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 
166 /* dir_rename_relevance: the reason we want rename information for a dir */
167 enum dir_rename_relevance {
168 	NOT_RELEVANT = 0,
169 	RELEVANT_FOR_ANCESTOR = 1,
170 	RELEVANT_FOR_SELF = 2
171 };
172 /* file_rename_relevance: the reason(s) we want rename information for a file */
173 enum file_rename_relevance {
174 	RELEVANT_NO_MORE = 0,  /* i.e. NOT relevant */
175 	RELEVANT_CONTENT = 1,
176 	RELEVANT_LOCATION = 2
177 };
178 
179 void partial_clear_dir_rename_count(struct strmap *dir_rename_count);
180 
181 void diffcore_break(struct repository *, int);
182 void diffcore_rename(struct diff_options *);
183 void diffcore_rename_extended(struct diff_options *options,
184 			      struct mem_pool *pool,
185 			      struct strintmap *relevant_sources,
186 			      struct strintmap *dirs_removed,
187 			      struct strmap *dir_rename_count,
188 			      struct strmap *cached_pairs);
189 void diffcore_merge_broken(void);
190 void diffcore_pickaxe(struct diff_options *);
191 void diffcore_order(const char *orderfile);
192 void diffcore_rotate(struct diff_options *);
193 
194 /* low-level interface to diffcore_order */
195 struct obj_order {
196 	void *obj;	/* setup by caller */
197 
198 	/* setup/used by order_objects() */
199 	int orig_order;
200 	int order;
201 };
202 
203 typedef const char *(*obj_path_fn_t)(void *obj);
204 
205 void order_objects(const char *orderfile, obj_path_fn_t obj_path,
206 		   struct obj_order *objs, int nr);
207 
208 #define DIFF_DEBUG 0
209 #if DIFF_DEBUG
210 void diff_debug_filespec(struct diff_filespec *, int, const char *);
211 void diff_debug_filepair(const struct diff_filepair *, int);
212 void diff_debug_queue(const char *, struct diff_queue_struct *);
213 #else
214 #define diff_debug_filespec(a,b,c) do { /* nothing */ } while (0)
215 #define diff_debug_filepair(a,b) do { /* nothing */ } while (0)
216 #define diff_debug_queue(a,b) do { /* nothing */ } while (0)
217 #endif
218 
219 int diffcore_count_changes(struct repository *r,
220 			   struct diff_filespec *src,
221 			   struct diff_filespec *dst,
222 			   void **src_count_p,
223 			   void **dst_count_p,
224 			   unsigned long *src_copied,
225 			   unsigned long *literal_added);
226 
227 /*
228  * If filespec contains an OID and if that object is missing from the given
229  * repository, add that OID to to_fetch.
230  */
231 void diff_add_if_missing(struct repository *r,
232 			 struct oid_array *to_fetch,
233 			 const struct diff_filespec *filespec);
234 
235 #endif
236