1 /*
2  * Copyright (c) 2020 Neels Hofmeyr <neels@hofmeyr.de>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #pragma once
18 
19 #define DEBUG 0
20 
21 #if DEBUG
22 #include <stdio.h>
23 #define print(args...) fprintf(stderr, ##args)
24 #define debug print
25 #define debug_dump dump
26 #define debug_dump_atom dump_atom
27 #define debug_dump_atoms dump_atoms
28 
29 static inline void dump_atom(const struct diff_data *left, const struct diff_data *right, const struct diff_atom *atom)
30 {
31 	if (!atom) {
32 		print("NULL atom\n");
33 		return;
34 	}
35 	if (left)
36 		print(" %3ld", diff_atom_root_idx(left, atom));
37 	if (right && atom->patience.pos_in_other)
38 		print(" %3ld", diff_atom_root_idx(right, atom->patience.pos_in_other));
39 
40 	print(" %s%s '", atom->patience.unique_here ? "u" : " ", atom->patience.unique_in_both ? "c" : " ");
41 	const char *s;
42 	for (s = atom->at; s < (const char*)(atom->at + atom->len); s++) {
43 		if (*s == '\r')
44 			print("\\r");
45 		else if (*s == '\n')
46 			print("\\n");
47 		else if ((*s < 32 || *s >= 127) && (*s != '\t'))
48 			print("\\x%02x", *s);
49 		else
50 			print("%c", *s);
51 	}
52 	print("'\n");
53 }
54 
55 static inline void dump_atoms(const struct diff_data *d, struct diff_atom *atom, unsigned int count)
56 {
57 	if (count > 42) {
58 		dump_atoms(d, atom, 20);
59 		print("[%u lines skipped]\n", count - 20 - 20);
60 		dump_atoms(d, atom + count - 20, 20);
61 		return;
62 	} else {
63 		struct diff_atom *i;
64 		foreach_diff_atom(i, atom, count) {
65 			dump_atom(d, NULL, i);
66 		}
67 	}
68 }
69 
70 static inline void dump(struct diff_data *d)
71 {
72 	dump_atoms(d, d->atoms.head, d->atoms.len);
73 }
74 
75 /* kd is a quadratic space myers matrix from the original Myers algorithm.
76  * kd_forward and kd_backward are linear slices of a myers matrix from the Myers Divide algorithm.
77  */
78 static inline void dump_myers_graph(const struct diff_data *l, const struct diff_data *r,
79 				    int *kd, int *kd_forward, int kd_forward_d, int *kd_backward, int kd_backward_d)
80 {
81 	#define COLOR_YELLOW "\033[1;33m"
82 	#define COLOR_GREEN "\033[1;32m"
83 	#define COLOR_BLUE "\033[1;34m"
84 	#define COLOR_RED "\033[1;31m"
85 	#define COLOR_END "\033[0;m"
86 	int x;
87 	int y;
88 	print("   ");
89 	for (x = 0; x <= l->atoms.len; x++)
90 		print("%2d", x % 100);
91 	print("\n");
92 
93 	for (y = 0; y <= r->atoms.len; y++) {
94 		print("%3d ", y);
95 		for (x = 0; x <= l->atoms.len; x++) {
96 
97 			/* print d advancements from kd, if any. */
98 			char label = 'o';
99 			char *color = NULL;
100 			if (kd) {
101 				int max = l->atoms.len + r->atoms.len;
102 				size_t kd_len = max + 1 + max;
103 				int *kd_pos = kd;
104 				int di;
105 #define xk_to_y(X, K) ((X) - (K))
106 				for (di = 0; di < max; di++) {
107 					int ki;
108 					for (ki = di; ki >= -di; ki -= 2) {
109 						if (x != kd_pos[ki]
110 						    || y != xk_to_y(x, ki))
111 							continue;
112 						label = '0' + (di % 10);
113 						color = COLOR_YELLOW;
114 						break;
115 					}
116 					if (label != 'o')
117 						break;
118 					kd_pos += kd_len;
119 				}
120 			}
121 			if (kd_forward && kd_forward_d >= 0) {
122 				int max = l->atoms.len + r->atoms.len;
123 				size_t kd_len = max + 1 + max;
124 				int di;
125 #define xc_to_y(X, C, DELTA) ((X) - (C) + (DELTA))
126 				int delta = (int)r->atoms.len - (int)l->atoms.len;
127 				int ki;
128 				for (ki = kd_forward_d; ki >= -kd_forward_d; ki -= 2) {
129 					if (x != kd_forward[ki])
130 						continue;
131 					if (y != xk_to_y(x, ki))
132 						continue;
133 					label = 'F';
134 					color = COLOR_GREEN;
135 					break;
136 				}
137 			}
138 			if (kd_backward && kd_backward_d >= 0) {
139 				int max = l->atoms.len + r->atoms.len;
140 				size_t kd_len = max + 1 + max;
141 				int di;
142 				int delta = (int)r->atoms.len - (int)l->atoms.len;
143 				int ki;
144 				for (ki = kd_backward_d; ki >= -kd_backward_d; ki -= 2) {
145 					if (x != kd_backward[ki])
146 						continue;
147 					if (y != xc_to_y(x, ki, delta))
148 						continue;
149 					if (label == 'o') {
150 						label = 'B';
151 						color = COLOR_BLUE;
152 					} else {
153 						label = 'X';
154 						color = COLOR_RED;
155 					}
156 					break;
157 				}
158 			}
159 			if (color)
160 				print("%s", color);
161 			print("%c", label);
162 			if (color)
163 				print("%s", COLOR_END);
164 			if (x < l->atoms.len)
165 				print("-");
166 		}
167 		print("\n");
168 		if (y == r->atoms.len)
169 			break;
170 
171 		print("    ");
172 		for (x = 0; x < l->atoms.len; x++) {
173 			if (diff_atom_same(&l->atoms.head[x], &r->atoms.head[y]))
174 				print("|\\");
175 			else
176 				print("| ");
177 		}
178 		print("|\n");
179 	}
180 }
181 
182 static inline void debug_dump_myers_graph(const struct diff_data *l, const struct diff_data *r,
183 				    int *kd, int *kd_forward, int kd_forward_d, int *kd_backward, int kd_backward_d)
184 {
185 	if (l->atoms.len > 99 || r->atoms.len > 99)
186 		return;
187 	dump_myers_graph(l, r, kd, kd_forward, kd_forward_d, kd_backward, kd_backward_d);
188 }
189 
190 #else
191 #define debug(args...)
192 #define debug_dump(args...)
193 #define debug_dump_atom(args...)
194 #define debug_dump_atoms(args...)
195 #define debug_dump_myers_graph(args...)
196 #endif