Protocol Buffers - Google's data interchange format (grpc依赖)
https://developers.google.com/protocol-buffers/
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60 lines
2.0 KiB
60 lines
2.0 KiB
13 years ago
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/*
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* upb - a minimalist implementation of protocol buffers.
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*
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* Copyright (c) 2011 Google Inc. See LICENSE for details.
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* Author: Josh Haberman <jhaberman@gmail.com>
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*
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* A simple example that demonstrates creating a standard message object
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* and parsing into it, using a dynamic reflection-based approach.
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*
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* Note that with this approach there are no strongly-typed struct or class
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* definitions to use from C -- this is essentially a reflection-based
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* interface. Note that parsing and serializing are still very fast since
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* they are JIT-based.
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*
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* If this seems a bit verbose, you may prefer an approach that generates
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* strongly-typed struct definitions (upb will likely provide this, but it is
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* not yet implemented).
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*
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* TODO: make this file compiled as part of "make examples"
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* TODO: test that this actually works (WARNING: UNTESTED!)
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*/
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#include "upb/msg.h"
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#include "upb/pb/glue.h"
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const char *descfile = "example.proto.pb";
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const char *type = "example.SampleMessage";
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const char *msgfile = "sample_message.pb";
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int main() {
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// First we load the descriptor that describes the message into a upb_msgdef.
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// This could come from a string that is compiled into the program or from a
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// separate file as we do here. Since defs always live in a symtab, we
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// create one of those also.
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upb_symtab *s = upb_symtab_new();
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upb_status status = UPB_STATUS_INIT;
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if (!upb_load_descriptor_file_into_symtab(s, descfile, &status)) {
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fprintf(stderr, "Couldn't load descriptor file '%s': %s\n", descfile,
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upb_status_getstr(&status));
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return -1;
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}
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const upb_msgdef *md = upb_symtab_lookupmsg(s, type);
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if (!md) {
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fprintf(stderr, "Descriptor did not contain type '%s'\n", type);
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return -1;
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}
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// Parse a file into a new message object.
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void *msg = upb_filetonewmsg(msgfile, md, &status);
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if (!msg) {
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fprintf(stderr, "Error parsing message file '%s': %s\n", msgfile,
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upb_status_getstr(&status));
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return -1;
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}
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// TODO: Inspect some fields.
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return 0;
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}
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