Merge branch 'jk/archive-zip-userdiff-config'
[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) == 4)
98                 return 0;
99         return error("flush packet write failed");
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         struct strbuf buf = STRBUF_INIT;
140         ssize_t count;
141
142         format_packet(&buf, fmt, args);
143         count = write_in_full(fd, buf.buf, buf.len);
144         if (count == buf.len)
145                 return 0;
146
147         if (!gently) {
148                 check_pipe(errno);
149                 die_errno("packet write with format failed");
150         }
151         return error("packet write with format failed");
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) == packet_size)
187                 return 0;
188         return error("packet write failed");
189 }
190
191 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
192 {
193         va_list args;
194
195         va_start(args, fmt);
196         format_packet(buf, fmt, args);
197         va_end(args);
198 }
199
200 int write_packetized_from_fd(int fd_in, int fd_out)
201 {
202         static char buf[LARGE_PACKET_DATA_MAX];
203         int err = 0;
204         ssize_t bytes_to_write;
205
206         while (!err) {
207                 bytes_to_write = xread(fd_in, buf, sizeof(buf));
208                 if (bytes_to_write < 0)
209                         return COPY_READ_ERROR;
210                 if (bytes_to_write == 0)
211                         break;
212                 err = packet_write_gently(fd_out, buf, bytes_to_write);
213         }
214         if (!err)
215                 err = packet_flush_gently(fd_out);
216         return err;
217 }
218
219 int write_packetized_from_buf(const char *src_in, size_t len, int fd_out)
220 {
221         int err = 0;
222         size_t bytes_written = 0;
223         size_t bytes_to_write;
224
225         while (!err) {
226                 if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
227                         bytes_to_write = LARGE_PACKET_DATA_MAX;
228                 else
229                         bytes_to_write = len - bytes_written;
230                 if (bytes_to_write == 0)
231                         break;
232                 err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
233                 bytes_written += bytes_to_write;
234         }
235         if (!err)
236                 err = packet_flush_gently(fd_out);
237         return err;
238 }
239
240 static int get_packet_data(int fd, char **src_buf, size_t *src_size,
241                            void *dst, unsigned size, int options)
242 {
243         ssize_t ret;
244
245         if (fd >= 0 && src_buf && *src_buf)
246                 die("BUG: multiple sources given to packet_read");
247
248         /* Read up to "size" bytes from our source, whatever it is. */
249         if (src_buf && *src_buf) {
250                 ret = size < *src_size ? size : *src_size;
251                 memcpy(dst, *src_buf, ret);
252                 *src_buf += ret;
253                 *src_size -= ret;
254         } else {
255                 ret = read_in_full(fd, dst, size);
256                 if (ret < 0)
257                         die_errno("read error");
258         }
259
260         /* And complain if we didn't get enough bytes to satisfy the read. */
261         if (ret < size) {
262                 if (options & PACKET_READ_GENTLE_ON_EOF)
263                         return -1;
264
265                 die("The remote end hung up unexpectedly");
266         }
267
268         return ret;
269 }
270
271 static int packet_length(const char *linelen)
272 {
273         int val = hex2chr(linelen);
274         return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
275 }
276
277 int packet_read(int fd, char **src_buf, size_t *src_len,
278                 char *buffer, unsigned size, int options)
279 {
280         int len, ret;
281         char linelen[4];
282
283         ret = get_packet_data(fd, src_buf, src_len, linelen, 4, options);
284         if (ret < 0)
285                 return ret;
286         len = packet_length(linelen);
287         if (len < 0)
288                 die("protocol error: bad line length character: %.4s", linelen);
289         if (!len) {
290                 packet_trace("0000", 4, 0);
291                 return 0;
292         }
293         len -= 4;
294         if (len >= size)
295                 die("protocol error: bad line length %d", len);
296         ret = get_packet_data(fd, src_buf, src_len, buffer, len, options);
297         if (ret < 0)
298                 return ret;
299
300         if ((options & PACKET_READ_CHOMP_NEWLINE) &&
301             len && buffer[len-1] == '\n')
302                 len--;
303
304         buffer[len] = 0;
305         packet_trace(buffer, len, 0);
306         return len;
307 }
308
309 static char *packet_read_line_generic(int fd,
310                                       char **src, size_t *src_len,
311                                       int *dst_len)
312 {
313         int len = packet_read(fd, src, src_len,
314                               packet_buffer, sizeof(packet_buffer),
315                               PACKET_READ_CHOMP_NEWLINE);
316         if (dst_len)
317                 *dst_len = len;
318         return len ? packet_buffer : NULL;
319 }
320
321 char *packet_read_line(int fd, int *len_p)
322 {
323         return packet_read_line_generic(fd, NULL, NULL, len_p);
324 }
325
326 char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
327 {
328         return packet_read_line_generic(-1, src, src_len, dst_len);
329 }
330
331 ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out)
332 {
333         int packet_len;
334
335         size_t orig_len = sb_out->len;
336         size_t orig_alloc = sb_out->alloc;
337
338         for (;;) {
339                 strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
340                 packet_len = packet_read(fd_in, NULL, NULL,
341                         /* strbuf_grow() above always allocates one extra byte to
342                          * store a '\0' at the end of the string. packet_read()
343                          * writes a '\0' extra byte at the end, too. Let it know
344                          * that there is already room for the extra byte.
345                          */
346                         sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
347                         PACKET_READ_GENTLE_ON_EOF);
348                 if (packet_len <= 0)
349                         break;
350                 sb_out->len += packet_len;
351         }
352
353         if (packet_len < 0) {
354                 if (orig_alloc == 0)
355                         strbuf_release(sb_out);
356                 else
357                         strbuf_setlen(sb_out, orig_len);
358                 return packet_len;
359         }
360         return sb_out->len - orig_len;
361 }