Initial implementation of OVSDB.

lib/ovsdb-parser.c

@@ -0,0 +1,167 @@
+/* Copyright (c) 2009 Nicira Networks
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+
+#include "ovsdb-parser.h"
+
+#include <ctype.h>
+#include <stdarg.h>
+
+#include "ovsdb-error.h"
+
+void
+ovsdb_parser_init(struct ovsdb_parser *parser, const struct json *json,
+                  const char *name, ...)
+{
+    va_list args;
+
+    va_start(args, name);
+    parser->name = xvasprintf(name, args);
+    va_end(args);
+
+    svec_init(&parser->used);
+    parser->error = NULL;
+
+    parser->json = (json && json->type == JSON_OBJECT ? json : NULL);
+    if (!parser->json) {
+        ovsdb_parser_raise_error(parser, "Object expected.");
+    }
+}
+
+static bool
+is_id(const char *string)
+{
+    unsigned char c;
+
+    c = *string;
+    if (!isalpha(c) && c != '_') {
+        return false;
+    }
+
+    for (;;) {
+        c = *++string;
+        if (c == '\0') {
+            return true;
+        } else if (!isalpha(c) && !isdigit(c) && c != '_') {
+            return false;
+        }
+    }
+}
+
+const struct json *
+ovsdb_parser_member(struct ovsdb_parser *parser, const char *name,
+                    enum ovsdb_parser_types types)
+{
+    struct json *value;
+
+    if (!parser->json) {
+        return NULL;
+    }
+
+    value = shash_find_data(json_object(parser->json), name);
+    if (!value) {
+        if (!(types & OP_OPTIONAL)) {
+            ovsdb_parser_raise_error(parser,
+                                     "Required '%s' member is missing.", name);
+        }
+        return NULL;
+    }
+
+    if (value->type >= 0 && value->type < JSON_N_TYPES
+        && (types & (1u << value->type)
+            || (types & OP_ID
+                && value->type == JSON_STRING
+                && is_id(value->u.string))))
+    {
+        svec_add(&parser->used, name);
+        return value;
+    } else {
+        ovsdb_parser_raise_error(parser, "Type mismatch for member '%s'.",
+                                 name);
+        return NULL;
+    }
+}
+
+void
+ovsdb_parser_raise_error(struct ovsdb_parser *parser, const char *format, ...)
+{
+    if (!parser->error) {
+        struct ovsdb_error *error;
+        va_list args;
+        char *message;
+
+        va_start(args, format);
+        message = xvasprintf(format, args);
+        va_end(args);
+
+        error = ovsdb_syntax_error(parser->json, NULL, "Parsing %s failed: %s",
+                                   parser->name, message);
+        free(message);
+
+        parser->error = error;
+    }
+}
+
+struct ovsdb_error *
+ovsdb_parser_get_error(const struct ovsdb_parser *parser)
+{
+    return parser->error ? ovsdb_error_clone(parser->error) : NULL;
+}
+
+bool
+ovsdb_parser_has_error(const struct ovsdb_parser *parser)
+{
+    return parser->error != NULL;
+}
+
+struct ovsdb_error *
+ovsdb_parser_finish(struct ovsdb_parser *parser)
+{
+    if (!parser->error) {
+        const struct shash *object = json_object(parser->json);
+        size_t n_unused;
+
+        /* XXX this method of detecting unused members can be made cheaper */
+        svec_sort_unique(&parser->used);
+        n_unused = shash_count(object) - parser->used.n;
+        if (n_unused) {
+            struct shash_node *node;
+
+            SHASH_FOR_EACH (node, object) {
+                if (!svec_contains(&parser->used, node->name)) {
+                    if (n_unused > 1) {
+                        ovsdb_parser_raise_error(
+                            parser,
+                            "Member '%s' and %zu other member%s "
+                            "are present but not allowed here.",
+                            node->name, n_unused - 1, n_unused > 2 ? "s" : "");
+                    } else {
+                        ovsdb_parser_raise_error(
+                            parser,
+                            "Member '%s' is present but not allowed here.",
+                            node->name);
+                    }
+                    break;
+                }
+            }
+        }
+    }
+
+    free(parser->name);
+    svec_destroy(&parser->used);
+
+    return parser->error;
+}