notes.h

   1 #ifndef NOTES_H
   2 #define NOTES_H
   3
   4 /*
   5  * Function type for combining two notes annotating the same object.
   6  *
   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.
  14  *
  15  * The two given SHA1s must both be non-NULL and different from each other.
  16  *
  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.
  20  */
  21 typedef int (*combine_notes_fn)(unsigned char *cur_sha1, const unsigned char *new_sha1);
  22
  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);
  27
  28 /*
  29  * Notes tree object
  30  *
  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.
  36  */
  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;
  45
  46 /*
  47  * Flags controlling behaviour of notes tree initialization
  48  *
  49  * Default behaviour is to initialize the notes tree from the tree object
  50  * specified by the given (or default) notes ref.
  51  */
  52 #define NOTES_INIT_EMPTY 1
  53
  54 /*
  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").
  59  *
  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 *).
  63  *
  64  * If you pass t == NULL, the default internal notes_tree will be initialized.
  65  *
  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().
  69  *
  70  * Precondition: The notes_tree structure is zeroed (this can be achieved with
  71  * memset(t, 0, sizeof(struct notes_tree)))
  72  */
  73 void init_notes(struct notes_tree *t, const char *notes_ref,
  74                 combine_notes_fn combine_notes, int flags);
  75
  76 /*
  77  * Add the given note object to the given notes_tree structure
  78  *
  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.
  82  */
  83 void add_note(struct notes_tree *t, const unsigned char *object_sha1,
  84                 const unsigned char *note_sha1, combine_notes_fn combine_notes);
  85
  86 /*
  87  * Remove the given note object from the given notes_tree structure
  88  *
  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.
  92  *
  93  * Return 0 if a note was removed; 1 if there was no note to remove.
  94  */
  95 int remove_note(struct notes_tree *t, const unsigned char *object_sha1);
  96
  97 /*
  98  * Get the note object SHA1 containing the note data for the given object
  99  *
 100  * Return NULL if the given object has no notes.
 101  */
 102 const unsigned char *get_note(struct notes_tree *t,
 103                 const unsigned char *object_sha1);
 104
 105 /*
 106  * Copy a note from one object to another in the given notes_tree.
 107  *
 108  * Fails if the to_obj already has a note unless 'force' is true.
 109  */
 110 int copy_note(struct notes_tree *t,
 111               const unsigned char *from_obj, const unsigned char *to_obj,
 112               int force, combine_notes_fn combine_fn);
 113
 114 /*
 115  * Flags controlling behaviour of for_each_note()
 116  *
 117  * Default behaviour of for_each_note() is to traverse every single note object
 118  * in the given notes tree, unpacking subtree entries along the way.
 119  * The following flags can be used to alter the default behaviour:
 120  *
 121  * - DONT_UNPACK_SUBTREES causes for_each_note() NOT to unpack and recurse into
 122  *   subtree entries while traversing the notes tree. This causes notes within
 123  *   those subtrees NOT to be passed to the callback. Use this flag if you
 124  *   don't want to traverse _all_ notes, but only want to traverse the parts
 125  *   of the notes tree that have already been unpacked (this includes at least
 126  *   all notes that have been added/changed).
 127  *
 128  * - YIELD_SUBTREES causes any subtree entries that are encountered to be
 129  *   passed to the callback, before recursing into them. Subtree entries are
 130  *   not note objects, but represent intermediate directories in the notes
 131  *   tree. When passed to the callback, subtree entries will have a trailing
 132  *   slash in their path, which the callback may use to differentiate between
 133  *   note entries and subtree entries. Note that already-unpacked subtree
 134  *   entries are not part of the notes tree, and will therefore not be yielded.
 135  *   If this flag is used together with DONT_UNPACK_SUBTREES, for_each_note()
 136  *   will yield the subtree entry, but not recurse into it.
 137  */
 138 #define FOR_EACH_NOTE_DONT_UNPACK_SUBTREES 1
 139 #define FOR_EACH_NOTE_YIELD_SUBTREES 2
 140
 141 /*
 142  * Invoke the specified callback function for each note in the given notes_tree
 143  *
 144  * If the callback returns nonzero, the note walk is aborted, and the return
 145  * value from the callback is returned from for_each_note(). Hence, a zero
 146  * return value from for_each_note() indicates that all notes were walked
 147  * successfully.
 148  *
 149  * IMPORTANT: The callback function is NOT allowed to change the notes tree.
 150  * In other words, the following functions can NOT be invoked (on the current
 151  * notes tree) from within the callback:
 152  * - add_note()
 153  * - remove_note()
 154  * - free_notes()
 155  */
 156 typedef int each_note_fn(const unsigned char *object_sha1,
 157                 const unsigned char *note_sha1, char *note_path,
 158                 void *cb_data);
 159 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
 160                 void *cb_data);
 161
 162 /*
 163  * Write the given notes_tree structure to the object database
 164  *
 165  * Creates a new tree object encapsulating the current state of the given
 166  * notes_tree, and stores its SHA1 into the 'result' argument.
 167  *
 168  * Returns zero on success, non-zero on failure.
 169  *
 170  * IMPORTANT: Changes made to the given notes_tree are not persistent until
 171  * this function has returned zero. Please also remember to create a
 172  * corresponding commit object, and update the appropriate notes ref.
 173  */
 174 int write_notes_tree(struct notes_tree *t, unsigned char *result);
 175
 176 /* Flags controlling the operation of prune */
 177 #define NOTES_PRUNE_VERBOSE 1
 178 #define NOTES_PRUNE_DRYRUN 2
 179 /*
 180  * Remove all notes annotating non-existing objects from the given notes tree
 181  *
 182  * All notes in the given notes_tree that are associated with objects that no
 183  * longer exist in the database, are removed from the notes tree.
 184  *
 185  * IMPORTANT: The changes made by prune_notes() to the given notes_tree
 186  * structure are not persistent until a subsequent call to write_notes_tree()
 187  * returns zero.
 188  */
 189 void prune_notes(struct notes_tree *t, int flags);
 190
 191 /*
 192  * Free (and de-initialize) the given notes_tree structure
 193  *
 194  * IMPORTANT: Changes made to the given notes_tree since the last, successful
 195  * call to write_notes_tree() will be lost.
 196  */
 197 void free_notes(struct notes_tree *t);
 198
 199 /* Flags controlling how notes are formatted */
 200 #define NOTES_SHOW_HEADER 1
 201 #define NOTES_INDENT 2
 202
 203 /*
 204  * Fill the given strbuf with the notes associated with the given object.
 205  *
 206  * If the given notes_tree structure is not initialized, it will be auto-
 207  * initialized to the default value (see documentation for init_notes() above).
 208  * If the given notes_tree is NULL, the internal/default notes_tree will be
 209  * used instead.
 210  *
 211  * 'flags' is a bitwise combination of the above formatting flags.
 212  */
 213 void format_note(struct notes_tree *t, const unsigned char *object_sha1,
 214                 struct strbuf *sb, const char *output_encoding, int flags);
 215
 216
 217 struct string_list;
 218
 219 struct display_notes_opt {
 220         unsigned int suppress_default_notes:1;
 221         struct string_list *extra_notes_refs;
 222 };
 223
 224 /*
 225  * Load the notes machinery for displaying several notes trees.
 226  *
 227  * If 'opt' is not NULL, then it specifies additional settings for the
 228  * displaying:
 229  *
 230  * - suppress_default_notes indicates that the notes from
 231  *   core.notesRef and notes.displayRef should not be loaded.
 232  *
 233  * - extra_notes_refs may contain a list of globs (in the same style
 234  *   as notes.displayRef) where notes should be loaded from.
 235  */
 236 void init_display_notes(struct display_notes_opt *opt);
 237
 238 /*
 239  * Append notes for the given 'object_sha1' from all trees set up by
 240  * init_display_notes() to 'sb'.  The 'flags' are a bitwise
 241  * combination of
 242  *
 243  * - NOTES_SHOW_HEADER: add a 'Notes (refname):' header
 244  *
 245  * - NOTES_INDENT: indent the notes by 4 places
 246  *
 247  * You *must* call init_display_notes() before using this function.
 248  */
 249 void format_display_notes(const unsigned char *object_sha1,
 250                           struct strbuf *sb, const char *output_encoding, int flags);
 251
 252 /*
 253  * Load the notes tree from each ref listed in 'refs'.  The output is
 254  * an array of notes_tree*, terminated by a NULL.
 255  */
 256 struct notes_tree **load_notes_trees(struct string_list *refs);
 257
 258 /*
 259  * Add all refs that match 'glob' to the 'list'.
 260  */
 261 void string_list_add_refs_by_glob(struct string_list *list, const char *glob);
 262
 263 /*
 264  * Add all refs from a colon-separated glob list 'globs' to the end of
 265  * 'list'.  Empty components are ignored.  This helper is used to
 266  * parse GIT_NOTES_DISPLAY_REF style environment variables.
 267  */
 268 void string_list_add_refs_from_colon_sep(struct string_list *list,
 269                                          const char *globs);
 270
 271 #endif