Introduce git_diff_get_stats, git_diff_stats_files_changed, git_diff_stats_insertions, git_diff_stats_deletions and git_diff_stats_to_buf

1 files changed, 343 insertions, 0 deletions

diff --git a/src/diff_stats.c b/src/diff_stats.c
new file mode 100644
index 000000000..bb436bf7b
--- /dev/null
+++ b/src/diff_stats.c
@@ -0,0 +1,343 @@
+/*
+ * 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 "common.h"
+#include "vector.h"
+#include "diff.h"
+#include "diff_patch.h"
+
+#define DIFF_RENAME_FILE_SEPARATOR " => "
+
+struct git_diff_stats {
+	git_vector patches;
+
+	size_t files_changed;
+	size_t insertions;
+	size_t deletions;
+};
+
+static size_t diff_get_filename_padding(
+	int has_renames,
+	const git_diff_stats *stats)
+{
+	const git_patch *patch = NULL;
+	size_t i, max_padding = 0;
+
+	if (has_renames) {
+		git_vector_foreach(&stats->patches, i, patch) {
+			const git_diff_delta *delta = NULL;
+			size_t len;
+
+			delta = git_patch_get_delta(patch);
+			if (strcmp(delta->old_file.path, delta->new_file.path) == 0)
+				continue;
+
+			if ((len = strlen(delta->old_file.path) + strlen(delta->new_file.path)) > max_padding)
+				max_padding = len;
+		}
+	}
+
+	git_vector_foreach(&stats->patches, i, patch) {
+		const git_diff_delta *delta = NULL;
+		size_t len;
+
+		delta = git_patch_get_delta(patch);
+		len = strlen(delta->new_file.path);
+
+		if (strcmp(delta->old_file.path, delta->new_file.path) != 0)
+			continue;
+
+		if (len > max_padding)
+			max_padding = len;
+	}
+
+	return max_padding;
+}
+
+int git_diff_file_stats__full_to_buf(
+	git_buf *out,
+	size_t max_padding,
+	int has_renames,
+	const git_patch *patch)
+{
+	const char *old_path = NULL, *new_path = NULL;
+	const git_diff_delta *delta = NULL;
+	size_t padding, old_size, new_size;
+	int error;
+
+	delta = git_patch_get_delta(patch);
+
+	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 ((error = git_buf_printf(out, " %s", old_path)) < 0)
+		goto on_error;
+
+	if (strcmp(old_path, new_path) != 0) {
+		padding = max_padding - strlen(old_path) - strlen(new_path);
+
+		if ((error = git_buf_printf(out, DIFF_RENAME_FILE_SEPARATOR "%s", new_path)) < 0)
+			goto on_error;
+	}
+	else {
+		padding = max_padding - strlen(old_path);
+
+		if (has_renames)
+			padding += strlen(DIFF_RENAME_FILE_SEPARATOR);
+	}
+
+	if ((error = git_buf_putcn(out, ' ', padding)) < 0 ||
+		(error = git_buf_puts(out, " | ")) < 0)
+			goto on_error;
+
+	if (delta->flags & GIT_DIFF_FLAG_BINARY) {
+		if ((error = git_buf_printf(out, "Bin %" PRIuZ " -> %" PRIuZ " bytes", old_size, new_size)) < 0)
+			goto on_error;
+	}
+	else {
+		size_t insertions, deletions;
+
+		if ((error = git_patch_line_stats(NULL, &insertions, &deletions, patch)) < 0)
+			goto on_error;
+
+		if ((error = git_buf_printf(out, "%" PRIuZ, insertions + deletions)) < 0)
+			goto on_error;
+
+		if (insertions || deletions) {
+			if ((error = git_buf_putc(out, ' ')) < 0 ||
+				(error = git_buf_putcn(out, '+', insertions)) < 0 ||
+				(error = git_buf_putcn(out, '-', deletions)) < 0)
+					goto on_error;
+		}
+	}
+
+	error = git_buf_putc(out, '\n');
+
+on_error:
+	return error;
+}
+
+int git_diff_file_stats__number_to_buf(
+	git_buf *out,
+	const git_patch *patch)
+{
+	const git_diff_delta *delta = NULL;
+	const char *path = NULL;
+	size_t insertions, deletions;
+	int error;
+
+	delta = git_patch_get_delta(patch);
+	path = delta->new_file.path;
+
+	if ((error = git_patch_line_stats(NULL, &insertions, &deletions, patch)) < 0)
+		return error;
+
+	if (delta->flags & GIT_DIFF_FLAG_BINARY)
+		error = git_buf_printf(out, "%-8c" "%-8c" "%s\n", '-', '-', path);
+	else
+		error = git_buf_printf(out, "%-8" PRIuZ "%-8" PRIuZ "%s\n", insertions, deletions, path);
+
+	return error;
+}
+
+int git_diff_file_stats__summary_to_buf(
+	git_buf *out,
+	const git_patch *patch)
+{
+	const git_diff_delta *delta = NULL;
+
+	delta = git_patch_get_delta(patch);
+
+	if (delta->old_file.mode != delta->new_file.mode) {
+		if (delta->old_file.mode == 0) {
+			git_buf_printf(out, " create mode %06o %s\n",
+				delta->new_file.mode, delta->new_file.path);
+		}
+		else if (delta->new_file.mode == 0) {
+			git_buf_printf(out, " delete mode %06o %s\n",
+				delta->old_file.mode, delta->old_file.path);
+		}
+		else {
+			git_buf_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_stats__has_renames(
+	const git_diff_stats *stats)
+{
+	git_patch *patch = NULL;
+	size_t i;
+
+	git_vector_foreach(&stats->patches, i, patch) {
+		const git_diff_delta *delta = git_patch_get_delta(patch);
+
+		if (strcmp(delta->old_file.path, delta->new_file.path) != 0) {
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+int git_diff_stats__add_file_stats(
+	git_diff_stats *stats,
+	git_patch *patch)
+{
+	const git_diff_delta *delta = NULL;
+	int error = 0;
+
+	if ((delta = git_patch_get_delta(patch)) == NULL)
+		return -1;
+
+	if ((error = git_vector_insert(&stats->patches, patch)) < 0)
+		return error;
+
+	return error;
+}
+
+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;
+
+	assert(out && diff);
+
+	stats = git__calloc(1, sizeof(git_diff_stats));
+	GITERR_CHECK_ALLOC(stats);
+
+	deltas = git_diff_num_deltas(diff);
+
+	for (i = 0; i < deltas; ++i) {
+		git_patch *patch = NULL;
+		size_t add, remove;
+
+		if ((error = git_patch_from_diff(&patch, diff, i)) < 0)
+			goto on_error;
+
+		if ((error = git_patch_line_stats(NULL, &add, &remove, patch)) < 0 ||
+			(error = git_diff_stats__add_file_stats(stats, patch)) < 0) {
+			git_patch_free(patch);
+			goto on_error;
+		}
+
+		total_insertions += add;
+		total_deletions += remove;
+	}
+
+	stats->files_changed = deltas;
+	stats->insertions = total_insertions;
+	stats->deletions = total_deletions;
+
+	*out = stats;
+
+	goto done;
+
+on_error:
+	git_diff_stats_free(stats);
+
+done:
+	return error;
+}
+
+size_t git_diff_stats_files_changed(
+	const git_diff_stats *stats)
+{
+	assert(stats);
+
+	return stats->files_changed;
+}
+
+size_t git_diff_stats_insertions(
+	const git_diff_stats *stats)
+{
+	assert(stats);
+
+	return stats->insertions;
+}
+
+size_t git_diff_stats_deletions(
+	const git_diff_stats *stats)
+{
+	assert(stats);
+
+	return stats->deletions;
+}
+
+int git_diff_stats_to_buf(
+	git_buf *out,
+	const git_diff_stats *stats,
+	git_diff_stats_format_t format)
+{
+	git_patch *patch = NULL;
+	size_t i;
+	int has_renames = 0, error = 0;
+
+	assert(out && stats);
+
+	/* check if we have renames, it affects the padding */
+	has_renames = git_diff_stats__has_renames(stats);
+
+	git_vector_foreach(&stats->patches, i, patch) {
+		if (format & GIT_DIFF_STATS_FULL) {
+			size_t max_padding = diff_get_filename_padding(has_renames, stats);
+
+			error = git_diff_file_stats__full_to_buf(out, max_padding, has_renames, patch);
+		}
+		else if (format & GIT_DIFF_STATS_NUMBER) {
+			error = git_diff_file_stats__number_to_buf(out, patch);
+		}
+
+		if (error < 0)
+			return error;
+	}
+
+	if (format & GIT_DIFF_STATS_FULL || format & GIT_DIFF_STATS_SHORT) {
+		error = git_buf_printf(out, " %" PRIuZ " file%s changed, %" PRIuZ " insertions(+), %" PRIuZ " deletions(-)\n",
+					stats->files_changed, stats->files_changed > 1 ? "s" : "",
+					stats->insertions, stats->deletions);
+
+		if (error < 0)
+			return error;
+	}
+
+	if (format & GIT_DIFF_STATS_INCLUDE_SUMMARY) {
+		git_vector_foreach(&stats->patches, i, patch) {
+			if ((error = git_diff_file_stats__summary_to_buf(out, patch)) < 0)
+				return error;
+		}
+
+		if (git_vector_length(&stats->patches) > 0)
+			git_buf_putc(out, '\n');
+	}
+
+	return error;
+}
+
+void git_diff_stats_free(git_diff_stats *stats)
+{
+	size_t i;
+	git_patch *patch;
+
+	if (stats == NULL)
+		return;
+
+	git_vector_foreach(&stats->patches, i, patch)
+		git_patch_free(patch);
+
+	git_vector_free(&stats->patches);
+	git__free(stats);
+}
+