From: Elijah Newren Date: Sat, 18 Apr 2026 00:32:27 +0000 (+0000) Subject: grep: prefetch necessary blobs X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=e775693160b65bee01ef56c2f240bfe7a0499d5a;p=thirdparty%2Fgit.git grep: prefetch necessary blobs In partial clones, `git grep` fetches necessary blobs on-demand one at a time, which can be very slow. In partial clones, add an extra preliminary walk over the tree similar to grep_tree() which collects the blobs of interest, and then prefetches them. Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano --- diff --git a/builtin/grep.c b/builtin/grep.c index e33285e5e6..d559c48d94 100644 --- a/builtin/grep.c +++ b/builtin/grep.c @@ -28,9 +28,12 @@ #include "object-file.h" #include "object-name.h" #include "odb.h" +#include "oid-array.h" +#include "oidset.h" #include "packfile.h" #include "pager.h" #include "path.h" +#include "promisor-remote.h" #include "read-cache-ll.h" #include "write-or-die.h" @@ -692,6 +695,143 @@ static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec, return hit; } +static void collect_blob_oids_for_tree(struct repository *repo, + const struct pathspec *pathspec, + struct tree_desc *tree, + struct strbuf *base, + int tn_len, + struct oidset *blob_oids) +{ + struct name_entry entry; + int old_baselen = base->len; + struct strbuf name = STRBUF_INIT; + enum interesting match = entry_not_interesting; + + while (tree_entry(tree, &entry)) { + if (match != all_entries_interesting) { + strbuf_addstr(&name, base->buf + tn_len); + match = tree_entry_interesting(repo->index, + &entry, &name, + pathspec); + strbuf_reset(&name); + + if (match == all_entries_not_interesting) + break; + if (match == entry_not_interesting) + continue; + } + + strbuf_add(base, entry.path, tree_entry_len(&entry)); + + if (S_ISREG(entry.mode)) { + oidset_insert(blob_oids, &entry.oid); + } else if (S_ISDIR(entry.mode)) { + enum object_type type; + struct tree_desc sub_tree; + void *data; + unsigned long size; + + data = odb_read_object(repo->objects, &entry.oid, + &type, &size); + if (!data) + die(_("unable to read tree (%s)"), + oid_to_hex(&entry.oid)); + + strbuf_addch(base, '/'); + init_tree_desc(&sub_tree, &entry.oid, data, size); + collect_blob_oids_for_tree(repo, pathspec, &sub_tree, + base, tn_len, blob_oids); + free(data); + } + /* + * ...no else clause for S_ISGITLINK: submodules have their + * own promisor configuration and would need separate fetches + * anyway. + */ + + strbuf_setlen(base, old_baselen); + } + + strbuf_release(&name); +} + +static void collect_blob_oids_for_treeish(struct grep_opt *opt, + const struct pathspec *pathspec, + const struct object_id *tree_ish_oid, + const char *name, + struct oidset *blob_oids) +{ + struct tree_desc tree; + void *data; + unsigned long size; + struct strbuf base = STRBUF_INIT; + int len; + + data = odb_read_object_peeled(opt->repo->objects, tree_ish_oid, + OBJ_TREE, &size, NULL); + + if (!data) + return; + + len = name ? strlen(name) : 0; + if (len) { + strbuf_add(&base, name, len); + strbuf_addch(&base, ':'); + } + init_tree_desc(&tree, tree_ish_oid, data, size); + + collect_blob_oids_for_tree(opt->repo, pathspec, &tree, + &base, base.len, blob_oids); + + strbuf_release(&base); + free(data); +} + +static void prefetch_grep_blobs(struct grep_opt *opt, + const struct pathspec *pathspec, + const struct object_array *list) +{ + struct oidset blob_oids = OIDSET_INIT; + + /* Exit if we're not in a partial clone */ + if (!repo_has_promisor_remote(opt->repo)) + return; + + /* For each tree, gather the blobs in it */ + for (int i = 0; i < list->nr; i++) { + struct object *real_obj; + + obj_read_lock(); + real_obj = deref_tag(opt->repo, list->objects[i].item, + NULL, 0); + obj_read_unlock(); + + if (real_obj && + (real_obj->type == OBJ_COMMIT || + real_obj->type == OBJ_TREE)) + collect_blob_oids_for_treeish(opt, pathspec, + &real_obj->oid, + list->objects[i].name, + &blob_oids); + } + + /* Prefetch the blobs we found */ + if (oidset_size(&blob_oids)) { + struct oid_array to_fetch = OID_ARRAY_INIT; + struct oidset_iter iter; + const struct object_id *oid; + + oidset_iter_init(&blob_oids, &iter); + while ((oid = oidset_iter_next(&iter))) + oid_array_append(&to_fetch, oid); + + promisor_remote_get_direct(opt->repo, to_fetch.oid, to_fetch.nr); + + oid_array_clear(&to_fetch); + } + oidset_clear(&blob_oids); +} + static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec, struct object *obj, const char *name, const char *path) { @@ -732,6 +872,8 @@ static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec, int hit = 0; const unsigned int nr = list->nr; + prefetch_grep_blobs(opt, pathspec, list); + for (i = 0; i < nr; i++) { struct object *real_obj; diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh index 64ac4f04ee..1f484502fe 100755 --- a/t/t7810-grep.sh +++ b/t/t7810-grep.sh @@ -1929,4 +1929,39 @@ test_expect_success 'grep does not report i-t-a and assume unchanged with -L' ' test_cmp expected actual ' +test_expect_success 'grep of revision in partial clone does bulk prefetch' ' + test_when_finished "rm -rf grep-partial-src grep-partial" && + + git init grep-partial-src && + ( + cd grep-partial-src && + git config uploadpack.allowfilter 1 && + git config uploadpack.allowanysha1inwant 1 && + echo "needle in haystack" >searchme && + echo "no match here" >other && + mkdir subdir && + echo "needle again" >subdir/deep && + git add . && + git commit -m "initial" + ) && + + git clone --no-checkout --filter=blob:none \ + "file://$(pwd)/grep-partial-src" grep-partial && + + # All blobs should be missing after a blobless clone. + git -C grep-partial rev-list --quiet --objects \ + --missing=print HEAD >missing && + test_line_count = 3 missing && + + # grep HEAD should batch-prefetch all blobs in one request. + GIT_TRACE2_EVENT="$(pwd)/grep-trace" \ + git -C grep-partial grep -c "needle" HEAD >result && + + # Should find matches in two files. + test_line_count = 2 result && + + # Should have prefetched all 3 objects at once + test_trace2_data promisor fetch_count 3