list-objects: support for skipping tree traversal
The tree:0 filter does not need to traverse the trees that it has filtered out, so optimize list-objects and list-objects-filter to skip traversing the trees entirely. Before this patch, we iterated over all children of the tree, and did nothing for all of them, which was wasteful. Signed-off-by: Matthew DeVore <matvore@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Matthew DeVore committed
Oct 17, 2018 at 17:39 UTC
8b10a206f090e01ce1ac4d9a10ec769e2409e2b0
4 files changed
+32
-3
list-objects-filter.c
+9
-2
@@ -102,9 +102,16 @@ static enum list_objects_filter_result filter_trees_none(
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case LOFS_BEGIN_TREE:
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case LOFS_BLOB:
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- if (filter_data->omits)
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+ if (filter_data->omits) {
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oidset_insert(filter_data->omits, &obj->oid);
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- return LOFR_MARK_SEEN; /* but not LOFR_DO_SHOW (hard omit) */
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+ /* _MARK_SEEN but not _DO_SHOW (hard omit) */
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+ return LOFR_MARK_SEEN;
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+ } else {
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+ /*
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+ * Not collecting omits so no need to to traverse tree.
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+ */
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+ return LOFR_SKIP_TREE | LOFR_MARK_SEEN;
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+ }
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case LOFS_END_TREE:
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assert(obj->type == OBJ_TREE);
list-objects-filter.h
+6
@@ -20,6 +20,11 @@
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* In general, objects should only be shown once, but
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* this result DOES NOT imply that we mark it SEEN.
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*
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+ * _SKIP_TREE : Used in LOFS_BEGIN_TREE situation - indicates that
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+ * the tree's children should not be iterated over. This
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+ * is used as an optimization when all children will
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+ * definitely be ignored.
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+ *
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* Most of the time, you want the combination (_MARK_SEEN | _DO_SHOW)
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* but they can be used independently, such as when sparse-checkout
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* pattern matching is being applied.
@@ -41,6 +46,7 @@ enum list_objects_filter_result {
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LOFR_ZERO = 0,
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LOFR_MARK_SEEN = 1<<0,
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LOFR_DO_SHOW = 1<<1,
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+ LOFR_SKIP_TREE = 1<<2,
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};
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enum list_objects_filter_situation {
list-objects.c
+4
-1
@@ -11,6 +11,7 @@
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#include "list-objects-filter-options.h"
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#include "packfile.h"
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#include "object-store.h"
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+#include "trace.h"
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struct traversal_context {
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struct rev_info *revs;
@@ -184,7 +185,9 @@ static void process_tree(struct traversal_context *ctx,
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if (base->len)
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strbuf_addch(base, '/');
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- if (!failed_parse)
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+ if (r & LOFR_SKIP_TREE)
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+ trace_printf("Skipping contents of tree %s...\n", base->buf);
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+ else if (!failed_parse)
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process_tree_contents(ctx, tree, base);
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if ((obj->flags & NOT_USER_GIVEN) && ctx->filter_fn) {
t/t6112-rev-list-filters-objects.sh
+13
@@ -245,6 +245,19 @@ test_expect_success 'verify tree:0 includes trees in "filtered" output' '
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test_cmp expected filtered_types
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'
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+# Make sure tree:0 does not iterate through any trees.
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+
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+test_expect_success 'filter a GIANT tree through tree:0' '
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+ GIT_TRACE=1 git -C r3 rev-list \
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+ --objects --filter=tree:0 HEAD 2>filter_trace &&
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+ grep "Skipping contents of tree [.][.][.]" filter_trace >actual &&
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+ # One line for each commit traversed.
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+ test_line_count = 2 actual &&
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+
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+ # Make sure no other trees were considered besides the root.
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+ ! grep "Skipping contents of tree [^.]" filter_trace
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+'
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+
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# Delete some loose objects and use rev-list, but WITHOUT any filtering.
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# This models previously omitted objects that we did not receive.
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