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 /* A range [start, end).  Lines are numbered starting at 0. */
  23 struct range {
  24         long start, end;
  25 };
  26
  27 /* A set of ranges.  The ranges must always be disjoint and sorted. */
  28 struct range_set {
  29         unsigned int alloc, nr;
  30         struct range *ranges;
  31 };
  32
  33 /* We internally use unsigned short as the score value,
  34  * and rely on an int capable to hold 32-bits.  -B can take
  35  * -Bmerge_score/break_score format and the two scores are
  36  * passed around in one int (high 16-bit for merge and low 16-bit
  37  * for break).
  38  */
  39 #define MAX_SCORE 60000.0
  40 #define DEFAULT_RENAME_SCORE 30000 /* rename/copy similarity minimum (50%) */
  41 #define DEFAULT_BREAK_SCORE  30000 /* minimum for break to happen (50%) */
  42 #define DEFAULT_MERGE_SCORE  36000 /* maximum for break-merge to happen (60%) */
  43
  44 #define MINIMUM_BREAK_SIZE     400 /* do not break a file smaller than this */
  45
  46 /**
  47  * the internal representation for a single file (blob).  It records the blob
  48  * object name (if known -- for a work tree file it typically is a NUL SHA-1),
  49  * filemode and pathname.  This is what the `diff_addremove()`, `diff_change()`
  50  * and `diff_unmerge()` synthesize and feed `diff_queue()` function with.
  51  */
  52 struct diff_filespec {
  53         struct object_id oid;
  54         char *path;
  55         void *data;
  56         void *cnt_data;
  57         unsigned long size;
  58         int count;               /* Reference count */
  59         int rename_used;         /* Count of rename users */
  60         unsigned short mode;     /* file mode */
  61         unsigned oid_valid : 1;  /* if true, use oid and trust mode;
  62                                   * if false, use the name and read from
  63                                   * the filesystem.
  64                                   */
  65 #define DIFF_FILE_VALID(spec) (((spec)->mode) != 0)
  66         unsigned should_free : 1; /* data should be free()'ed */
  67         unsigned should_munmap : 1; /* data should be munmap()'ed */
  68         unsigned dirty_submodule : 2;  /* For submodules: its work tree is dirty */
  69 #define DIRTY_SUBMODULE_UNTRACKED 1
  70 #define DIRTY_SUBMODULE_MODIFIED  2
  71         unsigned is_stdin : 1;
  72         unsigned has_more_entries : 1; /* only appear in combined diff */
  73         /* data should be considered "binary"; -1 means "don't know yet" */
  74         signed int is_binary : 2;
  75         struct userdiff_driver *driver;
  76 };
  77
  78 struct diff_filespec *alloc_filespec(const char *);
  79 void free_filespec(struct diff_filespec *);
  80 void fill_filespec(struct diff_filespec *, const struct object_id *,
  81                    int, unsigned short);
  82
  83 /*
  84  * Prefetch the entries in diff_queued_diff. The parameter is a pointer to a
  85  * struct repository.
  86  */
  87 void diff_queued_diff_prefetch(void *repository);
  88
  89 struct diff_populate_filespec_options {
  90         unsigned check_size_only : 1;
  91         unsigned check_binary : 1;
  92
  93         /*
  94          * If an object is missing, diff_populate_filespec() will invoke this
  95          * callback before attempting to read that object again.
  96          */
  97         void (*missing_object_cb)(void *);
  98         void *missing_object_data;
  99 };
 100 int diff_populate_filespec(struct repository *, struct diff_filespec *,
 101                            const struct diff_populate_filespec_options *);
 102 void diff_free_filespec_data(struct diff_filespec *);
 103 void diff_free_filespec_blob(struct diff_filespec *);
 104 int diff_filespec_is_binary(struct repository *, struct diff_filespec *);
 105
 106 /**
 107  * This records a pair of `struct diff_filespec`; the filespec for a file in
 108  * the "old" set (i.e. preimage) is called `one`, and the filespec for a file
 109  * in the "new" set (i.e. postimage) is called `two`.  A change that represents
 110  * file creation has NULL in `one`, and file deletion has NULL in `two`.
 111  *
 112  * A `filepair` starts pointing at `one` and `two` that are from the same
 113  * filename, but `diffcore_std()` can break pairs and match component filespecs
 114  * with other filespecs from a different filepair to form new filepair. This is
 115  * called 'rename detection'.
 116  */
 117 struct diff_filepair {
 118         struct diff_filespec *one;
 119         struct diff_filespec *two;
 120         /*
 121          * Tracked line ranges for -L filtering; borrowed from
 122          * line_log_data and must not be freed.
 123          */
 124         const struct range_set *line_ranges;
 125         unsigned short int score;
 126         char status; /* M C R A D U etc. (see Documentation/diff-format.adoc or DIFF_STATUS_* in diff.h) */
 127         unsigned broken_pair : 1;
 128         unsigned renamed_pair : 1;
 129         unsigned is_unmerged : 1;
 130         unsigned done_skip_stat_unmatch : 1;
 131         unsigned skip_stat_unmatch_result : 1;
 132 };
 133
 134 #define DIFF_PAIR_UNMERGED(p) ((p)->is_unmerged)
 135
 136 #define DIFF_PAIR_RENAME(p) ((p)->renamed_pair)
 137
 138 #define DIFF_PAIR_BROKEN(p) \
 139         ( (!DIFF_FILE_VALID((p)->one) != !DIFF_FILE_VALID((p)->two)) && \
 140           ((p)->broken_pair != 0) )
 141
 142 #define DIFF_PAIR_TYPE_CHANGED(p) \
 143         ((S_IFMT & (p)->one->mode) != (S_IFMT & (p)->two->mode))
 144
 145 #define DIFF_PAIR_MODE_CHANGED(p) ((p)->one->mode != (p)->two->mode)
 146
 147 void diff_free_filepair(struct diff_filepair *);
 148 void pool_diff_free_filepair(struct mem_pool *pool,
 149                              struct diff_filepair *p);
 150
 151 int diff_unmodified_pair(struct diff_filepair *);
 152
 153 /**
 154  * This is a collection of filepairs.  Notable members are:
 155  *
 156  * - `queue`:
 157  * An array of pointers to `struct diff_filepair`. This dynamically grows as
 158  * you add filepairs;
 159  *
 160  * - `alloc`:
 161  * The allocated size of the `queue` array;
 162  *
 163  * - `nr`:
 164  * The number of elements in the `queue` array.
 165  */
 166 struct diff_queue_struct {
 167         struct diff_filepair **queue;
 168         int alloc;
 169         int nr;
 170 };
 171
 172 #define DIFF_QUEUE_INIT { 0 }
 173
 174 void diff_queue_init(struct diff_queue_struct *q);
 175 void diff_queue_clear(struct diff_queue_struct *q);
 176
 177 extern struct diff_queue_struct diff_queued_diff;
 178 struct diff_filepair *diff_queue(struct diff_queue_struct *,
 179                                  struct diff_filespec *,
 180                                  struct diff_filespec *);
 181 void diff_q(struct diff_queue_struct *, struct diff_filepair *);
 182
 183 /* dir_rename_relevance: the reason we want rename information for a dir */
 184 enum dir_rename_relevance {
 185         NOT_RELEVANT = 0,
 186         RELEVANT_FOR_ANCESTOR = 1,
 187         RELEVANT_FOR_SELF = 2
 188 };
 189 /* file_rename_relevance: the reason(s) we want rename information for a file */
 190 enum file_rename_relevance {
 191         RELEVANT_NO_MORE = 0,  /* i.e. NOT relevant */
 192         RELEVANT_CONTENT = 1,
 193         RELEVANT_LOCATION = 2
 194 };
 195
 196 void partial_clear_dir_rename_count(struct strmap *dir_rename_count);
 197
 198 void diffcore_break(struct repository *, int);
 199 void diffcore_rename(struct diff_options *);
 200 void diffcore_rename_extended(struct diff_options *options,
 201                               struct mem_pool *pool,
 202                               struct strintmap *relevant_sources,
 203                               struct strintmap *dirs_removed,
 204                               struct strmap *dir_rename_count,
 205                               struct strmap *cached_pairs);
 206 void diffcore_merge_broken(void);
 207 void diffcore_pickaxe(struct diff_options *);
 208 void diffcore_order(const char *orderfile);
 209 void diffcore_rotate(struct diff_options *);
 210
 211 /* low-level interface to diffcore_order */
 212 struct obj_order {
 213         void *obj;      /* setup by caller */
 214
 215         /* setup/used by order_objects() */
 216         int orig_order;
 217         int order;
 218 };
 219
 220 typedef const char *(*obj_path_fn_t)(void *obj);
 221
 222 void order_objects(const char *orderfile, obj_path_fn_t obj_path,
 223                    struct obj_order *objs, int nr);
 224
 225 #define DIFF_DEBUG 0
 226 #if DIFF_DEBUG
 227 void diff_debug_filespec(struct diff_filespec *, int, const char *);
 228 void diff_debug_filepair(const struct diff_filepair *, int);
 229 void diff_debug_queue(const char *, struct diff_queue_struct *);
 230 #else
 231 #define diff_debug_filespec(a,b,c) do { /* nothing */ } while (0)
 232 #define diff_debug_filepair(a,b) do { /* nothing */ } while (0)
 233 #define diff_debug_queue(a,b) do { /* nothing */ } while (0)
 234 #endif
 235
 236 int diffcore_count_changes(struct repository *r,
 237                            struct diff_filespec *src,
 238                            struct diff_filespec *dst,
 239                            void **src_count_p,
 240                            void **dst_count_p,
 241                            unsigned long *src_copied,
 242                            unsigned long *literal_added);
 243
 244 /*
 245  * If filespec contains an OID and if that object is missing from the given
 246  * repository, add that OID to to_fetch.
 247  */
 248 void diff_add_if_missing(struct repository *r,
 249                          struct oid_array *to_fetch,
 250                          const struct diff_filespec *filespec);
 251
 252 #endif