tvl-depot/third_party/git/graph.c
Vincent Ambo f4609b896f merge(3p/git): Merge git subtree at v2.29.2
This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb
2020-11-21 19:45:56 +01:00

1536 lines
40 KiB
C

#include "cache.h"
#include "config.h"
#include "commit.h"
#include "color.h"
#include "graph.h"
#include "revision.h"
#include "strvec.h"
/* Internal API */
/*
* Output a padding line in the graph.
* This is similar to graph_next_line(). However, it is guaranteed to
* never print the current commit line. Instead, if the commit line is
* next, it will simply output a line of vertical padding, extending the
* branch lines downwards, but leaving them otherwise unchanged.
*/
static void graph_padding_line(struct git_graph *graph, struct strbuf *sb);
/*
* Print a strbuf. If the graph is non-NULL, all lines but the first will be
* prefixed with the graph output.
*
* If the strbuf ends with a newline, the output will end after this
* newline. A new graph line will not be printed after the final newline.
* If the strbuf is empty, no output will be printed.
*
* Since the first line will not include the graph output, the caller is
* responsible for printing this line's graph (perhaps via
* graph_show_commit() or graph_show_oneline()) before calling
* graph_show_strbuf().
*
* 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_strbuf can be called even with a NULL graph.
* If a NULL graph is supplied, the strbuf is printed as-is.
*/
static void graph_show_strbuf(struct git_graph *graph,
FILE *file,
struct strbuf const *sb);
/*
* TODO:
* - Limit the number of columns, similar to the way gitk does.
* If we reach more than a specified number of columns, omit
* sections of some columns.
*/
struct column {
/*
* The parent commit of this column.
*/
struct commit *commit;
/*
* The color to (optionally) print this column in. This is an
* index into column_colors.
*/
unsigned short color;
};
enum graph_state {
GRAPH_PADDING,
GRAPH_SKIP,
GRAPH_PRE_COMMIT,
GRAPH_COMMIT,
GRAPH_POST_MERGE,
GRAPH_COLLAPSING
};
static void graph_show_line_prefix(const struct diff_options *diffopt)
{
if (!diffopt || !diffopt->line_prefix)
return;
fwrite(diffopt->line_prefix,
sizeof(char),
diffopt->line_prefix_length,
diffopt->file);
}
static const char **column_colors;
static unsigned short column_colors_max;
static void parse_graph_colors_config(struct strvec *colors, const char *string)
{
const char *end, *start;
start = string;
end = string + strlen(string);
while (start < end) {
const char *comma = strchrnul(start, ',');
char color[COLOR_MAXLEN];
if (!color_parse_mem(start, comma - start, color))
strvec_push(colors, color);
else
warning(_("ignore invalid color '%.*s' in log.graphColors"),
(int)(comma - start), start);
start = comma + 1;
}
strvec_push(colors, GIT_COLOR_RESET);
}
void graph_set_column_colors(const char **colors, unsigned short colors_max)
{
column_colors = colors;
column_colors_max = colors_max;
}
static const char *column_get_color_code(unsigned short color)
{
return column_colors[color];
}
struct graph_line {
struct strbuf *buf;
size_t width;
};
static inline void graph_line_addch(struct graph_line *line, int c)
{
strbuf_addch(line->buf, c);
line->width++;
}
static inline void graph_line_addchars(struct graph_line *line, int c, size_t n)
{
strbuf_addchars(line->buf, c, n);
line->width += n;
}
static inline void graph_line_addstr(struct graph_line *line, const char *s)
{
strbuf_addstr(line->buf, s);
line->width += strlen(s);
}
static inline void graph_line_addcolor(struct graph_line *line, unsigned short color)
{
strbuf_addstr(line->buf, column_get_color_code(color));
}
static void graph_line_write_column(struct graph_line *line, const struct column *c,
char col_char)
{
if (c->color < column_colors_max)
graph_line_addcolor(line, c->color);
graph_line_addch(line, col_char);
if (c->color < column_colors_max)
graph_line_addcolor(line, column_colors_max);
}
struct git_graph {
/*
* The commit currently being processed
*/
struct commit *commit;
/* The rev-info used for the current traversal */
struct rev_info *revs;
/*
* The number of interesting parents that this commit has.
*
* Note that this is not the same as the actual number of parents.
* This count excludes parents that won't be printed in the graph
* output, as determined by graph_is_interesting().
*/
int num_parents;
/*
* The width of the graph output for this commit.
* All rows for this commit are padded to this width, so that
* messages printed after the graph output are aligned.
*/
int width;
/*
* The next expansion row to print
* when state is GRAPH_PRE_COMMIT
*/
int expansion_row;
/*
* The current output state.
* This tells us what kind of line graph_next_line() should output.
*/
enum graph_state state;
/*
* The output state for the previous line of output.
* This is primarily used to determine how the first merge line
* should appear, based on the last line of the previous commit.
*/
enum graph_state prev_state;
/*
* The index of the column that refers to this commit.
*
* If none of the incoming columns refer to this commit,
* this will be equal to num_columns.
*/
int commit_index;
/*
* The commit_index for the previously displayed commit.
*
* This is used to determine how the first line of a merge
* graph output should appear, based on the last line of the
* previous commit.
*/
int prev_commit_index;
/*
* Which layout variant to use to display merge commits. If the
* commit's first parent is known to be in a column to the left of the
* merge, then this value is 0 and we use the layout on the left.
* Otherwise, the value is 1 and the layout on the right is used. This
* field tells us how many columns the first parent occupies.
*
* 0) 1)
*
* | | | *-. | | *---.
* | |_|/|\ \ | | |\ \ \
* |/| | | | | | | | | | *
*/
int merge_layout;
/*
* The number of columns added to the graph by the current commit. For
* 2-way and octopus merges, this is usually one less than the
* number of parents:
*
* | | | | | \
* | * | | *---. \
* | |\ \ | |\ \ \ \
* | | | | | | | | | |
*
* num_parents: 2 num_parents: 4
* edges_added: 1 edges_added: 3
*
* For left-skewed merges, the first parent fuses with its neighbor and
* so one less column is added:
*
* | | | | | \
* | * | | *-. \
* |/| | |/|\ \ \
* | | | | | | | |
*
* num_parents: 2 num_parents: 4
* edges_added: 0 edges_added: 2
*
* This number determines how edges to the right of the merge are
* displayed in commit and post-merge lines; if no columns have been
* added then a vertical line should be used where a right-tracking
* line would otherwise be used.
*
* | * \ | * |
* | |\ \ |/| |
* | | * \ | * |
*/
int edges_added;
/*
* The number of columns added by the previous commit, which is used to
* smooth edges appearing to the right of a commit in a commit line
* following a post-merge line.
*/
int prev_edges_added;
/*
* The maximum number of columns that can be stored in the columns
* and new_columns arrays. This is also half the number of entries
* that can be stored in the mapping and old_mapping arrays.
*/
int column_capacity;
/*
* The number of columns (also called "branch lines" in some places)
*/
int num_columns;
/*
* The number of columns in the new_columns array
*/
int num_new_columns;
/*
* The number of entries in the mapping array
*/
int mapping_size;
/*
* The column state before we output the current commit.
*/
struct column *columns;
/*
* The new column state after we output the current commit.
* Only valid when state is GRAPH_COLLAPSING.
*/
struct column *new_columns;
/*
* An array that tracks the current state of each
* character in the output line during state GRAPH_COLLAPSING.
* Each entry is -1 if this character is empty, or a non-negative
* integer if the character contains a branch line. The value of
* the integer indicates the target position for this branch line.
* (I.e., this array maps the current column positions to their
* desired positions.)
*
* The maximum capacity of this array is always
* sizeof(int) * 2 * column_capacity.
*/
int *mapping;
/*
* A copy of the contents of the mapping array from the last commit,
* which we use to improve the display of columns that are tracking
* from right to left through a commit line. We also use this to
* avoid allocating a fresh array when we compute the next mapping.
*/
int *old_mapping;
/*
* The current default column color being used. This is
* stored as an index into the array column_colors.
*/
unsigned short default_column_color;
};
static struct strbuf *diff_output_prefix_callback(struct diff_options *opt, void *data)
{
struct git_graph *graph = data;
static struct strbuf msgbuf = STRBUF_INIT;
assert(opt);
strbuf_reset(&msgbuf);
if (opt->line_prefix)
strbuf_add(&msgbuf, opt->line_prefix,
opt->line_prefix_length);
if (graph)
graph_padding_line(graph, &msgbuf);
return &msgbuf;
}
static const struct diff_options *default_diffopt;
void graph_setup_line_prefix(struct diff_options *diffopt)
{
default_diffopt = diffopt;
/* setup an output prefix callback if necessary */
if (diffopt && !diffopt->output_prefix)
diffopt->output_prefix = diff_output_prefix_callback;
}
struct git_graph *graph_init(struct rev_info *opt)
{
struct git_graph *graph = xmalloc(sizeof(struct git_graph));
if (!column_colors) {
char *string;
if (git_config_get_string("log.graphcolors", &string)) {
/* not configured -- use default */
graph_set_column_colors(column_colors_ansi,
column_colors_ansi_max);
} else {
static struct strvec custom_colors = STRVEC_INIT;
strvec_clear(&custom_colors);
parse_graph_colors_config(&custom_colors, string);
free(string);
/* graph_set_column_colors takes a max-index, not a count */
graph_set_column_colors(custom_colors.v,
custom_colors.nr - 1);
}
}
graph->commit = NULL;
graph->revs = opt;
graph->num_parents = 0;
graph->expansion_row = 0;
graph->state = GRAPH_PADDING;
graph->prev_state = GRAPH_PADDING;
graph->commit_index = 0;
graph->prev_commit_index = 0;
graph->merge_layout = 0;
graph->edges_added = 0;
graph->prev_edges_added = 0;
graph->num_columns = 0;
graph->num_new_columns = 0;
graph->mapping_size = 0;
/*
* Start the column color at the maximum value, since we'll
* always increment it for the first commit we output.
* This way we start at 0 for the first commit.
*/
graph->default_column_color = column_colors_max - 1;
/*
* Allocate a reasonably large default number of columns
* We'll automatically grow columns later if we need more room.
*/
graph->column_capacity = 30;
ALLOC_ARRAY(graph->columns, graph->column_capacity);
ALLOC_ARRAY(graph->new_columns, graph->column_capacity);
ALLOC_ARRAY(graph->mapping, 2 * graph->column_capacity);
ALLOC_ARRAY(graph->old_mapping, 2 * graph->column_capacity);
/*
* The diff output prefix callback, with this we can make
* all the diff output to align with the graph lines.
*/
opt->diffopt.output_prefix = diff_output_prefix_callback;
opt->diffopt.output_prefix_data = graph;
return graph;
}
static void graph_update_state(struct git_graph *graph, enum graph_state s)
{
graph->prev_state = graph->state;
graph->state = s;
}
static void graph_ensure_capacity(struct git_graph *graph, int num_columns)
{
if (graph->column_capacity >= num_columns)
return;
do {
graph->column_capacity *= 2;
} while (graph->column_capacity < num_columns);
REALLOC_ARRAY(graph->columns, graph->column_capacity);
REALLOC_ARRAY(graph->new_columns, graph->column_capacity);
REALLOC_ARRAY(graph->mapping, graph->column_capacity * 2);
REALLOC_ARRAY(graph->old_mapping, graph->column_capacity * 2);
}
/*
* Returns 1 if the commit will be printed in the graph output,
* and 0 otherwise.
*/
static int graph_is_interesting(struct git_graph *graph, struct commit *commit)
{
/*
* If revs->boundary is set, commits whose children have
* been shown are always interesting, even if they have the
* UNINTERESTING or TREESAME flags set.
*/
if (graph->revs && graph->revs->boundary) {
if (commit->object.flags & CHILD_SHOWN)
return 1;
}
/*
* Otherwise, use get_commit_action() to see if this commit is
* interesting
*/
return get_commit_action(graph->revs, commit) == commit_show;
}
static struct commit_list *next_interesting_parent(struct git_graph *graph,
struct commit_list *orig)
{
struct commit_list *list;
/*
* If revs->first_parent_only is set, only the first
* parent is interesting. None of the others are.
*/
if (graph->revs->first_parent_only)
return NULL;
/*
* Return the next interesting commit after orig
*/
for (list = orig->next; list; list = list->next) {
if (graph_is_interesting(graph, list->item))
return list;
}
return NULL;
}
static struct commit_list *first_interesting_parent(struct git_graph *graph)
{
struct commit_list *parents = graph->commit->parents;
/*
* If this commit has no parents, ignore it
*/
if (!parents)
return NULL;
/*
* If the first parent is interesting, return it
*/
if (graph_is_interesting(graph, parents->item))
return parents;
/*
* Otherwise, call next_interesting_parent() to get
* the next interesting parent
*/
return next_interesting_parent(graph, parents);
}
static unsigned short graph_get_current_column_color(const struct git_graph *graph)
{
if (!want_color(graph->revs->diffopt.use_color))
return column_colors_max;
return graph->default_column_color;
}
/*
* Update the graph's default column color.
*/
static void graph_increment_column_color(struct git_graph *graph)
{
graph->default_column_color = (graph->default_column_color + 1) %
column_colors_max;
}
static unsigned short graph_find_commit_color(const struct git_graph *graph,
const struct commit *commit)
{
int i;
for (i = 0; i < graph->num_columns; i++) {
if (graph->columns[i].commit == commit)
return graph->columns[i].color;
}
return graph_get_current_column_color(graph);
}
static int graph_find_new_column_by_commit(struct git_graph *graph,
struct commit *commit)
{
int i;
for (i = 0; i < graph->num_new_columns; i++) {
if (graph->new_columns[i].commit == commit)
return i;
}
return -1;
}
static void graph_insert_into_new_columns(struct git_graph *graph,
struct commit *commit,
int idx)
{
int i = graph_find_new_column_by_commit(graph, commit);
int mapping_idx;
/*
* If the commit is not already in the new_columns array, then add it
* and record it as being in the final column.
*/
if (i < 0) {
i = graph->num_new_columns++;
graph->new_columns[i].commit = commit;
graph->new_columns[i].color = graph_find_commit_color(graph, commit);
}
if (graph->num_parents > 1 && idx > -1 && graph->merge_layout == -1) {
/*
* If this is the first parent of a merge, choose a layout for
* the merge line based on whether the parent appears in a
* column to the left of the merge
*/
int dist, shift;
dist = idx - i;
shift = (dist > 1) ? 2 * dist - 3 : 1;
graph->merge_layout = (dist > 0) ? 0 : 1;
graph->edges_added = graph->num_parents + graph->merge_layout - 2;
mapping_idx = graph->width + (graph->merge_layout - 1) * shift;
graph->width += 2 * graph->merge_layout;
} else if (graph->edges_added > 0 && i == graph->mapping[graph->width - 2]) {
/*
* If some columns have been added by a merge, but this commit
* was found in the last existing column, then adjust the
* numbers so that the two edges immediately join, i.e.:
*
* * | * |
* |\ \ => |\|
* | |/ | *
* | *
*/
mapping_idx = graph->width - 2;
graph->edges_added = -1;
} else {
mapping_idx = graph->width;
graph->width += 2;
}
graph->mapping[mapping_idx] = i;
}
static void graph_update_columns(struct git_graph *graph)
{
struct commit_list *parent;
int max_new_columns;
int i, seen_this, is_commit_in_columns;
/*
* Swap graph->columns with graph->new_columns
* graph->columns contains the state for the previous commit,
* and new_columns now contains the state for our commit.
*
* We'll re-use the old columns array as storage to compute the new
* columns list for the commit after this one.
*/
SWAP(graph->columns, graph->new_columns);
graph->num_columns = graph->num_new_columns;
graph->num_new_columns = 0;
/*
* Now update new_columns and mapping with the information for the
* commit after this one.
*
* First, make sure we have enough room. At most, there will
* be graph->num_columns + graph->num_parents columns for the next
* commit.
*/
max_new_columns = graph->num_columns + graph->num_parents;
graph_ensure_capacity(graph, max_new_columns);
/*
* Clear out graph->mapping
*/
graph->mapping_size = 2 * max_new_columns;
for (i = 0; i < graph->mapping_size; i++)
graph->mapping[i] = -1;
graph->width = 0;
graph->prev_edges_added = graph->edges_added;
graph->edges_added = 0;
/*
* Populate graph->new_columns and graph->mapping
*
* Some of the parents of this commit may already be in
* graph->columns. If so, graph->new_columns should only contain a
* single entry for each such commit. graph->mapping should
* contain information about where each current branch line is
* supposed to end up after the collapsing is performed.
*/
seen_this = 0;
is_commit_in_columns = 1;
for (i = 0; i <= graph->num_columns; i++) {
struct commit *col_commit;
if (i == graph->num_columns) {
if (seen_this)
break;
is_commit_in_columns = 0;
col_commit = graph->commit;
} else {
col_commit = graph->columns[i].commit;
}
if (col_commit == graph->commit) {
seen_this = 1;
graph->commit_index = i;
graph->merge_layout = -1;
for (parent = first_interesting_parent(graph);
parent;
parent = next_interesting_parent(graph, parent)) {
/*
* If this is a merge, or the start of a new
* childless column, increment the current
* color.
*/
if (graph->num_parents > 1 ||
!is_commit_in_columns) {
graph_increment_column_color(graph);
}
graph_insert_into_new_columns(graph, parent->item, i);
}
/*
* We always need to increment graph->width by at
* least 2, even if it has no interesting parents.
* The current commit always takes up at least 2
* spaces.
*/
if (graph->num_parents == 0)
graph->width += 2;
} else {
graph_insert_into_new_columns(graph, col_commit, -1);
}
}
/*
* Shrink mapping_size to be the minimum necessary
*/
while (graph->mapping_size > 1 &&
graph->mapping[graph->mapping_size - 1] < 0)
graph->mapping_size--;
}
static int graph_num_dashed_parents(struct git_graph *graph)
{
return graph->num_parents + graph->merge_layout - 3;
}
static int graph_num_expansion_rows(struct git_graph *graph)
{
/*
* Normally, we need two expansion rows for each dashed parent line from
* an octopus merge:
*
* | *
* | |\
* | | \
* | | \
* | *-. \
* | |\ \ \
*
* If the merge is skewed to the left, then its parents occupy one less
* column, and we don't need as many expansion rows to route around it;
* in some cases that means we don't need any expansion rows at all:
*
* | *
* | |\
* | * \
* |/|\ \
*/
return graph_num_dashed_parents(graph) * 2;
}
static int graph_needs_pre_commit_line(struct git_graph *graph)
{
return graph->num_parents >= 3 &&
graph->commit_index < (graph->num_columns - 1) &&
graph->expansion_row < graph_num_expansion_rows(graph);
}
void graph_update(struct git_graph *graph, struct commit *commit)
{
struct commit_list *parent;
/*
* Set the new commit
*/
graph->commit = commit;
/*
* Count how many interesting parents this commit has
*/
graph->num_parents = 0;
for (parent = first_interesting_parent(graph);
parent;
parent = next_interesting_parent(graph, parent))
{
graph->num_parents++;
}
/*
* Store the old commit_index in prev_commit_index.
* graph_update_columns() will update graph->commit_index for this
* commit.
*/
graph->prev_commit_index = graph->commit_index;
/*
* Call graph_update_columns() to update
* columns, new_columns, and mapping.
*/
graph_update_columns(graph);
graph->expansion_row = 0;
/*
* Update graph->state.
* Note that we don't call graph_update_state() here, since
* we don't want to update graph->prev_state. No line for
* graph->state was ever printed.
*
* If the previous commit didn't get to the GRAPH_PADDING state,
* it never finished its output. Goto GRAPH_SKIP, to print out
* a line to indicate that portion of the graph is missing.
*
* If there are 3 or more parents, we may need to print extra rows
* before the commit, to expand the branch lines around it and make
* room for it. We need to do this only if there is a branch row
* (or more) to the right of this commit.
*
* If there are less than 3 parents, we can immediately print the
* commit line.
*/
if (graph->state != GRAPH_PADDING)
graph->state = GRAPH_SKIP;
else if (graph_needs_pre_commit_line(graph))
graph->state = GRAPH_PRE_COMMIT;
else
graph->state = GRAPH_COMMIT;
}
static int graph_is_mapping_correct(struct git_graph *graph)
{
int i;
/*
* The mapping is up to date if each entry is at its target,
* or is 1 greater than its target.
* (If it is 1 greater than the target, '/' will be printed, so it
* will look correct on the next row.)
*/
for (i = 0; i < graph->mapping_size; i++) {
int target = graph->mapping[i];
if (target < 0)
continue;
if (target == (i / 2))
continue;
return 0;
}
return 1;
}
static void graph_pad_horizontally(struct git_graph *graph, struct graph_line *line)
{
/*
* Add additional spaces to the end of the strbuf, so that all
* lines for a particular commit have the same width.
*
* This way, fields printed to the right of the graph will remain
* aligned for the entire commit.
*/
if (line->width < graph->width)
graph_line_addchars(line, ' ', graph->width - line->width);
}
static void graph_output_padding_line(struct git_graph *graph,
struct graph_line *line)
{
int i;
/*
* Output a padding row, that leaves all branch lines unchanged
*/
for (i = 0; i < graph->num_new_columns; i++) {
graph_line_write_column(line, &graph->new_columns[i], '|');
graph_line_addch(line, ' ');
}
}
int graph_width(struct git_graph *graph)
{
return graph->width;
}
static void graph_output_skip_line(struct git_graph *graph, struct graph_line *line)
{
/*
* Output an ellipsis to indicate that a portion
* of the graph is missing.
*/
graph_line_addstr(line, "...");
if (graph_needs_pre_commit_line(graph))
graph_update_state(graph, GRAPH_PRE_COMMIT);
else
graph_update_state(graph, GRAPH_COMMIT);
}
static void graph_output_pre_commit_line(struct git_graph *graph,
struct graph_line *line)
{
int i, seen_this;
/*
* This function formats a row that increases the space around a commit
* with multiple parents, to make room for it. It should only be
* called when there are 3 or more parents.
*
* We need 2 extra rows for every parent over 2.
*/
assert(graph->num_parents >= 3);
/*
* graph->expansion_row tracks the current expansion row we are on.
* It should be in the range [0, num_expansion_rows - 1]
*/
assert(0 <= graph->expansion_row &&
graph->expansion_row < graph_num_expansion_rows(graph));
/*
* Output the row
*/
seen_this = 0;
for (i = 0; i < graph->num_columns; i++) {
struct column *col = &graph->columns[i];
if (col->commit == graph->commit) {
seen_this = 1;
graph_line_write_column(line, col, '|');
graph_line_addchars(line, ' ', graph->expansion_row);
} else if (seen_this && (graph->expansion_row == 0)) {
/*
* This is the first line of the pre-commit output.
* If the previous commit was a merge commit and
* ended in the GRAPH_POST_MERGE state, all branch
* lines after graph->prev_commit_index were
* printed as "\" on the previous line. Continue
* to print them as "\" on this line. Otherwise,
* print the branch lines as "|".
*/
if (graph->prev_state == GRAPH_POST_MERGE &&
graph->prev_commit_index < i)
graph_line_write_column(line, col, '\\');
else
graph_line_write_column(line, col, '|');
} else if (seen_this && (graph->expansion_row > 0)) {
graph_line_write_column(line, col, '\\');
} else {
graph_line_write_column(line, col, '|');
}
graph_line_addch(line, ' ');
}
/*
* Increment graph->expansion_row,
* and move to state GRAPH_COMMIT if necessary
*/
graph->expansion_row++;
if (!graph_needs_pre_commit_line(graph))
graph_update_state(graph, GRAPH_COMMIT);
}
static void graph_output_commit_char(struct git_graph *graph, struct graph_line *line)
{
/*
* For boundary commits, print 'o'
* (We should only see boundary commits when revs->boundary is set.)
*/
if (graph->commit->object.flags & BOUNDARY) {
assert(graph->revs->boundary);
graph_line_addch(line, 'o');
return;
}
/*
* get_revision_mark() handles all other cases without assert()
*/
graph_line_addstr(line, get_revision_mark(graph->revs, graph->commit));
}
/*
* Draw the horizontal dashes of an octopus merge.
*/
static void graph_draw_octopus_merge(struct git_graph *graph, struct graph_line *line)
{
/*
* The parents of a merge commit can be arbitrarily reordered as they
* are mapped onto display columns, for example this is a valid merge:
*
* | | *---.
* | | |\ \ \
* | | |/ / /
* | |/| | /
* | |_|_|/
* |/| | |
* 3 1 0 2
*
* The numbers denote which parent of the merge each visual column
* corresponds to; we can't assume that the parents will initially
* display in the order given by new_columns.
*
* To find the right color for each dash, we need to consult the
* mapping array, starting from the column 2 places to the right of the
* merge commit, and use that to find out which logical column each
* edge will collapse to.
*
* Commits are rendered once all edges have collapsed to their correct
* logcial column, so commit_index gives us the right visual offset for
* the merge commit.
*/
int i, j;
struct column *col;
int dashed_parents = graph_num_dashed_parents(graph);
for (i = 0; i < dashed_parents; i++) {
j = graph->mapping[(graph->commit_index + i + 2) * 2];
col = &graph->new_columns[j];
graph_line_write_column(line, col, '-');
graph_line_write_column(line, col, (i == dashed_parents - 1) ? '.' : '-');
}
return;
}
static void graph_output_commit_line(struct git_graph *graph, struct graph_line *line)
{
int seen_this = 0;
int i;
/*
* Output the row containing this commit
* Iterate up to and including graph->num_columns,
* since the current commit may not be in any of the existing
* columns. (This happens when the current commit doesn't have any
* children that we have already processed.)
*/
seen_this = 0;
for (i = 0; i <= graph->num_columns; i++) {
struct column *col = &graph->columns[i];
struct commit *col_commit;
if (i == graph->num_columns) {
if (seen_this)
break;
col_commit = graph->commit;
} else {
col_commit = graph->columns[i].commit;
}
if (col_commit == graph->commit) {
seen_this = 1;
graph_output_commit_char(graph, line);
if (graph->num_parents > 2)
graph_draw_octopus_merge(graph, line);
} else if (seen_this && (graph->edges_added > 1)) {
graph_line_write_column(line, col, '\\');
} else if (seen_this && (graph->edges_added == 1)) {
/*
* This is either a right-skewed 2-way merge
* commit, or a left-skewed 3-way merge.
* There is no GRAPH_PRE_COMMIT stage for such
* merges, so this is the first line of output
* for this commit. Check to see what the previous
* line of output was.
*
* If it was GRAPH_POST_MERGE, the branch line
* coming into this commit may have been '\',
* and not '|' or '/'. If so, output the branch
* line as '\' on this line, instead of '|'. This
* makes the output look nicer.
*/
if (graph->prev_state == GRAPH_POST_MERGE &&
graph->prev_edges_added > 0 &&
graph->prev_commit_index < i)
graph_line_write_column(line, col, '\\');
else
graph_line_write_column(line, col, '|');
} else if (graph->prev_state == GRAPH_COLLAPSING &&
graph->old_mapping[2 * i + 1] == i &&
graph->mapping[2 * i] < i) {
graph_line_write_column(line, col, '/');
} else {
graph_line_write_column(line, col, '|');
}
graph_line_addch(line, ' ');
}
/*
* Update graph->state
*/
if (graph->num_parents > 1)
graph_update_state(graph, GRAPH_POST_MERGE);
else if (graph_is_mapping_correct(graph))
graph_update_state(graph, GRAPH_PADDING);
else
graph_update_state(graph, GRAPH_COLLAPSING);
}
static const char merge_chars[] = {'/', '|', '\\'};
static void graph_output_post_merge_line(struct git_graph *graph, struct graph_line *line)
{
int seen_this = 0;
int i, j;
struct commit_list *first_parent = first_interesting_parent(graph);
struct column *parent_col = NULL;
/*
* Output the post-merge row
*/
for (i = 0; i <= graph->num_columns; i++) {
struct column *col = &graph->columns[i];
struct commit *col_commit;
if (i == graph->num_columns) {
if (seen_this)
break;
col_commit = graph->commit;
} else {
col_commit = col->commit;
}
if (col_commit == graph->commit) {
/*
* Since the current commit is a merge find
* the columns for the parent commits in
* new_columns and use those to format the
* edges.
*/
struct commit_list *parents = first_parent;
int par_column;
int idx = graph->merge_layout;
char c;
seen_this = 1;
for (j = 0; j < graph->num_parents; j++) {
par_column = graph_find_new_column_by_commit(graph, parents->item);
assert(par_column >= 0);
c = merge_chars[idx];
graph_line_write_column(line, &graph->new_columns[par_column], c);
if (idx == 2) {
if (graph->edges_added > 0 || j < graph->num_parents - 1)
graph_line_addch(line, ' ');
} else {
idx++;
}
parents = next_interesting_parent(graph, parents);
}
if (graph->edges_added == 0)
graph_line_addch(line, ' ');
} else if (seen_this) {
if (graph->edges_added > 0)
graph_line_write_column(line, col, '\\');
else
graph_line_write_column(line, col, '|');
graph_line_addch(line, ' ');
} else {
graph_line_write_column(line, col, '|');
if (graph->merge_layout != 0 || i != graph->commit_index - 1) {
if (parent_col)
graph_line_write_column(
line, parent_col, '_');
else
graph_line_addch(line, ' ');
}
}
if (col_commit == first_parent->item)
parent_col = col;
}
/*
* Update graph->state
*/
if (graph_is_mapping_correct(graph))
graph_update_state(graph, GRAPH_PADDING);
else
graph_update_state(graph, GRAPH_COLLAPSING);
}
static void graph_output_collapsing_line(struct git_graph *graph, struct graph_line *line)
{
int i;
short used_horizontal = 0;
int horizontal_edge = -1;
int horizontal_edge_target = -1;
/*
* Swap the mapping and old_mapping arrays
*/
SWAP(graph->mapping, graph->old_mapping);
/*
* Clear out the mapping array
*/
for (i = 0; i < graph->mapping_size; i++)
graph->mapping[i] = -1;
for (i = 0; i < graph->mapping_size; i++) {
int target = graph->old_mapping[i];
if (target < 0)
continue;
/*
* Since update_columns() always inserts the leftmost
* column first, each branch's target location should
* always be either its current location or to the left of
* its current location.
*
* We never have to move branches to the right. This makes
* the graph much more legible, since whenever branches
* cross, only one is moving directions.
*/
assert(target * 2 <= i);
if (target * 2 == i) {
/*
* This column is already in the
* correct place
*/
assert(graph->mapping[i] == -1);
graph->mapping[i] = target;
} else if (graph->mapping[i - 1] < 0) {
/*
* Nothing is to the left.
* Move to the left by one
*/
graph->mapping[i - 1] = target;
/*
* If there isn't already an edge moving horizontally
* select this one.
*/
if (horizontal_edge == -1) {
int j;
horizontal_edge = i;
horizontal_edge_target = target;
/*
* The variable target is the index of the graph
* column, and therefore target*2+3 is the
* actual screen column of the first horizontal
* line.
*/
for (j = (target * 2)+3; j < (i - 2); j += 2)
graph->mapping[j] = target;
}
} else if (graph->mapping[i - 1] == target) {
/*
* There is a branch line to our left
* already, and it is our target. We
* combine with this line, since we share
* the same parent commit.
*
* We don't have to add anything to the
* output or mapping, since the
* existing branch line has already taken
* care of it.
*/
} else {
/*
* There is a branch line to our left,
* but it isn't our target. We need to
* cross over it.
*
* The space just to the left of this
* branch should always be empty.
*/
assert(graph->mapping[i - 1] > target);
assert(graph->mapping[i - 2] < 0);
graph->mapping[i - 2] = target;
/*
* Mark this branch as the horizontal edge to
* prevent any other edges from moving
* horizontally.
*/
if (horizontal_edge == -1) {
int j;
horizontal_edge_target = target;
horizontal_edge = i - 1;
for (j = (target * 2) + 3; j < (i - 2); j += 2)
graph->mapping[j] = target;
}
}
}
/*
* Copy the current mapping array into old_mapping
*/
COPY_ARRAY(graph->old_mapping, graph->mapping, graph->mapping_size);
/*
* The new mapping may be 1 smaller than the old mapping
*/
if (graph->mapping[graph->mapping_size - 1] < 0)
graph->mapping_size--;
/*
* Output out a line based on the new mapping info
*/
for (i = 0; i < graph->mapping_size; i++) {
int target = graph->mapping[i];
if (target < 0)
graph_line_addch(line, ' ');
else if (target * 2 == i)
graph_line_write_column(line, &graph->new_columns[target], '|');
else if (target == horizontal_edge_target &&
i != horizontal_edge - 1) {
/*
* Set the mappings for all but the
* first segment to -1 so that they
* won't continue into the next line.
*/
if (i != (target * 2)+3)
graph->mapping[i] = -1;
used_horizontal = 1;
graph_line_write_column(line, &graph->new_columns[target], '_');
} else {
if (used_horizontal && i < horizontal_edge)
graph->mapping[i] = -1;
graph_line_write_column(line, &graph->new_columns[target], '/');
}
}
/*
* If graph->mapping indicates that all of the branch lines
* are already in the correct positions, we are done.
* Otherwise, we need to collapse some branch lines together.
*/
if (graph_is_mapping_correct(graph))
graph_update_state(graph, GRAPH_PADDING);
}
int graph_next_line(struct git_graph *graph, struct strbuf *sb)
{
int shown_commit_line = 0;
struct graph_line line = { .buf = sb, .width = 0 };
/*
* We could conceivable be called with a NULL commit
* if our caller has a bug, and invokes graph_next_line()
* immediately after graph_init(), without first calling
* graph_update(). Return without outputting anything in this
* case.
*/
if (!graph->commit)
return -1;
switch (graph->state) {
case GRAPH_PADDING:
graph_output_padding_line(graph, &line);
break;
case GRAPH_SKIP:
graph_output_skip_line(graph, &line);
break;
case GRAPH_PRE_COMMIT:
graph_output_pre_commit_line(graph, &line);
break;
case GRAPH_COMMIT:
graph_output_commit_line(graph, &line);
shown_commit_line = 1;
break;
case GRAPH_POST_MERGE:
graph_output_post_merge_line(graph, &line);
break;
case GRAPH_COLLAPSING:
graph_output_collapsing_line(graph, &line);
break;
}
graph_pad_horizontally(graph, &line);
return shown_commit_line;
}
static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
{
int i;
struct graph_line line = { .buf = sb, .width = 0 };
if (graph->state != GRAPH_COMMIT) {
graph_next_line(graph, sb);
return;
}
/*
* Output the row containing this commit
* Iterate up to and including graph->num_columns,
* since the current commit may not be in any of the existing
* columns. (This happens when the current commit doesn't have any
* children that we have already processed.)
*/
for (i = 0; i < graph->num_columns; i++) {
struct column *col = &graph->columns[i];
graph_line_write_column(&line, col, '|');
if (col->commit == graph->commit && graph->num_parents > 2) {
int len = (graph->num_parents - 2) * 2;
graph_line_addchars(&line, ' ', len);
} else {
graph_line_addch(&line, ' ');
}
}
graph_pad_horizontally(graph, &line);
/*
* Update graph->prev_state since we have output a padding line
*/
graph->prev_state = GRAPH_PADDING;
}
int graph_is_commit_finished(struct git_graph const *graph)
{
return (graph->state == GRAPH_PADDING);
}
void graph_show_commit(struct git_graph *graph)
{
struct strbuf msgbuf = STRBUF_INIT;
int shown_commit_line = 0;
graph_show_line_prefix(default_diffopt);
if (!graph)
return;
/*
* When showing a diff of a merge against each of its parents, we
* are called once for each parent without graph_update having been
* called. In this case, simply output a single padding line.
*/
if (graph_is_commit_finished(graph)) {
graph_show_padding(graph);
shown_commit_line = 1;
}
while (!shown_commit_line && !graph_is_commit_finished(graph)) {
shown_commit_line = graph_next_line(graph, &msgbuf);
fwrite(msgbuf.buf, sizeof(char), msgbuf.len,
graph->revs->diffopt.file);
if (!shown_commit_line) {
putc('\n', graph->revs->diffopt.file);
graph_show_line_prefix(&graph->revs->diffopt);
}
strbuf_setlen(&msgbuf, 0);
}
strbuf_release(&msgbuf);
}
void graph_show_oneline(struct git_graph *graph)
{
struct strbuf msgbuf = STRBUF_INIT;
graph_show_line_prefix(default_diffopt);
if (!graph)
return;
graph_next_line(graph, &msgbuf);
fwrite(msgbuf.buf, sizeof(char), msgbuf.len, graph->revs->diffopt.file);
strbuf_release(&msgbuf);
}
void graph_show_padding(struct git_graph *graph)
{
struct strbuf msgbuf = STRBUF_INIT;
graph_show_line_prefix(default_diffopt);
if (!graph)
return;
graph_padding_line(graph, &msgbuf);
fwrite(msgbuf.buf, sizeof(char), msgbuf.len, graph->revs->diffopt.file);
strbuf_release(&msgbuf);
}
int graph_show_remainder(struct git_graph *graph)
{
struct strbuf msgbuf = STRBUF_INIT;
int shown = 0;
graph_show_line_prefix(default_diffopt);
if (!graph)
return 0;
if (graph_is_commit_finished(graph))
return 0;
for (;;) {
graph_next_line(graph, &msgbuf);
fwrite(msgbuf.buf, sizeof(char), msgbuf.len,
graph->revs->diffopt.file);
strbuf_setlen(&msgbuf, 0);
shown = 1;
if (!graph_is_commit_finished(graph)) {
putc('\n', graph->revs->diffopt.file);
graph_show_line_prefix(&graph->revs->diffopt);
} else {
break;
}
}
strbuf_release(&msgbuf);
return shown;
}
static void graph_show_strbuf(struct git_graph *graph,
FILE *file,
struct strbuf const *sb)
{
char *p;
/*
* Print the strbuf line by line,
* and display the graph info before each line but the first.
*/
p = sb->buf;
while (p) {
size_t len;
char *next_p = strchr(p, '\n');
if (next_p) {
next_p++;
len = next_p - p;
} else {
len = (sb->buf + sb->len) - p;
}
fwrite(p, sizeof(char), len, file);
if (next_p && *next_p != '\0')
graph_show_oneline(graph);
p = next_p;
}
}
void graph_show_commit_msg(struct git_graph *graph,
FILE *file,
struct strbuf const *sb)
{
int newline_terminated;
/*
* Show the commit message
*/
graph_show_strbuf(graph, file, sb);
if (!graph)
return;
newline_terminated = (sb->len && sb->buf[sb->len - 1] == '\n');
/*
* If there is more output needed for this commit, show it now
*/
if (!graph_is_commit_finished(graph)) {
/*
* If sb doesn't have a terminating newline, print one now,
* so we can start the remainder of the graph output on a
* new line.
*/
if (!newline_terminated)
putc('\n', file);
graph_show_remainder(graph);
/*
* If sb ends with a newline, our output should too.
*/
if (newline_terminated)
putc('\n', file);
}
}