1 files changed, 376 insertions, 0 deletions

diff --git a/src/libgit2/diff_stats.c b/src/libgit2/diff_stats.c
new file mode 100644
index 000000000..259939844
--- /dev/null
+++ b/src/libgit2/diff_stats.c
@@ -0,0 +1,376 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "diff_stats.h"
+
+#include "buf.h"
+#include "common.h"
+#include "vector.h"
+#include "diff.h"
+#include "patch_generate.h"
+
+#define DIFF_RENAME_FILE_SEPARATOR " => "
+#define STATS_FULL_MIN_SCALE 7
+
+typedef struct {
+	size_t insertions;
+	size_t deletions;
+} diff_file_stats;
+
+struct git_diff_stats {
+	git_diff *diff;
+	diff_file_stats *filestats;
+
+	size_t files_changed;
+	size_t insertions;
+	size_t deletions;
+	size_t renames;
+
+	size_t max_name;
+	size_t max_filestat;
+	int max_digits;
+};
+
+static int digits_for_value(size_t val)
+{
+	int count = 1;
+	size_t placevalue = 10;
+
+	while (val >= placevalue) {
+		++count;
+		placevalue *= 10;
+	}
+
+	return count;
+}
+
+static int diff_file_stats_full_to_buf(
+	git_str *out,
+	const git_diff_delta *delta,
+	const diff_file_stats *filestat,
+	const git_diff_stats *stats,
+	size_t width)
+{
+	const char *old_path = NULL, *new_path = NULL, *adddel_path = NULL;
+	size_t padding;
+	git_object_size_t old_size, new_size;
+
+	old_path = delta->old_file.path;
+	new_path = delta->new_file.path;
+	old_size = delta->old_file.size;
+	new_size = delta->new_file.size;
+
+	if (old_path && new_path && strcmp(old_path, new_path) != 0) {
+		size_t common_dirlen;
+		int error;
+
+		padding = stats->max_name - strlen(old_path) - strlen(new_path);
+
+		if ((common_dirlen = git_fs_path_common_dirlen(old_path, new_path)) &&
+		    common_dirlen <= INT_MAX) {
+			error = git_str_printf(out, " %.*s{%s"DIFF_RENAME_FILE_SEPARATOR"%s}",
+					       (int) common_dirlen, old_path,
+					       old_path + common_dirlen,
+					       new_path + common_dirlen);
+		} else {
+			error = git_str_printf(out, " %s" DIFF_RENAME_FILE_SEPARATOR "%s",
+					       old_path, new_path);
+		}
+
+		if (error < 0)
+			goto on_error;
+	} else {
+		adddel_path = new_path ? new_path : old_path;
+		if (git_str_printf(out, " %s", adddel_path) < 0)
+			goto on_error;
+
+		padding = stats->max_name - strlen(adddel_path);
+
+		if (stats->renames > 0)
+			padding += strlen(DIFF_RENAME_FILE_SEPARATOR);
+	}
+
+	if (git_str_putcn(out, ' ', padding) < 0 ||
+		git_str_puts(out, " | ") < 0)
+		goto on_error;
+
+	if (delta->flags & GIT_DIFF_FLAG_BINARY) {
+		if (git_str_printf(out,
+				"Bin %" PRId64 " -> %" PRId64 " bytes", old_size, new_size) < 0)
+			goto on_error;
+	}
+	else {
+		if (git_str_printf(out,
+				"%*" PRIuZ, stats->max_digits,
+				filestat->insertions + filestat->deletions) < 0)
+			goto on_error;
+
+		if (filestat->insertions || filestat->deletions) {
+			if (git_str_putc(out, ' ') < 0)
+				goto on_error;
+
+			if (!width) {
+				if (git_str_putcn(out, '+', filestat->insertions) < 0 ||
+					git_str_putcn(out, '-', filestat->deletions) < 0)
+					goto on_error;
+			} else {
+				size_t total = filestat->insertions + filestat->deletions;
+				size_t full = (total * width + stats->max_filestat / 2) /
+					stats->max_filestat;
+				size_t plus = full * filestat->insertions / total;
+				size_t minus = full - plus;
+
+				if (git_str_putcn(out, '+', max(plus,  1)) < 0 ||
+					git_str_putcn(out, '-', max(minus, 1)) < 0)
+					goto on_error;
+			}
+		}
+	}
+
+	git_str_putc(out, '\n');
+
+on_error:
+	return (git_str_oom(out) ? -1 : 0);
+}
+
+static int diff_file_stats_number_to_buf(
+	git_str *out,
+	const git_diff_delta *delta,
+	const diff_file_stats *filestats)
+{
+	int error;
+	const char *path = delta->new_file.path;
+
+	if (delta->flags & GIT_DIFF_FLAG_BINARY)
+		error = git_str_printf(out, "%-8c" "%-8c" "%s\n", '-', '-', path);
+	else
+		error = git_str_printf(out, "%-8" PRIuZ "%-8" PRIuZ "%s\n",
+			filestats->insertions, filestats->deletions, path);
+
+	return error;
+}
+
+static int diff_file_stats_summary_to_buf(
+	git_str *out,
+	const git_diff_delta *delta)
+{
+	if (delta->old_file.mode != delta->new_file.mode) {
+		if (delta->old_file.mode == 0) {
+			git_str_printf(out, " create mode %06o %s\n",
+				delta->new_file.mode, delta->new_file.path);
+		}
+		else if (delta->new_file.mode == 0) {
+			git_str_printf(out, " delete mode %06o %s\n",
+				delta->old_file.mode, delta->old_file.path);
+		}
+		else {
+			git_str_printf(out, " mode change %06o => %06o %s\n",
+				delta->old_file.mode, delta->new_file.mode, delta->new_file.path);
+		}
+	}
+
+	return 0;
+}
+
+int git_diff_get_stats(
+	git_diff_stats **out,
+	git_diff *diff)
+{
+	size_t i, deltas;
+	size_t total_insertions = 0, total_deletions = 0;
+	git_diff_stats *stats = NULL;
+	int error = 0;
+
+	GIT_ASSERT_ARG(out);
+	GIT_ASSERT_ARG(diff);
+
+	stats = git__calloc(1, sizeof(git_diff_stats));
+	GIT_ERROR_CHECK_ALLOC(stats);
+
+	deltas = git_diff_num_deltas(diff);
+
+	stats->filestats = git__calloc(deltas, sizeof(diff_file_stats));
+	if (!stats->filestats) {
+		git__free(stats);
+		return -1;
+	}
+
+	stats->diff = diff;
+	GIT_REFCOUNT_INC(diff);
+
+	for (i = 0; i < deltas && !error; ++i) {
+		git_patch *patch = NULL;
+		size_t add = 0, remove = 0, namelen;
+		const git_diff_delta *delta;
+
+		if ((error = git_patch_from_diff(&patch, diff, i)) < 0)
+			break;
+
+		/* keep a count of renames because it will affect formatting */
+		delta = patch->delta;
+
+		/* TODO ugh */
+		namelen = strlen(delta->new_file.path);
+		if (delta->old_file.path && strcmp(delta->old_file.path, delta->new_file.path) != 0) {
+			namelen += strlen(delta->old_file.path);
+			stats->renames++;
+		}
+
+		/* and, of course, count the line stats */
+		error = git_patch_line_stats(NULL, &add, &remove, patch);
+
+		git_patch_free(patch);
+
+		stats->filestats[i].insertions = add;
+		stats->filestats[i].deletions = remove;
+
+		total_insertions += add;
+		total_deletions += remove;
+
+		if (stats->max_name < namelen)
+			stats->max_name = namelen;
+		if (stats->max_filestat < add + remove)
+			stats->max_filestat = add + remove;
+	}
+
+	stats->files_changed = deltas;
+	stats->insertions = total_insertions;
+	stats->deletions = total_deletions;
+	stats->max_digits = digits_for_value(stats->max_filestat + 1);
+
+	if (error < 0) {
+		git_diff_stats_free(stats);
+		stats = NULL;
+	}
+
+	*out = stats;
+	return error;
+}
+
+size_t git_diff_stats_files_changed(
+	const git_diff_stats *stats)
+{
+	GIT_ASSERT_ARG(stats);
+
+	return stats->files_changed;
+}
+
+size_t git_diff_stats_insertions(
+	const git_diff_stats *stats)
+{
+	GIT_ASSERT_ARG(stats);
+
+	return stats->insertions;
+}
+
+size_t git_diff_stats_deletions(
+	const git_diff_stats *stats)
+{
+	GIT_ASSERT_ARG(stats);
+
+	return stats->deletions;
+}
+
+int git_diff_stats_to_buf(
+	git_buf *out,
+	const git_diff_stats *stats,
+	git_diff_stats_format_t format,
+	size_t width)
+{
+	GIT_BUF_WRAP_PRIVATE(out, git_diff__stats_to_buf, stats, format, width);
+}
+
+int git_diff__stats_to_buf(
+	git_str *out,
+	const git_diff_stats *stats,
+	git_diff_stats_format_t format,
+	size_t width)
+{
+	int error = 0;
+	size_t i;
+	const git_diff_delta *delta;
+
+	GIT_ASSERT_ARG(out);
+	GIT_ASSERT_ARG(stats);
+
+	if (format & GIT_DIFF_STATS_NUMBER) {
+		for (i = 0; i < stats->files_changed; ++i) {
+			if ((delta = git_diff_get_delta(stats->diff, i)) == NULL)
+				continue;
+
+			error = diff_file_stats_number_to_buf(
+				out, delta, &stats->filestats[i]);
+			if (error < 0)
+				return error;
+		}
+	}
+
+	if (format & GIT_DIFF_STATS_FULL) {
+		if (width > 0) {
+			if (width > stats->max_name + stats->max_digits + 5)
+				width -= (stats->max_name + stats->max_digits + 5);
+			if (width < STATS_FULL_MIN_SCALE)
+				width = STATS_FULL_MIN_SCALE;
+		}
+		if (width > stats->max_filestat)
+			width = 0;
+
+		for (i = 0; i < stats->files_changed; ++i) {
+			if ((delta = git_diff_get_delta(stats->diff, i)) == NULL)
+				continue;
+
+			error = diff_file_stats_full_to_buf(
+				out, delta, &stats->filestats[i], stats, width);
+			if (error < 0)
+				return error;
+		}
+	}
+
+	if (format & GIT_DIFF_STATS_FULL || format & GIT_DIFF_STATS_SHORT) {
+		git_str_printf(
+			out, " %" PRIuZ " file%s changed",
+			stats->files_changed, stats->files_changed != 1 ? "s" : "");
+
+		if (stats->insertions || stats->deletions == 0)
+			git_str_printf(
+				out, ", %" PRIuZ " insertion%s(+)",
+				stats->insertions, stats->insertions != 1 ? "s" : "");
+
+		if (stats->deletions || stats->insertions == 0)
+			git_str_printf(
+				out, ", %" PRIuZ " deletion%s(-)",
+				stats->deletions, stats->deletions != 1 ? "s" : "");
+
+		git_str_putc(out, '\n');
+
+		if (git_str_oom(out))
+			return -1;
+	}
+
+	if (format & GIT_DIFF_STATS_INCLUDE_SUMMARY) {
+		for (i = 0; i < stats->files_changed; ++i) {
+			if ((delta = git_diff_get_delta(stats->diff, i)) == NULL)
+				continue;
+
+			error = diff_file_stats_summary_to_buf(out, delta);
+			if (error < 0)
+				return error;
+		}
+	}
+
+	return error;
+}
+
+void git_diff_stats_free(git_diff_stats *stats)
+{
+	if (stats == NULL)
+		return;
+
+	git_diff_free(stats->diff); /* bumped refcount in constructor */
+	git__free(stats->filestats);
+	git__free(stats);
+}