list-objects-filter: teach tree:# how to handle >0
authorMatthew DeVore <matvore@google.com>
Wed, 9 Jan 2019 02:59:13 +0000 (18:59 -0800)
committerJunio C Hamano <gitster@pobox.com>
Tue, 15 Jan 2019 23:39:34 +0000 (15:39 -0800)
Implement positive values for <depth> in the tree:<depth> filter. The
exact semantics are described in Documentation/rev-list-options.txt.

The long-term goal at the end of this is to allow a partial clone to
eagerly fetch an entire directory of files by fetching a tree and
specifying <depth>=1. This, for instance, would make a build operation
fast and convenient. It is fast because the partial clone does not need
to fetch each file individually, and convenient because the user does
not need to supply a sparse-checkout specification.

Another way of considering this feature is as a way to reduce
round-trips, since the client can get any number of levels of
directories in a single request, rather than wait for each level of tree
objects to come back, whose entries are used to construct a new request.

Signed-off-by: Matthew DeVore <matvore@google.com>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation/rev-list-options.txt
list-objects-filter-options.c
list-objects-filter-options.h
list-objects-filter.c
t/t6112-rev-list-filters-objects.sh
index bab5f50b1724913c7607180897b7f92d1517dda9..f8ab00f7c9e966b3c117a13fb19e152a9ae3a903 100644 (file)
@@ -734,8 +734,13 @@ specification contained in <path>.
 +
 The form '--filter=tree:<depth>' omits all blobs and trees whose depth
 from the root tree is >= <depth> (minimum depth if an object is located
-at multiple depths in the commits traversed). Currently, only <depth>=0
-is supported, which omits all blobs and trees.
+at multiple depths in the commits traversed). <depth>=0 will not include
+any trees or blobs unless included explicitly in the command-line (or
+standard input when --stdin is used). <depth>=1 will include only the
+tree and blobs which are referenced directly by a commit reachable from
+<commit> or an explicitly-given object. <depth>=2 is like <depth>=1
+while also including trees and blobs one more level removed from an
+explicitly-given commit or tree.
 
 --no-filter::
        Turn off any previous `--filter=` argument.
index e8da2e8581b2df956411f19e796ceb94adcef903..5285e7674dbbdc07d764f6b2b6dd5a54f061268b 100644 (file)
@@ -50,16 +50,15 @@ static int gently_parse_list_objects_filter(
                }
 
        } else if (skip_prefix(arg, "tree:", &v0)) {
-               unsigned long depth;
-               if (!git_parse_ulong(v0, &depth) || depth != 0) {
+               if (!git_parse_ulong(v0, &filter_options->tree_exclude_depth)) {
                        if (errbuf) {
                                strbuf_addstr(
                                        errbuf,
-                                       _("only 'tree:0' is supported"));
+                                       _("expected 'tree:<depth>'"));
                        }
                        return 1;
                }
-               filter_options->choice = LOFC_TREE_NONE;
+               filter_options->choice = LOFC_TREE_DEPTH;
                return 0;
 
        } else if (skip_prefix(arg, "sparse:oid=", &v0)) {
index af64e5c66fc4a242f9cc534380a9b3e8f1e67d00..477cd970295ba29c1bb092d9a88192b9a40d97fe 100644 (file)
@@ -10,7 +10,7 @@ enum list_objects_filter_choice {
        LOFC_DISABLED = 0,
        LOFC_BLOB_NONE,
        LOFC_BLOB_LIMIT,
-       LOFC_TREE_NONE,
+       LOFC_TREE_DEPTH,
        LOFC_SPARSE_OID,
        LOFC_SPARSE_PATH,
        LOFC__COUNT /* must be last */
@@ -44,6 +44,7 @@ struct list_objects_filter_options {
        struct object_id *sparse_oid_value;
        char *sparse_path_value;
        unsigned long blob_limit_value;
+       unsigned long tree_exclude_depth;
 };
 
 /* Normalized command line arguments */
index a62624a1ced704156395b3e30312f264aa46b862..786e0dd0b15a6d959515312cb9ceea8410c398a1 100644 (file)
@@ -10,6 +10,7 @@
 #include "list-objects.h"
 #include "list-objects-filter.h"
 #include "list-objects-filter-options.h"
+#include "oidmap.h"
 #include "oidset.h"
 #include "object-store.h"
 
@@ -84,11 +85,43 @@ static void *filter_blobs_none__init(
  * A filter for list-objects to omit ALL trees and blobs from the traversal.
  * Can OPTIONALLY collect a list of the omitted OIDs.
  */
-struct filter_trees_none_data {
+struct filter_trees_depth_data {
        struct oidset *omits;
+
+       /*
+        * Maps trees to the minimum depth at which they were seen. It is not
+        * necessary to re-traverse a tree at deeper or equal depths than it has
+        * already been traversed.
+        *
+        * We can't use LOFR_MARK_SEEN for tree objects since this will prevent
+        * it from being traversed at shallower depths.
+        */
+       struct oidmap seen_at_depth;
+
+       unsigned long exclude_depth;
+       unsigned long current_depth;
 };
 
-static enum list_objects_filter_result filter_trees_none(
+struct seen_map_entry {
+       struct oidmap_entry base;
+       size_t depth;
+};
+
+static void filter_trees_update_omits(
+       struct object *obj,
+       struct filter_trees_depth_data *filter_data,
+       int include_it)
+{
+       if (!filter_data->omits)
+               return;
+
+       if (include_it)
+               oidset_remove(filter_data->omits, &obj->oid);
+       else
+               oidset_insert(filter_data->omits, &obj->oid);
+}
+
+static enum list_objects_filter_result filter_trees_depth(
        struct repository *r,
        enum list_objects_filter_situation filter_situation,
        struct object *obj,
@@ -96,43 +129,86 @@ static enum list_objects_filter_result filter_trees_none(
        const char *filename,
        void *filter_data_)
 {
-       struct filter_trees_none_data *filter_data = filter_data_;
+       struct filter_trees_depth_data *filter_data = filter_data_;
+       struct seen_map_entry *seen_info;
+       int include_it = filter_data->current_depth <
+               filter_data->exclude_depth;
+       int filter_res;
+       int already_seen;
+
+       /*
+        * Note that we do not use _MARK_SEEN in order to allow re-traversal in
+        * case we encounter a tree or blob again at a shallower depth.
+        */
 
        switch (filter_situation) {
        default:
                BUG("unknown filter_situation: %d", filter_situation);
 
-       case LOFS_BEGIN_TREE:
+       case LOFS_END_TREE:
+               assert(obj->type == OBJ_TREE);
+               filter_data->current_depth--;
+               return LOFR_ZERO;
+
        case LOFS_BLOB:
-               if (filter_data->omits) {
-                       oidset_insert(filter_data->omits, &obj->oid);
-                       /* _MARK_SEEN but not _DO_SHOW (hard omit) */
-                       return LOFR_MARK_SEEN;
+               filter_trees_update_omits(obj, filter_data, include_it);
+               return include_it ? LOFR_MARK_SEEN | LOFR_DO_SHOW : LOFR_ZERO;
+
+       case LOFS_BEGIN_TREE:
+               seen_info = oidmap_get(
+                       &filter_data->seen_at_depth, &obj->oid);
+               if (!seen_info) {
+                       seen_info = xcalloc(1, sizeof(*seen_info));
+                       oidcpy(&seen_info->base.oid, &obj->oid);
+                       seen_info->depth = filter_data->current_depth;
+                       oidmap_put(&filter_data->seen_at_depth, seen_info);
+                       already_seen = 0;
                } else {
-                       /*
-                        * Not collecting omits so no need to to traverse tree.
-                        */
-                       return LOFR_SKIP_TREE | LOFR_MARK_SEEN;
+                       already_seen =
+                               filter_data->current_depth >= seen_info->depth;
                }
 
-       case LOFS_END_TREE:
-               assert(obj->type == OBJ_TREE);
-               return LOFR_ZERO;
+               if (already_seen) {
+                       filter_res = LOFR_SKIP_TREE;
+               } else {
+                       seen_info->depth = filter_data->current_depth;
+                       filter_trees_update_omits(obj, filter_data, include_it);
+
+                       if (include_it)
+                               filter_res = LOFR_DO_SHOW;
+                       else if (filter_data->omits)
+                               filter_res = LOFR_ZERO;
+                       else
+                               filter_res = LOFR_SKIP_TREE;
+               }
 
+               filter_data->current_depth++;
+               return filter_res;
        }
 }
 
-static void* filter_trees_none__init(
+static void filter_trees_free(void *filter_data) {
+       struct filter_trees_depth_data *d = filter_data;
+       if (!d)
+               return;
+       oidmap_free(&d->seen_at_depth, 1);
+       free(d);
+}
+
+static void *filter_trees_depth__init(
        struct oidset *omitted,
        struct list_objects_filter_options *filter_options,
        filter_object_fn *filter_fn,
        filter_free_fn *filter_free_fn)
 {
-       struct filter_trees_none_data *d = xcalloc(1, sizeof(*d));
+       struct filter_trees_depth_data *d = xcalloc(1, sizeof(*d));
        d->omits = omitted;
+       oidmap_init(&d->seen_at_depth, 0);
+       d->exclude_depth = filter_options->tree_exclude_depth;
+       d->current_depth = 0;
 
-       *filter_fn = filter_trees_none;
-       *filter_free_fn = free;
+       *filter_fn = filter_trees_depth;
+       *filter_free_fn = filter_trees_free;
        return d;
 }
 
@@ -430,7 +506,7 @@ static filter_init_fn s_filters[] = {
        NULL,
        filter_blobs_none__init,
        filter_blobs_limit__init,
-       filter_trees_none__init,
+       filter_trees_depth__init,
        filter_sparse_oid__init,
        filter_sparse_path__init,
 };
index eb32505a6ef8804f4f7762ce0332f00beeacbe99..706845f1d9f8f8031031785129a7042049c4f1a9 100755 (executable)
@@ -294,6 +294,117 @@ test_expect_success 'filter a GIANT tree through tree:0' '
        ! grep "Skipping contents of tree [^.]" filter_trace
 '
 
+# Test tree:# filters.
+
+expect_has () {
+       commit=$1 &&
+       name=$2 &&
+
+       hash=$(git -C r3 rev-parse $commit:$name) &&
+       grep "^$hash $name$" actual
+}
+
+test_expect_success 'verify tree:1 includes root trees' '
+       git -C r3 rev-list --objects --filter=tree:1 HEAD >actual &&
+
+       # We should get two root directories and two commits.
+       expect_has HEAD "" &&
+       expect_has HEAD~1 ""  &&
+       test_line_count = 4 actual
+'
+
+test_expect_success 'verify tree:2 includes root trees and immediate children' '
+       git -C r3 rev-list --objects --filter=tree:2 HEAD >actual &&
+
+       expect_has HEAD "" &&
+       expect_has HEAD~1 "" &&
+       expect_has HEAD dir1 &&
+       expect_has HEAD pattern &&
+       expect_has HEAD sparse1 &&
+       expect_has HEAD sparse2 &&
+
+       # There are also 2 commit objects
+       test_line_count = 8 actual
+'
+
+test_expect_success 'verify tree:3 includes everything expected' '
+       git -C r3 rev-list --objects --filter=tree:3 HEAD >actual &&
+
+       expect_has HEAD "" &&
+       expect_has HEAD~1 "" &&
+       expect_has HEAD dir1 &&
+       expect_has HEAD dir1/sparse1 &&
+       expect_has HEAD dir1/sparse2 &&
+       expect_has HEAD pattern &&
+       expect_has HEAD sparse1 &&
+       expect_has HEAD sparse2 &&
+
+       # There are also 2 commit objects
+       test_line_count = 10 actual
+'
+
+# Test provisional omit collection logic with a repo that has objects appearing
+# at multiple depths - first deeper than the filter's threshold, then shallow.
+
+test_expect_success 'setup r4' '
+       git init r4 &&
+
+       echo foo > r4/foo &&
+       mkdir r4/subdir &&
+       echo bar > r4/subdir/bar &&
+
+       mkdir r4/filt &&
+       cp -r r4/foo r4/subdir r4/filt &&
+
+       git -C r4 add foo subdir filt &&
+       git -C r4 commit -m "commit msg"
+'
+
+expect_has_with_different_name () {
+       repo=$1 &&
+       name=$2 &&
+
+       hash=$(git -C $repo rev-parse HEAD:$name) &&
+       ! grep "^$hash $name$" actual &&
+       grep "^$hash " actual &&
+       ! grep "~$hash" actual
+}
+
+test_expect_success 'test tree:# filter provisional omit for blob and tree' '
+       git -C r4 rev-list --objects --filter-print-omitted --filter=tree:2 \
+               HEAD >actual &&
+       expect_has_with_different_name r4 filt/foo &&
+       expect_has_with_different_name r4 filt/subdir
+'
+
+# Test tree:<depth> where a tree is iterated to twice - once where a subentry is
+# too deep to be included, and again where the blob inside it is shallow enough
+# to be included. This makes sure we don't use LOFR_MARK_SEEN incorrectly (we
+# can't use it because a tree can be iterated over again at a lower depth).
+
+test_expect_success 'tree:<depth> where we iterate over tree at two levels' '
+       git init r5 &&
+
+       mkdir -p r5/a/subdir/b &&
+       echo foo > r5/a/subdir/b/foo &&
+
+       mkdir -p r5/subdir/b &&
+       echo foo > r5/subdir/b/foo &&
+
+       git -C r5 add a subdir &&
+       git -C r5 commit -m "commit msg" &&
+
+       git -C r5 rev-list --objects --filter=tree:4 HEAD >actual &&
+       expect_has_with_different_name r5 a/subdir/b/foo
+'
+
+test_expect_success 'tree:<depth> which filters out blob but given as arg' '
+       blob_hash=$(git -C r4 rev-parse HEAD:subdir/bar) &&
+
+       git -C r4 rev-list --objects --filter=tree:1 HEAD $blob_hash >actual &&
+       grep ^$blob_hash actual
+'
+
 # Delete some loose objects and use rev-list, but WITHOUT any filtering.
 # This models previously omitted objects that we did not receive.