added TDB_MODIFY flag - patch from from luke

(This used to be commit 90b574296e06cd6ed4fedc1e5a8ae412a5e78b45)

3 files changed, 30 insertions, 5 deletions

diff --git a/source3/tdb/README b/source3/tdb/README
index 9eef521075..96fdcf5c99 100644
--- a/source3/tdb/README
+++ b/source3/tdb/README
@@ -137,6 +137,9 @@ int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag);
    store an element in the database, replacing any existing element
    with the same key 
 
+   If flag==TDB_INSERT then don't overwrite an existing entry
+   If flag==TDB_MODIFY then don't create a new entry
+
    return 0 on success, -1 on failure
 
 ----------------------------------------------------------------------
diff --git a/source3/tdb/tdb.c b/source3/tdb/tdb.c
index 5f30db21e4..3b85b71217 100644
--- a/source3/tdb/tdb.c
+++ b/source3/tdb/tdb.c
@@ -2,7 +2,8 @@
    Unix SMB/Netbios implementation.
    Version 3.0
    Samba database functions
-   Copyright (C) Andrew Tridgell 1999
+   Copyright (C) Andrew Tridgell              1999-2000
+   Copyright (C) Luke Kenneth Casson Leighton      2000
    
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -600,6 +601,7 @@ char *tdb_error(TDB_CONTEXT *tdb)
 		{TDB_ERR_LOCK, "Locking error"},
 		{TDB_ERR_OOM, "Out of memory"},
 		{TDB_ERR_EXISTS, "Record exists"},
+		{TDB_ERR_NOEXIST, "Record does not exist"},
 		{-1, NULL}};
         if (tdb != NULL) {
             for (i=0;emap[i].estring;i++) {
@@ -630,14 +632,19 @@ int tdb_update(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf)
             return -1;
         }
 
+	/* initialise error code to ok, first */
+	tdb->ecode = 0;
+
 	/* find which hash bucket it is in */
 	hash = tdb_hash(&key);
 
 	tdb_lock(tdb, BUCKET(hash));
 	rec_ptr = tdb_find(tdb, key, hash, &rec);
 
-	if (!rec_ptr)
+	if (!rec_ptr) {
+		tdb->ecode = TDB_ERR_NOEXIST;
 		goto out;
+	}
 
 	/* must be long enough */
 	if (rec.rec_len < key.dsize + dbuf.dsize)
@@ -1025,17 +1032,31 @@ int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag)
 	/* find which hash bucket it is in */
 	hash = tdb_hash(&key);
 
-	/* check for it existing */
+	/* check for it existing, on insert. */
 	if (flag == TDB_INSERT && tdb_exists(tdb, key)) {
 		tdb->ecode = TDB_ERR_EXISTS;
 		return -1;
 	}
 
-	/* first try in-place update */
+	/* first try in-place update, on modify or replace. */
 	if (flag != TDB_INSERT && tdb_update(tdb, key, dbuf) == 0) {
 		return 0;
 	}
 
+	/* check for it _not_ existing, from error code of the update. */
+	if (flag == TDB_MODIFY && tdb->ecode == TDB_ERR_NOEXIST) {
+		return -1;
+	}
+
+	/* reset the error code potentially set by the tdb_update() */
+	tdb->ecode = 0;
+
+	/*
+	 * now we're into insert / modify / replace of a record
+	 * which we know could not be optimised by an in-place
+	 * store (for various reasons).
+	 */
+
 	rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize);
 	if (rec_ptr == 0) {
 		return -1;
diff --git a/source3/tdb/tdb.h b/source3/tdb/tdb.h
index 949a843e8a..90a1cccfac 100644
--- a/source3/tdb/tdb.h
+++ b/source3/tdb/tdb.h
@@ -51,13 +51,14 @@ typedef struct {
 /* flags to tdb_store() */
 #define TDB_REPLACE 1
 #define TDB_INSERT 2
+#define TDB_MODIFY 3
 
 /* flags for tdb_open() */
 #define TDB_CLEAR_IF_FIRST 1
 
 /* error codes */
 enum TDB_ERROR {TDB_SUCCESS=0, TDB_ERR_CORRUPT, TDB_ERR_IO, TDB_ERR_LOCK, 
-		TDB_ERR_OOM, TDB_ERR_EXISTS};
+		TDB_ERR_OOM, TDB_ERR_EXISTS, TDB_ERR_NOEXIST };
 
 typedef int (*tdb_traverse_func)(TDB_CONTEXT *, TDB_DATA, TDB_DATA, void *);