Re: [PATCH v4] Refactor recv_sideband()
Junio C Hamano <gitster@pobox.com> writes:
> It's just that if you take the latter, then the conditional after
> the loop exits (i.e. the last transmission was an incomplete line)
> cannot be "is outbuf empty?", as your base state is "has PREFIX and
> can never be empty". I was working back from that if statement.
Let's try this again. How does this look?
In this version:
- "outbuf" is where we keep the (possibly partial) data collected
to be eventually shown;
- output of pending (possibly partial) data is handled by a helper
function drain(). It is responsible for prepending of the
PREFIX, which is treated purely as a cosmetic thing. It also is
responsible for completing an incomplete line at the end of the
transmission (e.g. flushing of the buffered input upon reception of
the emergency exit packet).
- locally generated errors go directly to fprintf(stderr),
bypassing outbuf (hence drain()).
sideband.c | 43 +++++++++++++++++++++++++------------------
1 file changed, 25 insertions(+), 18 deletions(-)
diff --git a/sideband.c b/sideband.c
index 226a8c2..6873137 100644
--- a/sideband.c
+++ b/sideband.c
@@ -18,6 +18,16 @@
#define ANSI_SUFFIX "\033[K"
#define DUMB_SUFFIX " "
+static void drain(struct strbuf *outbuf)
+{
+ if (!outbuf->len)
+ return;
+ strbuf_splice(outbuf, 0, 0, PREFIX, strlen(PREFIX));
+ strbuf_complete_line(outbuf);
+ fwrite(outbuf->buf, 1, outbuf->len, stderr);
+ strbuf_reset(outbuf);
+}
+
int recv_sideband(const char *me, int in_stream, int out)
{
const char *term, *suffix;
@@ -26,20 +36,21 @@ int recv_sideband(const char *me, int in_stream, int out)
const char *b, *brk;
int retval = 0;
- strbuf_addf(&outbuf, "%s", PREFIX);
term = getenv("TERM");
if (isatty(2) && term && strcmp(term, "dumb"))
suffix = ANSI_SUFFIX;
else
suffix = DUMB_SUFFIX;
- while (retval == 0) {
+ while (!retval) {
int band, len;
len = packet_read(in_stream, NULL, NULL, buf, LARGE_PACKET_MAX, 0);
if (len == 0)
break;
if (len < 1) {
- fprintf(stderr, "%s: protocol error: no band designator\n", me);
+ drain(&outbuf);
+ fprintf(stderr, "%s: protocol error: no band designator\n",
+ me);
retval = SIDEBAND_PROTOCOL_ERROR;
break;
}
@@ -48,7 +59,8 @@ int recv_sideband(const char *me, int in_stream, int out)
len--;
switch (band) {
case 3:
- fprintf(stderr, "%s%s\n", PREFIX, buf + 1);
+ drain(&outbuf);
+ strbuf_addf(&outbuf, "%s\n", buf + 1);
retval = SIDEBAND_REMOTE_ERROR;
break;
case 2:
@@ -58,13 +70,12 @@ int recv_sideband(const char *me, int in_stream, int out)
* Append a suffix to each nonempty line to clear the
* end of the screen line.
*
- * The output is accumulated in a buffer and each line
- * is printed to stderr using fprintf() with a single
- * conversion specifier. This is a "best effort"
- * approach to supporting both inter-process atomicity
- * (single conversion specifiers are likely to end up
- * in single atomic write() system calls) and the ANSI
- * control code emulation under Windows.
+ * The output is accumulated in a buffer and
+ * each line is printed to stderr using
+ * fwrite(3). This is a "best effort"
+ * approach to support inter-process atomicity
+ * (single fwrite(3) call is likely to end up
+ * in single atomic write() system calls).
*/
while ((brk = strpbrk(b, "\n\r"))) {
int linelen = brk - b;
@@ -75,11 +86,7 @@ int recv_sideband(const char *me, int in_stream, int out)
} else {
strbuf_addf(&outbuf, "%c", *brk);
}
- fprintf(stderr, "%.*s", (int)outbuf.len,
- outbuf.buf);
- strbuf_reset(&outbuf);
- strbuf_addf(&outbuf, "%s", PREFIX);
-
+ drain(&outbuf);
b = brk + 1;
}
@@ -90,6 +97,7 @@ int recv_sideband(const char *me, int in_stream, int out)
write_or_die(out, buf + 1, len);
break;
default:
+ drain(&outbuf);
fprintf(stderr, "%s: protocol error: bad band #%d\n",
me, band);
retval = SIDEBAND_PROTOCOL_ERROR;
@@ -97,8 +105,7 @@ int recv_sideband(const char *me, int in_stream, int out)
}
}
- if (outbuf.len > 0)
- fprintf(stderr, "%.*s", (int)outbuf.len, outbuf.buf);
+ drain(&outbuf);
strbuf_release(&outbuf);
return retval;
}
Junio C Hamano <gitster@pobox.com>