blame.c: Properly initialize strbuf after calling, textconv_object()
[git/dscho.git] / notes.h
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 must both be non-NULL and different from each other.
17 * The default combine_notes function (you get this when passing NULL) is
18 * combine_notes_concatenate(), which appends the contents of the new note to
19 * the contents of the existing note.
21 typedef int (*combine_notes_fn)(unsigned char *cur_sha1, const unsigned char *new_sha1);
23 /* Common notes combinators */
24 int combine_notes_concatenate(unsigned char *cur_sha1, const unsigned char *new_sha1);
25 int combine_notes_overwrite(unsigned char *cur_sha1, const unsigned char *new_sha1);
26 int combine_notes_ignore(unsigned char *cur_sha1, const unsigned char *new_sha1);
29 * Notes tree object
31 * Encapsulates the internal notes tree structure associated with a notes ref.
32 * Whenever a struct notes_tree pointer is required below, you may pass NULL in
33 * order to use the default/internal notes tree. E.g. you only need to pass a
34 * non-NULL value if you need to refer to several different notes trees
35 * simultaneously.
37 extern struct notes_tree {
38 struct int_node *root;
39 struct non_note *first_non_note, *prev_non_note;
40 char *ref;
41 combine_notes_fn combine_notes;
42 int initialized;
43 int dirty;
44 } default_notes_tree;
47 * Flags controlling behaviour of notes tree initialization
49 * Default behaviour is to initialize the notes tree from the tree object
50 * specified by the given (or default) notes ref.
52 #define NOTES_INIT_EMPTY 1
55 * Initialize the given notes_tree with the notes tree structure at the given
56 * ref. If given ref is NULL, the value of the $GIT_NOTES_REF environment
57 * variable is used, and if that is missing, the default notes ref is used
58 * ("refs/notes/commits").
60 * If you need to re-intialize a notes_tree structure (e.g. when switching from
61 * one notes ref to another), you must first de-initialize the notes_tree
62 * structure by calling free_notes(struct notes_tree *).
64 * If you pass t == NULL, the default internal notes_tree will be initialized.
66 * The combine_notes function that is passed becomes the default combine_notes
67 * function for the given notes_tree. If NULL is passed, the default
68 * combine_notes function is combine_notes_concatenate().
70 * Precondition: The notes_tree structure is zeroed (this can be achieved with
71 * memset(t, 0, sizeof(struct notes_tree)))
73 void init_notes(struct notes_tree *t, const char *notes_ref,
74 combine_notes_fn combine_notes, int flags);
77 * Add the given note object to the given notes_tree structure
79 * IMPORTANT: The changes made by add_note() to the given notes_tree structure
80 * are not persistent until a subsequent call to write_notes_tree() returns
81 * zero.
83 void add_note(struct notes_tree *t, const unsigned char *object_sha1,
84 const unsigned char *note_sha1, combine_notes_fn combine_notes);
87 * Remove the given note object from the given notes_tree structure
89 * IMPORTANT: The changes made by remove_note() to the given notes_tree
90 * structure are not persistent until a subsequent call to write_notes_tree()
91 * returns zero.
93 void remove_note(struct notes_tree *t, const unsigned char *object_sha1);
96 * Get the note object SHA1 containing the note data for the given object
98 * Return NULL if the given object has no notes.
100 const unsigned char *get_note(struct notes_tree *t,
101 const unsigned char *object_sha1);
104 * Copy a note from one object to another in the given notes_tree.
106 * Fails if the to_obj already has a note unless 'force' is true.
108 int copy_note(struct notes_tree *t,
109 const unsigned char *from_obj, const unsigned char *to_obj,
110 int force, combine_notes_fn combine_fn);
113 * Flags controlling behaviour of for_each_note()
115 * Default behaviour of for_each_note() is to traverse every single note object
116 * in the given notes tree, unpacking subtree entries along the way.
117 * The following flags can be used to alter the default behaviour:
119 * - DONT_UNPACK_SUBTREES causes for_each_note() NOT to unpack and recurse into
120 * subtree entries while traversing the notes tree. This causes notes within
121 * those subtrees NOT to be passed to the callback. Use this flag if you
122 * don't want to traverse _all_ notes, but only want to traverse the parts
123 * of the notes tree that have already been unpacked (this includes at least
124 * all notes that have been added/changed).
126 * - YIELD_SUBTREES causes any subtree entries that are encountered to be
127 * passed to the callback, before recursing into them. Subtree entries are
128 * not note objects, but represent intermediate directories in the notes
129 * tree. When passed to the callback, subtree entries will have a trailing
130 * slash in their path, which the callback may use to differentiate between
131 * note entries and subtree entries. Note that already-unpacked subtree
132 * entries are not part of the notes tree, and will therefore not be yielded.
133 * If this flag is used together with DONT_UNPACK_SUBTREES, for_each_note()
134 * will yield the subtree entry, but not recurse into it.
140 * Invoke the specified callback function for each note in the given notes_tree
142 * If the callback returns nonzero, the note walk is aborted, and the return
143 * value from the callback is returned from for_each_note(). Hence, a zero
144 * return value from for_each_note() indicates that all notes were walked
145 * successfully.
147 * IMPORTANT: The callback function is NOT allowed to change the notes tree.
148 * In other words, the following functions can NOT be invoked (on the current
149 * notes tree) from within the callback:
150 * - add_note()
151 * - remove_note()
152 * - free_notes()
154 typedef int each_note_fn(const unsigned char *object_sha1,
155 const unsigned char *note_sha1, char *note_path,
156 void *cb_data);
157 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
158 void *cb_data);
161 * Write the given notes_tree structure to the object database
163 * Creates a new tree object encapsulating the current state of the given
164 * notes_tree, and stores its SHA1 into the 'result' argument.
166 * Returns zero on success, non-zero on failure.
168 * IMPORTANT: Changes made to the given notes_tree are not persistent until
169 * this function has returned zero. Please also remember to create a
170 * corresponding commit object, and update the appropriate notes ref.
172 int write_notes_tree(struct notes_tree *t, unsigned char *result);
174 /* Flags controlling the operation of prune */
176 #define NOTES_PRUNE_DRYRUN 2
178 * Remove all notes annotating non-existing objects from the given notes tree
180 * All notes in the given notes_tree that are associated with objects that no
181 * longer exist in the database, are removed from the notes tree.
183 * IMPORTANT: The changes made by prune_notes() to the given notes_tree
184 * structure are not persistent until a subsequent call to write_notes_tree()
185 * returns zero.
187 void prune_notes(struct notes_tree *t, int flags);
190 * Free (and de-initialize) the given notes_tree structure
192 * IMPORTANT: Changes made to the given notes_tree since the last, successful
193 * call to write_notes_tree() will be lost.
195 void free_notes(struct notes_tree *t);
197 /* Flags controlling how notes are formatted */
198 #define NOTES_SHOW_HEADER 1
199 #define NOTES_INDENT 2
202 * Fill the given strbuf with the notes associated with the given object.
204 * If the given notes_tree structure is not initialized, it will be auto-
205 * initialized to the default value (see documentation for init_notes() above).
206 * If the given notes_tree is NULL, the internal/default notes_tree will be
207 * used instead.
209 * 'flags' is a bitwise combination of the above formatting flags.
211 void format_note(struct notes_tree *t, const unsigned char *object_sha1,
212 struct strbuf *sb, const char *output_encoding, int flags);
215 struct string_list;
217 struct display_notes_opt {
218 unsigned int suppress_default_notes:1;
219 struct string_list *extra_notes_refs;
223 * Load the notes machinery for displaying several notes trees.
225 * If 'opt' is not NULL, then it specifies additional settings for the
226 * displaying:
228 * - suppress_default_notes indicates that the notes from
229 * core.notesRef and notes.displayRef should not be loaded.
231 * - extra_notes_refs may contain a list of globs (in the same style
232 * as notes.displayRef) where notes should be loaded from.
234 void init_display_notes(struct display_notes_opt *opt);
237 * Append notes for the given 'object_sha1' from all trees set up by
238 * init_display_notes() to 'sb'. The 'flags' are a bitwise
239 * combination of
241 * - NOTES_SHOW_HEADER: add a 'Notes (refname):' header
243 * - NOTES_INDENT: indent the notes by 4 places
245 * You *must* call init_display_notes() before using this function.
247 void format_display_notes(const unsigned char *object_sha1,
248 struct strbuf *sb, const char *output_encoding, int flags);
251 * Load the notes tree from each ref listed in 'refs'. The output is
252 * an array of notes_tree*, terminated by a NULL.
254 struct notes_tree **load_notes_trees(struct string_list *refs);
257 * Add all refs that match 'glob' to the 'list'.
259 void string_list_add_refs_by_glob(struct string_list *list, const char *glob);
262 * Add all refs from a colon-separated glob list 'globs' to the end of
263 * 'list'. Empty components are ignored. This helper is used to
264 * parse GIT_NOTES_DISPLAY_REF style environment variables.
266 void string_list_add_refs_from_colon_sep(struct string_list *list,
267 const char *globs);
269 #endif