diffcore.h

   1 /*
   2  * Copyright (C) 2005 Junio C Hamano
   3  */
   4 #ifndef DIFFCORE_H
   5 #define DIFFCORE_H
   6
   7 #include "cache.h"
   8
   9 struct diff_options;
  10 struct repository;
  11 struct strmap;
  12 struct strset;
  13 struct userdiff_driver;
  14
  15 /* This header file is internal between diff.c and its diff transformers
  16  * (e.g. diffcore-rename, diffcore-pickaxe).  Never include this header
  17  * in anything else.
  18  */
  19
  20 /* We internally use unsigned short as the score value,
  21  * and rely on an int capable to hold 32-bits.  -B can take
  22  * -Bmerge_score/break_score format and the two scores are
  23  * passed around in one int (high 16-bit for merge and low 16-bit
  24  * for break).
  25  */
  26 #define MAX_SCORE 60000.0
  27 #define DEFAULT_RENAME_SCORE 30000 /* rename/copy similarity minimum (50%) */
  28 #define DEFAULT_BREAK_SCORE  30000 /* minimum for break to happen (50%) */
  29 #define DEFAULT_MERGE_SCORE  36000 /* maximum for break-merge to happen (60%) */
  30
  31 #define MINIMUM_BREAK_SIZE     400 /* do not break a file smaller than this */
  32
  33 /**
  34  * the internal representation for a single file (blob).  It records the blob
  35  * object name (if known -- for a work tree file it typically is a NUL SHA-1),
  36  * filemode and pathname.  This is what the `diff_addremove()`, `diff_change()`
  37  * and `diff_unmerge()` synthesize and feed `diff_queue()` function with.
  38  */
  39 struct diff_filespec {
  40         struct object_id oid;
  41         char *path;
  42         void *data;
  43         void *cnt_data;
  44         unsigned long size;
  45         int count;               /* Reference count */
  46         int rename_used;         /* Count of rename users */
  47         unsigned short mode;     /* file mode */
  48         unsigned oid_valid : 1;  /* if true, use oid and trust mode;
  49                                   * if false, use the name and read from
  50                                   * the filesystem.
  51                                   */
  52 #define DIFF_FILE_VALID(spec) (((spec)->mode) != 0)
  53         unsigned should_free : 1; /* data should be free()'ed */
  54         unsigned should_munmap : 1; /* data should be munmap()'ed */
  55         unsigned dirty_submodule : 2;  /* For submodules: its work tree is dirty */
  56 #define DIRTY_SUBMODULE_UNTRACKED 1
  57 #define DIRTY_SUBMODULE_MODIFIED  2
  58         unsigned is_stdin : 1;
  59         unsigned has_more_entries : 1; /* only appear in combined diff */
  60         /* data should be considered "binary"; -1 means "don't know yet" */
  61         signed int is_binary : 2;
  62         struct userdiff_driver *driver;
  63 };
  64
  65 struct diff_filespec *alloc_filespec(const char *);
  66 void free_filespec(struct diff_filespec *);
  67 void fill_filespec(struct diff_filespec *, const struct object_id *,
  68                    int, unsigned short);
  69
  70 /*
  71  * Prefetch the entries in diff_queued_diff. The parameter is a pointer to a
  72  * struct repository.
  73  */
  74 void diff_queued_diff_prefetch(void *repository);
  75
  76 struct diff_populate_filespec_options {
  77         unsigned check_size_only : 1;
  78         unsigned check_binary : 1;
  79
  80         /*
  81          * If an object is missing, diff_populate_filespec() will invoke this
  82          * callback before attempting to read that object again.
  83          */
  84         void (*missing_object_cb)(void *);
  85         void *missing_object_data;
  86 };
  87 int diff_populate_filespec(struct repository *, struct diff_filespec *,
  88                            const struct diff_populate_filespec_options *);
  89 void diff_free_filespec_data(struct diff_filespec *);
  90 void diff_free_filespec_blob(struct diff_filespec *);
  91 int diff_filespec_is_binary(struct repository *, struct diff_filespec *);
  92
  93 /**
  94  * This records a pair of `struct diff_filespec`; the filespec for a file in
  95  * the "old" set (i.e. preimage) is called `one`, and the filespec for a file
  96  * in the "new" set (i.e. postimage) is called `two`.  A change that represents
  97  * file creation has NULL in `one`, and file deletion has NULL in `two`.
  98  *
  99  * A `filepair` starts pointing at `one` and `two` that are from the same
 100  * filename, but `diffcore_std()` can break pairs and match component filespecs
 101  * with other filespecs from a different filepair to form new filepair. This is
 102  * called 'rename detection'.
 103  */
 104 struct diff_filepair {
 105         struct diff_filespec *one;
 106         struct diff_filespec *two;
 107         unsigned short int score;
 108         char status; /* M C R A D U etc. (see Documentation/diff-format.txt or DIFF_STATUS_* in diff.h) */
 109         unsigned broken_pair : 1;
 110         unsigned renamed_pair : 1;
 111         unsigned is_unmerged : 1;
 112         unsigned done_skip_stat_unmatch : 1;
 113         unsigned skip_stat_unmatch_result : 1;
 114 };
 115
 116 #define DIFF_PAIR_UNMERGED(p) ((p)->is_unmerged)
 117
 118 #define DIFF_PAIR_RENAME(p) ((p)->renamed_pair)
 119
 120 #define DIFF_PAIR_BROKEN(p) \
 121         ( (!DIFF_FILE_VALID((p)->one) != !DIFF_FILE_VALID((p)->two)) && \
 122           ((p)->broken_pair != 0) )
 123
 124 #define DIFF_PAIR_TYPE_CHANGED(p) \
 125         ((S_IFMT & (p)->one->mode) != (S_IFMT & (p)->two->mode))
 126
 127 #define DIFF_PAIR_MODE_CHANGED(p) ((p)->one->mode != (p)->two->mode)
 128
 129 void diff_free_filepair(struct diff_filepair *);
 130
 131 int diff_unmodified_pair(struct diff_filepair *);
 132
 133 /**
 134  * This is a collection of filepairs.  Notable members are:
 135  *
 136  * - `queue`:
 137  * An array of pointers to `struct diff_filepair`. This dynamically grows as
 138  * you add filepairs;
 139  *
 140  * - `alloc`:
 141  * The allocated size of the `queue` array;
 142  *
 143  * - `nr`:
 144  * The number of elements in the `queue` array.
 145  */
 146 struct diff_queue_struct {
 147         struct diff_filepair **queue;
 148         int alloc;
 149         int nr;
 150 };
 151
 152 #define DIFF_QUEUE_CLEAR(q) \
 153         do { \
 154                 (q)->queue = NULL; \
 155                 (q)->nr = (q)->alloc = 0; \
 156         } while (0)
 157
 158 extern struct diff_queue_struct diff_queued_diff;
 159 struct diff_filepair *diff_queue(struct diff_queue_struct *,
 160                                  struct diff_filespec *,
 161                                  struct diff_filespec *);
 162 void diff_q(struct diff_queue_struct *, struct diff_filepair *);
 163
 164 void partial_clear_dir_rename_count(struct strmap *dir_rename_count);
 165
 166 void diffcore_break(struct repository *, int);
 167 void diffcore_rename(struct diff_options *);
 168 void diffcore_rename_extended(struct diff_options *options,
 169                               struct strset *relevant_sources,
 170                               struct strset *dirs_removed,
 171                               struct strmap *dir_rename_count);
 172 void diffcore_merge_broken(void);
 173 void diffcore_pickaxe(struct diff_options *);
 174 void diffcore_order(const char *orderfile);
 175 void diffcore_rotate(struct diff_options *);
 176
 177 /* low-level interface to diffcore_order */
 178 struct obj_order {
 179         void *obj;      /* setup by caller */
 180
 181         /* setup/used by order_objects() */
 182         int orig_order;
 183         int order;
 184 };
 185
 186 typedef const char *(*obj_path_fn_t)(void *obj);
 187
 188 void order_objects(const char *orderfile, obj_path_fn_t obj_path,
 189                    struct obj_order *objs, int nr);
 190
 191 #define DIFF_DEBUG 0
 192 #if DIFF_DEBUG
 193 void diff_debug_filespec(struct diff_filespec *, int, const char *);
 194 void diff_debug_filepair(const struct diff_filepair *, int);
 195 void diff_debug_queue(const char *, struct diff_queue_struct *);
 196 #else
 197 #define diff_debug_filespec(a,b,c) do { /* nothing */ } while (0)
 198 #define diff_debug_filepair(a,b) do { /* nothing */ } while (0)
 199 #define diff_debug_queue(a,b) do { /* nothing */ } while (0)
 200 #endif
 201
 202 int diffcore_count_changes(struct repository *r,
 203                            struct diff_filespec *src,
 204                            struct diff_filespec *dst,
 205                            void **src_count_p,
 206                            void **dst_count_p,
 207                            unsigned long *src_copied,
 208                            unsigned long *literal_added);
 209
 210 /*
 211  * If filespec contains an OID and if that object is missing from the given
 212  * repository, add that OID to to_fetch.
 213  */
 214 void diff_add_if_missing(struct repository *r,
 215                          struct oid_array *to_fetch,
 216                          const struct diff_filespec *filespec);
 217
 218 #endif