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[git/mjg.git] / notes.h
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1 #ifndef NOTES_H
2 #define NOTES_H
4 #include "string-list.h"
6 /*
7 * Function type for combining two notes annotating the same object.
9 * When adding a new note annotating the same object as an existing note, it is
10 * up to the caller to decide how to combine the two notes. The decision is
11 * made by passing in a function of the following form. The function accepts
12 * two SHA1s -- of the existing note and the new note, respectively. The
13 * function then combines the notes in whatever way it sees fit, and writes the
14 * resulting SHA1 into the first SHA1 argument (cur_sha1). A non-zero return
15 * value indicates failure.
17 * The two given SHA1s shall both be non-NULL and different from each other.
18 * Either of them (but not both) may be == null_sha1, which indicates an
19 * empty/non-existent note. If the resulting SHA1 (cur_sha1) is == null_sha1,
20 * the note will be removed from the notes tree.
22 * The default combine_notes function (you get this when passing NULL) is
23 * combine_notes_concatenate(), which appends the contents of the new note to
24 * the contents of the existing note.
26 typedef int (*combine_notes_fn)(unsigned char *cur_sha1, const unsigned char *new_sha1);
28 /* Common notes combinators */
29 int combine_notes_concatenate(unsigned char *cur_sha1, const unsigned char *new_sha1);
30 int combine_notes_overwrite(unsigned char *cur_sha1, const unsigned char *new_sha1);
31 int combine_notes_ignore(unsigned char *cur_sha1, const unsigned char *new_sha1);
32 int combine_notes_cat_sort_uniq(unsigned char *cur_sha1, const unsigned char *new_sha1);
35 * Notes tree object
37 * Encapsulates the internal notes tree structure associated with a notes ref.
38 * Whenever a struct notes_tree pointer is required below, you may pass NULL in
39 * order to use the default/internal notes tree. E.g. you only need to pass a
40 * non-NULL value if you need to refer to several different notes trees
41 * simultaneously.
43 extern struct notes_tree {
44 struct int_node *root;
45 struct non_note *first_non_note, *prev_non_note;
46 char *ref;
47 combine_notes_fn combine_notes;
48 int initialized;
49 int dirty;
50 } default_notes_tree;
53 * Return the default notes ref.
55 * The default notes ref is the notes ref that is used when notes_ref == NULL
56 * is passed to init_notes().
58 * This the first of the following to be defined:
59 * 1. The '--ref' option to 'git notes', if given
60 * 2. The $GIT_NOTES_REF environment variable, if set
61 * 3. The value of the core.notesRef config variable, if set
62 * 4. GIT_NOTES_DEFAULT_REF (i.e. "refs/notes/commits")
64 const char *default_notes_ref(void);
67 * Flags controlling behaviour of notes tree initialization
69 * Default behaviour is to initialize the notes tree from the tree object
70 * specified by the given (or default) notes ref.
72 #define NOTES_INIT_EMPTY 1
75 * Initialize the given notes_tree with the notes tree structure at the given
76 * ref. If given ref is NULL, the value of the $GIT_NOTES_REF environment
77 * variable is used, and if that is missing, the default notes ref is used
78 * ("refs/notes/commits").
80 * If you need to re-initialize a notes_tree structure (e.g. when switching from
81 * one notes ref to another), you must first de-initialize the notes_tree
82 * structure by calling free_notes(struct notes_tree *).
84 * If you pass t == NULL, the default internal notes_tree will be initialized.
86 * The combine_notes function that is passed becomes the default combine_notes
87 * function for the given notes_tree. If NULL is passed, the default
88 * combine_notes function is combine_notes_concatenate().
90 * Precondition: The notes_tree structure is zeroed (this can be achieved with
91 * memset(t, 0, sizeof(struct notes_tree)))
93 void init_notes(struct notes_tree *t, const char *notes_ref,
94 combine_notes_fn combine_notes, int flags);
97 * Add the given note object to the given notes_tree structure
99 * If there already exists a note for the given object_sha1, the given
100 * combine_notes function is invoked to break the tie. If not given (i.e.
101 * combine_notes == NULL), the default combine_notes function for the given
102 * notes_tree is used.
104 * Passing note_sha1 == null_sha1 indicates the addition of an
105 * empty/non-existent note. This is a (potentially expensive) no-op unless
106 * there already exists a note for the given object_sha1, AND combining that
107 * note with the empty note (using the given combine_notes function) results
108 * in a new/changed note.
110 * Returns zero on success; non-zero means combine_notes failed.
112 * IMPORTANT: The changes made by add_note() to the given notes_tree structure
113 * are not persistent until a subsequent call to write_notes_tree() returns
114 * zero.
116 int add_note(struct notes_tree *t, const unsigned char *object_sha1,
117 const unsigned char *note_sha1, combine_notes_fn combine_notes);
120 * Remove the given note object from the given notes_tree structure
122 * IMPORTANT: The changes made by remove_note() to the given notes_tree
123 * structure are not persistent until a subsequent call to write_notes_tree()
124 * returns zero.
126 * Return 0 if a note was removed; 1 if there was no note to remove.
128 int remove_note(struct notes_tree *t, const unsigned char *object_sha1);
131 * Get the note object SHA1 containing the note data for the given object
133 * Return NULL if the given object has no notes.
135 const unsigned char *get_note(struct notes_tree *t,
136 const unsigned char *object_sha1);
139 * Copy a note from one object to another in the given notes_tree.
141 * Returns 1 if the to_obj already has a note and 'force' is false. Otherwise,
142 * returns non-zero if 'force' is true, but the given combine_notes function
143 * failed to combine from_obj's note with to_obj's existing note.
144 * Returns zero on success.
146 * IMPORTANT: The changes made by copy_note() to the given notes_tree structure
147 * are not persistent until a subsequent call to write_notes_tree() returns
148 * zero.
150 int copy_note(struct notes_tree *t,
151 const unsigned char *from_obj, const unsigned char *to_obj,
152 int force, combine_notes_fn combine_notes);
155 * Flags controlling behaviour of for_each_note()
157 * Default behaviour of for_each_note() is to traverse every single note object
158 * in the given notes tree, unpacking subtree entries along the way.
159 * The following flags can be used to alter the default behaviour:
161 * - DONT_UNPACK_SUBTREES causes for_each_note() NOT to unpack and recurse into
162 * subtree entries while traversing the notes tree. This causes notes within
163 * those subtrees NOT to be passed to the callback. Use this flag if you
164 * don't want to traverse _all_ notes, but only want to traverse the parts
165 * of the notes tree that have already been unpacked (this includes at least
166 * all notes that have been added/changed).
168 * - YIELD_SUBTREES causes any subtree entries that are encountered to be
169 * passed to the callback, before recursing into them. Subtree entries are
170 * not note objects, but represent intermediate directories in the notes
171 * tree. When passed to the callback, subtree entries will have a trailing
172 * slash in their path, which the callback may use to differentiate between
173 * note entries and subtree entries. Note that already-unpacked subtree
174 * entries are not part of the notes tree, and will therefore not be yielded.
175 * If this flag is used together with DONT_UNPACK_SUBTREES, for_each_note()
176 * will yield the subtree entry, but not recurse into it.
178 #define FOR_EACH_NOTE_DONT_UNPACK_SUBTREES 1
179 #define FOR_EACH_NOTE_YIELD_SUBTREES 2
182 * Invoke the specified callback function for each note in the given notes_tree
184 * If the callback returns nonzero, the note walk is aborted, and the return
185 * value from the callback is returned from for_each_note(). Hence, a zero
186 * return value from for_each_note() indicates that all notes were walked
187 * successfully.
189 * IMPORTANT: The callback function is NOT allowed to change the notes tree.
190 * In other words, the following functions can NOT be invoked (on the current
191 * notes tree) from within the callback:
192 * - add_note()
193 * - remove_note()
194 * - copy_note()
195 * - free_notes()
197 typedef int each_note_fn(const unsigned char *object_sha1,
198 const unsigned char *note_sha1, char *note_path,
199 void *cb_data);
200 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
201 void *cb_data);
204 * Write the given notes_tree structure to the object database
206 * Creates a new tree object encapsulating the current state of the given
207 * notes_tree, and stores its SHA1 into the 'result' argument.
209 * Returns zero on success, non-zero on failure.
211 * IMPORTANT: Changes made to the given notes_tree are not persistent until
212 * this function has returned zero. Please also remember to create a
213 * corresponding commit object, and update the appropriate notes ref.
215 int write_notes_tree(struct notes_tree *t, unsigned char *result);
217 /* Flags controlling the operation of prune */
218 #define NOTES_PRUNE_VERBOSE 1
219 #define NOTES_PRUNE_DRYRUN 2
221 * Remove all notes annotating non-existing objects from the given notes tree
223 * All notes in the given notes_tree that are associated with objects that no
224 * longer exist in the database, are removed from the notes tree.
226 * IMPORTANT: The changes made by prune_notes() to the given notes_tree
227 * structure are not persistent until a subsequent call to write_notes_tree()
228 * returns zero.
230 void prune_notes(struct notes_tree *t, int flags);
233 * Free (and de-initialize) the given notes_tree structure
235 * IMPORTANT: Changes made to the given notes_tree since the last, successful
236 * call to write_notes_tree() will be lost.
238 void free_notes(struct notes_tree *t);
240 struct string_list;
242 struct display_notes_opt {
243 int use_default_notes;
244 struct string_list extra_notes_refs;
248 * Load the notes machinery for displaying several notes trees.
250 * If 'opt' is not NULL, then it specifies additional settings for the
251 * displaying:
253 * - suppress_default_notes indicates that the notes from
254 * core.notesRef and notes.displayRef should not be loaded.
256 * - extra_notes_refs may contain a list of globs (in the same style
257 * as notes.displayRef) where notes should be loaded from.
259 void init_display_notes(struct display_notes_opt *opt);
262 * Append notes for the given 'object_sha1' from all trees set up by
263 * init_display_notes() to 'sb'. The 'flags' are a bitwise
264 * combination of
266 * - NOTES_SHOW_HEADER: add a 'Notes (refname):' header
268 * - NOTES_INDENT: indent the notes by 4 places
270 * You *must* call init_display_notes() before using this function.
272 void format_display_notes(const unsigned char *object_sha1,
273 struct strbuf *sb, const char *output_encoding, int raw);
276 * Load the notes tree from each ref listed in 'refs'. The output is
277 * an array of notes_tree*, terminated by a NULL.
279 struct notes_tree **load_notes_trees(struct string_list *refs);
282 * Add all refs that match 'glob' to the 'list'.
284 void string_list_add_refs_by_glob(struct string_list *list, const char *glob);
287 * Add all refs from a colon-separated glob list 'globs' to the end of
288 * 'list'. Empty components are ignored. This helper is used to
289 * parse GIT_NOTES_DISPLAY_REF style environment variables.
291 void string_list_add_refs_from_colon_sep(struct string_list *list,
292 const char *globs);
294 /* Expand inplace a note ref like "foo" or "notes/foo" into "refs/notes/foo" */
295 void expand_notes_ref(struct strbuf *sb);
297 #endif