git/graph.c
Michał Kiedrowicz 656197ad38 graph.c: infinite loop in git whatchanged --graph -m
Running "whatchanged --graph -m" on a simple two-head merges
can fall into infinite loop.

Signed-off-by: Michał Kiedrowicz <michal.kiedrowicz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-09-25 11:07:15 -07:00

1340 lines
34 KiB
C

#include "cache.h"
#include "commit.h"
#include "color.h"
#include "graph.h"
#include "diff.h"
#include "revision.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 to stdout. 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().
*/
static void graph_show_strbuf(struct git_graph *graph, 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 const char **column_colors;
static unsigned short column_colors_max;
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];
}
static void strbuf_write_column(struct strbuf *sb, const struct column *c,
char col_char)
{
if (c->color < column_colors_max)
strbuf_addstr(sb, column_get_color_code(c->color));
strbuf_addch(sb, col_char);
if (c->color < column_colors_max)
strbuf_addstr(sb, column_get_color_code(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;
/*
* 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 new_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 temporary array for computing the next mapping state
* while we are outputting a mapping line. This is stored as part
* of the git_graph simply so we don't have to allocate a new
* temporary array each time we have to output a collapsing line.
*/
int *new_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);
assert(graph);
opt->output_prefix_length = graph->width;
strbuf_reset(&msgbuf);
graph_padding_line(graph, &msgbuf);
return &msgbuf;
}
struct git_graph *graph_init(struct rev_info *opt)
{
struct git_graph *graph = xmalloc(sizeof(struct git_graph));
if (!column_colors)
graph_set_column_colors(column_colors_ansi,
column_colors_ansi_max);
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->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;
graph->columns = xmalloc(sizeof(struct column) *
graph->column_capacity);
graph->new_columns = xmalloc(sizeof(struct column) *
graph->column_capacity);
graph->mapping = xmalloc(sizeof(int) * 2 * graph->column_capacity);
graph->new_mapping = xmalloc(sizeof(int) * 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;
opt->diffopt.output_prefix_length = 0;
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);
graph->columns = xrealloc(graph->columns,
sizeof(struct column) *
graph->column_capacity);
graph->new_columns = xrealloc(graph->new_columns,
sizeof(struct column) *
graph->column_capacity);
graph->mapping = xrealloc(graph->mapping,
sizeof(int) * 2 * graph->column_capacity);
graph->new_mapping = xrealloc(graph->new_mapping,
sizeof(int) * 2 * graph->column_capacity);
}
/*
* 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 void graph_insert_into_new_columns(struct git_graph *graph,
struct commit *commit,
int *mapping_index)
{
int i;
/*
* If the commit is already in the new_columns list, we don't need to
* add it. Just update the mapping correctly.
*/
for (i = 0; i < graph->num_new_columns; i++) {
if (graph->new_columns[i].commit == commit) {
graph->mapping[*mapping_index] = i;
*mapping_index += 2;
return;
}
}
/*
* This commit isn't already in new_columns. Add it.
*/
graph->new_columns[graph->num_new_columns].commit = commit;
graph->new_columns[graph->num_new_columns].color = graph_find_commit_color(graph, commit);
graph->mapping[*mapping_index] = graph->num_new_columns;
*mapping_index += 2;
graph->num_new_columns++;
}
static void graph_update_width(struct git_graph *graph,
int is_commit_in_existing_columns)
{
/*
* Compute the width needed to display the graph for this commit.
* This is the maximum width needed for any row. All other rows
* will be padded to this width.
*
* Compute the number of columns in the widest row:
* Count each existing column (graph->num_columns), and each new
* column added by this commit.
*/
int max_cols = graph->num_columns + graph->num_parents;
/*
* Even if the current commit has no parents to be printed, it
* still takes up a column for itself.
*/
if (graph->num_parents < 1)
max_cols++;
/*
* We added a column for the current commit as part of
* graph->num_parents. If the current commit was already in
* graph->columns, then we have double counted it.
*/
if (is_commit_in_existing_columns)
max_cols--;
/*
* Each column takes up 2 spaces
*/
graph->width = max_cols * 2;
}
static void graph_update_columns(struct git_graph *graph)
{
struct commit_list *parent;
struct column *tmp_columns;
int max_new_columns;
int mapping_idx;
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.
*/
tmp_columns = graph->columns;
graph->columns = graph->new_columns;
graph->num_columns = graph->num_new_columns;
graph->new_columns = tmp_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;
/*
* 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;
mapping_idx = 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) {
int old_mapping_idx = mapping_idx;
seen_this = 1;
graph->commit_index = i;
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,
&mapping_idx);
}
/*
* We always need to increment mapping_idx by at
* least 2, even if it has no interesting parents.
* The current commit always takes up at least 2
* spaces.
*/
if (mapping_idx == old_mapping_idx)
mapping_idx += 2;
} else {
graph_insert_into_new_columns(graph, col_commit,
&mapping_idx);
}
}
/*
* Shrink mapping_size to be the minimum necessary
*/
while (graph->mapping_size > 1 &&
graph->mapping[graph->mapping_size - 1] < 0)
graph->mapping_size--;
/*
* Compute graph->width for this commit
*/
graph_update_width(graph, is_commit_in_columns);
}
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->num_parents >= 3 &&
graph->commit_index < (graph->num_columns - 1))
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 strbuf *sb,
int chars_written)
{
/*
* 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.
*/
int extra;
if (chars_written >= graph->width)
return;
extra = graph->width - chars_written;
strbuf_addf(sb, "%*s", (int) extra, "");
}
static void graph_output_padding_line(struct git_graph *graph,
struct strbuf *sb)
{
int i;
/*
* 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;
/*
* Output a padding row, that leaves all branch lines unchanged
*/
for (i = 0; i < graph->num_new_columns; i++) {
strbuf_write_column(sb, &graph->new_columns[i], '|');
strbuf_addch(sb, ' ');
}
graph_pad_horizontally(graph, sb, graph->num_new_columns * 2);
}
static void graph_output_skip_line(struct git_graph *graph, struct strbuf *sb)
{
/*
* Output an ellipsis to indicate that a portion
* of the graph is missing.
*/
strbuf_addstr(sb, "...");
graph_pad_horizontally(graph, sb, 3);
if (graph->num_parents >= 3 &&
graph->commit_index < (graph->num_columns - 1))
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 strbuf *sb)
{
int num_expansion_rows;
int i, seen_this;
int chars_written;
/*
* 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);
num_expansion_rows = (graph->num_parents - 2) * 2;
/*
* 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 < num_expansion_rows);
/*
* Output the row
*/
seen_this = 0;
chars_written = 0;
for (i = 0; i < graph->num_columns; i++) {
struct column *col = &graph->columns[i];
if (col->commit == graph->commit) {
seen_this = 1;
strbuf_write_column(sb, col, '|');
strbuf_addf(sb, "%*s", graph->expansion_row, "");
chars_written += 1 + 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)
strbuf_write_column(sb, col, '\\');
else
strbuf_write_column(sb, col, '|');
chars_written++;
} else if (seen_this && (graph->expansion_row > 0)) {
strbuf_write_column(sb, col, '\\');
chars_written++;
} else {
strbuf_write_column(sb, col, '|');
chars_written++;
}
strbuf_addch(sb, ' ');
chars_written++;
}
graph_pad_horizontally(graph, sb, chars_written);
/*
* Increment graph->expansion_row,
* and move to state GRAPH_COMMIT if necessary
*/
graph->expansion_row++;
if (graph->expansion_row >= num_expansion_rows)
graph_update_state(graph, GRAPH_COMMIT);
}
static void graph_output_commit_char(struct git_graph *graph, struct strbuf *sb)
{
/*
* 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);
strbuf_addch(sb, 'o');
return;
}
/*
* get_revision_mark() handles all other cases without assert()
*/
strbuf_addstr(sb, get_revision_mark(graph->revs, graph->commit));
}
/*
* Draw an octopus merge and return the number of characters written.
*/
static int graph_draw_octopus_merge(struct git_graph *graph,
struct strbuf *sb)
{
/*
* Here dashless_commits represents the number of parents
* which don't need to have dashes (because their edges fit
* neatly under the commit).
*/
const int dashless_commits = 2;
int col_num, i;
int num_dashes =
((graph->num_parents - dashless_commits) * 2) - 1;
for (i = 0; i < num_dashes; i++) {
col_num = (i / 2) + dashless_commits;
strbuf_write_column(sb, &graph->new_columns[col_num], '-');
}
col_num = (i / 2) + dashless_commits;
strbuf_write_column(sb, &graph->new_columns[col_num], '.');
return num_dashes + 1;
}
static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
{
int seen_this = 0;
int i, chars_written;
/*
* 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;
chars_written = 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, sb);
chars_written++;
if (graph->num_parents > 2)
chars_written += graph_draw_octopus_merge(graph,
sb);
} else if (seen_this && (graph->num_parents > 2)) {
strbuf_write_column(sb, col, '\\');
chars_written++;
} else if (seen_this && (graph->num_parents == 2)) {
/*
* This is a 2-way merge commit.
* There is no GRAPH_PRE_COMMIT stage for 2-way
* 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_commit_index < i)
strbuf_write_column(sb, col, '\\');
else
strbuf_write_column(sb, col, '|');
chars_written++;
} else {
strbuf_write_column(sb, col, '|');
chars_written++;
}
strbuf_addch(sb, ' ');
chars_written++;
}
graph_pad_horizontally(graph, sb, chars_written);
/*
* 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 struct column *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 &graph->new_columns[i];
}
return NULL;
}
static void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
{
int seen_this = 0;
int i, j, chars_written;
/*
* Output the post-merge row
*/
chars_written = 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 = 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 = NULL;
struct column *par_column;
seen_this = 1;
parents = first_interesting_parent(graph);
assert(parents);
par_column = find_new_column_by_commit(graph, parents->item);
assert(par_column);
strbuf_write_column(sb, par_column, '|');
chars_written++;
for (j = 0; j < graph->num_parents - 1; j++) {
parents = next_interesting_parent(graph, parents);
assert(parents);
par_column = find_new_column_by_commit(graph, parents->item);
assert(par_column);
strbuf_write_column(sb, par_column, '\\');
strbuf_addch(sb, ' ');
}
chars_written += j * 2;
} else if (seen_this) {
strbuf_write_column(sb, col, '\\');
strbuf_addch(sb, ' ');
chars_written += 2;
} else {
strbuf_write_column(sb, col, '|');
strbuf_addch(sb, ' ');
chars_written += 2;
}
}
graph_pad_horizontally(graph, sb, chars_written);
/*
* 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 strbuf *sb)
{
int i;
int *tmp_mapping;
short used_horizontal = 0;
int horizontal_edge = -1;
int horizontal_edge_target = -1;
/*
* Clear out the new_mapping array
*/
for (i = 0; i < graph->mapping_size; i++)
graph->new_mapping[i] = -1;
for (i = 0; i < graph->mapping_size; i++) {
int target = graph->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->new_mapping[i] == -1);
graph->new_mapping[i] = target;
} else if (graph->new_mapping[i - 1] < 0) {
/*
* Nothing is to the left.
* Move to the left by one
*/
graph->new_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->new_mapping[j] = target;
}
} else if (graph->new_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 new_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.
*
* The branch to the left of that space
* should be our eventual target.
*/
assert(graph->new_mapping[i - 1] > target);
assert(graph->new_mapping[i - 2] < 0);
assert(graph->new_mapping[i - 3] == target);
graph->new_mapping[i - 2] = target;
/*
* Mark this branch as the horizontal edge to
* prevent any other edges from moving
* horizontally.
*/
if (horizontal_edge == -1)
horizontal_edge = i;
}
}
/*
* The new mapping may be 1 smaller than the old mapping
*/
if (graph->new_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->new_mapping[i];
if (target < 0)
strbuf_addch(sb, ' ');
else if (target * 2 == i)
strbuf_write_column(sb, &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->new_mapping[i] = -1;
used_horizontal = 1;
strbuf_write_column(sb, &graph->new_columns[target], '_');
} else {
if (used_horizontal && i < horizontal_edge)
graph->new_mapping[i] = -1;
strbuf_write_column(sb, &graph->new_columns[target], '/');
}
}
graph_pad_horizontally(graph, sb, graph->mapping_size);
/*
* Swap mapping and new_mapping
*/
tmp_mapping = graph->mapping;
graph->mapping = graph->new_mapping;
graph->new_mapping = tmp_mapping;
/*
* 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)
{
switch (graph->state) {
case GRAPH_PADDING:
graph_output_padding_line(graph, sb);
return 0;
case GRAPH_SKIP:
graph_output_skip_line(graph, sb);
return 0;
case GRAPH_PRE_COMMIT:
graph_output_pre_commit_line(graph, sb);
return 0;
case GRAPH_COMMIT:
graph_output_commit_line(graph, sb);
return 1;
case GRAPH_POST_MERGE:
graph_output_post_merge_line(graph, sb);
return 0;
case GRAPH_COLLAPSING:
graph_output_collapsing_line(graph, sb);
return 0;
}
assert(0);
return 0;
}
static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
{
int i, j;
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];
struct commit *col_commit = col->commit;
if (col_commit == graph->commit) {
strbuf_write_column(sb, col, '|');
if (graph->num_parents < 3)
strbuf_addch(sb, ' ');
else {
int num_spaces = ((graph->num_parents - 2) * 2);
for (j = 0; j < num_spaces; j++)
strbuf_addch(sb, ' ');
}
} else {
strbuf_write_column(sb, col, '|');
strbuf_addch(sb, ' ');
}
}
graph_pad_horizontally(graph, sb, graph->num_columns);
/*
* 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;
if (!graph)
return;
while (!shown_commit_line && !graph_is_commit_finished(graph)) {
shown_commit_line = graph_next_line(graph, &msgbuf);
fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
if (!shown_commit_line)
putchar('\n');
strbuf_setlen(&msgbuf, 0);
}
strbuf_release(&msgbuf);
}
void graph_show_oneline(struct git_graph *graph)
{
struct strbuf msgbuf = STRBUF_INIT;
if (!graph)
return;
graph_next_line(graph, &msgbuf);
fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
strbuf_release(&msgbuf);
}
void graph_show_padding(struct git_graph *graph)
{
struct strbuf msgbuf = STRBUF_INIT;
if (!graph)
return;
graph_padding_line(graph, &msgbuf);
fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
strbuf_release(&msgbuf);
}
int graph_show_remainder(struct git_graph *graph)
{
struct strbuf msgbuf = STRBUF_INIT;
int shown = 0;
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, stdout);
strbuf_setlen(&msgbuf, 0);
shown = 1;
if (!graph_is_commit_finished(graph))
putchar('\n');
else
break;
}
strbuf_release(&msgbuf);
return shown;
}
static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb)
{
char *p;
if (!graph) {
fwrite(sb->buf, sizeof(char), sb->len, stdout);
return;
}
/*
* 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, stdout);
if (next_p && *next_p != '\0')
graph_show_oneline(graph);
p = next_p;
}
}
void graph_show_commit_msg(struct git_graph *graph,
struct strbuf const *sb)
{
int newline_terminated;
if (!graph) {
/*
* If there's no graph, just print the message buffer.
*
* The message buffer for CMIT_FMT_ONELINE and
* CMIT_FMT_USERFORMAT are already missing a terminating
* newline. All of the other formats should have it.
*/
fwrite(sb->buf, sizeof(char), sb->len, stdout);
return;
}
newline_terminated = (sb->len && sb->buf[sb->len - 1] == '\n');
/*
* Show the commit message
*/
graph_show_strbuf(graph, sb);
/*
* 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)
putchar('\n');
graph_show_remainder(graph);
/*
* If sb ends with a newline, our output should too.
*/
if (newline_terminated)
putchar('\n');
}
}