The second stage of our JSON parser is a simple state machine that identifies
individual JSON values by counting the levels of nesting of tokens. It does
not perform grammar validation. We use this to emit a full JSON value to the
parser.
Signed-off-by: Anthony Liguori <aligu...@us.ibm.com>
---
Makefile | 1 +
json-streamer.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
json-streamer.h | 39 ++++++++++++++++++++++++
3 files changed, 128 insertions(+), 0 deletions(-)
create mode 100644 json-streamer.c
create mode 100644 json-streamer.h
diff --git a/Makefile b/Makefile
index e5ab879..a2aab60 100644
--- a/Makefile
+++ b/Makefile
@@ -136,6 +136,7 @@ obj-y += qemu-char.o aio.o savevm.o
obj-y += msmouse.o ps2.o
obj-y += qdev.o qdev-properties.o
obj-y += qint.o qstring.o qdict.o qlist.o qfloat.o qbool.o json-lexer.o
+obj-y += json-streamer.o
obj-y += qemu-config.o
obj-$(CONFIG_BRLAPI) += baum.o
diff --git a/json-streamer.c b/json-streamer.c
new file mode 100644
index 0000000..610ffea
--- /dev/null
+++ b/json-streamer.c
@@ -0,0 +1,88 @@
+/*
+ * JSON streaming support
+ *
+ * Copyright IBM, Corp. 2009
+ *
+ * Authors:
+ * Anthony Liguori <aligu...@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include "qlist.h"
+#include "qint.h"
+#include "qdict.h"
+#include "qemu-common.h"
+#include "json-lexer.h"
+#include "json-streamer.h"
+
+static void json_message_process_token(JSONLexer *lexer, QString *token,
JSONTokenType type, int x, int y)
+{
+ JSONMessageParser *parser = container_of(lexer, JSONMessageParser, lexer);
+ QDict *dict;
+
+ if (type == JSON_OPERATOR) {
+ switch (qstring_get_str(token)[0]) {
+ case '{':
+ parser->brace_count++;
+ break;
+ case '}':
+ parser->brace_count--;
+ break;
+ case '[':
+ parser->bracket_count++;
+ break;
+ case ']':
+ parser->bracket_count--;
+ break;
+ default:
+ break;
+ }
+ }
+
+ dict = qdict_new();
+ qdict_put_obj(dict, "type", QOBJECT(qint_from_int(type)));
+ QINCREF(token);
+ qdict_put_obj(dict, "token", QOBJECT(token));
+ qdict_put_obj(dict, "x", QOBJECT(qint_from_int(x)));
+ qdict_put_obj(dict, "y", QOBJECT(qint_from_int(y)));
+
+ qlist_append(parser->tokens, dict);
+
+ if (parser->brace_count == 0 &&
+ parser->bracket_count == 0) {
+ parser->emit(parser, parser->tokens);
+ QDECREF(parser->tokens);
+ parser->tokens = qlist_new();
+ }
+}
+
+void json_message_parser_init(JSONMessageParser *parser,
+ void (*func)(JSONMessageParser *, QList *))
+{
+ parser->emit = func;
+ parser->brace_count = 0;
+ parser->bracket_count = 0;
+ parser->tokens = qlist_new();
+
+ json_lexer_init(&parser->lexer, json_message_process_token);
+}
+
+int json_message_parser_feed(JSONMessageParser *parser,
+ const char *buffer, size_t size)
+{
+ return json_lexer_feed(&parser->lexer, buffer, size);
+}
+
+int json_message_parser_flush(JSONMessageParser *parser)
+{
+ return json_lexer_flush(&parser->lexer);
+}
+
+void json_message_parser_destroy(JSONMessageParser *parser)
+{
+ json_lexer_destroy(&parser->lexer);
+ QDECREF(parser->tokens);
+}
diff --git a/json-streamer.h b/json-streamer.h
new file mode 100644
index 0000000..09f3bd7
--- /dev/null
+++ b/json-streamer.h
@@ -0,0 +1,39 @@
+/*
+ * JSON streaming support
+ *
+ * Copyright IBM, Corp. 2009
+ *
+ * Authors:
+ * Anthony Liguori <aligu...@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#ifndef QEMU_JSON_STREAMER_H
+#define QEMU_JSON_STREAMER_H
+
+#include "qlist.h"
+#include "json-lexer.h"
+
+typedef struct JSONMessageParser
+{
+ void (*emit)(struct JSONMessageParser *parser, QList *tokens);
+ JSONLexer lexer;
+ int brace_count;
+ int bracket_count;
+ QList *tokens;
+} JSONMessageParser;
+
+void json_message_parser_init(JSONMessageParser *parser,
+ void (*func)(JSONMessageParser *, QList *));
+
+int json_message_parser_feed(JSONMessageParser *parser,
+ const char *buffer, size_t size);
+
+int json_message_parser_flush(JSONMessageParser *parser);
+
+void json_message_parser_destroy(JSONMessageParser *parser);
+
+#endif
--
1.6.2.5
