@matheusbsbs / matheus-bagliano / commits / a4cfd41c7b

pkt-line: add delim packet support

One of the design goals of protocol-v2 is to improve the semantics of flush packets. Currently in protocol-v1, flush packets are used both to indicate a break in a list of packet lines as well as an indication that one side has finished speaking. This makes it particularly difficult to implement proxies as a proxy would need to completely understand git protocol instead of simply looking for a flush packet. To do this, introduce the special deliminator packet '0001'. A delim packet can then be used as a deliminator between lists of packet lines while flush packets can be reserved to indicate the end of a response. Documentation for how this packet will be used in protocol v2 will included in a future patch. Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Brandon Williams committed Mar 14, 2018 at 11:31 UTC a4cfd41c7be81c10b925532979e81e4d07f6b376

2 files changed +19

pkt-line.c

+16

@@ -91,6 +91,12 @@ void packet_flush(int fd)

91 write_or_die(fd, "0000", 4);

92 }

94 +void packet_delim(int fd)

95 +{

96 + packet_trace("0001", 4, 1);

97 + write_or_die(fd, "0001", 4);

98 +}

99 +

100 int packet_flush_gently(int fd)

101 {

102 packet_trace("0000", 4, 1);

@@ -105,6 +111,12 @@ void packet_buf_flush(struct strbuf *buf)

111 strbuf_add(buf, "0000", 4);

112 }

113

114 +void packet_buf_delim(struct strbuf *buf)

115 +{

116 + packet_trace("0001", 4, 1);

117 + strbuf_add(buf, "0001", 4);

118 +}

119 +

120 static void set_packet_header(char *buf, const int size)

121 {

122 static char hexchar[] = "0123456789abcdef";

@@ -301,6 +313,10 @@ enum packet_read_status packet_read_with_status(int fd, char **src_buffer,

313 packet_trace("0000", 4, 0);

314 *pktlen = 0;

315 return PACKET_READ_FLUSH;

316 + } else if (len == 1) {

317 + packet_trace("0001", 4, 0);

318 + *pktlen = 0;

319 + return PACKET_READ_DELIM;

320 } else if (len < 4) {

321 die("protocol error: bad line length %d", len);

322 }

pkt-line.h

@@ -20,8 +20,10 @@

20 * side can't, we stay with pure read/write interfaces.

21 */

22 void packet_flush(int fd);

23 +void packet_delim(int fd);

24 void packet_write_fmt(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));

25 void packet_buf_flush(struct strbuf *buf);

26 +void packet_buf_delim(struct strbuf *buf);

27 void packet_write(int fd_out, const char *buf, size_t size);

28 void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));

29 int packet_flush_gently(int fd);

@@ -75,6 +77,7 @@ enum packet_read_status {

77 PACKET_READ_EOF,

78 PACKET_READ_NORMAL,

79 PACKET_READ_FLUSH,

80 + PACKET_READ_DELIM,

81 };

82 enum packet_read_status packet_read_with_status(int fd, char **src_buffer,

83 size_t *src_len, char *buffer,