Add an API to validate configuration strings.

9 files changed, 100 insertions, 3 deletions

diff --git a/build_win/wiredtiger.def b/build_win/wiredtiger.def
index 86096fb778d..25e7a01e0d9 100644
--- a/build_win/wiredtiger.def
+++ b/build_win/wiredtiger.def
@@ -1,6 +1,7 @@
 LIBRARY WIREDTIGER
 EXPORTS
     wiredtiger_config_parser_open
+    wiredtiger_config_validate
     wiredtiger_open
     wiredtiger_pack_close
     wiredtiger_pack_int
diff --git a/dist/api_config.py b/dist/api_config.py
index 83a57ad4e0d..0514b20c7c2 100644
--- a/dist/api_config.py
+++ b/dist/api_config.py
@@ -311,6 +311,21 @@ __wt_conn_config_discard(WT_SESSION_IMPL *session)
 
 \t__wt_free(session, conn->config_entries);
 }
+
+/*        
+ * __wt_conn_config_match --
+ *      Return the static configuration entry for a method.
+ */
+const WT_CONFIG_ENTRY *
+__wt_conn_config_match(const char *method)
+{
+\tconst WT_CONFIG_ENTRY *ep;
+
+\tfor (ep = config_entries; ep->method != NULL; ++ep)
+\t\tif (strcmp(method, ep->method) == 0)
+\t\t\treturn (ep);
+\treturn (NULL);
+}
 ''')
 
 tfile.close()
diff --git a/dist/s_export.list b/dist/s_export.list
index d3803bc3afa..c7f088bc2d5 100644
--- a/dist/s_export.list
+++ b/dist/s_export.list
@@ -1,5 +1,6 @@
 # List of OK external symbols.
 wiredtiger_config_parser_open
+wiredtiger_config_validate
 wiredtiger_open
 wiredtiger_pack_close
 wiredtiger_pack_int
diff --git a/dist/s_funcs.list b/dist/s_funcs.list
index 4bb9796c11f..9b343e21507 100644
--- a/dist/s_funcs.list
+++ b/dist/s_funcs.list
@@ -30,6 +30,7 @@ __wt_nlpo2_round
 __wt_print_huffman_code
 __wt_try_readlock
 wiredtiger_config_parser_open
+wiredtiger_config_validate
 wiredtiger_pack_int
 wiredtiger_pack_item
 wiredtiger_pack_str
diff --git a/examples/c/ex_all.c b/examples/c/ex_all.c
index 51c63e307c6..b27fcbfdcea 100644
--- a/examples/c/ex_all.c
+++ b/examples/c/ex_all.c
@@ -885,6 +885,11 @@ connection_ops(WT_CONNECTION *conn)
 	}
 	/*! [Check if the database is newly created] */
 
+	/*! [Validate a configuration string] */
+	ret = wiredtiger_config_validate(
+	    NULL, "session.create", "allocation_size=32KB");
+	/*! [Validate a configuration string] */
+
 	{
 	/*! [Open a session] */
 	WT_SESSION *session;
diff --git a/src/config/config_api.c b/src/config/config_api.c
index d956b2d677d..d65bd742347 100644
--- a/src/config/config_api.c
+++ b/src/config/config_api.c
@@ -94,8 +94,7 @@ wiredtiger_config_parser_open(WT_SESSION *wt_session,
 	 * structure for iterations through the configuration string.
 	 */
 	memcpy(&config_parser->config_item, &config_item, sizeof(config_item));
-	WT_ERR(__wt_config_initn(
-	    session, &config_parser->config, config, len));
+	WT_ERR(__wt_config_initn(session, &config_parser->config, config, len));
 
 	if (ret == 0)
 		*config_parserp = (WT_CONFIG_PARSER *)config_parser;
@@ -104,3 +103,44 @@ err:		__wt_free(session, config_parser);
 
 	return (ret);
 }
+
+/*
+ * wiredtiger_config_validate --
+ *	Validate a configuration string.
+ */
+int
+wiredtiger_config_validate(
+    WT_SESSION *wt_session, const char *method, const char *config)
+{
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL *session;
+	const WT_CONFIG_ENTRY *ep, **epp;
+
+	session = (WT_SESSION_IMPL *)wt_session;
+
+	if (method == NULL)
+		WT_RET_MSG(session, EINVAL, "no method specified");
+	if (config == NULL)
+		WT_RET_MSG(session, EINVAL, "no configuration specified");
+
+	/*
+	 * If we don't yet have a connection, look for a matching method in
+	 * the static list, otherwise look in the configuration list (which
+	 * has any configuration information the application has added).
+	 */
+	if (session == NULL)
+		ep = __wt_conn_config_match(method);
+	else {
+		conn = S2C(session);
+
+		for (epp = conn->config_entries; (*epp)->method != NULL; ++epp)
+			if (strcmp((*epp)->method, method) == 0)
+				break;
+		ep = *epp;
+	}
+	if (ep == NULL || ep->method == NULL)
+		WT_RET_MSG(session,
+		    WT_NOTFOUND, "no method matching %s found", method);
+
+	return (__wt_config_check(session, ep, config, 0));
+}
diff --git a/src/config/config_def.c b/src/config/config_def.c
index 43d87c518e4..19d2f0a49a1 100644
--- a/src/config/config_def.c
+++ b/src/config/config_def.c
@@ -793,3 +793,18 @@ __wt_conn_config_discard(WT_SESSION_IMPL *session)
 
 	__wt_free(session, conn->config_entries);
 }
+
+/*        
+ * __wt_conn_config_match --
+ *      Return the static configuration entry for a method.
+ */
+const WT_CONFIG_ENTRY *
+__wt_conn_config_match(const char *method)
+{
+	const WT_CONFIG_ENTRY *ep;
+
+	for (ep = config_entries; ep->method != NULL; ++ep)
+		if (strcmp(method, ep->method) == 0)
+			return (ep);
+	return (NULL);
+}
diff --git a/src/include/extern.h b/src/include/extern.h
index bddbb5e01eb..afc48fb3dcd 100644
--- a/src/include/extern.h
+++ b/src/include/extern.h
@@ -196,6 +196,7 @@ extern int __wt_config_merge( WT_SESSION_IMPL *session, const char **cfg, const
 extern int __wt_config_concat( WT_SESSION_IMPL *session, const char **cfg, char **config_ret);
 extern int __wt_conn_config_init(WT_SESSION_IMPL *session);
 extern void __wt_conn_config_discard(WT_SESSION_IMPL *session);
+extern const WT_CONFIG_ENTRY *__wt_conn_config_match(const char *method);
 extern int __wt_ext_config_parser_open(WT_EXTENSION_API *wt_ext, WT_SESSION *wt_session, const char *config, size_t len, WT_CONFIG_PARSER **config_parserp);
 extern int __wt_ext_config_get(WT_EXTENSION_API *wt_api, WT_SESSION *wt_session, WT_CONFIG_ARG *cfg_arg, const char *key, WT_CONFIG_ITEM *cval);
 extern int __wt_config_upgrade(WT_SESSION_IMPL *session, WT_ITEM *buf);
diff --git a/src/include/wiredtiger.in b/src/include/wiredtiger.in
index fea6fc6c948..4796280e908 100644
--- a/src/include/wiredtiger.in
+++ b/src/include/wiredtiger.in
@@ -2399,7 +2399,7 @@ int wiredtiger_unpack_uint(WT_PACK_STREAM *ps, uint64_t *up);
 /*! @} */
 
 /*!
- * @name Configuration string parsing
+ * @name Configuration strings
  * @{
  */
 
@@ -2456,6 +2456,22 @@ struct __wt_config_item {
 };
 
 /*!
+ * Validate a configuration string for a WiredTiger API.
+ * This API is outside the scope of a WiredTiger connection handle, since
+ * applications may need to validate configuration strings prior to calling
+ * ::wiredtiger_open.
+ * @param session the session handle to be used for error reporting (if NULL,
+ * error messages will be written to stderr).
+ * @param method the WiredTiger function or method to check.
+ * @param config the configuration string being parsed.
+ * @returns zero for success, non-zero to indicate an error.
+ *
+ * @snippet ex_all.c Validate a configuration string
+ */
+int wiredtiger_config_validate(
+    WT_SESSION *session, const char *method, const char *config);
+
+/*!
  * Create a handle that can be used to parse or create configuration strings
  * compatible with WiredTiger APIs.
  * This API is outside the scope of a WiredTiger connection handle, since
@@ -2468,6 +2484,8 @@ struct __wt_config_item {
  * @param len the number of valid bytes in \c config
  * @param[out] config_parserp A pointer to the newly opened handle
  * @errors
+ *
+ * @snippet ex_config_parse.c Create a configuration parser
  */
 int wiredtiger_config_parser_open(WT_SESSION *session,
     const char *config, size_t len, WT_CONFIG_PARSER **config_parserp);