diff options
Diffstat (limited to 'notes.h')
| -rw-r--r-- | notes.h | 34 |
1 files changed, 32 insertions, 2 deletions
@@ -2,6 +2,30 @@ #define NOTES_H /* + * 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. @@ -13,6 +37,7 @@ extern struct notes_tree { struct int_node *root; char *ref; + combine_notes_fn *combine_notes; int initialized; } default_notes_tree; @@ -36,10 +61,15 @@ extern 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, int flags); +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 @@ -49,7 +79,7 @@ void init_notes(struct notes_tree *t, const char *notes_ref, int flags); * zero. */ void add_note(struct notes_tree *t, const unsigned char *object_sha1, - const unsigned char *note_sha1); + const unsigned char *note_sha1, combine_notes_fn combine_notes); /* * Remove the given note object from the given notes_tree structure |