Izumo.HTTP.Parser

Zero-copy no-memory-alloc HTTP Parser used by Izumo.

Features

• Zero-copy
• No memory allocation
• No dependencies
• Guaranteed to be stateless (i. e. free of local static objects)

Example (Pseudo-code)

Parsing request line:

struct izm_http_request_line_parser rlp;
struct izm_http_request_line rl;

bzero(&rlp, sizeof(rlp));
bzero(&rl, sizeof(rl));

while (1) {
	bytes_read += recv(client, buf + bytes_read, buf_size - bytes_read);
	int ret = izm_http_parse_request_line(&rlp, &rl, &bytes_parsed, buf, bytes_read);
	if (ret == IZM_PARSER_OK) {
		handle_request_line(rl);
		break ;
	} else if (ret == IZM_PARSER_CONTINUE) {
		continue;
	} else if (ret == IZM_PARSER_BAD_REQUEST) {
		bad_request();
	}
}

Parsing status line:

struct izm_http_status_line_parser slp;
struct izm_http_status_line sl;

bzero(&hp, sizeof(slp));
bzero(h, sizeof(sl));

while (1) {
	bytes_read += recv(client, buf + bytes_read, buf_size - bytes_read);
	int ret = izm_http_parse_status_line(&slp, sl, &bytes_parsed, buf, bytes_read);
	headers_count += headers_filled;
	if (ret == IZM_PARSER_OK) {
		handle_status_line(sl);
		break;
	} else if (ret == IZM_PARSER_CONTINUE) {
		continue;
	} else if (ret == IZM_PARSER_BAD_REQUEST) {
		bad_request();
	}
}

Parsing headers:

struct izm_http_headers_parser hp;
struct izm_http_header h[32];

bzero(&hp, sizeof(rlp));
bzero(h, sizeof(rl));

while (1) {
	bytes_read += recv(client, buf + bytes_read, buf_size - bytes_read);
	int ret = izm_http_parse_headers(&hp, h + headers_count, 32 - headers_count, &headers_filled, &bytes_parsed, buf + start_line_size, bytes_read - start_line_size);
	headers_count += headers_filled;
	if (ret == IZM_PARSER_OK) {
		handle_headers(h, headers_count);
		break;
	} else if (ret == IZM_PARSER_CONTINUE) {
		continue;
	} else if (ret == IZM_PARSER_BAD_REQUEST) {
		bad_request();
	}
}

Detailed information can be found in wiki.