1 #ifndef GRAPH_H 2 #define GRAPH_H 3 #include "diff.h" 4 5 /** 6 * The graph API is used to draw a text-based representation of the commit 7 * history. The API generates the graph in a line-by-line fashion. 8 * 9 * Calling sequence 10 * ---------------- 11 * 12 * - Create a `struct git_graph` by calling `graph_init()`. When using the 13 * revision walking API, this is done automatically by `setup_revisions()` if 14 * the '--graph' option is supplied. 15 * 16 * - Use the revision walking API to walk through a group of contiguous commits. 17 * The `get_revision()` function automatically calls `graph_update()` each time 18 * it is invoked. 19 * 20 * - For each commit, call `graph_next_line()` repeatedly, until 21 * `graph_is_commit_finished()` returns non-zero. Each call to 22 * `graph_next_line()` will output a single line of the graph. The resulting 23 * lines will not contain any newlines. `graph_next_line()` returns 1 if the 24 * resulting line contains the current commit, or 0 if this is merely a line 25 * needed to adjust the graph before or after the current commit. This return 26 * value can be used to determine where to print the commit summary information 27 * alongside the graph output. 28 * 29 * Limitations 30 * ----------- 31 * - Check the graph_update() function for its limitations. 32 * 33 * - The graph API does not currently support reverse commit ordering. In 34 * order to implement reverse ordering, the graphing API needs an 35 * (efficient) mechanism to find the children of a commit. 36 * 37 * Sample usage 38 * ------------ 39 * 40 * ------------ 41 * struct commit *commit; 42 * struct git_graph *graph = graph_init(opts); 43 * 44 * while ((commit = get_revision(opts)) != NULL) { 45 * while (!graph_is_commit_finished(graph)) 46 * { 47 * struct strbuf sb; 48 * int is_commit_line; 49 * 50 * strbuf_init(&sb, 0); 51 * is_commit_line = graph_next_line(graph, &sb); 52 * fputs(sb.buf, stdout); 53 * 54 * if (is_commit_line) 55 * log_tree_commit(opts, commit); 56 * else 57 * putchar(opts->diffopt.line_termination); 58 * } 59 * } 60 * ------------ 61 * Sample output 62 * ------------- 63 * 64 * The following is an example of the output from the graph API. This output does 65 * not include any commit summary information--callers are responsible for 66 * outputting that information, if desired. 67 * ------------ 68 * * 69 * * 70 * * 71 * |\ 72 * * | 73 * | | * 74 * | \ \ 75 * | \ \ 76 * *-. \ \ 77 * |\ \ \ \ 78 * | | * | | 79 * | | | | | * 80 * | | | | | * 81 * | | | | | * 82 * | | | | | |\ 83 * | | | | | | * 84 * | * | | | | | 85 * | | | | | * \ 86 * | | | | | |\ | 87 * | | | | * | | | 88 * | | | | * | | | 89 * * | | | | | | | 90 * | |/ / / / / / 91 * |/| / / / / / 92 * * | | | | | | 93 * |/ / / / / / 94 * * | | | | | 95 * | | | | | * 96 * | | | | |/ 97 * | | | | * 98 * ------------ 99 * 100 */ 101 102 /* A graph is a pointer to this opaque structure */ 103 struct git_graph; 104 105 /* 106 * Called to setup global display of line_prefix diff option. 107 * 108 * Passed a diff_options structure which indicates the line_prefix and the 109 * file to output the prefix to. This is sort of a hack used so that the 110 * line_prefix will be honored by all flows which also honor "--graph" 111 * regardless of whether a graph has actually been setup. The normal graph 112 * flow will honor the exact diff_options passed, but a NULL graph will cause 113 * display of a line_prefix to stdout. 114 */ 115 void graph_setup_line_prefix(struct diff_options *diffopt); 116 117 /* 118 * Set up a custom scheme for column colors. 119 * 120 * The default column color scheme inserts ANSI color escapes to colorize 121 * the graph. The various color escapes are stored in an array of strings 122 * where each entry corresponds to a color, except for the last entry, 123 * which denotes the escape for resetting the color back to the default. 124 * When generating the graph, strings from this array are inserted before 125 * and after the various column characters. 126 * 127 * This function allows you to enable a custom array of color escapes. 128 * The 'colors_max' argument is the index of the last "reset" entry. 129 * 130 * This functions must be called BEFORE graph_init() is called. 131 * 132 * NOTE: This function isn't used in Git outside graph.c but it is used 133 * by CGit (http://git.zx2c4.com/cgit/) to use HTML for colors. 134 */ 135 void graph_set_column_colors(const char **colors, unsigned short colors_max); 136 137 /* 138 * Create a new struct git_graph. 139 */ 140 struct git_graph *graph_init(struct rev_info *opt); 141 142 /* 143 * Update a git_graph with a new commit. 144 * This will cause the graph to begin outputting lines for the new commit 145 * the next time graph_next_line() is called. 146 * 147 * If graph_update() is called before graph_is_commit_finished() returns 1, 148 * the next call to graph_next_line() will output an ellipsis ("...") 149 * to indicate that a portion of the graph is missing. 150 * 151 * Limitations: 152 * ----------- 153 * 154 * - `graph_update()` must be called with commits in topological order. It should 155 * not be called on a commit if it has already been invoked with an ancestor of 156 * that commit, or the graph output will be incorrect. 157 * 158 * - `graph_update()` must be called on a contiguous group of commits. If 159 * `graph_update()` is called on a particular commit, it should later be called 160 * on all parents of that commit. Parents must not be skipped, or the graph 161 * output will appear incorrect. 162 * 163 * - `graph_update()` may be used on a pruned set of commits only if the parent list 164 * has been rewritten so as to include only ancestors from the pruned set. 165 */ 166 void graph_update(struct git_graph *graph, struct commit *commit); 167 168 /* 169 * Determine if a graph has finished outputting lines for the current 170 * commit. 171 * 172 * Returns 1 if graph_next_line() needs to be called again before 173 * graph_update() should be called. Returns 0 if no more lines are needed 174 * for this commit. If 0 is returned, graph_next_line() may still be 175 * called without calling graph_update(), and it will merely output 176 * appropriate "vertical padding" in the graph. 177 * 178 * If `graph_update()` is called before all lines for the current commit have 179 * been printed, the next call to `graph_next_line()` will output an ellipsis, 180 * to indicate that a portion of the graph was omitted. 181 */ 182 int graph_is_commit_finished(struct git_graph const *graph); 183 184 /* 185 * Output the next line for a graph. 186 * This formats the next graph line into the specified strbuf. It is not 187 * terminated with a newline. 188 * 189 * Returns 1 if the line includes the current commit, and 0 otherwise. 190 * graph_next_line() will return 1 exactly once for each time 191 * graph_update() is called. 192 * 193 * NOTE: This function isn't used in Git outside graph.c but it is used 194 * by CGit (http://git.zx2c4.com/cgit/) to wrap HTML around graph lines. 195 */ 196 int graph_next_line(struct git_graph *graph, struct strbuf *sb); 197 198 199 /* 200 * Return current width of the graph in on-screen characters. 201 */ 202 int graph_width(struct git_graph *graph); 203 204 /* 205 * graph_show_*: helper functions for printing to stdout 206 */ 207 208 209 /* 210 * If the graph is non-NULL, print the history graph to stdout, 211 * up to and including the line containing this commit. 212 * Does not print a terminating newline on the last line. 213 */ 214 void graph_show_commit(struct git_graph *graph); 215 216 /* 217 * If the graph is non-NULL, print one line of the history graph to stdout. 218 * Does not print a terminating newline on the last line. 219 */ 220 void graph_show_oneline(struct git_graph *graph); 221 222 /* 223 * If the graph is non-NULL, print one line of vertical graph padding to 224 * stdout. Does not print a terminating newline on the last line. 225 */ 226 void graph_show_padding(struct git_graph *graph); 227 228 /* 229 * If the graph is non-NULL, print the rest of the history graph for this 230 * commit to stdout. Does not print a terminating newline on the last line. 231 * Returns 1 if output was printed, and 0 if no output was necessary. 232 */ 233 int graph_show_remainder(struct git_graph *graph); 234 235 /* 236 * Print a commit message strbuf and the remainder of the graph to stdout. 237 * 238 * This is similar to graph_show_strbuf(), but it always prints the 239 * remainder of the graph. 240 * 241 * It is better than directly calling `graph_show_strbuf()` followed by 242 * `graph_show_remainder()` since it properly handles buffers that do not end in 243 * a terminating newline. 244 * 245 * If the strbuf ends with a newline, the output printed by 246 * graph_show_commit_msg() will end with a newline. If the strbuf is 247 * missing a terminating newline (including if it is empty), the output 248 * printed by graph_show_commit_msg() will also be missing a terminating 249 * newline. 250 * 251 * Note that unlike some other graph display functions, you must pass the file 252 * handle directly. It is assumed that this is the same file handle as the 253 * file specified by the graph diff options. This is necessary so that 254 * graph_show_commit_msg can be called even with a NULL graph. 255 */ 256 void graph_show_commit_msg(struct git_graph *graph, 257 FILE *file, 258 struct strbuf const *sb); 259 260 #endif /* GRAPH_H */ 261