[PATCH v2 05/13] graph: remove `mapping_idx` and `graph_update_width()`
- From
James Coglan via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Oct 15, 2019, 23:40 UTC
- Message-ID
- <d2e8958eed3c51650de4b1dc18d3ec94df2cfe08.1571182864.git.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.383.v2.git.1571182864.gitgitgadget@gmail.com>
From: James Coglan <jcoglan@gmail.com>
There's a duplication of logic between `graph_insert_into_new_columns()` and `graph_update_width()`. `graph_insert_into_new_columns()` is called repeatedly by `graph_update_columns()` with an `int *` that tracks the offset into the `mapping` array where we should write the next value. Each call to `graph_insert_into_new_columns()` effectively pushes one column index and one "null" value (-1) onto the `mapping` array and therefore increments `mapping_idx` by 2.
`graph_update_width()` duplicates this process: the `width` of the graph is essentially the initial width of the `mapping` array before edges begin collapsing. The `graph_update_width()` function's logic effectively works out how many times `graph_insert_into_new_columns()` was called based on the relationship of the current commit to the rest of the graph.
I'm about to make some changes that make the assignment of values into the `mapping` array more complicated. Rather than make `graph_update_width()` more complicated at the same time, we can simply remove this function and use `graph->width` to track the offset into the `mapping` array as we're building it. This removes the duplication and makes sure that `graph->width` is the same as the visual width of the `mapping` array once `graph_update_columns()` is complete.
Signed-off-by: James Coglan <jcoglan@gmail.com> --- graph.c | 65 +++++++++------------------------------------------------ 1 file changed, 10 insertions(+), 55 deletions(-)
diff --git a/graph.c b/graph.c index 512ae16535..d724ef25c3 100644 --- a/graph.c +++ b/graph.c @@ -472,8 +472,7 @@ static int graph_find_new_column_by_commit(struct git_graph *graph, } static void graph_insert_into_new_columns(struct git_graph *graph, - struct commit *commit, - int *mapping_index) + struct commit *commit) { int i = graph_find_new_column_by_commit(graph, commit); @@ -487,50 +486,14 @@ static void graph_insert_into_new_columns(struct git_graph *graph, graph->new_columns[i].color = graph_find_commit_color(graph, commit); } - graph->mapping[*mapping_index] = i; - *mapping_index += 2; -} - -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; + graph->mapping[graph->width] = i; + graph->width += 2; } static void graph_update_columns(struct git_graph *graph) { struct commit_list *parent; int max_new_columns; - int mapping_idx; int i, seen_this, is_commit_in_columns; /* @@ -563,6 +526,8 @@ static void graph_update_columns(struct git_graph *graph) for (i = 0; i < graph->mapping_size; i++) graph->mapping[i] = -1; + graph->width = 0; + /* * Populate graph->new_columns and graph->mapping * @@ -573,7 +538,6 @@ static void graph_update_columns(struct git_graph *graph) * 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; @@ -587,7 +551,6 @@ static void graph_update_columns(struct git_graph *graph) } if (col_commit == graph->commit) { - int old_mapping_idx = mapping_idx; seen_this = 1; graph->commit_index = i; for (parent = first_interesting_parent(graph); @@ -602,21 +565,18 @@ static void graph_update_columns(struct git_graph *graph) !is_commit_in_columns) { graph_increment_column_color(graph); } - graph_insert_into_new_columns(graph, - parent->item, - &mapping_idx); + graph_insert_into_new_columns(graph, parent->item); } /* - * We always need to increment mapping_idx by at + * 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 (mapping_idx == old_mapping_idx) - mapping_idx += 2; + if (graph->num_parents == 0) + graph->width += 2; } else { - graph_insert_into_new_columns(graph, col_commit, - &mapping_idx); + graph_insert_into_new_columns(graph, col_commit); } } @@ -626,11 +586,6 @@ static void graph_update_columns(struct git_graph *graph) 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)
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