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