ref-filter.c: filter & format refs in the same callback
Update 'filter_and_format_refs()' to try to perform ref filtering & formatting in a single ref iteration, without an intermediate 'struct ref_array'. This can only be done if no operations need to be performed on a pre-filtered array; specifically, if the refs are - filtered on reachability, - sorted, or - formatted with ahead-behind information they cannot be filtered & formatted in the same iteration. In that case, fall back on the current filter-then-sort-then-format flow. This optimization substantially improves memory usage due to no longer storing a ref array in memory. In some cases, it also dramatically reduces runtime (e.g. 'git for-each-ref --no-sort --count=1', which no longer loads all refs into a 'struct ref_array' to printing only the first ref). Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Victoria Dye committed
Nov 14, 2023 at 19:53 UTC
bd98f9774e10808276c13f8438aa3c71093bc6a4
1 file changed
+82
-6
ref-filter.c
+82
-6
@@ -2779,6 +2779,49 @@ static void free_array_item(struct ref_array_item *item)
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free(item);
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}
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+struct ref_filter_and_format_cbdata {
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+ struct ref_filter *filter;
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+ struct ref_format *format;
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+
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+ struct ref_filter_and_format_internal {
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+ int count;
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+ } internal;
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+};
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+
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+static int filter_and_format_one(const char *refname, const struct object_id *oid, int flag, void *cb_data)
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+{
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+ struct ref_filter_and_format_cbdata *ref_cbdata = cb_data;
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+ struct ref_array_item *ref;
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+ struct strbuf output = STRBUF_INIT, err = STRBUF_INIT;
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+
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+ ref = apply_ref_filter(refname, oid, flag, ref_cbdata->filter);
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+ if (!ref)
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+ return 0;
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+
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+ if (format_ref_array_item(ref, ref_cbdata->format, &output, &err))
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+ die("%s", err.buf);
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+
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+ if (output.len || !ref_cbdata->format->array_opts.omit_empty) {
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+ fwrite(output.buf, 1, output.len, stdout);
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+ putchar('\n');
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+ }
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+
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+ strbuf_release(&output);
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+ strbuf_release(&err);
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+ free_array_item(ref);
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+
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+ /*
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+ * Increment the running count of refs that match the filter. If
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+ * max_count is set and we've reached the max, stop the ref
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+ * iteration by returning a nonzero value.
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+ */
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+ if (ref_cbdata->format->array_opts.max_count &&
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+ ++ref_cbdata->internal.count >= ref_cbdata->format->array_opts.max_count)
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+ return 1;
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+
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+ return 0;
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+}
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+
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/* Free all memory allocated for ref_array */
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void ref_array_clear(struct ref_array *array)
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{
@@ -2962,16 +3005,49 @@ int filter_refs(struct ref_array *array, struct ref_filter *filter, unsigned int
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return ret;
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}
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+static inline int can_do_iterative_format(struct ref_filter *filter,
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+ struct ref_sorting *sorting,
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+ struct ref_format *format)
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+{
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+ /*
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+ * Filtering & formatting results within a single ref iteration
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+ * callback is not compatible with options that require
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+ * post-processing a filtered ref_array. These include:
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+ * - filtering on reachability
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+ * - sorting the filtered results
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+ * - including ahead-behind information in the formatted output
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+ */
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+ return !(filter->reachable_from ||
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+ filter->unreachable_from ||
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+ sorting ||
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+ format->bases.nr);
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+}
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+
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void filter_and_format_refs(struct ref_filter *filter, unsigned int type,
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struct ref_sorting *sorting,
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struct ref_format *format)
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{
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- struct ref_array array = { 0 };
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- filter_refs(&array, filter, type);
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- filter_ahead_behind(the_repository, format, &array);
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- ref_array_sort(sorting, &array);
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- print_formatted_ref_array(&array, format);
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- ref_array_clear(&array);
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+ if (can_do_iterative_format(filter, sorting, format)) {
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+ int save_commit_buffer_orig;
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+ struct ref_filter_and_format_cbdata ref_cbdata = {
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+ .filter = filter,
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+ .format = format,
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+ };
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+
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+ save_commit_buffer_orig = save_commit_buffer;
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+ save_commit_buffer = 0;
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+
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+ do_filter_refs(filter, type, filter_and_format_one, &ref_cbdata);
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+
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+ save_commit_buffer = save_commit_buffer_orig;
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+ } else {
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+ struct ref_array array = { 0 };
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+ filter_refs(&array, filter, type);
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+ filter_ahead_behind(the_repository, format, &array);
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+ ref_array_sort(sorting, &array);
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+ print_formatted_ref_array(&array, format);
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+ ref_array_clear(&array);
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+ }
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}
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static int compare_detached_head(struct ref_array_item *a, struct ref_array_item *b)