diff options
Diffstat (limited to 'graph.c')
| -rw-r--r-- | graph.c | 1132 | 
1 files changed, 1132 insertions, 0 deletions
| diff --git a/graph.c b/graph.c new file mode 100644 index 0000000000..e2633f8376 --- /dev/null +++ b/graph.c @@ -0,0 +1,1132 @@ +#include "cache.h" +#include "commit.h" +#include "graph.h" +#include "diff.h" +#include "revision.h" + +/* + * TODO: + * - Add colors to the graph. + *   Pick a color for each column, and print all characters + *   in that column with the specified color. + * + * - 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. + * + * - The output during the GRAPH_PRE_COMMIT and GRAPH_COLLAPSING states + *   could be made more compact by printing horizontal lines, instead of + *   long diagonal lines.  For example, during collapsing, something like + *   this:          instead of this: + *   | | | | |      | | | | | + *   | |_|_|/       | | | |/ + *   |/| | |        | | |/| + *   | | | |        | |/| | + *                  |/| | | + *                  | | | | + * + *   If there are several parallel diagonal lines, they will need to be + *   replaced with horizontal lines on subsequent rows. + */ + +struct column { +	/* +	 * The parent commit of this column. +	 */ +	struct commit *commit; +	/* +	 * XXX: Once we add support for colors, struct column could also +	 * contain the color of its branch line. +	 */ +}; + +enum graph_state { +	GRAPH_PADDING, +	GRAPH_SKIP, +	GRAPH_PRE_COMMIT, +	GRAPH_COMMIT, +	GRAPH_POST_MERGE, +	GRAPH_COLLAPSING +}; + +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; +}; + +struct git_graph *graph_init(struct rev_info *opt) +{ +	struct git_graph *graph = xmalloc(sizeof(struct git_graph)); +	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; + +	/* +	 * 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); + +	return graph; +} + +void graph_release(struct git_graph *graph) +{ +	free(graph->columns); +	free(graph->new_columns); +	free(graph->mapping); +	free(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; +	} + +	/* +	 * Uninteresting and pruned commits won't be printed +	 */ +	return (commit->object.flags & (UNINTERESTING | TREESAME)) ? 0 : 1; +} + +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 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->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 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)) { +				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) +{ +	/* +	 * 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 (sb->len >= graph->width) +		return; + +	extra = graph->width - sb->len; +	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_addstr(sb, "| "); +	} + +	graph_pad_horizontally(graph, sb); +} + +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); + +	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; + +	/* +	 * 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; +	for (i = 0; i < graph->num_columns; i++) { +		struct column *col = &graph->columns[i]; +		if (col->commit == graph->commit) { +			seen_this = 1; +			strbuf_addf(sb, "| %*s", 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_addstr(sb, "\\ "); +			else +				strbuf_addstr(sb, "| "); +		} else if (seen_this && (graph->expansion_row > 0)) { +			strbuf_addstr(sb, "\\ "); +		} else { +			strbuf_addstr(sb, "| "); +		} +	} + +	graph_pad_horizontally(graph, sb); + +	/* +	 * 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; +	} + +	/* +	 * If revs->left_right is set, print '<' for commits that +	 * come from the left side, and '>' for commits from the right +	 * side. +	 */ +	if (graph->revs && graph->revs->left_right) { +		if (graph->commit->object.flags & SYMMETRIC_LEFT) +			strbuf_addch(sb, '<'); +		else +			strbuf_addch(sb, '>'); +		return; +	} + +	/* +	 * Print '*' in all other cases +	 */ +	strbuf_addch(sb, '*'); +} + +void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb) +{ +	int seen_this = 0; +	int i, j; + +	/* +	 * 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 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); + +			if (graph->num_parents < 3) +				strbuf_addch(sb, ' '); +			else { +				int num_dashes = +					((graph->num_parents - 2) * 2) - 1; +				for (j = 0; j < num_dashes; j++) +					strbuf_addch(sb, '-'); +				strbuf_addstr(sb, ". "); +			} +		} else if (seen_this && (graph->num_parents > 2)) { +			strbuf_addstr(sb, "\\ "); +		} 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_addstr(sb, "\\ "); +			else +				strbuf_addstr(sb, "| "); +		} else { +			strbuf_addstr(sb, "| "); +		} +	} + +	graph_pad_horizontally(graph, sb); + +	/* +	 * 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); +} + +void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb) +{ +	int seen_this = 0; +	int i, j; + +	/* +	 * Output the post-merge row +	 */ +	for (i = 0; i <= graph->num_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; +			strbuf_addch(sb, '|'); +			for (j = 0; j < graph->num_parents - 1; j++) +				strbuf_addstr(sb, "\\ "); +		} else if (seen_this) { +			strbuf_addstr(sb, "\\ "); +		} else { +			strbuf_addstr(sb, "| "); +		} +	} + +	graph_pad_horizontally(graph, sb); + +	/* +	 * Update graph->state +	 */ +	if (graph_is_mapping_correct(graph)) +		graph_update_state(graph, GRAPH_PADDING); +	else +		graph_update_state(graph, GRAPH_COLLAPSING); +} + +void graph_output_collapsing_line(struct git_graph *graph, struct strbuf *sb) +{ +	int i; +	int *tmp_mapping; + +	/* +	 * 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; +		} 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. +			 */ +			assert(graph->new_mapping[i - 1] > target); +			assert(graph->new_mapping[i - 2] < 0); +			graph->new_mapping[i - 2] = target; +		} +	} + +	/* +	 * 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_addch(sb, '|'); +		else +			strbuf_addch(sb, '/'); +	} + +	graph_pad_horizontally(graph, sb); + +	/* +	 * 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; +} + +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 commit *col_commit = graph->columns[i].commit; +		if (col_commit == graph->commit) { +			strbuf_addch(sb, '|'); + +			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_addstr(sb, "| "); +		} +	} + +	graph_pad_horizontally(graph, sb); + +	/* +	 * 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; +	int shown_commit_line = 0; + +	if (!graph) +		return; + +	strbuf_init(&msgbuf, 0); + +	while (!shown_commit_line) { +		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; + +	if (!graph) +		return; + +	strbuf_init(&msgbuf, 0); +	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; + +	if (!graph) +		return; + +	strbuf_init(&msgbuf, 0); +	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; +	int shown = 0; + +	if (!graph) +		return 0; + +	if (graph_is_commit_finished(graph)) +		return 0; + +	strbuf_init(&msgbuf, 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; +} + + +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'); +	} +} | 
