat tdb_fetch
+#endif
+
+#endif /* TDB_COMPAT_H */
diff --git a/lib/tdb_compat/wscript b/lib/tdb_compat/wscript
new file mode 100644
index 0000000000..14be4e7fe0
--- /dev/null
+++ b/lib/tdb_compat/wscript
@@ -0,0 +1,7 @@
+#!/usr/bin/env python
+
+def build(bld):
+ bld.SAMBA_LIBRARY('tdb_compat',
+ source='tdb_compat.c',
+ deps='replace tdb',
+ private_library=True)