diffcore.h

   1 /*
   2  * Copyright (C) 2005 Junio C Hamano
   3  */
   4 #ifndef DIFFCORE_H
   5 #define DIFFCORE_H
   6
   7 #include "hash.h"
   8
   9 struct diff_options;
  10 struct mem_pool;
  11 struct oid_array;
  12 struct repository;
  13 struct strintmap;
  14 struct strmap;
  15 struct userdiff_driver;
  16
  17 /* This header file is internal between diff.c and its diff transformers
  18  * (e.g. diffcore-rename, diffcore-pickaxe).  Never include this header
  19  * in anything else.
  20  */
  21
  22 /* We internally use unsigned short as the score value,
  23  * and rely on an int capable to hold 32-bits.  -B can take
  24  * -Bmerge_score/break_score format and the two scores are
  25  * passed around in one int (high 16-bit for merge and low 16-bit
  26  * for break).
  27  */
  28 #define MAX_SCORE 60000.0
  29 #define DEFAULT_RENAME_SCORE 30000 /* rename/copy similarity minimum (50%) */
  30 #define DEFAULT_BREAK_SCORE  30000 /* minimum for break to happen (50%) */
  31 #define DEFAULT_MERGE_SCORE  36000 /* maximum for break-merge to happen (60%) */
  32
  33 #define MINIMUM_BREAK_SIZE     400 /* do not break a file smaller than this */
  34
  35 /**
  36  * the internal representation for a single file (blob).  It records the blob
  37  * object name (if known -- for a work tree file it typically is a NUL SHA-1),
  38  * filemode and pathname.  This is what the `diff_addremove()`, `diff_change()`
  39  * and `diff_unmerge()` synthesize and feed `diff_queue()` function with.
  40  */
  41 struct diff_filespec {
  42         struct object_id oid;
  43         char *path;
  44         void *data;
  45         void *cnt_data;
  46         unsigned long size;
  47         int count;               /* Reference count */
  48         int rename_used;         /* Count of rename users */
  49         unsigned short mode;     /* file mode */
  50         unsigned oid_valid : 1;  /* if true, use oid and trust mode;
  51                                   * if false, use the name and read from
  52                                   * the filesystem.
  53                                   */
  54 #define DIFF_FILE_VALID(spec) (((spec)->mode) != 0)
  55         unsigned should_free : 1; /* data should be free()'ed */
  56         unsigned should_munmap : 1; /* data should be munmap()'ed */
  57         unsigned dirty_submodule : 2;  /* For submodules: its work tree is dirty */
  58 #define DIRTY_SUBMODULE_UNTRACKED 1
  59 #define DIRTY_SUBMODULE_MODIFIED  2
  60         unsigned is_stdin : 1;
  61         unsigned has_more_entries : 1; /* only appear in combined diff */
  62         /* data should be considered "binary"; -1 means "don't know yet" */
  63         signed int is_binary : 2;
  64         struct userdiff_driver *driver;
  65 };
  66
  67 struct diff_filespec *alloc_filespec(const char *);
  68 void free_filespec(struct diff_filespec *);
  69 void fill_filespec(struct diff_filespec *, const struct object_id *,
  70                    int, unsigned short);
  71
  72 /*
  73  * Prefetch the entries in diff_queued_diff. The parameter is a pointer to a
  74  * struct repository.
  75  */
  76 void diff_queued_diff_prefetch(void *repository);
  77
  78 struct diff_populate_filespec_options {
  79         unsigned check_size_only : 1;
  80         unsigned check_binary : 1;
  81
  82         /*
  83          * If an object is missing, diff_populate_filespec() will invoke this
  84          * callback before attempting to read that object again.
  85          */
  86         void (*missing_object_cb)(void *);
  87         void *missing_object_data;
  88 };
  89 int diff_populate_filespec(struct repository *, struct diff_filespec *,
  90                            const struct diff_populate_filespec_options *);
  91 void diff_free_filespec_data(struct diff_filespec *);
  92 void diff_free_filespec_blob(struct diff_filespec *);
  93 int diff_filespec_is_binary(struct repository *, struct diff_filespec *);
  94
  95 /**
  96  * This records a pair of `struct diff_filespec`; the filespec for a file in
  97  * the "old" set (i.e. preimage) is called `one`, and the filespec for a file
  98  * in the "new" set (i.e. postimage) is called `two`.  A change that represents
  99  * file creation has NULL in `one`, and file deletion has NULL in `two`.
 100  *
 101  * A `filepair` starts pointing at `one` and `two` that are from the same
 102  * filename, but `diffcore_std()` can break pairs and match component filespecs
 103  * with other filespecs from a different filepair to form new filepair. This is
 104  * called 'rename detection'.
 105  */
 106 struct diff_filepair {
 107         struct diff_filespec *one;
 108         struct diff_filespec *two;
 109         unsigned short int score;
 110         char status; /* M C R A D U etc. (see Documentation/diff-format.txt or DIFF_STATUS_* in diff.h) */
 111         unsigned broken_pair : 1;
 112         unsigned renamed_pair : 1;
 113         unsigned is_unmerged : 1;
 114         unsigned done_skip_stat_unmatch : 1;
 115         unsigned skip_stat_unmatch_result : 1;
 116 };
 117
 118 #define DIFF_PAIR_UNMERGED(p) ((p)->is_unmerged)
 119
 120 #define DIFF_PAIR_RENAME(p) ((p)->renamed_pair)
 121
 122 #define DIFF_PAIR_BROKEN(p) \
 123         ( (!DIFF_FILE_VALID((p)->one) != !DIFF_FILE_VALID((p)->two)) && \
 124           ((p)->broken_pair != 0) )
 125
 126 #define DIFF_PAIR_TYPE_CHANGED(p) \
 127         ((S_IFMT & (p)->one->mode) != (S_IFMT & (p)->two->mode))
 128
 129 #define DIFF_PAIR_MODE_CHANGED(p) ((p)->one->mode != (p)->two->mode)
 130
 131 void diff_free_filepair(struct diff_filepair *);
 132 void pool_diff_free_filepair(struct mem_pool *pool,
 133                              struct diff_filepair *p);
 134
 135 int diff_unmodified_pair(struct diff_filepair *);
 136
 137 /**
 138  * This is a collection of filepairs.  Notable members are:
 139  *
 140  * - `queue`:
 141  * An array of pointers to `struct diff_filepair`. This dynamically grows as
 142  * you add filepairs;
 143  *
 144  * - `alloc`:
 145  * The allocated size of the `queue` array;
 146  *
 147  * - `nr`:
 148  * The number of elements in the `queue` array.
 149  */
 150 struct diff_queue_struct {
 151         struct diff_filepair **queue;
 152         int alloc;
 153         int nr;
 154 };
 155
 156 #define DIFF_QUEUE_CLEAR(q) \
 157         do { \
 158                 (q)->queue = NULL; \
 159                 (q)->nr = (q)->alloc = 0; \
 160         } while (0)
 161
 162 extern struct diff_queue_struct diff_queued_diff;
 163 struct diff_filepair *diff_queue(struct diff_queue_struct *,
 164                                  struct diff_filespec *,
 165                                  struct diff_filespec *);
 166 void diff_q(struct diff_queue_struct *, struct diff_filepair *);
 167 void diff_free_queue(struct diff_queue_struct *q);
 168
 169 /* dir_rename_relevance: the reason we want rename information for a dir */
 170 enum dir_rename_relevance {
 171         NOT_RELEVANT = 0,
 172         RELEVANT_FOR_ANCESTOR = 1,
 173         RELEVANT_FOR_SELF = 2
 174 };
 175 /* file_rename_relevance: the reason(s) we want rename information for a file */
 176 enum file_rename_relevance {
 177         RELEVANT_NO_MORE = 0,  /* i.e. NOT relevant */
 178         RELEVANT_CONTENT = 1,
 179         RELEVANT_LOCATION = 2
 180 };
 181
 182 void partial_clear_dir_rename_count(struct strmap *dir_rename_count);
 183
 184 void diffcore_break(struct repository *, int);
 185 void diffcore_rename(struct diff_options *);
 186 void diffcore_rename_extended(struct diff_options *options,
 187                               struct mem_pool *pool,
 188                               struct strintmap *relevant_sources,
 189                               struct strintmap *dirs_removed,
 190                               struct strmap *dir_rename_count,
 191                               struct strmap *cached_pairs);
 192 void diffcore_merge_broken(void);
 193 void diffcore_pickaxe(struct diff_options *);
 194 void diffcore_order(const char *orderfile);
 195 void diffcore_rotate(struct diff_options *);
 196
 197 /* low-level interface to diffcore_order */
 198 struct obj_order {
 199         void *obj;      /* setup by caller */
 200
 201         /* setup/used by order_objects() */
 202         int orig_order;
 203         int order;
 204 };
 205
 206 typedef const char *(*obj_path_fn_t)(void *obj);
 207
 208 void order_objects(const char *orderfile, obj_path_fn_t obj_path,
 209                    struct obj_order *objs, int nr);
 210
 211 #define DIFF_DEBUG 0
 212 #if DIFF_DEBUG
 213 void diff_debug_filespec(struct diff_filespec *, int, const char *);
 214 void diff_debug_filepair(const struct diff_filepair *, int);
 215 void diff_debug_queue(const char *, struct diff_queue_struct *);
 216 #else
 217 #define diff_debug_filespec(a,b,c) do { /* nothing */ } while (0)
 218 #define diff_debug_filepair(a,b) do { /* nothing */ } while (0)
 219 #define diff_debug_queue(a,b) do { /* nothing */ } while (0)
 220 #endif
 221
 222 int diffcore_count_changes(struct repository *r,
 223                            struct diff_filespec *src,
 224                            struct diff_filespec *dst,
 225                            void **src_count_p,
 226                            void **dst_count_p,
 227                            unsigned long *src_copied,
 228                            unsigned long *literal_added);
 229
 230 /*
 231  * If filespec contains an OID and if that object is missing from the given
 232  * repository, add that OID to to_fetch.
 233  */
 234 void diff_add_if_missing(struct repository *r,
 235                          struct oid_array *to_fetch,
 236                          const struct diff_filespec *filespec);
 237
 238 #endif