Implement JSON parsing and serialization.

This will be used by the upcoming Open vSwitch configuration database.

1 files changed, 122 insertions, 0 deletions

diff --git a/lib/json.h b/lib/json.h
new file mode 100644
index 000000000..767401536
--- /dev/null
+++ b/lib/json.h
@@ -0,0 +1,122 @@
+/*
+ * 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.
+ */
+
+#ifndef JSON_H
+#define JSON_H 1
+
+/* This is an implementation of JavaScript Object Notation (JSON) as specified
+ * by RFC 4627.  It is intended to fully comply with RFC 4627, with the
+ * following known exceptions and clarifications:
+ *
+ *      - Null bytes (\u0000) are not allowed in strings.
+ *
+ *      - Only UTF-8 encoding is supported (RFC 4627 allows for other Unicode
+ *        encodings).
+ *
+ *      - Names within an object must be unique (RFC 4627 says that they
+ *        "should" be unique).
+ */
+
+#include "shash.h"
+
+/* Type of a JSON value. */
+enum json_type {
+    JSON_NULL,                  /* null */
+    JSON_FALSE,                 /* false */
+    JSON_TRUE,                  /* true */
+    JSON_OBJECT,                /* {"a": b, "c": d, ...} */
+    JSON_ARRAY,                 /* [1, 2, 3, ...] */
+    JSON_INTEGER,               /* 123. */
+    JSON_REAL,                  /* 123.456. */
+    JSON_STRING,                /* "..." */
+    JSON_N_TYPES
+};
+
+const char *json_type_to_string(enum json_type);
+
+/* A JSON array. */
+struct json_array {
+    size_t n, n_allocated;
+    struct json **elems;
+};
+
+/* A JSON value. */
+struct json {
+    enum json_type type;
+    union {
+        struct shash *object;   /* Contains "struct json *"s. */
+        struct json_array array;
+        long long int integer;
+        double real;
+        char *string;
+    } u;
+};
+
+struct json *json_null_create(void);
+struct json *json_boolean_create(bool);
+struct json *json_string_create(const char *);
+struct json *json_string_create_nocopy(char *);
+struct json *json_integer_create(long long int);
+struct json *json_real_create(double);
+
+struct json *json_array_create_empty(void);
+void json_array_add(struct json *, struct json *element);
+void json_array_trim(struct json *);
+struct json *json_array_create(struct json **, size_t n);
+struct json *json_array_create_2(struct json *, struct json *);
+struct json *json_array_create_3(struct json *, struct json *, struct json *);
+
+struct json *json_object_create(void);
+void json_object_put(struct json *, const char *name, struct json *value);
+void json_object_put_string(struct json *,
+                            const char *name, const char *value);
+
+const char *json_string(const struct json *);
+struct json_array *json_array(const struct json *);
+struct shash *json_object(const struct json *);
+bool json_boolean(const struct json *);
+double json_real(const struct json *);
+int64_t json_integer(const struct json *);
+
+struct json *json_clone(const struct json *);
+void json_destroy(struct json *);
+
+size_t json_hash(const struct json *, size_t basis);
+bool json_equal(const struct json *, const struct json *);
+
+/* Parsing JSON. */
+enum {
+    JSPF_TRAILER = 1 << 0       /* Check for garbage following input.  */
+};
+
+struct json_parser *json_parser_create(int flags);
+size_t json_parser_feed(struct json_parser *, const char *, size_t);
+bool json_parser_is_done(const struct json_parser *);
+struct json *json_parser_finish(struct json_parser *);
+void json_parser_abort(struct json_parser *);
+
+struct json *json_from_string(const char *string);
+struct json *json_from_file(const char *file_name);
+
+/* Serializing JSON. */
+
+enum {
+    JSSF_PRETTY = 1 << 0,       /* Multiple lines with indentation, if true. */
+    JSSF_SORT = 1 << 1          /* Object members in sorted order, if true. */
+};
+char *json_to_string(const struct json *, int flags);
+
+#endif /* json.h */