diff options
Diffstat (limited to 'notes.h')
| -rw-r--r-- | notes.h | 196 |
1 files changed, 192 insertions, 4 deletions
@@ -1,13 +1,201 @@ #ifndef NOTES_H #define NOTES_H -/* Free (and de-initialize) the internal notes tree structure */ -void free_notes(void); +/* + * Function type for combining two notes annotating the same object. + * + * When adding a new note annotating the same object as an existing note, it is + * up to the caller to decide how to combine the two notes. The decision is + * made by passing in a function of the following form. The function accepts + * two SHA1s -- of the existing note and the new note, respectively. The + * function then combines the notes in whatever way it sees fit, and writes the + * resulting SHA1 into the first SHA1 argument (cur_sha1). A non-zero return + * value indicates failure. + * + * The two given SHA1s must both be non-NULL and different from each other. + * + * The default combine_notes function (you get this when passing NULL) is + * combine_notes_concatenate(), which appends the contents of the new note to + * the contents of the existing note. + */ +typedef int combine_notes_fn(unsigned char *cur_sha1, const unsigned char *new_sha1); +/* Common notes combinators */ +int combine_notes_concatenate(unsigned char *cur_sha1, const unsigned char *new_sha1); +int combine_notes_overwrite(unsigned char *cur_sha1, const unsigned char *new_sha1); +int combine_notes_ignore(unsigned char *cur_sha1, const unsigned char *new_sha1); + +/* + * Notes tree object + * + * Encapsulates the internal notes tree structure associated with a notes ref. + * Whenever a struct notes_tree pointer is required below, you may pass NULL in + * order to use the default/internal notes tree. E.g. you only need to pass a + * non-NULL value if you need to refer to several different notes trees + * simultaneously. + */ +extern struct notes_tree { + struct int_node *root; + struct non_note *first_non_note, *prev_non_note; + char *ref; + combine_notes_fn *combine_notes; + int initialized; +} default_notes_tree; + +/* + * Flags controlling behaviour of notes tree initialization + * + * Default behaviour is to initialize the notes tree from the tree object + * specified by the given (or default) notes ref. + */ +#define NOTES_INIT_EMPTY 1 + +/* + * Initialize the given notes_tree with the notes tree structure at the given + * ref. If given ref is NULL, the value of the $GIT_NOTES_REF environment + * variable is used, and if that is missing, the default notes ref is used + * ("refs/notes/commits"). + * + * If you need to re-intialize a notes_tree structure (e.g. when switching from + * one notes ref to another), you must first de-initialize the notes_tree + * structure by calling free_notes(struct notes_tree *). + * + * If you pass t == NULL, the default internal notes_tree will be initialized. + * + * The combine_notes function that is passed becomes the default combine_notes + * function for the given notes_tree. If NULL is passed, the default + * combine_notes function is combine_notes_concatenate(). + * + * Precondition: The notes_tree structure is zeroed (this can be achieved with + * memset(t, 0, sizeof(struct notes_tree))) + */ +void init_notes(struct notes_tree *t, const char *notes_ref, + combine_notes_fn combine_notes, int flags); + +/* + * Add the given note object to the given notes_tree structure + * + * IMPORTANT: The changes made by add_note() to the given notes_tree structure + * are not persistent until a subsequent call to write_notes_tree() returns + * zero. + */ +void add_note(struct notes_tree *t, const unsigned char *object_sha1, + const unsigned char *note_sha1, combine_notes_fn combine_notes); + +/* + * Remove the given note object from the given notes_tree structure + * + * IMPORTANT: The changes made by remove_note() to the given notes_tree + * structure are not persistent until a subsequent call to write_notes_tree() + * returns zero. + */ +void remove_note(struct notes_tree *t, const unsigned char *object_sha1); + +/* + * Get the note object SHA1 containing the note data for the given object + * + * Return NULL if the given object has no notes. + */ +const unsigned char *get_note(struct notes_tree *t, + const unsigned char *object_sha1); + +/* + * Flags controlling behaviour of for_each_note() + * + * Default behaviour of for_each_note() is to traverse every single note object + * in the given notes tree, unpacking subtree entries along the way. + * The following flags can be used to alter the default behaviour: + * + * - DONT_UNPACK_SUBTREES causes for_each_note() NOT to unpack and recurse into + * subtree entries while traversing the notes tree. This causes notes within + * those subtrees NOT to be passed to the callback. Use this flag if you + * don't want to traverse _all_ notes, but only want to traverse the parts + * of the notes tree that have already been unpacked (this includes at least + * all notes that have been added/changed). + * + * - YIELD_SUBTREES causes any subtree entries that are encountered to be + * passed to the callback, before recursing into them. Subtree entries are + * not note objects, but represent intermediate directories in the notes + * tree. When passed to the callback, subtree entries will have a trailing + * slash in their path, which the callback may use to differentiate between + * note entries and subtree entries. Note that already-unpacked subtree + * entries are not part of the notes tree, and will therefore not be yielded. + * If this flag is used together with DONT_UNPACK_SUBTREES, for_each_note() + * will yield the subtree entry, but not recurse into it. + */ +#define FOR_EACH_NOTE_DONT_UNPACK_SUBTREES 1 +#define FOR_EACH_NOTE_YIELD_SUBTREES 2 + +/* + * Invoke the specified callback function for each note in the given notes_tree + * + * If the callback returns nonzero, the note walk is aborted, and the return + * value from the callback is returned from for_each_note(). Hence, a zero + * return value from for_each_note() indicates that all notes were walked + * successfully. + * + * IMPORTANT: The callback function is NOT allowed to change the notes tree. + * In other words, the following functions can NOT be invoked (on the current + * notes tree) from within the callback: + * - add_note() + * - remove_note() + * - free_notes() + */ +typedef int each_note_fn(const unsigned char *object_sha1, + const unsigned char *note_sha1, char *note_path, + void *cb_data); +int for_each_note(struct notes_tree *t, int flags, each_note_fn fn, + void *cb_data); + +/* + * Write the given notes_tree structure to the object database + * + * Creates a new tree object encapsulating the current state of the given + * notes_tree, and stores its SHA1 into the 'result' argument. + * + * Returns zero on success, non-zero on failure. + * + * IMPORTANT: Changes made to the given notes_tree are not persistent until + * this function has returned zero. Please also remember to create a + * corresponding commit object, and update the appropriate notes ref. + */ +int write_notes_tree(struct notes_tree *t, unsigned char *result); + +/* + * Remove all notes annotating non-existing objects from the given notes tree + * + * All notes in the given notes_tree that are associated with objects that no + * longer exist in the database, are removed from the notes tree. + * + * IMPORTANT: The changes made by prune_notes() to the given notes_tree + * structure are not persistent until a subsequent call to write_notes_tree() + * returns zero. + */ +void prune_notes(struct notes_tree *t); + +/* + * Free (and de-initialize) the given notes_tree structure + * + * IMPORTANT: Changes made to the given notes_tree since the last, successful + * call to write_notes_tree() will be lost. + */ +void free_notes(struct notes_tree *t); + +/* Flags controlling how notes are formatted */ #define NOTES_SHOW_HEADER 1 #define NOTES_INDENT 2 -void get_commit_notes(const struct commit *commit, struct strbuf *sb, - const char *output_encoding, int flags); +/* + * Fill the given strbuf with the notes associated with the given object. + * + * If the given notes_tree structure is not initialized, it will be auto- + * initialized to the default value (see documentation for init_notes() above). + * If the given notes_tree is NULL, the internal/default notes_tree will be + * used instead. + * + * 'flags' is a bitwise combination of the above formatting flags. + */ +void format_note(struct notes_tree *t, const unsigned char *object_sha1, + struct strbuf *sb, const char *output_encoding, int flags); #endif |