1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
/*
* upb - a minimalist implementation of protocol buffers.
*
* Copyright (c) 2011 Google Inc. See LICENSE for details.
* Author: Josh Haberman <jhaberman@gmail.com>
*
* A simple example that demonstrates creating a standard message object
* and parsing into it, using a dynamic reflection-based approach.
*
* Note that with this approach there are no strongly-typed struct or class
* definitions to use from C -- this is essentially a reflection-based
* interface. Note that parsing and serializing are still very fast since
* they are JIT-based.
*
* If this seems a bit verbose, you may prefer an approach that generates
* strongly-typed struct definitions (upb will likely provide this, but it is
* not yet implemented).
*
* TODO: make this file compiled as part of "make examples"
* TODO: test that this actually works (WARNING: UNTESTED!)
*/
#include "upb/msg.h"
#include "upb/pb/glue.h"
const char *descfile = "example.proto.pb";
const char *type = "example.SampleMessage";
const char *msgfile = "sample_message.pb";
int main() {
// First we load the descriptor that describes the message into a upb_msgdef.
// This could come from a string that is compiled into the program or from a
// separate file as we do here. Since defs always live in a symtab, we
// create one of those also.
upb_symtab *s = upb_symtab_new();
upb_status status = UPB_STATUS_INIT;
if (!upb_load_descriptor_file_into_symtab(s, descfile, &status)) {
fprintf(stderr, "Couldn't load descriptor file '%s': %s\n", descfile,
upb_status_getstr(&status));
return -1;
}
const upb_msgdef *md = upb_symtab_lookupmsg(s, type);
if (!md) {
fprintf(stderr, "Descriptor did not contain type '%s'\n", type);
return -1;
}
// Parse a file into a new message object.
void *msg = upb_filetonewmsg(msgfile, md, &status);
if (!msg) {
fprintf(stderr, "Error parsing message file '%s': %s\n", msgfile,
upb_status_getstr(&status));
return -1;
}
// TODO: Inspect some fields.
return 0;
}
|
