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