Merge branch 'cb/test-use-ere-for-alternation'
[git.git] / tree-walk.h
bloba5058469e9b3a83fdd58a04f2af72690742d08bd
1 #ifndef TREE_WALK_H
2 #define TREE_WALK_H
4 #include "cache.h"
6 #define MAX_TRAVERSE_TREES 8
8 /**
9 * The tree walking API is used to traverse and inspect trees.
12 /**
13 * An entry in a tree. Each entry has a sha1 identifier, pathname, and mode.
15 struct name_entry {
16 struct object_id oid;
17 const char *path;
18 int pathlen;
19 unsigned int mode;
22 /**
23 * A semi-opaque data structure used to maintain the current state of the walk.
25 struct tree_desc {
27 * pointer into the memory representation of the tree. It always
28 * points at the current entry being visited.
30 const void *buffer;
32 /* points to the current entry being visited. */
33 struct name_entry entry;
35 /* counts the number of bytes left in the `buffer`. */
36 unsigned int size;
39 /**
40 * Decode the entry currently being visited (the one pointed to by
41 * `tree_desc's` `entry` member) and return the sha1 of the entry. The
42 * `pathp` and `modep` arguments are set to the entry's pathname and mode
43 * respectively.
45 static inline const struct object_id *tree_entry_extract(struct tree_desc *desc, const char **pathp, unsigned short *modep)
47 *pathp = desc->entry.path;
48 *modep = desc->entry.mode;
49 return &desc->entry.oid;
52 /**
53 * Calculate the length of a tree entry's pathname. This utilizes the
54 * memory structure of a tree entry to avoid the overhead of using a
55 * generic strlen().
57 static inline int tree_entry_len(const struct name_entry *ne)
59 return ne->pathlen;
63 * The _gently versions of these functions warn and return false on a
64 * corrupt tree entry rather than dying,
67 /**
68 * Walk to the next entry in a tree. This is commonly used in conjunction
69 * with `tree_entry_extract` to inspect the current entry.
71 void update_tree_entry(struct tree_desc *);
73 int update_tree_entry_gently(struct tree_desc *);
75 /**
76 * Initialize a `tree_desc` and decode its first entry. The buffer and
77 * size parameters are assumed to be the same as the buffer and size
78 * members of `struct tree`.
80 void init_tree_desc(struct tree_desc *desc, const void *buf, unsigned long size);
82 int init_tree_desc_gently(struct tree_desc *desc, const void *buf, unsigned long size);
85 * Visit the next entry in a tree. Returns 1 when there are more entries
86 * left to visit and 0 when all entries have been visited. This is
87 * commonly used in the test of a while loop.
89 int tree_entry(struct tree_desc *, struct name_entry *);
91 int tree_entry_gently(struct tree_desc *, struct name_entry *);
93 /**
94 * Initialize a `tree_desc` and decode its first entry given the
95 * object ID of a tree. Returns the `buffer` member if the latter
96 * is a valid tree identifier and NULL otherwise.
98 void *fill_tree_descriptor(struct repository *r,
99 struct tree_desc *desc,
100 const struct object_id *oid);
102 struct traverse_info;
103 typedef int (*traverse_callback_t)(int n, unsigned long mask, unsigned long dirmask, struct name_entry *entry, struct traverse_info *);
106 * Traverse `n` number of trees in parallel. The `fn` callback member of
107 * `traverse_info` is called once for each tree entry.
109 int traverse_trees(struct index_state *istate, int n, struct tree_desc *t, struct traverse_info *info);
111 enum get_oid_result get_tree_entry_follow_symlinks(struct repository *r, struct object_id *tree_oid, const char *name, struct object_id *result, struct strbuf *result_path, unsigned short *mode);
114 * A structure used to maintain the state of a traversal.
116 struct traverse_info {
117 const char *traverse_path;
120 * points to the traverse_info which was used to descend into the
121 * current tree. If this is the top-level tree `prev` will point to
122 * a dummy traverse_info.
124 struct traverse_info *prev;
126 /* is the entry for the current tree (if the tree is a subtree). */
127 const char *name;
129 size_t namelen;
130 unsigned mode;
132 /* is the length of the full path for the current tree. */
133 size_t pathlen;
135 struct pathspec *pathspec;
137 /* can be used by callbacks to maintain directory-file conflicts. */
138 unsigned long df_conflicts;
140 /* a callback called for each entry in the tree.
142 * The arguments passed to the traverse callback are as follows:
144 * - `n` counts the number of trees being traversed.
146 * - `mask` has its nth bit set if something exists in the nth entry.
148 * - `dirmask` has its nth bit set if the nth tree's entry is a directory.
150 * - `entry` is an array of size `n` where the nth entry is from the nth tree.
152 * - `info` maintains the state of the traversal.
154 * Returning a negative value will terminate the traversal. Otherwise the
155 * return value is treated as an update mask. If the nth bit is set the nth tree
156 * will be updated and if the bit is not set the nth tree entry will be the
157 * same in the next callback invocation.
159 traverse_callback_t fn;
161 /* can be anything the `fn` callback would want to use. */
162 void *data;
164 /* tells whether to stop at the first error or not. */
165 int show_all_errors;
169 * Find an entry in a tree given a pathname and the sha1 of a tree to
170 * search. Returns 0 if the entry is found and -1 otherwise. The third
171 * and fourth parameters are set to the entry's sha1 and mode respectively.
173 int get_tree_entry(struct repository *, const struct object_id *, const char *, struct object_id *, unsigned short *);
176 * Generate the full pathname of a tree entry based from the root of the
177 * traversal. For example, if the traversal has recursed into another
178 * tree named "bar" the pathname of an entry "baz" in the "bar"
179 * tree would be "bar/baz".
181 char *make_traverse_path(char *path, size_t pathlen, const struct traverse_info *info,
182 const char *name, size_t namelen);
185 * Convenience wrapper to `make_traverse_path` into a strbuf.
187 void strbuf_make_traverse_path(struct strbuf *out,
188 const struct traverse_info *info,
189 const char *name, size_t namelen);
192 * Initialize a `traverse_info` given the pathname of the tree to start
193 * traversing from.
195 void setup_traverse_info(struct traverse_info *info, const char *base);
198 * Calculate the length of a pathname returned by `make_traverse_path`.
199 * This utilizes the memory structure of a tree entry to avoid the
200 * overhead of using a generic strlen().
202 static inline size_t traverse_path_len(const struct traverse_info *info,
203 size_t namelen)
205 return st_add(info->pathlen, namelen);
208 /* in general, positive means "kind of interesting" */
209 enum interesting {
210 all_entries_not_interesting = -1, /* no, and no subsequent entries will be either */
211 entry_not_interesting = 0,
212 entry_interesting = 1,
213 all_entries_interesting = 2 /* yes, and all subsequent entries will be */
216 enum interesting tree_entry_interesting(struct index_state *istate,
217 const struct name_entry *,
218 struct strbuf *, int,
219 const struct pathspec *ps);
221 #endif