#ifndef GRAPH_H
#define GRAPH_H
#include "diff.h"
/**
* The graph API is used to draw a text-based representation of the commit
* history. The API generates the graph in a line-by-line fashion.
*
* Calling sequence
* ----------------
*
* - Create a `struct git_graph` by calling `graph_init()`. When using the
* revision walking API, this is done automatically by `setup_revisions()` if
* the '--graph' option is supplied.
*
* - Use the revision walking API to walk through a group of contiguous commits.
* The `get_revision()` function automatically calls `graph_update()` each time
* it is invoked.
*
* - For each commit, call `graph_next_line()` repeatedly, until
* `graph_is_commit_finished()` returns non-zero. Each call to
* `graph_next_line()` will output a single line of the graph. The resulting
* lines will not contain any newlines. `graph_next_line()` returns 1 if the
* resulting line contains the current commit, or 0 if this is merely a line
* needed to adjust the graph before or after the current commit. This return
* value can be used to determine where to print the commit summary information
* alongside the graph output.
*
* Limitations
* -----------
* - Check the graph_update() function for its limitations.
*
* - The graph API does not currently support reverse commit ordering. In
* order to implement reverse ordering, the graphing API needs an
* (efficient) mechanism to find the children of a commit.
*
* Sample usage
* ------------
*
* ------------
* struct commit *commit;
* struct git_graph *graph = graph_init(opts);
*
* while ((commit = get_revision(opts)) != NULL) {
* while (!graph_is_commit_finished(graph))
* {
* struct strbuf sb;
* int is_commit_line;
*
* strbuf_init(&sb, 0);
* is_commit_line = graph_next_line(graph, &sb);
* fputs(sb.buf, stdout);
*
* if (is_commit_line)
* log_tree_commit(opts, commit);
* else
* putchar(opts->diffopt.line_termination);
* }
* }
* ------------
* Sample output
* -------------
*
* The following is an example of the output from the graph API. This output does
* not include any commit summary information--callers are responsible for
* outputting that information, if desired.
* ------------
* *
* *
* *
* |\
* * |
* | | *
* | \ \
* | \ \
* *-. \ \
* |\ \ \ \
* | | * | |
* | | | | | *
* | | | | | *
* | | | | | *
* | | | | | |\
* | | | | | | *
* | * | | | | |
* | | | | | * \
* | | | | | |\ |
* | | | | * | | |
* | | | | * | | |
* * | | | | | | |
* | |/ / / / / /
* |/| / / / / /
* * | | | | | |
* |/ / / / / /
* * | | | | |
* | | | | | *
* | | | | |/
* | | | | *
* ------------
*
*/
/* A graph is a pointer to this opaque structure */
struct git_graph;
/*
* Called to setup global display of line_prefix diff option.
*
* Passed a diff_options structure which indicates the line_prefix and the
* file to output the prefix to. This is sort of a hack used so that the
* line_prefix will be honored by all flows which also honor "--graph"
* regardless of whether a graph has actually been setup. The normal graph
* flow will honor the exact diff_options passed, but a NULL graph will cause
* display of a line_prefix to stdout.
*/
void graph_setup_line_prefix(struct diff_options *diffopt);
/*
* Set up a custom scheme for column colors.
*
* The default column color scheme inserts ANSI color escapes to colorize
* the graph. The various color escapes are stored in an array of strings
* where each entry corresponds to a color, except for the last entry,
* which denotes the escape for resetting the color back to the default.
* When generating the graph, strings from this array are inserted before
* and after the various column characters.
*
* This function allows you to enable a custom array of color escapes.
* The 'colors_max' argument is the index of the last "reset" entry.
*
* This functions must be called BEFORE graph_init() is called.
*
* NOTE: This function isn't used in Git outside graph.c but it is used
* by CGit (http://git.zx2c4.com/cgit/) to use HTML for colors.
*/
void graph_set_column_colors(const char **colors, unsigned short colors_max);
/*
* Create a new struct git_graph.
*/
struct git_graph *graph_init(struct rev_info *opt);
/*
* Update a git_graph with a new commit.
* This will cause the graph to begin outputting lines for the new commit
* the next time graph_next_line() is called.
*
* If graph_update() is called before graph_is_commit_finished() returns 1,
* the next call to graph_next_line() will output an ellipsis ("...")
* to indicate that a portion of the graph is missing.
*
* Limitations:
* -----------
*
* - `graph_update()` must be called with commits in topological order. It should
* not be called on a commit if it has already been invoked with an ancestor of
* that commit, or the graph output will be incorrect.
*
* - `graph_update()` must be called on a contiguous group of commits. If
* `graph_update()` is called on a particular commit, it should later be called
* on all parents of that commit. Parents must not be skipped, or the graph
* output will appear incorrect.
*
* - `graph_update()` may be used on a pruned set of commits only if the parent list
* has been rewritten so as to include only ancestors from the pruned set.
*/
void graph_update(struct git_graph *graph, struct commit *commit);
/*
* Determine if a graph has finished outputting lines for the current
* commit.
*
* Returns 1 if graph_next_line() needs to be called again before
* graph_update() should be called. Returns 0 if no more lines are needed
* for this commit. If 0 is returned, graph_next_line() may still be
* called without calling graph_update(), and it will merely output
* appropriate "vertical padding" in the graph.
*
* If `graph_update()` is called before all lines for the current commit have
* been printed, the next call to `graph_next_line()` will output an ellipsis,
* to indicate that a portion of the graph was omitted.
*/
int graph_is_commit_finished(struct git_graph const *graph);
/*
* Output the next line for a graph.
* This formats the next graph line into the specified strbuf. It is not
* terminated with a newline.
*
* Returns 1 if the line includes the current commit, and 0 otherwise.
* graph_next_line() will return 1 exactly once for each time
* graph_update() is called.
*
* NOTE: This function isn't used in Git outside graph.c but it is used
* by CGit (http://git.zx2c4.com/cgit/) to wrap HTML around graph lines.
*/
int graph_next_line(struct git_graph *graph, struct strbuf *sb);
/*
* Return current width of the graph in on-screen characters.
*/
int graph_width(struct git_graph *graph);
/*
* graph_show_*: helper functions for printing to stdout
*/
/*
* If the graph is non-NULL, print the history graph to stdout,
* up to and including the line containing this commit.
* Does not print a terminating newline on the last line.
*/
void graph_show_commit(struct git_graph *graph);
/*
* If the graph is non-NULL, print one line of the history graph to stdout.
* Does not print a terminating newline on the last line.
*/
void graph_show_oneline(struct git_graph *graph);
/*
* If the graph is non-NULL, print one line of vertical graph padding to
* stdout. Does not print a terminating newline on the last line.
*/
void graph_show_padding(struct git_graph *graph);
/*
* If the graph is non-NULL, print the rest of the history graph for this
* commit to stdout. Does not print a terminating newline on the last line.
* Returns 1 if output was printed, and 0 if no output was necessary.
*/
int graph_show_remainder(struct git_graph *graph);
/*
* Print a commit message strbuf and the remainder of the graph to stdout.
*
* This is similar to graph_show_strbuf(), but it always prints the
* remainder of the graph.
*
* It is better than directly calling `graph_show_strbuf()` followed by
* `graph_show_remainder()` since it properly handles buffers that do not end in
* a terminating newline.
*
* If the strbuf ends with a newline, the output printed by
* graph_show_commit_msg() will end with a newline. If the strbuf is
* missing a terminating newline (including if it is empty), the output
* printed by graph_show_commit_msg() will also be missing a terminating
* newline.
*
* Note that unlike some other graph display functions, you must pass the file
* handle directly. It is assumed that this is the same file handle as the
* file specified by the graph diff options. This is necessary so that
* graph_show_commit_msg can be called even with a NULL graph.
*/
void graph_show_commit_msg(struct git_graph *graph,
FILE *file,
struct strbuf const *sb);
#endif /* GRAPH_H */
