Added a more complex example. See Test3_protobuf.c

protobuf.c

@@ -23,6 +23,7 @@ int protobuf_encode_string(int field_number, enum WireType field_type, const cha
 	unsigned int field_no = field_number << 3;
 	unsigned long long field = field_no | field_type;
 	size_t bytes_processed;
+	*bytes_written = 0;
 	// field type & number
 	varint_encode(field, buffer, max_buffer_length, &bytes_processed);
 	*bytes_written += bytes_processed;

test/Makefile

@@ -2,7 +2,7 @@ CC = gcc
 CFLAGS = -O0 -g3 -Wall -I../
 LFLAGS = 
 DEPS = ../protobuf.h
-OBJS = testit.o ../protobuf.o ../varint.o Test1_protobuf.o Test2_protobuf.o
+OBJS = testit.o ../protobuf.o ../varint.o Test1_protobuf.o Test2_protobuf.o Test3_protobuf.o
 
 %.o: %.c $(DEPS)
 	$(CC) -c -o $@ $< $(CFLAGS)

test/Test3_protobuf.c

@@ -0,0 +1,69 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "protobuf.h"
+#include "varint.h"
+#include "Test3_protobuf.h"
+
+enum WireType Test3_message_fields[] = { WIRETYPE_LENGTH_DELIMITED, WIRETYPE_VARINT, WIRETYPE_LENGTH_DELIMITED };
+
+int Test3_new(struct Test3** test3) {
+	*test3 = (struct Test3*)malloc(sizeof(struct Test3));
+	if (*test3 == NULL)
+		return 0;
+	(*test3)->a_string = NULL;
+	(*test3)->an_int = 0;
+	(*test3)->test2 = NULL;
+	return 1;
+}
+
+int Test3_free(struct Test3* test3) {
+	if (test3->a_string != NULL)
+		free(test3->a_string);
+	if (test3->test2 != NULL)
+		Test2_free(test3->test2);
+	free(test3);
+	return 1;
+}
+
+int Test3_protobuf_encode(struct Test3* incoming, unsigned char* buffer, size_t max_buffer_length, size_t* bytes_written) {
+	size_t bytes_used;
+	*bytes_written = 0;
+	protobuf_encode_string(1, Test3_message_fields[0], incoming->a_string, buffer, max_buffer_length, &bytes_used);
+	*bytes_written += bytes_used;
+	protobuf_encode_varint(2, Test3_message_fields[1], incoming->an_int, &buffer[*bytes_written], max_buffer_length - *bytes_written, &bytes_used);
+	*bytes_written += bytes_used;
+	return Test2_protobuf_encode(incoming->test2, &buffer[*bytes_written], max_buffer_length - *bytes_written, &bytes_used);
+}
+
+int Test3_protobuf_decode(unsigned char* buffer, size_t buffer_length, struct Test3** output) {
+	size_t pos = 0;
+	if (Test3_new(output) == 0)
+		return 0;
+
+	while (pos < buffer_length) { // loop through buffer
+		size_t bytes_read = 0;
+		int field_no;
+		enum WireType field_type;
+		if (protobuf_decode_field_and_type(&buffer[pos], buffer_length, &field_no, &field_type, &bytes_read) == 0) {
+			Test3_free(*output);
+			return 0;
+		}
+		pos += bytes_read;
+		switch (field_no) {
+			case(1):
+				protobuf_decode_string(&buffer[pos], buffer_length - pos, &((*output)->a_string), &bytes_read);
+				pos += bytes_read;
+				break;
+			case (2):
+				(*output)->an_int = varint_decode(&buffer[pos], buffer_length - pos, &bytes_read);
+				pos += bytes_read;
+				break;
+			case(3):
+				Test2_protobuf_decode(&buffer[pos], buffer_length - pos, &((*output)->test2));
+				pos += bytes_read;
+				break;
+		}
+	}
+	return 1;
+}

test/Test3_protobuf.h

@@ -0,0 +1,22 @@
+/*
+ * Test3_protobuf.h
+ */
+
+#pragma once
+
+#include "protobuf.h"
+
+#include "Test2_protobuf.h"
+
+struct Test3 {
+	char* a_string;
+	int an_int;
+	struct Test2* test2;
+};
+
+int Test3_new(struct Test3** test1);
+int Test3_free(struct Test3* test1);
+
+int Test3_protobuf_encode(struct Test3* incoming, unsigned char* buffer, size_t max_buffer_length, size_t* bytes_written);
+int Test3_protobuf_decode(unsigned char* buffer, size_t buffer_length, struct Test3** output);
+

test/test_protobuf.h

@@ -17,10 +17,65 @@
  * int Test1_protobuf_encode(struct Test1* incoming, unsigned char* buffer, size_t max_buffer_length, size_t* bytes_written);
  * int Test1_protobuf_decode(unsigned char* buffer, size_t buffer_length, struct Test1** output);
  */
+#include <stdlib.h>
+#include <string.h>
 
+#include "Test3_protobuf.h"
 #include "Test1_protobuf.h"
 #include "Test2_protobuf.h"
 
+int test_complex_protobuf() {
+	int buffer_length = 255;
+	size_t bytes_used = 0;
+	unsigned char buffer[buffer_length];
+
+	// build the objects
+	struct Test2* test2;
+	Test2_new(&test2);
+	struct Test3* test3;
+	Test3_new(&test3);
+	test3->test2 = test2;
+
+	// set values
+	test3->a_string = malloc(15);
+	strcpy(test3->a_string, "Hello, World!");
+	test3->an_int = 29;
+	test3->test2->a = malloc(10);
+	strcpy(test3->test2->a, "Testing");
+
+	// encode
+	Test3_protobuf_encode(test3, buffer, buffer_length, &bytes_used);
+
+	// decode
+	struct Test3* results;
+	Test3_protobuf_decode(buffer, bytes_used, &results);
+
+	// view results
+	if (strcmp(results->a_string, test3->a_string) != 0) {
+		printf("String a does not match: %s vs %s\n", test3->a_string, results->a_string);
+		Test3_free(test3);
+		Test3_free(results);
+		return 0;
+	}
+
+	if (results->an_int != test3->an_int) {
+		printf("Integers do not match: %d vs %d\n", test3->an_int, results->an_int);
+		Test3_free(test3);
+		Test3_free(results);
+		return 0;
+	}
+
+	if (strcmp(results->test2->a, test3->test2->a) == 0) {
+		printf("String a does not match: %s vs %s\n", test3->test2->a, results->test2->a);
+		Test3_free(test3);
+		Test3_free(results);
+		return 0;
+	}
+
+	return 1;
+
+}
+
 int test_rightshift() {
 	struct Test1 test1;
 	test1.a = 0;

test/testit.c

@@ -19,6 +19,7 @@ const char* names[] = {
 		"test_write_negative",
 		"test_write_string",
 		"test_rightshift",
+		"test_complex_protobuf",
 		"test_varint"
 };
 
@@ -27,6 +28,7 @@ int (*funcs[])(void) = {
 		test_write_negative,
 		test_write_string,
 		test_rightshift,
+		test_complex_protobuf,
 		test_varint
 };