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sideband: reverse its dependency on pkt-line

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A subsequent patch will teach struct packet_reader a new field that, if
set, instructs it to interpret read data as multiplexed. This will
create a dependency from pkt-line to sideband.

To avoid a circular dependency, split recv_sideband() into 2 parts: the
reading loop (left in recv_sideband()) and the processing of the
contents (in demultiplex_sideband()), and move the former into pkt-line.
This reverses the direction of dependency: sideband no longer depends on
pkt-line, and pkt-line now depends on sideband.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jonathan Tan 2019-01-16 11:28:13 -08:00 committed by Junio C Hamano
parent bc2e795cea
commit fbd76cd450
4 changed files with 143 additions and 97 deletions
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23
pkt-line.c
View File

@ -439,6 +439,29 @@ ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out)
return sb_out->len - orig_len;
}
int recv_sideband(const char *me, int in_stream, int out)
{
char buf[LARGE_PACKET_MAX + 1];
int len;
struct strbuf scratch = STRBUF_INIT;
enum sideband_type sideband_type;
while (1) {
len = packet_read(in_stream, NULL, NULL, buf, LARGE_PACKET_MAX,
0);
if (!demultiplex_sideband(me, buf, len, &scratch,
&sideband_type))
continue;
switch (sideband_type) {
case SIDEBAND_PRIMARY:
write_or_die(out, buf + 1, len - 1);
break;
default: /* errors: message already written */
return sideband_type;
}
}
}
/* Packet Reader Functions */
void packet_reader_init(struct packet_reader *reader, int fd,
char *src_buffer, size_t src_len,

16
pkt-line.h
View File

@ -3,6 +3,7 @@
#include "git-compat-util.h"
#include "strbuf.h"
#include "sideband.h"
/*
* Write a packetized stream, where each line is preceded by
@ -120,6 +121,21 @@ char *packet_read_line_buf(char **src_buf, size_t *src_len, int *size);
*/
ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out);
/*
* Receive multiplexed output stream over git native protocol.
* in_stream is the input stream from the remote, which carries data
* in pkt_line format with band designator. Demultiplex it into out
* and err and return error appropriately. Band #1 carries the
* primary payload. Things coming over band #2 is not necessarily
* error; they are usually informative message on the standard error
* stream, aka "verbose"). A message over band #3 is a signal that
* the remote died unexpectedly. A flush() concludes the stream.
*
* Returns SIDEBAND_FLUSH upon a normal conclusion, and SIDEBAND_PROTOCOL_ERROR
* or SIDEBAND_REMOTE_ERROR if an error occurred.
*/
int recv_sideband(const char *me, int in_stream, int out);
struct packet_reader {
/* source file descriptor */
int fd;

177
sideband.c
View File

@ -1,7 +1,6 @@
#include "cache.h"
#include "color.h"
#include "config.h"
#include "pkt-line.h"
#include "sideband.h"
#include "help.h"
@ -109,109 +108,99 @@ static void maybe_colorize_sideband(struct strbuf *dest, const char *src, int n)
}
/*
* Receive multiplexed output stream over git native protocol.
* in_stream is the input stream from the remote, which carries data
* in pkt_line format with band designator. Demultiplex it into out
* and err and return error appropriately. Band #1 carries the
* primary payload. Things coming over band #2 is not necessarily
* error; they are usually informative message on the standard error
* stream, aka "verbose"). A message over band #3 is a signal that
* the remote died unexpectedly. A flush() concludes the stream.
*/
#define DISPLAY_PREFIX "remote: "
#define ANSI_SUFFIX "\033[K"
#define DUMB_SUFFIX " "
int recv_sideband(const char *me, int in_stream, int out)
int demultiplex_sideband(const char *me, char *buf, int len,
struct strbuf *scratch,
enum sideband_type *sideband_type)
{
const char *suffix;
char buf[LARGE_PACKET_MAX + 1];
struct strbuf outbuf = STRBUF_INIT;
int retval = 0;
static const char *suffix;
const char *b, *brk;
int band;
if (isatty(2) && !is_terminal_dumb())
suffix = ANSI_SUFFIX;
else
suffix = DUMB_SUFFIX;
while (!retval) {
const char *b, *brk;
int band, len;
len = packet_read(in_stream, NULL, NULL, buf, LARGE_PACKET_MAX, 0);
if (len == 0)
break;
if (len < 1) {
strbuf_addf(&outbuf,
"%s%s: protocol error: no band designator",
outbuf.len ? "\n" : "", me);
retval = SIDEBAND_PROTOCOL_ERROR;
break;
}
band = buf[0] & 0xff;
buf[len] = '\0';
len--;
switch (band) {
case 3:
strbuf_addf(&outbuf, "%s%s", outbuf.len ? "\n" : "",
DISPLAY_PREFIX);
maybe_colorize_sideband(&outbuf, buf + 1, len);
retval = SIDEBAND_REMOTE_ERROR;
break;
case 2:
b = buf + 1;
/*
* 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
* write(2) to ensure inter-process atomicity.
*/
while ((brk = strpbrk(b, "\n\r"))) {
int linelen = brk - b;
if (!outbuf.len)
strbuf_addstr(&outbuf, DISPLAY_PREFIX);
if (linelen > 0) {
maybe_colorize_sideband(&outbuf, b, linelen);
strbuf_addstr(&outbuf, suffix);
}
strbuf_addch(&outbuf, *brk);
xwrite(2, outbuf.buf, outbuf.len);
strbuf_reset(&outbuf);
b = brk + 1;
}
if (*b) {
strbuf_addstr(&outbuf, outbuf.len ?
"" : DISPLAY_PREFIX);
maybe_colorize_sideband(&outbuf, b, strlen(b));
}
break;
case 1:
write_or_die(out, buf + 1, len);
break;
default:
strbuf_addf(&outbuf, "%s%s: protocol error: bad band #%d",
outbuf.len ? "\n" : "", me, band);
retval = SIDEBAND_PROTOCOL_ERROR;
break;
}
if (!suffix) {
if (isatty(2) && !is_terminal_dumb())
suffix = ANSI_SUFFIX;
else
suffix = DUMB_SUFFIX;
}
if (outbuf.len) {
strbuf_addch(&outbuf, '\n');
xwrite(2, outbuf.buf, outbuf.len);
if (len == 0) {
*sideband_type = SIDEBAND_FLUSH;
goto cleanup;
}
strbuf_release(&outbuf);
return retval;
if (len < 1) {
strbuf_addf(scratch,
"%s%s: protocol error: no band designator",
scratch->len ? "\n" : "", me);
*sideband_type = SIDEBAND_PROTOCOL_ERROR;
goto cleanup;
}
band = buf[0] & 0xff;
buf[len] = '\0';
len--;
switch (band) {
case 3:
strbuf_addf(scratch, "%s%s", scratch->len ? "\n" : "",
DISPLAY_PREFIX);
maybe_colorize_sideband(scratch, buf + 1, len);
*sideband_type = SIDEBAND_REMOTE_ERROR;
break;
case 2:
b = buf + 1;
/*
* 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
* write(2) to ensure inter-process atomicity.
*/
while ((brk = strpbrk(b, "\n\r"))) {
int linelen = brk - b;
if (!scratch->len)
strbuf_addstr(scratch, DISPLAY_PREFIX);
if (linelen > 0) {
maybe_colorize_sideband(scratch, b, linelen);
strbuf_addstr(scratch, suffix);
}
strbuf_addch(scratch, *brk);
xwrite(2, scratch->buf, scratch->len);
strbuf_reset(scratch);
b = brk + 1;
}
if (*b) {
strbuf_addstr(scratch, scratch->len ?
"" : DISPLAY_PREFIX);
maybe_colorize_sideband(scratch, b, strlen(b));
}
return 0;
case 1:
*sideband_type = SIDEBAND_PRIMARY;
break;
default:
strbuf_addf(scratch, "%s%s: protocol error: bad band #%d",
scratch->len ? "\n" : "", me, band);
*sideband_type = SIDEBAND_PROTOCOL_ERROR;
break;
}
cleanup:
if (scratch->len) {
strbuf_addch(scratch, '\n');
xwrite(2, scratch->buf, scratch->len);
}
strbuf_release(scratch);
return 1;
}
/*

24
sideband.h
View File

@ -1,10 +1,28 @@
#ifndef SIDEBAND_H
#define SIDEBAND_H
#define SIDEBAND_PROTOCOL_ERROR -2
#define SIDEBAND_REMOTE_ERROR -1
enum sideband_type {
SIDEBAND_PROTOCOL_ERROR = -2,
SIDEBAND_REMOTE_ERROR = -1,
SIDEBAND_FLUSH = 0,
SIDEBAND_PRIMARY = 1
};
/*
* Inspects a multiplexed packet read from the remote. If this packet is a
* progress packet and thus should not be processed by the caller, returns 0.
* Otherwise, returns 1, releases scratch, and sets sideband_type.
*
* If this packet is SIDEBAND_PROTOCOL_ERROR, SIDEBAND_REMOTE_ERROR, or a
* progress packet, also prints a message to stderr.
*
* scratch must be a struct strbuf allocated by the caller. It is used to store
* progress messages split across multiple packets.
*/
int demultiplex_sideband(const char *me, char *buf, int len,
struct strbuf *scratch,
enum sideband_type *sideband_type);
int recv_sideband(const char *me, int in_stream, int out);
void send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max);
#endif