Sync with 2.3.1
[git] / builtin / cat-file.c
1 /*
2  * GIT - The information manager from hell
3  *
4  * Copyright (C) Linus Torvalds, 2005
5  */
6 #include "cache.h"
7 #include "builtin.h"
8 #include "parse-options.h"
9 #include "userdiff.h"
10 #include "streaming.h"
11
12 static int cat_one_file(int opt, const char *exp_type, const char *obj_name)
13 {
14         unsigned char sha1[20];
15         enum object_type type;
16         char *buf;
17         unsigned long size;
18         struct object_context obj_context;
19
20         if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
21                 die("Not a valid object name %s", obj_name);
22
23         buf = NULL;
24         switch (opt) {
25         case 't':
26                 type = sha1_object_info(sha1, NULL);
27                 if (type > 0) {
28                         printf("%s\n", typename(type));
29                         return 0;
30                 }
31                 break;
32
33         case 's':
34                 type = sha1_object_info(sha1, &size);
35                 if (type > 0) {
36                         printf("%lu\n", size);
37                         return 0;
38                 }
39                 break;
40
41         case 'e':
42                 return !has_sha1_file(sha1);
43
44         case 'c':
45                 if (!obj_context.path[0])
46                         die("git cat-file --textconv %s: <object> must be <sha1:path>",
47                             obj_name);
48
49                 if (textconv_object(obj_context.path, obj_context.mode, sha1, 1, &buf, &size))
50                         break;
51
52         case 'p':
53                 type = sha1_object_info(sha1, NULL);
54                 if (type < 0)
55                         die("Not a valid object name %s", obj_name);
56
57                 /* custom pretty-print here */
58                 if (type == OBJ_TREE) {
59                         const char *ls_args[3] = { NULL };
60                         ls_args[0] =  "ls-tree";
61                         ls_args[1] =  obj_name;
62                         return cmd_ls_tree(2, ls_args, NULL);
63                 }
64
65                 if (type == OBJ_BLOB)
66                         return stream_blob_to_fd(1, sha1, NULL, 0);
67                 buf = read_sha1_file(sha1, &type, &size);
68                 if (!buf)
69                         die("Cannot read object %s", obj_name);
70
71                 /* otherwise just spit out the data */
72                 break;
73
74         case 0:
75                 if (type_from_string(exp_type) == OBJ_BLOB) {
76                         unsigned char blob_sha1[20];
77                         if (sha1_object_info(sha1, NULL) == OBJ_TAG) {
78                                 char *buffer = read_sha1_file(sha1, &type, &size);
79                                 const char *target;
80                                 if (!skip_prefix(buffer, "object ", &target) ||
81                                     get_sha1_hex(target, blob_sha1))
82                                         die("%s not a valid tag", sha1_to_hex(sha1));
83                                 free(buffer);
84                         } else
85                                 hashcpy(blob_sha1, sha1);
86
87                         if (sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
88                                 return stream_blob_to_fd(1, blob_sha1, NULL, 0);
89                         /*
90                          * we attempted to dereference a tag to a blob
91                          * and failed; there may be new dereference
92                          * mechanisms this code is not aware of.
93                          * fall-back to the usual case.
94                          */
95                 }
96                 buf = read_object_with_reference(sha1, exp_type, &size, NULL);
97                 break;
98
99         default:
100                 die("git cat-file: unknown option: %s", exp_type);
101         }
102
103         if (!buf)
104                 die("git cat-file %s: bad file", obj_name);
105
106         write_or_die(1, buf, size);
107         return 0;
108 }
109
110 struct expand_data {
111         unsigned char sha1[20];
112         enum object_type type;
113         unsigned long size;
114         unsigned long disk_size;
115         const char *rest;
116         unsigned char delta_base_sha1[20];
117
118         /*
119          * If mark_query is true, we do not expand anything, but rather
120          * just mark the object_info with items we wish to query.
121          */
122         int mark_query;
123
124         /*
125          * Whether to split the input on whitespace before feeding it to
126          * get_sha1; this is decided during the mark_query phase based on
127          * whether we have a %(rest) token in our format.
128          */
129         int split_on_whitespace;
130
131         /*
132          * After a mark_query run, this object_info is set up to be
133          * passed to sha1_object_info_extended. It will point to the data
134          * elements above, so you can retrieve the response from there.
135          */
136         struct object_info info;
137 };
138
139 static int is_atom(const char *atom, const char *s, int slen)
140 {
141         int alen = strlen(atom);
142         return alen == slen && !memcmp(atom, s, alen);
143 }
144
145 static void expand_atom(struct strbuf *sb, const char *atom, int len,
146                         void *vdata)
147 {
148         struct expand_data *data = vdata;
149
150         if (is_atom("objectname", atom, len)) {
151                 if (!data->mark_query)
152                         strbuf_addstr(sb, sha1_to_hex(data->sha1));
153         } else if (is_atom("objecttype", atom, len)) {
154                 if (data->mark_query)
155                         data->info.typep = &data->type;
156                 else
157                         strbuf_addstr(sb, typename(data->type));
158         } else if (is_atom("objectsize", atom, len)) {
159                 if (data->mark_query)
160                         data->info.sizep = &data->size;
161                 else
162                         strbuf_addf(sb, "%lu", data->size);
163         } else if (is_atom("objectsize:disk", atom, len)) {
164                 if (data->mark_query)
165                         data->info.disk_sizep = &data->disk_size;
166                 else
167                         strbuf_addf(sb, "%lu", data->disk_size);
168         } else if (is_atom("rest", atom, len)) {
169                 if (data->mark_query)
170                         data->split_on_whitespace = 1;
171                 else if (data->rest)
172                         strbuf_addstr(sb, data->rest);
173         } else if (is_atom("deltabase", atom, len)) {
174                 if (data->mark_query)
175                         data->info.delta_base_sha1 = data->delta_base_sha1;
176                 else
177                         strbuf_addstr(sb, sha1_to_hex(data->delta_base_sha1));
178         } else
179                 die("unknown format element: %.*s", len, atom);
180 }
181
182 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
183 {
184         const char *end;
185
186         if (*start != '(')
187                 return 0;
188         end = strchr(start + 1, ')');
189         if (!end)
190                 die("format element '%s' does not end in ')'", start);
191
192         expand_atom(sb, start + 1, end - start - 1, data);
193
194         return end - start + 1;
195 }
196
197 static void print_object_or_die(int fd, struct expand_data *data)
198 {
199         const unsigned char *sha1 = data->sha1;
200
201         assert(data->info.typep);
202
203         if (data->type == OBJ_BLOB) {
204                 if (stream_blob_to_fd(fd, sha1, NULL, 0) < 0)
205                         die("unable to stream %s to stdout", sha1_to_hex(sha1));
206         }
207         else {
208                 enum object_type type;
209                 unsigned long size;
210                 void *contents;
211
212                 contents = read_sha1_file(sha1, &type, &size);
213                 if (!contents)
214                         die("object %s disappeared", sha1_to_hex(sha1));
215                 if (type != data->type)
216                         die("object %s changed type!?", sha1_to_hex(sha1));
217                 if (data->info.sizep && size != data->size)
218                         die("object %s changed size!?", sha1_to_hex(sha1));
219
220                 write_or_die(fd, contents, size);
221                 free(contents);
222         }
223 }
224
225 struct batch_options {
226         int enabled;
227         int print_contents;
228         const char *format;
229 };
230
231 static int batch_one_object(const char *obj_name, struct batch_options *opt,
232                             struct expand_data *data)
233 {
234         struct strbuf buf = STRBUF_INIT;
235
236         if (!obj_name)
237            return 1;
238
239         if (get_sha1(obj_name, data->sha1)) {
240                 printf("%s missing\n", obj_name);
241                 fflush(stdout);
242                 return 0;
243         }
244
245         if (sha1_object_info_extended(data->sha1, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
246                 printf("%s missing\n", obj_name);
247                 fflush(stdout);
248                 return 0;
249         }
250
251         strbuf_expand(&buf, opt->format, expand_format, data);
252         strbuf_addch(&buf, '\n');
253         write_or_die(1, buf.buf, buf.len);
254         strbuf_release(&buf);
255
256         if (opt->print_contents) {
257                 print_object_or_die(1, data);
258                 write_or_die(1, "\n", 1);
259         }
260         return 0;
261 }
262
263 static int batch_objects(struct batch_options *opt)
264 {
265         struct strbuf buf = STRBUF_INIT;
266         struct expand_data data;
267         int save_warning;
268         int retval = 0;
269
270         if (!opt->format)
271                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
272
273         /*
274          * Expand once with our special mark_query flag, which will prime the
275          * object_info to be handed to sha1_object_info_extended for each
276          * object.
277          */
278         memset(&data, 0, sizeof(data));
279         data.mark_query = 1;
280         strbuf_expand(&buf, opt->format, expand_format, &data);
281         data.mark_query = 0;
282
283         /*
284          * If we are printing out the object, then always fill in the type,
285          * since we will want to decide whether or not to stream.
286          */
287         if (opt->print_contents)
288                 data.info.typep = &data.type;
289
290         /*
291          * We are going to call get_sha1 on a potentially very large number of
292          * objects. In most large cases, these will be actual object sha1s. The
293          * cost to double-check that each one is not also a ref (just so we can
294          * warn) ends up dwarfing the actual cost of the object lookups
295          * themselves. We can work around it by just turning off the warning.
296          */
297         save_warning = warn_on_object_refname_ambiguity;
298         warn_on_object_refname_ambiguity = 0;
299
300         while (strbuf_getline(&buf, stdin, '\n') != EOF) {
301                 if (data.split_on_whitespace) {
302                         /*
303                          * Split at first whitespace, tying off the beginning
304                          * of the string and saving the remainder (or NULL) in
305                          * data.rest.
306                          */
307                         char *p = strpbrk(buf.buf, " \t");
308                         if (p) {
309                                 while (*p && strchr(" \t", *p))
310                                         *p++ = '\0';
311                         }
312                         data.rest = p;
313                 }
314
315                 retval = batch_one_object(buf.buf, opt, &data);
316                 if (retval)
317                         break;
318         }
319
320         strbuf_release(&buf);
321         warn_on_object_refname_ambiguity = save_warning;
322         return retval;
323 }
324
325 static const char * const cat_file_usage[] = {
326         N_("git cat-file (-t | -s | -e | -p | <type> | --textconv) <object>"),
327         N_("git cat-file (--batch | --batch-check) < <list-of-objects>"),
328         NULL
329 };
330
331 static int git_cat_file_config(const char *var, const char *value, void *cb)
332 {
333         if (userdiff_config(var, value) < 0)
334                 return -1;
335
336         return git_default_config(var, value, cb);
337 }
338
339 static int batch_option_callback(const struct option *opt,
340                                  const char *arg,
341                                  int unset)
342 {
343         struct batch_options *bo = opt->value;
344
345         if (unset) {
346                 memset(bo, 0, sizeof(*bo));
347                 return 0;
348         }
349
350         bo->enabled = 1;
351         bo->print_contents = !strcmp(opt->long_name, "batch");
352         bo->format = arg;
353
354         return 0;
355 }
356
357 int cmd_cat_file(int argc, const char **argv, const char *prefix)
358 {
359         int opt = 0;
360         const char *exp_type = NULL, *obj_name = NULL;
361         struct batch_options batch = {0};
362
363         const struct option options[] = {
364                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
365                 OPT_SET_INT('t', NULL, &opt, N_("show object type"), 't'),
366                 OPT_SET_INT('s', NULL, &opt, N_("show object size"), 's'),
367                 OPT_SET_INT('e', NULL, &opt,
368                             N_("exit with zero when there's no error"), 'e'),
369                 OPT_SET_INT('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
370                 OPT_SET_INT(0, "textconv", &opt,
371                             N_("for blob objects, run textconv on object's content"), 'c'),
372                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
373                         N_("show info and content of objects fed from the standard input"),
374                         PARSE_OPT_OPTARG, batch_option_callback },
375                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
376                         N_("show info about objects fed from the standard input"),
377                         PARSE_OPT_OPTARG, batch_option_callback },
378                 OPT_END()
379         };
380
381         git_config(git_cat_file_config, NULL);
382
383         if (argc != 3 && argc != 2)
384                 usage_with_options(cat_file_usage, options);
385
386         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
387
388         if (opt) {
389                 if (argc == 1)
390                         obj_name = argv[0];
391                 else
392                         usage_with_options(cat_file_usage, options);
393         }
394         if (!opt && !batch.enabled) {
395                 if (argc == 2) {
396                         exp_type = argv[0];
397                         obj_name = argv[1];
398                 } else
399                         usage_with_options(cat_file_usage, options);
400         }
401         if (batch.enabled && (opt || argc)) {
402                 usage_with_options(cat_file_usage, options);
403         }
404
405         if (batch.enabled)
406                 return batch_objects(&batch);
407
408         return cat_one_file(opt, exp_type, obj_name);
409 }