pkt-line: provide a LARGE_PACKET_MAX static buffer
[git/git.git] / sideband.c
CommitLineData
cdf4fb8e 1#include "cache.h"
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JH
2#include "pkt-line.h"
3#include "sideband.h"
4
5/*
6 * Receive multiplexed output stream over git native protocol.
7 * in_stream is the input stream from the remote, which carries data
8 * in pkt_line format with band designator. Demultiplex it into out
9 * and err and return error appropriately. Band #1 carries the
10 * primary payload. Things coming over band #2 is not necessarily
11 * error; they are usually informative message on the standard error
12 * stream, aka "verbose"). A message over band #3 is a signal that
13 * the remote died unexpectedly. A flush() concludes the stream.
14 */
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NP
15
16#define PREFIX "remote:"
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17
18#define ANSI_SUFFIX "\033[K"
19#define DUMB_SUFFIX " "
20
21#define FIX_SIZE 10 /* large enough for any of the above */
ebe8fa73 22
34df8aba 23int recv_sideband(const char *me, int in_stream, int out)
49a52b1d 24{
ebe8fa73 25 unsigned pf = strlen(PREFIX);
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26 unsigned sf;
27 char buf[LARGE_PACKET_MAX + 2*FIX_SIZE];
28 char *suffix, *term;
6b9c42b4 29 int skip_pf = 0;
13e4760a 30
ebe8fa73 31 memcpy(buf, PREFIX, pf);
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32 term = getenv("TERM");
33 if (term && strcmp(term, "dumb"))
34 suffix = ANSI_SUFFIX;
35 else
36 suffix = DUMB_SUFFIX;
37 sf = strlen(suffix);
38
49a52b1d 39 while (1) {
9ac13ec9 40 int band, len;
819b929d 41 len = packet_read(in_stream, buf + pf, LARGE_PACKET_MAX, 0);
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42 if (len == 0)
43 break;
44 if (len < 1) {
34df8aba 45 fprintf(stderr, "%s: protocol error: no band designator\n", me);
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46 return SIDEBAND_PROTOCOL_ERROR;
47 }
ebe8fa73 48 band = buf[pf] & 0xff;
49a52b1d 49 len--;
9ac13ec9 50 switch (band) {
49a52b1d 51 case 3:
ebe8fa73 52 buf[pf] = ' ';
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JS
53 buf[pf+1+len] = '\0';
54 fprintf(stderr, "%s\n", buf);
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55 return SIDEBAND_REMOTE_ERROR;
56 case 2:
ebe8fa73 57 buf[pf] = ' ';
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NP
58 do {
59 char *b = buf;
60 int brk = 0;
ebe8fa73 61
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NP
62 /*
63 * If the last buffer didn't end with a line
64 * break then we should not print a prefix
65 * this time around.
66 */
67 if (skip_pf) {
68 b += pf+1;
69 } else {
70 len += pf+1;
71 brk += pf+1;
72 }
73
74 /* Look for a line break. */
75 for (;;) {
ed1902ef 76 brk++;
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NP
77 if (brk > len) {
78 brk = 0;
79 break;
80 }
81 if (b[brk-1] == '\n' ||
82 b[brk-1] == '\r')
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NP
83 break;
84 }
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NP
85
86 /*
87 * Let's insert a suffix to clear the end
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NP
88 * of the screen line if a line break was
89 * found. Also, if we don't skip the
90 * prefix, then a non-empty string must be
91 * present too.
ebe8fa73 92 */
6b9c42b4 93 if (brk > (skip_pf ? 0 : (pf+1 + 1))) {
13e4760a 94 char save[FIX_SIZE];
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NP
95 memcpy(save, b + brk, sf);
96 b[brk + sf - 1] = b[brk - 1];
97 memcpy(b + brk - 1, suffix, sf);
34df8aba 98 fprintf(stderr, "%.*s", brk + sf, b);
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NP
99 memcpy(b + brk, save, sf);
100 len -= brk;
101 } else {
102 int l = brk ? brk : len;
34df8aba 103 fprintf(stderr, "%.*s", l, b);
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104 len -= l;
105 }
ebe8fa73 106
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107 skip_pf = !brk;
108 memmove(buf + pf+1, b + brk, len);
109 } while (len);
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110 continue;
111 case 1:
cdf4fb8e 112 write_or_die(out, buf + pf+1, len);
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113 continue;
114 default:
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115 fprintf(stderr, "%s: protocol error: bad band #%d\n",
116 me, band);
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117 return SIDEBAND_PROTOCOL_ERROR;
118 }
119 }
120 return 0;
121}
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122
123/*
124 * fd is connected to the remote side; send the sideband data
125 * over multiplexed packet stream.
126 */
127ssize_t send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max)
128{
129 ssize_t ssz = sz;
130 const char *p = data;
131
132 while (sz) {
133 unsigned n;
134 char hdr[5];
135
136 n = sz;
137 if (packet_max - 5 < n)
138 n = packet_max - 5;
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139 if (0 <= band) {
140 sprintf(hdr, "%04x", n + 5);
141 hdr[4] = band;
cdf4fb8e 142 write_or_die(fd, hdr, 5);
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SP
143 } else {
144 sprintf(hdr, "%04x", n + 4);
cdf4fb8e 145 write_or_die(fd, hdr, 4);
de1a2fdd 146 }
cdf4fb8e 147 write_or_die(fd, p, n);
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148 p += n;
149 sz -= n;
150 }
151 return ssz;
152}