[CRIU] [PATCH v2] protobuf: "pretty" engine

[Kinsbursky Stanislav]

v2:
1) parser updated to properly parse strings like this: "11:%x 1:%d"

Protobuf generic show function now accept a string with pretty specificators.
The string have to look like below (an example):

"0:%d 3:%u"

where numbers with colon specifies field number (the same number as in
proto-file) and "%[a-zA-Z]" specifies output format.
If pretty specificator for specified for a field, then it will be used for
output instead of generic hexidecimal view.

Signed-off-by: Stanislav Kinsbursky <skinsbursky at openvz.org>

---
 include/protobuf.h |    6 +++---
 protobuf.c         |   46 +++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/include/protobuf.h b/include/protobuf.h
index e13c3e4..2607c06 100644
--- a/include/protobuf.h
+++ b/include/protobuf.h
@@ -61,14 +61,14 @@ extern int pb_write_object_with_header(int fd, void *obj,
 extern void do_pb_show_plain(int fd, const ProtobufCMessageDescriptor *d,
 		pb_unpack_t unpack, pb_free_t free, int single_entry,
 		void (*payload_hadler)(int fd, void *obj, int flags),
-		int flags);
+		int flags, const char *pretty_fmt);
 
 /* Don't have objects at hands to also do typechecking here */
 #define pb_show_plain_payload(__fd, __proto_message_name, payload_hadler, flags)	\
 	do_pb_show_plain(__fd, &__proto_message_name##__descriptor,	\
 			(pb_unpack_t)__proto_message_name##__unpack,			\
 			(pb_free_t)__proto_message_name##__free_unpacked,		\
-			0, payload_hadler, flags)
+			0, payload_hadler, flags, NULL)
 
 #define pb_show_plain(__fd, __proto_message_name)			\
 	pb_show_plain_payload(__fd, __proto_message_name, NULL, 0)
@@ -77,6 +77,6 @@ extern void do_pb_show_plain(int fd, const ProtobufCMessageDescriptor *d,
 	do_pb_show_plain(__fd, &__proto_message_name##__descriptor,	\
 			(pb_unpack_t)__proto_message_name##__unpack,			\
 			(pb_free_t)__proto_message_name##__free_unpacked,		\
-			1, NULL, 0)
+			1, NULL, 0, NULL)
 
 #endif /* PROTOBUF_H__ */
diff --git a/protobuf.c b/protobuf.c
index 50ce9af..647786f 100644
--- a/protobuf.c
+++ b/protobuf.c
@@ -10,6 +10,7 @@
 #include "types.h"
 #include "log.h"
 #include "util.h"
+#include "string.h"
 
 #include "protobuf.h"
 
@@ -22,7 +23,9 @@
 
 struct pb_pr_field_s {
 	void *data;
+	int number;
 	int depth;
+	char fmt[32];
 };
 
 typedef struct pb_pr_field_s pb_pr_field_t;
@@ -30,6 +33,7 @@ typedef struct pb_pr_field_s pb_pr_field_t;
 struct pb_pr_ctrl_s {
 	void *arg;
 	int single_entry;
+	const char *pretty_fmt;
 	pb_pr_field_t cur;
 };
 
@@ -150,6 +154,34 @@ static size_t pb_show_prepare_field_context(const ProtobufCFieldDescriptor *fd,
 	return fsize;
 }
 
+static void pb_show_pretty(pb_pr_field_t *field)
+{
+	pr_msg(field->fmt, *(long *)field->data);
+}
+
+static int pb_field_show_pretty(pb_pr_ctl_t *ctl)
+{
+	pb_pr_field_t *field = &ctl->cur;
+	int found;
+	char cookie[32];
+	const char *ptr;
+
+	if (!ctl->pretty_fmt)
+		return 0;
+
+	sprintf(cookie, " %d:", field->number);
+	if (!strncmp(ctl->pretty_fmt, &cookie[1], strlen(&cookie[1])))
+		ptr = ctl->pretty_fmt;
+	else {
+		ptr = strstr(ctl->pretty_fmt, cookie);
+		if (!ptr)
+			return 0;
+	}
+	found = sscanf(ptr, "%*[ 1-9:]%s", field->fmt);
+	BUG_ON(found > 1);
+	return found;
+}
+
 static pb_pr_show_t get_pb_show_function(int type)
 {
 	switch (type) {
@@ -182,6 +214,13 @@ static pb_pr_show_t get_pb_show_function(int type)
 	return pb_msg_unk;
 }
 
+static pb_pr_show_t get_show_function(int type, pb_pr_ctl_t *ctl)
+{
+	if (pb_field_show_pretty(ctl))
+		return pb_show_pretty;
+	return get_pb_show_function(type);
+}
+
 static void do_show_field(pb_pr_ctl_t *ctl, int nr_fields, pb_pr_show_t show,
 			  size_t fsize)
 {
@@ -210,7 +249,7 @@ static void pb_show_field(const ProtobufCFieldDescriptor *fd,
 	print_tabs(ctl);
 	pr_msg("%s: ", fd->name);
 
-	show = get_pb_show_function(fd->type);
+	show = get_show_function(fd->type, ctl);
 
 	do_show_field(ctl, nr_fields, show, pb_show_prepare_field_context(fd, ctl));
 }
@@ -259,6 +298,7 @@ static void pb_show_msg(const void *msg, pb_pr_ctl_t *ctl)
 		}
 
 		ctl->cur.data = data;
+		ctl->cur.number = i + 1;
 
 		pb_show_field(&fd, nr_fields, ctl);
 	}
@@ -269,9 +309,9 @@ static inline void pb_no_payload(int fd, void *obj, int flags) { }
 void do_pb_show_plain(int fd, const ProtobufCMessageDescriptor *md,
 		pb_unpack_t unpack, pb_free_t free, int single_entry,
 		void (*payload_hadler)(int fd, void *obj, int flags),
-		int flags)
+		int flags, const char *pretty_fmt)
 {
-	pb_pr_ctl_t ctl = {NULL, single_entry};
+	pb_pr_ctl_t ctl = {NULL, single_entry, pretty_fmt};
 	void (*handle_payload)(int fd, void *obj, int flags);
 
 	handle_payload = (payload_hadler) ? : pb_no_payload;