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819b929d33
The packets sent during ref negotiation are all terminated by newline; even though the code to chomp these newlines is short, we end up doing it in a lot of places. This patch teaches packet_read_line to auto-chomp the trailing newline; this lets us get rid of a lot of inline chomping code. As a result, some call-sites which are not reading line-oriented data (e.g., when reading chunks of packfiles alongside sideband) transition away from packet_read_line to the generic packet_read interface. This patch converts all of the existing callsites. Since the function signature of packet_read_line does not change (but its behavior does), there is a possibility of new callsites being introduced in later commits, silently introducing an incompatibility. However, since a later patch in this series will change the signature, such a commit would have to be merged directly into this commit, not to the tip of the series; we can therefore ignore the issue. This is an internal cleanup and should produce no change of behavior in the normal case. However, there is one corner case to note. Callers of packet_read_line have never been able to tell the difference between a flush packet ("0000") and an empty packet ("0004"), as both cause packet_read_line to return a length of 0. Readers treat them identically, even though Documentation/technical/protocol-common.txt says we must not; it also says that implementations should not send an empty pkt-line. By stripping out the newline before the result gets to the caller, we will now treat the newline-only packet ("0005\n") the same as an empty packet, which in turn gets treated like a flush packet. In practice this doesn't matter, as neither empty nor newline-only packets are part of git's protocols (at least not for the line-oriented bits, and readers who are not expecting line-oriented packets will be calling packet_read directly, anyway). But even if we do decide to care about the distinction later, it is orthogonal to this patch. The right place to tighten would be to stop treating empty packets as flush packets, and this change does not make doing so any harder. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
153 lines
3.4 KiB
C
153 lines
3.4 KiB
C
#include "cache.h"
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#include "pkt-line.h"
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#include "sideband.h"
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/*
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* Receive multiplexed output stream over git native protocol.
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* in_stream is the input stream from the remote, which carries data
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* in pkt_line format with band designator. Demultiplex it into out
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* and err and return error appropriately. Band #1 carries the
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* primary payload. Things coming over band #2 is not necessarily
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* error; they are usually informative message on the standard error
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* stream, aka "verbose"). A message over band #3 is a signal that
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* the remote died unexpectedly. A flush() concludes the stream.
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*/
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#define PREFIX "remote:"
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#define ANSI_SUFFIX "\033[K"
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#define DUMB_SUFFIX " "
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#define FIX_SIZE 10 /* large enough for any of the above */
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int recv_sideband(const char *me, int in_stream, int out)
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{
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unsigned pf = strlen(PREFIX);
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unsigned sf;
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char buf[LARGE_PACKET_MAX + 2*FIX_SIZE];
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char *suffix, *term;
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int skip_pf = 0;
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memcpy(buf, PREFIX, pf);
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term = getenv("TERM");
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if (term && strcmp(term, "dumb"))
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suffix = ANSI_SUFFIX;
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else
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suffix = DUMB_SUFFIX;
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sf = strlen(suffix);
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while (1) {
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int band, len;
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len = packet_read(in_stream, buf + pf, LARGE_PACKET_MAX, 0);
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if (len == 0)
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break;
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if (len < 1) {
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fprintf(stderr, "%s: protocol error: no band designator\n", me);
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return SIDEBAND_PROTOCOL_ERROR;
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}
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band = buf[pf] & 0xff;
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len--;
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switch (band) {
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case 3:
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buf[pf] = ' ';
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buf[pf+1+len] = '\0';
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fprintf(stderr, "%s\n", buf);
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return SIDEBAND_REMOTE_ERROR;
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case 2:
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buf[pf] = ' ';
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do {
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char *b = buf;
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int brk = 0;
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/*
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* If the last buffer didn't end with a line
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* break then we should not print a prefix
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* this time around.
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*/
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if (skip_pf) {
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b += pf+1;
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} else {
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len += pf+1;
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brk += pf+1;
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}
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/* Look for a line break. */
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for (;;) {
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brk++;
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if (brk > len) {
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brk = 0;
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break;
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}
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if (b[brk-1] == '\n' ||
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b[brk-1] == '\r')
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break;
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}
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/*
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* Let's insert a suffix to clear the end
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* of the screen line if a line break was
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* found. Also, if we don't skip the
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* prefix, then a non-empty string must be
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* present too.
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*/
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if (brk > (skip_pf ? 0 : (pf+1 + 1))) {
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char save[FIX_SIZE];
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memcpy(save, b + brk, sf);
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b[brk + sf - 1] = b[brk - 1];
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memcpy(b + brk - 1, suffix, sf);
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fprintf(stderr, "%.*s", brk + sf, b);
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memcpy(b + brk, save, sf);
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len -= brk;
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} else {
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int l = brk ? brk : len;
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fprintf(stderr, "%.*s", l, b);
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len -= l;
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}
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skip_pf = !brk;
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memmove(buf + pf+1, b + brk, len);
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} while (len);
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continue;
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case 1:
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write_or_die(out, buf + pf+1, len);
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continue;
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default:
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fprintf(stderr, "%s: protocol error: bad band #%d\n",
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me, band);
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return SIDEBAND_PROTOCOL_ERROR;
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}
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}
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return 0;
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}
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/*
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* fd is connected to the remote side; send the sideband data
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* over multiplexed packet stream.
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*/
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ssize_t send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max)
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{
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ssize_t ssz = sz;
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const char *p = data;
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while (sz) {
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unsigned n;
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char hdr[5];
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n = sz;
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if (packet_max - 5 < n)
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n = packet_max - 5;
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if (0 <= band) {
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sprintf(hdr, "%04x", n + 5);
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hdr[4] = band;
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write_or_die(fd, hdr, 5);
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} else {
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sprintf(hdr, "%04x", n + 4);
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write_or_die(fd, hdr, 4);
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}
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write_or_die(fd, p, n);
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p += n;
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sz -= n;
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}
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return ssz;
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}
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