added encode / decode for length delimited fields

protobuf.c

@@ -7,6 +7,47 @@
 #include "varint.h"
 #include "protobuf.h"
 
+int protobuf_encode_length_delimited(int field_number, enum WireType field_type, const char* incoming, size_t incoming_length,
+		unsigned char* buffer, size_t max_buffer_length, size_t* bytes_written)
+{
+	// push the field number and wire type together
+	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;
+	// field size
+	varint_encode(incoming_length, &buffer[*bytes_written], max_buffer_length - *bytes_written, &bytes_processed);
+	*bytes_written += bytes_processed;
+	// field value
+	memcpy(&buffer[*bytes_written], incoming, incoming_length);
+	*bytes_written += incoming_length;
+	return 1;
+}
+
+int protobuf_decode_length_delimited(const unsigned char* buffer, size_t buffer_length, char** results, size_t *results_length, size_t* bytes_read) {
+	size_t pos = 0;
+	*bytes_read = 0;
+	// grab the field size
+	*results_length = varint_decode(&buffer[pos], buffer_length - pos, bytes_read);
+	pos += *bytes_read;
+
+	// allocate memory
+	*results = malloc(sizeof(char) * (*results_length));
+	if ((*results) == NULL)
+		return 0;
+
+	// copy the bytes
+	memcpy((*results), &buffer[pos], (*results_length));
+	pos += (*results_length);
+	*bytes_read = pos;
+
+	return 1;
+}
+
+
 /***
  * encode a string into the buffer
  * @param field_number the field number
@@ -19,21 +60,7 @@
  */
 int protobuf_encode_string(int field_number, enum WireType field_type, const char* incoming, unsigned char* buffer,
 		size_t max_buffer_length, size_t* bytes_written) {
-	// push the field number and wire type together
-	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;
-	// field size
-	varint_encode(strlen(incoming), &buffer[*bytes_written], max_buffer_length - *bytes_written, &bytes_processed);
-	*bytes_written += bytes_processed;
-	// field value
-	memcpy(&buffer[*bytes_written], incoming, strlen(incoming));
-	*bytes_written += strlen(incoming);
-	return 1;
+	return protobuf_encode_length_delimited(field_number, field_type, incoming, strlen(incoming), buffer, max_buffer_length, bytes_written);
 }
 
 /***

protobuf.h

@@ -20,6 +20,22 @@ enum WireType {
 	WIRETYPE_32BIT
 };
 
+/***
+ * Encode a length delimited field into the buffer
+ * @param field_number the field number
+ * @param wire_type the wire type
+ * @param incoming the values
+ * @param incoming_length the lenght of incoming
+ * @param buffer the pointer to where to place the encoded value
+ * @param max_buffer_length the buffer length remaining
+ * @param bytes_written the number of bytes written
+ * @returns true(1) on success
+ */
+int protobuf_encode_length_delimited(int field_number, enum WireType wire_type, const char* incoming, size_t incoming_length,
+		unsigned char* buffer, size_t max_buffer_size, size_t* bytes_written);
+
+int protobuf_decode_length_delimited(const unsigned char* buffer, size_t buffer_length, char** results, size_t *results_length, size_t* bytes_read);
+
 /***
  * encode a string into the buffer
  * @param field_number the field number