Merge branch 'jk/diff-highlight-graph-fix'
[git] / pkt-line.c
1 #include "cache.h"
2 #include "pkt-line.h"
3 #include "run-command.h"
4
5 char packet_buffer[LARGE_PACKET_MAX];
6 static const char *packet_trace_prefix = "git";
7 static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);
8 static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);
9
10 void packet_trace_identity(const char *prog)
11 {
12         packet_trace_prefix = xstrdup(prog);
13 }
14
15 static const char *get_trace_prefix(void)
16 {
17         return in_async() ? "sideband" : packet_trace_prefix;
18 }
19
20 static int packet_trace_pack(const char *buf, unsigned int len, int sideband)
21 {
22         if (!sideband) {
23                 trace_verbatim(&trace_pack, buf, len);
24                 return 1;
25         } else if (len && *buf == '\1') {
26                 trace_verbatim(&trace_pack, buf + 1, len - 1);
27                 return 1;
28         } else {
29                 /* it's another non-pack sideband */
30                 return 0;
31         }
32 }
33
34 static void packet_trace(const char *buf, unsigned int len, int write)
35 {
36         int i;
37         struct strbuf out;
38         static int in_pack, sideband;
39
40         if (!trace_want(&trace_packet) && !trace_want(&trace_pack))
41                 return;
42
43         if (in_pack) {
44                 if (packet_trace_pack(buf, len, sideband))
45                         return;
46         } else if (starts_with(buf, "PACK") || starts_with(buf, "\1PACK")) {
47                 in_pack = 1;
48                 sideband = *buf == '\1';
49                 packet_trace_pack(buf, len, sideband);
50
51                 /*
52                  * Make a note in the human-readable trace that the pack data
53                  * started.
54                  */
55                 buf = "PACK ...";
56                 len = strlen(buf);
57         }
58
59         if (!trace_want(&trace_packet))
60                 return;
61
62         /* +32 is just a guess for header + quoting */
63         strbuf_init(&out, len+32);
64
65         strbuf_addf(&out, "packet: %12s%c ",
66                     get_trace_prefix(), write ? '>' : '<');
67
68         /* XXX we should really handle printable utf8 */
69         for (i = 0; i < len; i++) {
70                 /* suppress newlines */
71                 if (buf[i] == '\n')
72                         continue;
73                 if (buf[i] >= 0x20 && buf[i] <= 0x7e)
74                         strbuf_addch(&out, buf[i]);
75                 else
76                         strbuf_addf(&out, "\\%o", buf[i]);
77         }
78
79         strbuf_addch(&out, '\n');
80         trace_strbuf(&trace_packet, &out);
81         strbuf_release(&out);
82 }
83
84 /*
85  * If we buffered things up above (we don't, but we should),
86  * we'd flush it here
87  */
88 void packet_flush(int fd)
89 {
90         packet_trace("0000", 4, 1);
91         write_or_die(fd, "0000", 4);
92 }
93
94 int packet_flush_gently(int fd)
95 {
96         packet_trace("0000", 4, 1);
97         if (write_in_full(fd, "0000", 4) < 0)
98                 return error("flush packet write failed");
99         return 0;
100 }
101
102 void packet_buf_flush(struct strbuf *buf)
103 {
104         packet_trace("0000", 4, 1);
105         strbuf_add(buf, "0000", 4);
106 }
107
108 static void set_packet_header(char *buf, const int size)
109 {
110         static char hexchar[] = "0123456789abcdef";
111
112         #define hex(a) (hexchar[(a) & 15])
113         buf[0] = hex(size >> 12);
114         buf[1] = hex(size >> 8);
115         buf[2] = hex(size >> 4);
116         buf[3] = hex(size);
117         #undef hex
118 }
119
120 static void format_packet(struct strbuf *out, const char *fmt, va_list args)
121 {
122         size_t orig_len, n;
123
124         orig_len = out->len;
125         strbuf_addstr(out, "0000");
126         strbuf_vaddf(out, fmt, args);
127         n = out->len - orig_len;
128
129         if (n > LARGE_PACKET_MAX)
130                 die("protocol error: impossibly long line");
131
132         set_packet_header(&out->buf[orig_len], n);
133         packet_trace(out->buf + orig_len + 4, n - 4, 1);
134 }
135
136 static int packet_write_fmt_1(int fd, int gently,
137                               const char *fmt, va_list args)
138 {
139         static struct strbuf buf = STRBUF_INIT;
140
141         strbuf_reset(&buf);
142         format_packet(&buf, fmt, args);
143         if (write_in_full(fd, buf.buf, buf.len) < 0) {
144                 if (!gently) {
145                         check_pipe(errno);
146                         die_errno("packet write with format failed");
147                 }
148                 return error("packet write with format failed");
149         }
150
151         return 0;
152 }
153
154 void packet_write_fmt(int fd, const char *fmt, ...)
155 {
156         va_list args;
157
158         va_start(args, fmt);
159         packet_write_fmt_1(fd, 0, fmt, args);
160         va_end(args);
161 }
162
163 int packet_write_fmt_gently(int fd, const char *fmt, ...)
164 {
165         int status;
166         va_list args;
167
168         va_start(args, fmt);
169         status = packet_write_fmt_1(fd, 1, fmt, args);
170         va_end(args);
171         return status;
172 }
173
174 static int packet_write_gently(const int fd_out, const char *buf, size_t size)
175 {
176         static char packet_write_buffer[LARGE_PACKET_MAX];
177         size_t packet_size;
178
179         if (size > sizeof(packet_write_buffer) - 4)
180                 return error("packet write failed - data exceeds max packet size");
181
182         packet_trace(buf, size, 1);
183         packet_size = size + 4;
184         set_packet_header(packet_write_buffer, packet_size);
185         memcpy(packet_write_buffer + 4, buf, size);
186         if (write_in_full(fd_out, packet_write_buffer, packet_size) < 0)
187                 return error("packet write failed");
188         return 0;
189 }
190
191 void packet_write(int fd_out, const char *buf, size_t size)
192 {
193         if (packet_write_gently(fd_out, buf, size))
194                 die_errno("packet write failed");
195 }
196
197 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
198 {
199         va_list args;
200
201         va_start(args, fmt);
202         format_packet(buf, fmt, args);
203         va_end(args);
204 }
205
206 int write_packetized_from_fd(int fd_in, int fd_out)
207 {
208         static char buf[LARGE_PACKET_DATA_MAX];
209         int err = 0;
210         ssize_t bytes_to_write;
211
212         while (!err) {
213                 bytes_to_write = xread(fd_in, buf, sizeof(buf));
214                 if (bytes_to_write < 0)
215                         return COPY_READ_ERROR;
216                 if (bytes_to_write == 0)
217                         break;
218                 err = packet_write_gently(fd_out, buf, bytes_to_write);
219         }
220         if (!err)
221                 err = packet_flush_gently(fd_out);
222         return err;
223 }
224
225 int write_packetized_from_buf(const char *src_in, size_t len, int fd_out)
226 {
227         int err = 0;
228         size_t bytes_written = 0;
229         size_t bytes_to_write;
230
231         while (!err) {
232                 if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
233                         bytes_to_write = LARGE_PACKET_DATA_MAX;
234                 else
235                         bytes_to_write = len - bytes_written;
236                 if (bytes_to_write == 0)
237                         break;
238                 err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
239                 bytes_written += bytes_to_write;
240         }
241         if (!err)
242                 err = packet_flush_gently(fd_out);
243         return err;
244 }
245
246 static int get_packet_data(int fd, char **src_buf, size_t *src_size,
247                            void *dst, unsigned size, int options)
248 {
249         ssize_t ret;
250
251         if (fd >= 0 && src_buf && *src_buf)
252                 die("BUG: multiple sources given to packet_read");
253
254         /* Read up to "size" bytes from our source, whatever it is. */
255         if (src_buf && *src_buf) {
256                 ret = size < *src_size ? size : *src_size;
257                 memcpy(dst, *src_buf, ret);
258                 *src_buf += ret;
259                 *src_size -= ret;
260         } else {
261                 ret = read_in_full(fd, dst, size);
262                 if (ret < 0)
263                         die_errno("read error");
264         }
265
266         /* And complain if we didn't get enough bytes to satisfy the read. */
267         if (ret != size) {
268                 if (options & PACKET_READ_GENTLE_ON_EOF)
269                         return -1;
270
271                 die("The remote end hung up unexpectedly");
272         }
273
274         return ret;
275 }
276
277 static int packet_length(const char *linelen)
278 {
279         int val = hex2chr(linelen);
280         return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
281 }
282
283 int packet_read(int fd, char **src_buf, size_t *src_len,
284                 char *buffer, unsigned size, int options)
285 {
286         int len, ret;
287         char linelen[4];
288
289         ret = get_packet_data(fd, src_buf, src_len, linelen, 4, options);
290         if (ret < 0)
291                 return ret;
292         len = packet_length(linelen);
293         if (len < 0)
294                 die("protocol error: bad line length character: %.4s", linelen);
295         if (!len) {
296                 packet_trace("0000", 4, 0);
297                 return 0;
298         }
299         len -= 4;
300         if (len >= size)
301                 die("protocol error: bad line length %d", len);
302         ret = get_packet_data(fd, src_buf, src_len, buffer, len, options);
303         if (ret < 0)
304                 return ret;
305
306         if ((options & PACKET_READ_CHOMP_NEWLINE) &&
307             len && buffer[len-1] == '\n')
308                 len--;
309
310         buffer[len] = 0;
311         packet_trace(buffer, len, 0);
312         return len;
313 }
314
315 static char *packet_read_line_generic(int fd,
316                                       char **src, size_t *src_len,
317                                       int *dst_len)
318 {
319         int len = packet_read(fd, src, src_len,
320                               packet_buffer, sizeof(packet_buffer),
321                               PACKET_READ_CHOMP_NEWLINE);
322         if (dst_len)
323                 *dst_len = len;
324         return (len > 0) ? packet_buffer : NULL;
325 }
326
327 char *packet_read_line(int fd, int *len_p)
328 {
329         return packet_read_line_generic(fd, NULL, NULL, len_p);
330 }
331
332 int packet_read_line_gently(int fd, int *dst_len, char **dst_line)
333 {
334         int len = packet_read(fd, NULL, NULL,
335                               packet_buffer, sizeof(packet_buffer),
336                               PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
337         if (dst_len)
338                 *dst_len = len;
339         if (dst_line)
340                 *dst_line = (len > 0) ? packet_buffer : NULL;
341         return len;
342 }
343
344 char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
345 {
346         return packet_read_line_generic(-1, src, src_len, dst_len);
347 }
348
349 ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out)
350 {
351         int packet_len;
352
353         size_t orig_len = sb_out->len;
354         size_t orig_alloc = sb_out->alloc;
355
356         for (;;) {
357                 strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
358                 packet_len = packet_read(fd_in, NULL, NULL,
359                         /* strbuf_grow() above always allocates one extra byte to
360                          * store a '\0' at the end of the string. packet_read()
361                          * writes a '\0' extra byte at the end, too. Let it know
362                          * that there is already room for the extra byte.
363                          */
364                         sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
365                         PACKET_READ_GENTLE_ON_EOF);
366                 if (packet_len <= 0)
367                         break;
368                 sb_out->len += packet_len;
369         }
370
371         if (packet_len < 0) {
372                 if (orig_alloc == 0)
373                         strbuf_release(sb_out);
374                 else
375                         strbuf_setlen(sb_out, orig_len);
376                 return packet_len;
377         }
378         return sb_out->len - orig_len;
379 }