notes.h

   1 #ifndef NOTES_H
   2 #define NOTES_H
   3
   4 #include "string-list.h"
   5
   6 struct object_id;
   7 struct strbuf;
   8
   9 /*
  10  * Function type for combining two notes annotating the same object.
  11  *
  12  * When adding a new note annotating the same object as an existing note, it is
  13  * up to the caller to decide how to combine the two notes. The decision is
  14  * made by passing in a function of the following form. The function accepts
  15  * two object_ids -- of the existing note and the new note, respectively. The
  16  * function then combines the notes in whatever way it sees fit, and writes the
  17  * resulting oid into the first argument (cur_oid). A non-zero return
  18  * value indicates failure.
  19  *
  20  * The two given object_ids shall both be non-NULL and different from each
  21  * other. Either of them (but not both) may be == null_oid, which indicates an
  22  * empty/non-existent note. If the resulting oid (cur_oid) is == null_oid,
  23  * the note will be removed from the notes tree.
  24  *
  25  * The default combine_notes function (you get this when passing NULL) is
  26  * combine_notes_concatenate(), which appends the contents of the new note to
  27  * the contents of the existing note.
  28  */
  29 typedef int (*combine_notes_fn)(struct object_id *cur_oid,
  30                                 const struct object_id *new_oid);
  31
  32 /* Common notes combinators */
  33 int combine_notes_concatenate(struct object_id *cur_oid,
  34                               const struct object_id *new_oid);
  35 int combine_notes_overwrite(struct object_id *cur_oid,
  36                             const struct object_id *new_oid);
  37 int combine_notes_ignore(struct object_id *cur_oid,
  38                          const struct object_id *new_oid);
  39 int combine_notes_cat_sort_uniq(struct object_id *cur_oid,
  40                                 const struct object_id *new_oid);
  41
  42 /*
  43  * Notes tree object
  44  *
  45  * Encapsulates the internal notes tree structure associated with a notes ref.
  46  * Whenever a struct notes_tree pointer is required below, you may pass NULL in
  47  * order to use the default/internal notes tree. E.g. you only need to pass a
  48  * non-NULL value if you need to refer to several different notes trees
  49  * simultaneously.
  50  */
  51 extern struct notes_tree {
  52         struct int_node *root;
  53         struct non_note *first_non_note, *prev_non_note;
  54         char *ref;
  55         char *update_ref;
  56         combine_notes_fn combine_notes;
  57         int initialized;
  58         int dirty;
  59 } default_notes_tree;
  60
  61 /*
  62  * Return the default notes ref.
  63  *
  64  * The default notes ref is the notes ref that is used when notes_ref == NULL
  65  * is passed to init_notes().
  66  *
  67  * This the first of the following to be defined:
  68  * 1. The '--ref' option to 'git notes', if given
  69  * 2. The $GIT_NOTES_REF environment variable, if set
  70  * 3. The value of the core.notesRef config variable, if set
  71  * 4. GIT_NOTES_DEFAULT_REF (i.e. "refs/notes/commits")
  72  */
  73 const char *default_notes_ref(void);
  74
  75 /*
  76  * Flags controlling behaviour of notes tree initialization
  77  *
  78  * Default behaviour is to initialize the notes tree from the tree object
  79  * specified by the given (or default) notes ref.
  80  */
  81 #define NOTES_INIT_EMPTY 1
  82
  83 /*
  84  * By default, the notes tree is only readable, and the notes ref can be
  85  * any treeish. The notes tree can however be made writable with this flag,
  86  * in which case only strict ref names can be used.
  87  */
  88 #define NOTES_INIT_WRITABLE 2
  89
  90 /*
  91  * Initialize the given notes_tree with the notes tree structure at the given
  92  * ref. If given ref is NULL, the value of the $GIT_NOTES_REF environment
  93  * variable is used, and if that is missing, the default notes ref is used
  94  * ("refs/notes/commits").
  95  *
  96  * If you need to re-initialize a notes_tree structure (e.g. when switching from
  97  * one notes ref to another), you must first de-initialize the notes_tree
  98  * structure by calling free_notes(struct notes_tree *).
  99  *
 100  * If you pass t == NULL, the default internal notes_tree will be initialized.
 101  *
 102  * The combine_notes function that is passed becomes the default combine_notes
 103  * function for the given notes_tree. If NULL is passed, the default
 104  * combine_notes function is combine_notes_concatenate().
 105  *
 106  * Precondition: The notes_tree structure is zeroed (this can be achieved with
 107  * memset(t, 0, sizeof(struct notes_tree)))
 108  */
 109 void init_notes(struct notes_tree *t, const char *notes_ref,
 110                 combine_notes_fn combine_notes, int flags);
 111
 112 /*
 113  * Add the given note object to the given notes_tree structure
 114  *
 115  * If there already exists a note for the given object_sha1, the given
 116  * combine_notes function is invoked to break the tie. If not given (i.e.
 117  * combine_notes == NULL), the default combine_notes function for the given
 118  * notes_tree is used.
 119  *
 120  * Passing note_sha1 == null_sha1 indicates the addition of an
 121  * empty/non-existent note. This is a (potentially expensive) no-op unless
 122  * there already exists a note for the given object_sha1, AND combining that
 123  * note with the empty note (using the given combine_notes function) results
 124  * in a new/changed note.
 125  *
 126  * Returns zero on success; non-zero means combine_notes failed.
 127  *
 128  * IMPORTANT: The changes made by add_note() to the given notes_tree structure
 129  * are not persistent until a subsequent call to write_notes_tree() returns
 130  * zero.
 131  */
 132 int add_note(struct notes_tree *t, const struct object_id *object_oid,
 133                 const struct object_id *note_oid, combine_notes_fn combine_notes);
 134
 135 /*
 136  * Remove the given note object from the given notes_tree structure
 137  *
 138  * IMPORTANT: The changes made by remove_note() to the given notes_tree
 139  * structure are not persistent until a subsequent call to write_notes_tree()
 140  * returns zero.
 141  *
 142  * Return 0 if a note was removed; 1 if there was no note to remove.
 143  */
 144 int remove_note(struct notes_tree *t, const unsigned char *object_sha1);
 145
 146 /*
 147  * Get the note object SHA1 containing the note data for the given object
 148  *
 149  * Return NULL if the given object has no notes.
 150  */
 151 const struct object_id *get_note(struct notes_tree *t,
 152                 const struct object_id *object_oid);
 153
 154 /*
 155  * Copy a note from one object to another in the given notes_tree.
 156  *
 157  * Returns 1 if the to_obj already has a note and 'force' is false. Otherwise,
 158  * returns non-zero if 'force' is true, but the given combine_notes function
 159  * failed to combine from_obj's note with to_obj's existing note.
 160  * Returns zero on success.
 161  *
 162  * IMPORTANT: The changes made by copy_note() to the given notes_tree structure
 163  * are not persistent until a subsequent call to write_notes_tree() returns
 164  * zero.
 165  */
 166 int copy_note(struct notes_tree *t,
 167               const struct object_id *from_obj, const struct object_id *to_obj,
 168               int force, combine_notes_fn combine_notes);
 169
 170 /*
 171  * Flags controlling behaviour of for_each_note()
 172  *
 173  * Default behaviour of for_each_note() is to traverse every single note object
 174  * in the given notes tree, unpacking subtree entries along the way.
 175  * The following flags can be used to alter the default behaviour:
 176  *
 177  * - DONT_UNPACK_SUBTREES causes for_each_note() NOT to unpack and recurse into
 178  *   subtree entries while traversing the notes tree. This causes notes within
 179  *   those subtrees NOT to be passed to the callback. Use this flag if you
 180  *   don't want to traverse _all_ notes, but only want to traverse the parts
 181  *   of the notes tree that have already been unpacked (this includes at least
 182  *   all notes that have been added/changed).
 183  *
 184  * - YIELD_SUBTREES causes any subtree entries that are encountered to be
 185  *   passed to the callback, before recursing into them. Subtree entries are
 186  *   not note objects, but represent intermediate directories in the notes
 187  *   tree. When passed to the callback, subtree entries will have a trailing
 188  *   slash in their path, which the callback may use to differentiate between
 189  *   note entries and subtree entries. Note that already-unpacked subtree
 190  *   entries are not part of the notes tree, and will therefore not be yielded.
 191  *   If this flag is used together with DONT_UNPACK_SUBTREES, for_each_note()
 192  *   will yield the subtree entry, but not recurse into it.
 193  */
 194 #define FOR_EACH_NOTE_DONT_UNPACK_SUBTREES 1
 195 #define FOR_EACH_NOTE_YIELD_SUBTREES 2
 196
 197 /*
 198  * Invoke the specified callback function for each note in the given notes_tree
 199  *
 200  * If the callback returns nonzero, the note walk is aborted, and the return
 201  * value from the callback is returned from for_each_note(). Hence, a zero
 202  * return value from for_each_note() indicates that all notes were walked
 203  * successfully.
 204  *
 205  * IMPORTANT: The callback function is NOT allowed to change the notes tree.
 206  * In other words, the following functions can NOT be invoked (on the current
 207  * notes tree) from within the callback:
 208  * - add_note()
 209  * - remove_note()
 210  * - copy_note()
 211  * - free_notes()
 212  */
 213 typedef int each_note_fn(const struct object_id *object_oid,
 214                 const struct object_id *note_oid, char *note_path,
 215                 void *cb_data);
 216 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
 217                 void *cb_data);
 218
 219 /*
 220  * Write the given notes_tree structure to the object database
 221  *
 222  * Creates a new tree object encapsulating the current state of the given
 223  * notes_tree, and stores its object id into the 'result' argument.
 224  *
 225  * Returns zero on success, non-zero on failure.
 226  *
 227  * IMPORTANT: Changes made to the given notes_tree are not persistent until
 228  * this function has returned zero. Please also remember to create a
 229  * corresponding commit object, and update the appropriate notes ref.
 230  */
 231 int write_notes_tree(struct notes_tree *t, struct object_id *result);
 232
 233 /* Flags controlling the operation of prune */
 234 #define NOTES_PRUNE_VERBOSE 1
 235 #define NOTES_PRUNE_DRYRUN 2
 236 /*
 237  * Remove all notes annotating non-existing objects from the given notes tree
 238  *
 239  * All notes in the given notes_tree that are associated with objects that no
 240  * longer exist in the database, are removed from the notes tree.
 241  *
 242  * IMPORTANT: The changes made by prune_notes() to the given notes_tree
 243  * structure are not persistent until a subsequent call to write_notes_tree()
 244  * returns zero.
 245  */
 246 void prune_notes(struct notes_tree *t, int flags);
 247
 248 /*
 249  * Free (and de-initialize) the given notes_tree structure
 250  *
 251  * IMPORTANT: Changes made to the given notes_tree since the last, successful
 252  * call to write_notes_tree() will be lost.
 253  */
 254 void free_notes(struct notes_tree *t);
 255
 256 struct string_list;
 257
 258 struct display_notes_opt {
 259         int use_default_notes;
 260         struct string_list extra_notes_refs;
 261 };
 262
 263 /*
 264  * Initialize a display_notes_opt to its default value.
 265  */
 266 void init_display_notes(struct display_notes_opt *opt);
 267
 268 /*
 269  * This family of functions enables or disables the display of notes. In
 270  * particular, 'enable_default_display_notes' will display the default notes,
 271  * 'enable_ref_display_notes' will display the notes ref 'ref' and
 272  * 'disable_display_notes' will disable notes, including those added by previous
 273  * invocations of the 'enable_*_display_notes' functions.
 274  *
 275  * 'show_notes' is a pointer to a boolean which will be set to 1 if notes are
 276  * displayed, else 0. It must not be NULL.
 277  */
 278 void enable_default_display_notes(struct display_notes_opt *opt, int *show_notes);
 279 void enable_ref_display_notes(struct display_notes_opt *opt, int *show_notes,
 280                 const char *ref);
 281 void disable_display_notes(struct display_notes_opt *opt, int *show_notes);
 282
 283 /*
 284  * Load the notes machinery for displaying several notes trees.
 285  *
 286  * If 'opt' is not NULL, then it specifies additional settings for the
 287  * displaying:
 288  *
 289  * - suppress_default_notes indicates that the notes from
 290  *   core.notesRef and notes.displayRef should not be loaded.
 291  *
 292  * - extra_notes_refs may contain a list of globs (in the same style
 293  *   as notes.displayRef) where notes should be loaded from.
 294  */
 295 void load_display_notes(struct display_notes_opt *opt);
 296
 297 /*
 298  * Append notes for the given 'object_sha1' from all trees set up by
 299  * load_display_notes() to 'sb'.
 300  *
 301  * If 'raw' is false the note will be indented by 4 places and
 302  * a 'Notes (refname):' header added.
 303  *
 304  * You *must* call load_display_notes() before using this function.
 305  */
 306 void format_display_notes(const struct object_id *object_oid,
 307                           struct strbuf *sb, const char *output_encoding, int raw);
 308
 309 /*
 310  * Load the notes tree from each ref listed in 'refs'.  The output is
 311  * an array of notes_tree*, terminated by a NULL.
 312  */
 313 struct notes_tree **load_notes_trees(struct string_list *refs, int flags);
 314
 315 /*
 316  * Add all refs that match 'glob' to the 'list'.
 317  */
 318 void string_list_add_refs_by_glob(struct string_list *list, const char *glob);
 319
 320 /*
 321  * Add all refs from a colon-separated glob list 'globs' to the end of
 322  * 'list'.  Empty components are ignored.  This helper is used to
 323  * parse GIT_NOTES_DISPLAY_REF style environment variables.
 324  */
 325 void string_list_add_refs_from_colon_sep(struct string_list *list,
 326                                          const char *globs);
 327
 328 /* Expand inplace a note ref like "foo" or "notes/foo" into "refs/notes/foo" */
 329 void expand_notes_ref(struct strbuf *sb);
 330
 331 /*
 332  * Similar to expand_notes_ref, but will check whether the ref can be located
 333  * via get_sha1 first, and only falls back to expand_notes_ref in the case
 334  * where get_sha1 fails.
 335  */
 336 void expand_loose_notes_ref(struct strbuf *sb);
 337
 338 #endif