gitweb: Create Gitweb::Util module
[git/jnareb-git/bp-gitweb.git] / notes.h
blob83bd6e0ec02a1a8650004f14cd7476eedbdff518
1 #ifndef NOTES_H
2 #define NOTES_H
4 /*
5 * Function type for combining two notes annotating the same object.
7 * When adding a new note annotating the same object as an existing note, it is
8 * up to the caller to decide how to combine the two notes. The decision is
9 * made by passing in a function of the following form. The function accepts
10 * two SHA1s -- of the existing note and the new note, respectively. The
11 * function then combines the notes in whatever way it sees fit, and writes the
12 * resulting SHA1 into the first SHA1 argument (cur_sha1). A non-zero return
13 * value indicates failure.
15 * The two given SHA1s shall both be non-NULL and different from each other.
16 * Either of them (but not both) may be == null_sha1, which indicates an
17 * empty/non-existent note. If the resulting SHA1 (cur_sha1) is == null_sha1,
18 * the note will be removed from the notes tree.
20 * The default combine_notes function (you get this when passing NULL) is
21 * combine_notes_concatenate(), which appends the contents of the new note to
22 * the contents of the existing note.
24 typedef int (*combine_notes_fn)(unsigned char *cur_sha1, const unsigned char *new_sha1);
26 /* Common notes combinators */
27 int combine_notes_concatenate(unsigned char *cur_sha1, const unsigned char *new_sha1);
28 int combine_notes_overwrite(unsigned char *cur_sha1, const unsigned char *new_sha1);
29 int combine_notes_ignore(unsigned char *cur_sha1, const unsigned char *new_sha1);
30 int combine_notes_cat_sort_uniq(unsigned char *cur_sha1, const unsigned char *new_sha1);
33 * Notes tree object
35 * Encapsulates the internal notes tree structure associated with a notes ref.
36 * Whenever a struct notes_tree pointer is required below, you may pass NULL in
37 * order to use the default/internal notes tree. E.g. you only need to pass a
38 * non-NULL value if you need to refer to several different notes trees
39 * simultaneously.
41 extern struct notes_tree {
42 struct int_node *root;
43 struct non_note *first_non_note, *prev_non_note;
44 char *ref;
45 combine_notes_fn combine_notes;
46 int initialized;
47 int dirty;
48 } default_notes_tree;
51 * Return the default notes ref.
53 * The default notes ref is the notes ref that is used when notes_ref == NULL
54 * is passed to init_notes().
56 * This the first of the following to be defined:
57 * 1. The '--ref' option to 'git notes', if given
58 * 2. The $GIT_NOTES_REF environment variable, if set
59 * 3. The value of the core.notesRef config variable, if set
60 * 4. GIT_NOTES_DEFAULT_REF (i.e. "refs/notes/commits")
62 const char *default_notes_ref(void);
65 * Flags controlling behaviour of notes tree initialization
67 * Default behaviour is to initialize the notes tree from the tree object
68 * specified by the given (or default) notes ref.
70 #define NOTES_INIT_EMPTY 1
73 * Initialize the given notes_tree with the notes tree structure at the given
74 * ref. If given ref is NULL, the value of the $GIT_NOTES_REF environment
75 * variable is used, and if that is missing, the default notes ref is used
76 * ("refs/notes/commits").
78 * If you need to re-intialize a notes_tree structure (e.g. when switching from
79 * one notes ref to another), you must first de-initialize the notes_tree
80 * structure by calling free_notes(struct notes_tree *).
82 * If you pass t == NULL, the default internal notes_tree will be initialized.
84 * The combine_notes function that is passed becomes the default combine_notes
85 * function for the given notes_tree. If NULL is passed, the default
86 * combine_notes function is combine_notes_concatenate().
88 * Precondition: The notes_tree structure is zeroed (this can be achieved with
89 * memset(t, 0, sizeof(struct notes_tree)))
91 void init_notes(struct notes_tree *t, const char *notes_ref,
92 combine_notes_fn combine_notes, int flags);
95 * Add the given note object to the given notes_tree structure
97 * If there already exists a note for the given object_sha1, the given
98 * combine_notes function is invoked to break the tie. If not given (i.e.
99 * combine_notes == NULL), the default combine_notes function for the given
100 * notes_tree is used.
102 * Passing note_sha1 == null_sha1 indicates the addition of an
103 * empty/non-existent note. This is a (potentially expensive) no-op unless
104 * there already exists a note for the given object_sha1, AND combining that
105 * note with the empty note (using the given combine_notes function) results
106 * in a new/changed note.
108 * Returns zero on success; non-zero means combine_notes failed.
110 * IMPORTANT: The changes made by add_note() to the given notes_tree structure
111 * are not persistent until a subsequent call to write_notes_tree() returns
112 * zero.
114 int add_note(struct notes_tree *t, const unsigned char *object_sha1,
115 const unsigned char *note_sha1, combine_notes_fn combine_notes);
118 * Remove the given note object from the given notes_tree structure
120 * IMPORTANT: The changes made by remove_note() to the given notes_tree
121 * structure are not persistent until a subsequent call to write_notes_tree()
122 * returns zero.
124 * Return 0 if a note was removed; 1 if there was no note to remove.
126 int remove_note(struct notes_tree *t, const unsigned char *object_sha1);
129 * Get the note object SHA1 containing the note data for the given object
131 * Return NULL if the given object has no notes.
133 const unsigned char *get_note(struct notes_tree *t,
134 const unsigned char *object_sha1);
137 * Copy a note from one object to another in the given notes_tree.
139 * Returns 1 if the to_obj already has a note and 'force' is false. Otherwise,
140 * returns non-zero if 'force' is true, but the given combine_notes function
141 * failed to combine from_obj's note with to_obj's existing note.
142 * Returns zero on success.
144 * IMPORTANT: The changes made by copy_note() to the given notes_tree structure
145 * are not persistent until a subsequent call to write_notes_tree() returns
146 * zero.
148 int copy_note(struct notes_tree *t,
149 const unsigned char *from_obj, const unsigned char *to_obj,
150 int force, combine_notes_fn combine_notes);
153 * Flags controlling behaviour of for_each_note()
155 * Default behaviour of for_each_note() is to traverse every single note object
156 * in the given notes tree, unpacking subtree entries along the way.
157 * The following flags can be used to alter the default behaviour:
159 * - DONT_UNPACK_SUBTREES causes for_each_note() NOT to unpack and recurse into
160 * subtree entries while traversing the notes tree. This causes notes within
161 * those subtrees NOT to be passed to the callback. Use this flag if you
162 * don't want to traverse _all_ notes, but only want to traverse the parts
163 * of the notes tree that have already been unpacked (this includes at least
164 * all notes that have been added/changed).
166 * - YIELD_SUBTREES causes any subtree entries that are encountered to be
167 * passed to the callback, before recursing into them. Subtree entries are
168 * not note objects, but represent intermediate directories in the notes
169 * tree. When passed to the callback, subtree entries will have a trailing
170 * slash in their path, which the callback may use to differentiate between
171 * note entries and subtree entries. Note that already-unpacked subtree
172 * entries are not part of the notes tree, and will therefore not be yielded.
173 * If this flag is used together with DONT_UNPACK_SUBTREES, for_each_note()
174 * will yield the subtree entry, but not recurse into it.
176 #define FOR_EACH_NOTE_DONT_UNPACK_SUBTREES 1
177 #define FOR_EACH_NOTE_YIELD_SUBTREES 2
180 * Invoke the specified callback function for each note in the given notes_tree
182 * If the callback returns nonzero, the note walk is aborted, and the return
183 * value from the callback is returned from for_each_note(). Hence, a zero
184 * return value from for_each_note() indicates that all notes were walked
185 * successfully.
187 * IMPORTANT: The callback function is NOT allowed to change the notes tree.
188 * In other words, the following functions can NOT be invoked (on the current
189 * notes tree) from within the callback:
190 * - add_note()
191 * - remove_note()
192 * - copy_note()
193 * - free_notes()
195 typedef int each_note_fn(const unsigned char *object_sha1,
196 const unsigned char *note_sha1, char *note_path,
197 void *cb_data);
198 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
199 void *cb_data);
202 * Write the given notes_tree structure to the object database
204 * Creates a new tree object encapsulating the current state of the given
205 * notes_tree, and stores its SHA1 into the 'result' argument.
207 * Returns zero on success, non-zero on failure.
209 * IMPORTANT: Changes made to the given notes_tree are not persistent until
210 * this function has returned zero. Please also remember to create a
211 * corresponding commit object, and update the appropriate notes ref.
213 int write_notes_tree(struct notes_tree *t, unsigned char *result);
215 /* Flags controlling the operation of prune */
216 #define NOTES_PRUNE_VERBOSE 1
217 #define NOTES_PRUNE_DRYRUN 2
219 * Remove all notes annotating non-existing objects from the given notes tree
221 * All notes in the given notes_tree that are associated with objects that no
222 * longer exist in the database, are removed from the notes tree.
224 * IMPORTANT: The changes made by prune_notes() to the given notes_tree
225 * structure are not persistent until a subsequent call to write_notes_tree()
226 * returns zero.
228 void prune_notes(struct notes_tree *t, int flags);
231 * Free (and de-initialize) the given notes_tree structure
233 * IMPORTANT: Changes made to the given notes_tree since the last, successful
234 * call to write_notes_tree() will be lost.
236 void free_notes(struct notes_tree *t);
238 /* Flags controlling how notes are formatted */
239 #define NOTES_SHOW_HEADER 1
240 #define NOTES_INDENT 2
243 * Fill the given strbuf with the notes associated with the given object.
245 * If the given notes_tree structure is not initialized, it will be auto-
246 * initialized to the default value (see documentation for init_notes() above).
247 * If the given notes_tree is NULL, the internal/default notes_tree will be
248 * used instead.
250 * 'flags' is a bitwise combination of the above formatting flags.
252 void format_note(struct notes_tree *t, const unsigned char *object_sha1,
253 struct strbuf *sb, const char *output_encoding, int flags);
256 struct string_list;
258 struct display_notes_opt {
259 unsigned int suppress_default_notes:1;
260 struct string_list *extra_notes_refs;
264 * Load the notes machinery for displaying several notes trees.
266 * If 'opt' is not NULL, then it specifies additional settings for the
267 * displaying:
269 * - suppress_default_notes indicates that the notes from
270 * core.notesRef and notes.displayRef should not be loaded.
272 * - extra_notes_refs may contain a list of globs (in the same style
273 * as notes.displayRef) where notes should be loaded from.
275 void init_display_notes(struct display_notes_opt *opt);
278 * Append notes for the given 'object_sha1' from all trees set up by
279 * init_display_notes() to 'sb'. The 'flags' are a bitwise
280 * combination of
282 * - NOTES_SHOW_HEADER: add a 'Notes (refname):' header
284 * - NOTES_INDENT: indent the notes by 4 places
286 * You *must* call init_display_notes() before using this function.
288 void format_display_notes(const unsigned char *object_sha1,
289 struct strbuf *sb, const char *output_encoding, int flags);
292 * Load the notes tree from each ref listed in 'refs'. The output is
293 * an array of notes_tree*, terminated by a NULL.
295 struct notes_tree **load_notes_trees(struct string_list *refs);
298 * Add all refs that match 'glob' to the 'list'.
300 void string_list_add_refs_by_glob(struct string_list *list, const char *glob);
303 * Add all refs from a colon-separated glob list 'globs' to the end of
304 * 'list'. Empty components are ignored. This helper is used to
305 * parse GIT_NOTES_DISPLAY_REF style environment variables.
307 void string_list_add_refs_from_colon_sep(struct string_list *list,
308 const char *globs);
310 #endif