1 /* Diff output generators and invocation shims. */
2 /*
3  * Copyright (c) 2020 Neels Hofmeyr <neels@hofmeyr.de>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 struct diff_input_info {
19 	const char *left_path;
20 	const char *right_path;
21 
22 	/* Set by caller of diff_output_* functions. */
23 	int flags;
24 #define DIFF_INPUT_LEFT_NONEXISTENT	0x00000001
25 #define DIFF_INPUT_RIGHT_NONEXISTENT	0x00000002
26 };
27 
28 struct diff_output_info {
29 	/*
30 	 * Byte offset to each line in the generated output file.
31 	 * The total number of lines in the file is line_offsets.len - 1.
32 	 * The last offset in this array corresponds to end-of-file.
33 	 */
34 	ARRAYLIST(off_t) line_offsets;
35 };
36 
37 void diff_output_info_free(struct diff_output_info *output_info);
38 
39 struct diff_chunk_context {
40 	struct diff_range chunk;
41 	struct diff_range left, right;
42 };
43 
44 int diff_output_plain(struct diff_output_info **output_info, FILE *dest,
45 			const struct diff_input_info *info,
46 			const struct diff_result *result);
47 int diff_output_unidiff(struct diff_output_info **output_info,
48 			FILE *dest, const struct diff_input_info *info,
49 			const struct diff_result *result,
50 			unsigned int context_lines);
51 int diff_output_edscript(struct diff_output_info **output_info,
52 			 FILE *dest, const struct diff_input_info *info,
53 			 const struct diff_result *result);
54 int diff_chunk_get_left_start(const struct diff_chunk *c,
55 			      const struct diff_result *r,
56 			      int context_lines);
57 int diff_chunk_get_left_end(const struct diff_chunk *c,
58 			    const struct diff_result *r,
59 			    int context_lines);
60 int diff_chunk_get_right_start(const struct diff_chunk *c,
61 			       const struct diff_result *r,
62 			       int context_lines);
63 int diff_chunk_get_right_end(const struct diff_chunk *c,
64 			     const struct diff_result *r,
65 			     int context_lines);
66 struct diff_chunk *diff_chunk_get(const struct diff_result *r, int chunk_idx);
67 int diff_chunk_get_left_count(struct diff_chunk *c);
68 int diff_chunk_get_right_count(struct diff_chunk *c);
69 void diff_chunk_context_get(struct diff_chunk_context *cc,
70 				 const struct diff_result *r,
71 				 int chunk_idx, int context_lines);
72 void diff_chunk_context_load_change(struct diff_chunk_context *cc,
73 				    int *nchunks_used,
74 				    struct diff_result *result,
75 				    int start_chunk_idx,
76 				    int context_lines);
77 
78 struct diff_output_unidiff_state;
79 struct diff_output_unidiff_state *diff_output_unidiff_state_alloc(void);
80 void diff_output_unidiff_state_reset(struct diff_output_unidiff_state *state);
81 void diff_output_unidiff_state_free(struct diff_output_unidiff_state *state);
82 int diff_output_unidiff_chunk(struct diff_output_info **output_info, FILE *dest,
83 			  struct diff_output_unidiff_state *state,
84 			  const struct diff_input_info *info,
85 			  const struct diff_result *result,
86 			  const struct diff_chunk_context *cc);
87 int diff_output_chunk_left_version(struct diff_output_info **output_info,
88 			       FILE *dest,
89 			       const struct diff_input_info *info,
90 			       const struct diff_result *result,
91 			       const struct diff_chunk_context *cc);
92 int diff_output_chunk_right_version(struct diff_output_info **output_info,
93 				FILE *dest,
94 				const struct diff_input_info *info,
95 				const struct diff_result *result,
96 				const struct diff_chunk_context *cc);
97 
98 const char *diff_output_get_label_left(const struct diff_input_info *info);
99 const char *diff_output_get_label_right(const struct diff_input_info *info);