blame.h

   1 #ifndef BLAME_H
   2 #define BLAME_H
   3
   4 #include "cache.h"
   5 #include "commit.h"
   6 #include "xdiff-interface.h"
   7 #include "revision.h"
   8 #include "prio-queue.h"
   9 #include "diff.h"
  10
  11 #define PICKAXE_BLAME_MOVE              01
  12 #define PICKAXE_BLAME_COPY              02
  13 #define PICKAXE_BLAME_COPY_HARDER       04
  14 #define PICKAXE_BLAME_COPY_HARDEST      010
  15
  16 /*
  17  * One blob in a commit that is being suspected
  18  */
  19 struct blame_origin {
  20         int refcnt;
  21         /* Record preceding blame record for this blob */
  22         struct blame_origin *previous;
  23         /* origins are put in a list linked via `next' hanging off the
  24          * corresponding commit's util field in order to make finding
  25          * them fast.  The presence in this chain does not count
  26          * towards the origin's reference count.  It is tempting to
  27          * let it count as long as the commit is pending examination,
  28          * but even under circumstances where the commit will be
  29          * present multiple times in the priority queue of unexamined
  30          * commits, processing the first instance will not leave any
  31          * work requiring the origin data for the second instance.  An
  32          * interspersed commit changing that would have to be
  33          * preexisting with a different ancestry and with the same
  34          * commit date in order to wedge itself between two instances
  35          * of the same commit in the priority queue _and_ produce
  36          * blame entries relevant for it.  While we don't want to let
  37          * us get tripped up by this case, it certainly does not seem
  38          * worth optimizing for.
  39          */
  40         struct blame_origin *next;
  41         struct commit *commit;
  42         /* `suspects' contains blame entries that may be attributed to
  43          * this origin's commit or to parent commits.  When a commit
  44          * is being processed, all suspects will be moved, either by
  45          * assigning them to an origin in a different commit, or by
  46          * shipping them to the scoreboard's ent list because they
  47          * cannot be attributed to a different commit.
  48          */
  49         struct blame_entry *suspects;
  50         mmfile_t file;
  51         struct object_id blob_oid;
  52         unsigned mode;
  53         /* guilty gets set when shipping any suspects to the final
  54          * blame list instead of other commits
  55          */
  56         char guilty;
  57         char path[FLEX_ARRAY];
  58 };
  59
  60 /*
  61  * Each group of lines is described by a blame_entry; it can be split
  62  * as we pass blame to the parents.  They are arranged in linked lists
  63  * kept as `suspects' of some unprocessed origin, or entered (when the
  64  * blame origin has been finalized) into the scoreboard structure.
  65  * While the scoreboard structure is only sorted at the end of
  66  * processing (according to final image line number), the lists
  67  * attached to an origin are sorted by the target line number.
  68  */
  69 struct blame_entry {
  70         struct blame_entry *next;
  71
  72         /* the first line of this group in the final image;
  73          * internally all line numbers are 0 based.
  74          */
  75         int lno;
  76
  77         /* how many lines this group has */
  78         int num_lines;
  79
  80         /* the commit that introduced this group into the final image */
  81         struct blame_origin *suspect;
  82
  83         /* the line number of the first line of this group in the
  84          * suspect's file; internally all line numbers are 0 based.
  85          */
  86         int s_lno;
  87
  88         /* how significant this entry is -- cached to avoid
  89          * scanning the lines over and over.
  90          */
  91         unsigned score;
  92 };
  93
  94 /*
  95  * The current state of the blame assignment.
  96  */
  97 struct blame_scoreboard {
  98         /* the final commit (i.e. where we started digging from) */
  99         struct commit *final;
 100         /* Priority queue for commits with unassigned blame records */
 101         struct prio_queue commits;
 102         struct rev_info *revs;
 103         const char *path;
 104
 105         /*
 106          * The contents in the final image.
 107          * Used by many functions to obtain contents of the nth line,
 108          * indexed with scoreboard.lineno[blame_entry.lno].
 109          */
 110         const char *final_buf;
 111         unsigned long final_buf_size;
 112
 113         /* linked list of blames */
 114         struct blame_entry *ent;
 115
 116         /* look-up a line in the final buffer */
 117         int num_lines;
 118         int *lineno;
 119
 120         /* stats */
 121         int num_read_blob;
 122         int num_get_patch;
 123         int num_commits;
 124
 125         /*
 126          * blame for a blame_entry with score lower than these thresholds
 127          * is not passed to the parent using move/copy logic.
 128          */
 129         unsigned move_score;
 130         unsigned copy_score;
 131
 132         /* use this file's contents as the final image */
 133         const char *contents_from;
 134
 135         /* flags */
 136         int reverse;
 137         int show_root;
 138         int xdl_opts;
 139         int no_whole_file_rename;
 140         int debug;
 141
 142         /* callbacks */
 143         void(*on_sanity_fail)(struct blame_scoreboard *, int);
 144         void(*found_guilty_entry)(struct blame_entry *, void *);
 145
 146         void *found_guilty_entry_data;
 147 };
 148
 149 /*
 150  * Origin is refcounted and usually we keep the blob contents to be
 151  * reused.
 152  */
 153 static inline struct blame_origin *blame_origin_incref(struct blame_origin *o)
 154 {
 155         if (o)
 156                 o->refcnt++;
 157         return o;
 158 }
 159 extern void blame_origin_decref(struct blame_origin *o);
 160
 161 extern struct blame_origin *get_origin(struct commit *commit, const char *path);
 162
 163 extern struct commit *fake_working_tree_commit(struct diff_options *opt, const char *path, const char *contents_from);
 164
 165 extern void blame_coalesce(struct blame_scoreboard *sb);
 166 extern void blame_sort_final(struct blame_scoreboard *sb);
 167 extern unsigned blame_entry_score(struct blame_scoreboard *sb, struct blame_entry *e);
 168 extern void assign_blame(struct blame_scoreboard *sb, int opt);
 169 extern const char *blame_nth_line(struct blame_scoreboard *sb, long lno);
 170
 171 #endif /* BLAME_H */