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@xxxxxxxxxx>
---
pkt-line.c | 17 +++++++++++++++++
pkt-line.h | 3 +++
2 files changed, 20 insertions(+)
diff --git a/pkt-line.c b/pkt-line.c
index 6307fa4a3..87a24bd17 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -91,6 +91,12 @@ void packet_flush(int fd)
write_or_die(fd, "0000", 4);
}
+void packet_delim(int fd)
+{
+ packet_trace("0001", 4, 1);
+ write_or_die(fd, "0001", 4);
+}
+
int packet_flush_gently(int fd)
{
packet_trace("0000", 4, 1);
@@ -105,6 +111,12 @@ void packet_buf_flush(struct strbuf *buf)
strbuf_add(buf, "0000", 4);
}
+void packet_buf_delim(struct strbuf *buf)
+{
+ packet_trace("0001", 4, 1);
+ strbuf_add(buf, "0001", 4);
+}
+
static void set_packet_header(char *buf, const int size)
{
static char hexchar[] = "0123456789abcdef";
@@ -298,6 +310,9 @@ enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
} else if (!len) {
packet_trace("0000", 4, 0);
return PACKET_READ_FLUSH;
+ } else if (len == 1) {
+ packet_trace("0001", 4, 0);
+ return PACKET_READ_DELIM;
} else if (len < 4) {
die("protocol error: bad line length %d", len);
}
@@ -331,6 +346,7 @@ int packet_read(int fd, char **src_buffer, size_t *src_len,
break;
case PACKET_READ_NORMAL:
break;
+ case PACKET_READ_DELIM:
case PACKET_READ_FLUSH:
pktlen = 0;
break;
@@ -443,6 +459,7 @@ enum packet_read_status packet_reader_read(struct packet_reader *reader)
case PACKET_READ_NORMAL:
reader->line = reader->buffer;
break;
+ case PACKET_READ_DELIM:
case PACKET_READ_FLUSH:
reader->pktlen = 0;
reader->line = NULL;
diff --git a/pkt-line.h b/pkt-line.h
index f2edfae9a..3f836f01a 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -20,8 +20,10 @@
* side can't, we stay with pure read/write interfaces.
*/
void packet_flush(int fd);
+void packet_delim(int fd);
void packet_write_fmt(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
void packet_buf_flush(struct strbuf *buf);
+void packet_buf_delim(struct strbuf *buf);
void packet_write(int fd_out, const char *buf, size_t size);
void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
int packet_flush_gently(int fd);
@@ -75,6 +77,7 @@ enum packet_read_status {
PACKET_READ_EOF = -1,
PACKET_READ_NORMAL,
PACKET_READ_FLUSH,
+ PACKET_READ_DELIM,
};
enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
size_t *src_len, char *buffer,
--
2.16.2.395.g2e18187dfd-goog
