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 strintmap;
  12 struct strmap;
  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 void pool_diff_free_filepair(struct mem_pool *pool,
 131                              struct diff_filepair *p);
 132
 133 int diff_unmodified_pair(struct diff_filepair *);
 134
 135 /**
 136  * This is a collection of filepairs.  Notable members are:
 137  *
 138  * - `queue`:
 139  * An array of pointers to `struct diff_filepair`. This dynamically grows as
 140  * you add filepairs;
 141  *
 142  * - `alloc`:
 143  * The allocated size of the `queue` array;
 144  *
 145  * - `nr`:
 146  * The number of elements in the `queue` array.
 147  */
 148 struct diff_queue_struct {
 149         struct diff_filepair **queue;
 150         int alloc;
 151         int nr;
 152 };
 153
 154 #define DIFF_QUEUE_CLEAR(q) \
 155         do { \
 156                 (q)->queue = NULL; \
 157                 (q)->nr = (q)->alloc = 0; \
 158         } while (0)
 159
 160 extern struct diff_queue_struct diff_queued_diff;
 161 struct diff_filepair *diff_queue(struct diff_queue_struct *,
 162                                  struct diff_filespec *,
 163                                  struct diff_filespec *);
 164 void diff_q(struct diff_queue_struct *, struct diff_filepair *);
 165 void diff_free_queue(struct diff_queue_struct *q);
 166
 167 /* dir_rename_relevance: the reason we want rename information for a dir */
 168 enum dir_rename_relevance {
 169         NOT_RELEVANT = 0,
 170         RELEVANT_FOR_ANCESTOR = 1,
 171         RELEVANT_FOR_SELF = 2
 172 };
 173 /* file_rename_relevance: the reason(s) we want rename information for a file */
 174 enum file_rename_relevance {
 175         RELEVANT_NO_MORE = 0,  /* i.e. NOT relevant */
 176         RELEVANT_CONTENT = 1,
 177         RELEVANT_LOCATION = 2
 178 };
 179
 180 void partial_clear_dir_rename_count(struct strmap *dir_rename_count);
 181
 182 void diffcore_break(struct repository *, int);
 183 void diffcore_rename(struct diff_options *);
 184 void diffcore_rename_extended(struct diff_options *options,
 185                               struct mem_pool *pool,
 186                               struct strintmap *relevant_sources,
 187                               struct strintmap *dirs_removed,
 188                               struct strmap *dir_rename_count,
 189                               struct strmap *cached_pairs);
 190 void diffcore_merge_broken(void);
 191 void diffcore_pickaxe(struct diff_options *);
 192 void diffcore_order(const char *orderfile);
 193 void diffcore_rotate(struct diff_options *);
 194
 195 /* low-level interface to diffcore_order */
 196 struct obj_order {
 197         void *obj;      /* setup by caller */
 198
 199         /* setup/used by order_objects() */
 200         int orig_order;
 201         int order;
 202 };
 203
 204 typedef const char *(*obj_path_fn_t)(void *obj);
 205
 206 void order_objects(const char *orderfile, obj_path_fn_t obj_path,
 207                    struct obj_order *objs, int nr);
 208
 209 #define DIFF_DEBUG 0
 210 #if DIFF_DEBUG
 211 void diff_debug_filespec(struct diff_filespec *, int, const char *);
 212 void diff_debug_filepair(const struct diff_filepair *, int);
 213 void diff_debug_queue(const char *, struct diff_queue_struct *);
 214 #else
 215 #define diff_debug_filespec(a,b,c) do { /* nothing */ } while (0)
 216 #define diff_debug_filepair(a,b) do { /* nothing */ } while (0)
 217 #define diff_debug_queue(a,b) do { /* nothing */ } while (0)
 218 #endif
 219
 220 int diffcore_count_changes(struct repository *r,
 221                            struct diff_filespec *src,
 222                            struct diff_filespec *dst,
 223                            void **src_count_p,
 224                            void **dst_count_p,
 225                            unsigned long *src_copied,
 226                            unsigned long *literal_added);
 227
 228 /*
 229  * If filespec contains an OID and if that object is missing from the given
 230  * repository, add that OID to to_fetch.
 231  */
 232 void diff_add_if_missing(struct repository *r,
 233                          struct oid_array *to_fetch,
 234                          const struct diff_filespec *filespec);
 235
 236 #endif