Git/Packet: clarify that packet_required_key_val_read allows EOF
[git] / tree.c
1 #define NO_THE_INDEX_COMPATIBILITY_MACROS
2 #include "cache.h"
3 #include "cache-tree.h"
4 #include "tree.h"
5 #include "blob.h"
6 #include "commit.h"
7 #include "tag.h"
8 #include "tree-walk.h"
9
10 const char *tree_type = "tree";
11
12 static int read_one_entry_opt(struct index_state *istate,
13                               const unsigned char *sha1,
14                               const char *base, int baselen,
15                               const char *pathname,
16                               unsigned mode, int stage, int opt)
17 {
18         int len;
19         unsigned int size;
20         struct cache_entry *ce;
21
22         if (S_ISDIR(mode))
23                 return READ_TREE_RECURSIVE;
24
25         len = strlen(pathname);
26         size = cache_entry_size(baselen + len);
27         ce = xcalloc(1, size);
28
29         ce->ce_mode = create_ce_mode(mode);
30         ce->ce_flags = create_ce_flags(stage);
31         ce->ce_namelen = baselen + len;
32         memcpy(ce->name, base, baselen);
33         memcpy(ce->name + baselen, pathname, len+1);
34         hashcpy(ce->oid.hash, sha1);
35         return add_index_entry(istate, ce, opt);
36 }
37
38 static int read_one_entry(const unsigned char *sha1, struct strbuf *base,
39                           const char *pathname, unsigned mode, int stage,
40                           void *context)
41 {
42         struct index_state *istate = context;
43         return read_one_entry_opt(istate, sha1, base->buf, base->len, pathname,
44                                   mode, stage,
45                                   ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
46 }
47
48 /*
49  * This is used when the caller knows there is no existing entries at
50  * the stage that will conflict with the entry being added.
51  */
52 static int read_one_entry_quick(const unsigned char *sha1, struct strbuf *base,
53                                 const char *pathname, unsigned mode, int stage,
54                                 void *context)
55 {
56         struct index_state *istate = context;
57         return read_one_entry_opt(istate, sha1, base->buf, base->len, pathname,
58                                   mode, stage,
59                                   ADD_CACHE_JUST_APPEND);
60 }
61
62 static int read_tree_1(struct tree *tree, struct strbuf *base,
63                        int stage, const struct pathspec *pathspec,
64                        read_tree_fn_t fn, void *context)
65 {
66         struct tree_desc desc;
67         struct name_entry entry;
68         struct object_id oid;
69         int len, oldlen = base->len;
70         enum interesting retval = entry_not_interesting;
71
72         if (parse_tree(tree))
73                 return -1;
74
75         init_tree_desc(&desc, tree->buffer, tree->size);
76
77         while (tree_entry(&desc, &entry)) {
78                 if (retval != all_entries_interesting) {
79                         retval = tree_entry_interesting(&entry, base, 0, pathspec);
80                         if (retval == all_entries_not_interesting)
81                                 break;
82                         if (retval == entry_not_interesting)
83                                 continue;
84                 }
85
86                 switch (fn(entry.oid->hash, base,
87                            entry.path, entry.mode, stage, context)) {
88                 case 0:
89                         continue;
90                 case READ_TREE_RECURSIVE:
91                         break;
92                 default:
93                         return -1;
94                 }
95
96                 if (S_ISDIR(entry.mode))
97                         oidcpy(&oid, entry.oid);
98                 else if (S_ISGITLINK(entry.mode)) {
99                         struct commit *commit;
100
101                         commit = lookup_commit(entry.oid);
102                         if (!commit)
103                                 die("Commit %s in submodule path %s%s not found",
104                                     oid_to_hex(entry.oid),
105                                     base->buf, entry.path);
106
107                         if (parse_commit(commit))
108                                 die("Invalid commit %s in submodule path %s%s",
109                                     oid_to_hex(entry.oid),
110                                     base->buf, entry.path);
111
112                         oidcpy(&oid, &commit->tree->object.oid);
113                 }
114                 else
115                         continue;
116
117                 len = tree_entry_len(&entry);
118                 strbuf_add(base, entry.path, len);
119                 strbuf_addch(base, '/');
120                 retval = read_tree_1(lookup_tree(&oid),
121                                      base, stage, pathspec,
122                                      fn, context);
123                 strbuf_setlen(base, oldlen);
124                 if (retval)
125                         return -1;
126         }
127         return 0;
128 }
129
130 int read_tree_recursive(struct tree *tree,
131                         const char *base, int baselen,
132                         int stage, const struct pathspec *pathspec,
133                         read_tree_fn_t fn, void *context)
134 {
135         struct strbuf sb = STRBUF_INIT;
136         int ret;
137
138         strbuf_add(&sb, base, baselen);
139         ret = read_tree_1(tree, &sb, stage, pathspec, fn, context);
140         strbuf_release(&sb);
141         return ret;
142 }
143
144 static int cmp_cache_name_compare(const void *a_, const void *b_)
145 {
146         const struct cache_entry *ce1, *ce2;
147
148         ce1 = *((const struct cache_entry **)a_);
149         ce2 = *((const struct cache_entry **)b_);
150         return cache_name_stage_compare(ce1->name, ce1->ce_namelen, ce_stage(ce1),
151                                   ce2->name, ce2->ce_namelen, ce_stage(ce2));
152 }
153
154 int read_tree(struct tree *tree, int stage, struct pathspec *match,
155               struct index_state *istate)
156 {
157         read_tree_fn_t fn = NULL;
158         int i, err;
159
160         /*
161          * Currently the only existing callers of this function all
162          * call it with stage=1 and after making sure there is nothing
163          * at that stage; we could always use read_one_entry_quick().
164          *
165          * But when we decide to straighten out git-read-tree not to
166          * use unpack_trees() in some cases, this will probably start
167          * to matter.
168          */
169
170         /*
171          * See if we have cache entry at the stage.  If so,
172          * do it the original slow way, otherwise, append and then
173          * sort at the end.
174          */
175         for (i = 0; !fn && i < istate->cache_nr; i++) {
176                 const struct cache_entry *ce = istate->cache[i];
177                 if (ce_stage(ce) == stage)
178                         fn = read_one_entry;
179         }
180
181         if (!fn)
182                 fn = read_one_entry_quick;
183         err = read_tree_recursive(tree, "", 0, stage, match, fn, istate);
184         if (fn == read_one_entry || err)
185                 return err;
186
187         /*
188          * Sort the cache entry -- we need to nuke the cache tree, though.
189          */
190         cache_tree_free(&istate->cache_tree);
191         QSORT(istate->cache, istate->cache_nr, cmp_cache_name_compare);
192         return 0;
193 }
194
195 struct tree *lookup_tree(const struct object_id *oid)
196 {
197         struct object *obj = lookup_object(oid->hash);
198         if (!obj)
199                 return create_object(oid->hash, alloc_tree_node());
200         return object_as_type(obj, OBJ_TREE, 0);
201 }
202
203 int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
204 {
205         if (item->object.parsed)
206                 return 0;
207         item->object.parsed = 1;
208         item->buffer = buffer;
209         item->size = size;
210
211         return 0;
212 }
213
214 int parse_tree_gently(struct tree *item, int quiet_on_missing)
215 {
216          enum object_type type;
217          void *buffer;
218          unsigned long size;
219
220         if (item->object.parsed)
221                 return 0;
222         buffer = read_sha1_file(item->object.oid.hash, &type, &size);
223         if (!buffer)
224                 return quiet_on_missing ? -1 :
225                         error("Could not read %s",
226                              oid_to_hex(&item->object.oid));
227         if (type != OBJ_TREE) {
228                 free(buffer);
229                 return error("Object %s not a tree",
230                              oid_to_hex(&item->object.oid));
231         }
232         return parse_tree_buffer(item, buffer, size);
233 }
234
235 void free_tree_buffer(struct tree *tree)
236 {
237         FREE_AND_NULL(tree->buffer);
238         tree->size = 0;
239         tree->object.parsed = 0;
240 }
241
242 struct tree *parse_tree_indirect(const struct object_id *oid)
243 {
244         struct object *obj = parse_object(oid);
245         do {
246                 if (!obj)
247                         return NULL;
248                 if (obj->type == OBJ_TREE)
249                         return (struct tree *) obj;
250                 else if (obj->type == OBJ_COMMIT)
251                         obj = &(((struct commit *) obj)->tree->object);
252                 else if (obj->type == OBJ_TAG)
253                         obj = ((struct tag *) obj)->tagged;
254                 else
255                         return NULL;
256                 if (!obj->parsed)
257                         parse_object(&obj->oid);
258         } while (1);
259 }