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