@@ -1090,6 +1090,7 @@ LIB_OBJS += parse-options.o
LIB_OBJS += patch-delta.o
LIB_OBJS += patch-ids.o
LIB_OBJS += path.o
+LIB_OBJS += path-walk.o
LIB_OBJS += pathspec.o
LIB_OBJS += pkt-line.o
LIB_OBJS += preload-index.o
new file mode 100644
@@ -0,0 +1,235 @@
+/*
+ * path-walk.c: implementation for path-based walks of the object graph.
+ */
+#include "git-compat-util.h"
+#include "path-walk.h"
+#include "blob.h"
+#include "commit.h"
+#include "dir.h"
+#include "hashmap.h"
+#include "hex.h"
+#include "object.h"
+#include "oid-array.h"
+#include "revision.h"
+#include "string-list.h"
+#include "strmap.h"
+#include "trace2.h"
+#include "tree.h"
+#include "tree-walk.h"
+
+struct type_and_oid_list
+{
+ enum object_type type;
+ struct oid_array oids;
+};
+
+#define TYPE_AND_OID_LIST_INIT { \
+ .type = OBJ_NONE, \
+ .oids = OID_ARRAY_INIT \
+}
+
+struct path_walk_context {
+ /**
+ * Repeats of data in 'struct path_walk_info' for
+ * access with fewer characters.
+ */
+ struct repository *repo;
+ struct rev_info *revs;
+ struct path_walk_info *info;
+
+ /**
+ * Map a path to a 'struct type_and_oid_list'
+ * containing the objects discovered at that
+ * path.
+ */
+ struct strmap paths_to_lists;
+
+ /**
+ * Store the current list of paths in a stack, to
+ * facilitate depth-first-search without recursion.
+ */
+ struct string_list path_stack;
+};
+
+static int add_children(struct path_walk_context *ctx,
+ const char *base_path,
+ struct object_id *oid)
+{
+ struct tree_desc desc;
+ struct name_entry entry;
+ struct strbuf path = STRBUF_INIT;
+ size_t base_len;
+ struct tree *tree = lookup_tree(ctx->repo, oid);
+
+ if (!tree) {
+ error(_("failed to walk children of tree %s: not found"),
+ oid_to_hex(oid));
+ return -1;
+ }
+
+ strbuf_addstr(&path, base_path);
+ base_len = path.len;
+
+ parse_tree(tree);
+ init_tree_desc(&desc, &tree->object.oid, tree->buffer, tree->size);
+ while (tree_entry(&desc, &entry)) {
+ struct type_and_oid_list *list;
+ struct object *o;
+ /* Not actually true, but we will ignore submodules later. */
+ enum object_type type = S_ISDIR(entry.mode) ? OBJ_TREE : OBJ_BLOB;
+
+ /* Skip submodules. */
+ if (S_ISGITLINK(entry.mode))
+ continue;
+
+ if (type == OBJ_TREE) {
+ struct tree *child = lookup_tree(ctx->repo, &entry.oid);
+ o = child ? &child->object : NULL;
+ } else if (type == OBJ_BLOB) {
+ struct blob *child = lookup_blob(ctx->repo, &entry.oid);
+ o = child ? &child->object : NULL;
+ } else {
+ /* Wrong type? */
+ continue;
+ }
+
+ if (!o) /* report error?*/
+ continue;
+
+ /* Skip this object if already seen. */
+ if (o->flags & SEEN)
+ continue;
+ o->flags |= SEEN;
+
+ strbuf_setlen(&path, base_len);
+ strbuf_add(&path, entry.path, entry.pathlen);
+
+ /*
+ * Trees will end with "/" for concatenation and distinction
+ * from blobs at the same path.
+ */
+ if (type == OBJ_TREE)
+ strbuf_addch(&path, '/');
+
+ if (!(list = strmap_get(&ctx->paths_to_lists, path.buf))) {
+ CALLOC_ARRAY(list, 1);
+ list->type = type;
+ strmap_put(&ctx->paths_to_lists, path.buf, list);
+ string_list_append(&ctx->path_stack, path.buf);
+ }
+ oid_array_append(&list->oids, &entry.oid);
+ }
+
+ free_tree_buffer(tree);
+ strbuf_release(&path);
+ return 0;
+}
+
+/*
+ * For each path in paths_to_explore, walk the trees another level
+ * and add any found blobs to the batch (but only if they don't
+ * exist and haven't been added yet).
+ */
+static int walk_path(struct path_walk_context *ctx,
+ const char *path)
+{
+ struct type_and_oid_list *list;
+ int ret = 0;
+
+ list = strmap_get(&ctx->paths_to_lists, path);
+
+ /* Evaluate function pointer on this data. */
+ ret = ctx->info->path_fn(path, &list->oids, list->type,
+ ctx->info->path_fn_data);
+
+ /* Expand data for children. */
+ if (list->type == OBJ_TREE) {
+ for (size_t i = 0; i < list->oids.nr; i++) {
+ ret |= add_children(ctx,
+ path,
+ &list->oids.oid[i]);
+ }
+ }
+
+ oid_array_clear(&list->oids);
+ strmap_remove(&ctx->paths_to_lists, path, 1);
+ return ret;
+}
+
+static void clear_strmap(struct strmap *map)
+{
+ struct hashmap_iter iter;
+ struct strmap_entry *e;
+
+ hashmap_for_each_entry(&map->map, &iter, e, ent) {
+ struct type_and_oid_list *list = e->value;
+ oid_array_clear(&list->oids);
+ }
+ strmap_clear(map, 1);
+ strmap_init(map);
+}
+
+/**
+ * Given the configuration of 'info', walk the commits based on 'info->revs' and
+ * call 'info->path_fn' on each discovered path.
+ *
+ * Returns nonzero on an error.
+ */
+int walk_objects_by_path(struct path_walk_info *info)
+{
+ const char *root_path = "";
+ int ret = 0;
+ size_t commits_nr = 0, paths_nr = 0;
+ struct commit *c;
+ struct type_and_oid_list *root_tree_list;
+ struct path_walk_context ctx = {
+ .repo = info->revs->repo,
+ .revs = info->revs,
+ .info = info,
+ .path_stack = STRING_LIST_INIT_DUP,
+ .paths_to_lists = STRMAP_INIT
+ };
+
+ trace2_region_enter("path-walk", "commit-walk", info->revs->repo);
+
+ /* Insert a single list for the root tree into the paths. */
+ CALLOC_ARRAY(root_tree_list, 1);
+ root_tree_list->type = OBJ_TREE;
+ strmap_put(&ctx.paths_to_lists, root_path, root_tree_list);
+
+ if (prepare_revision_walk(info->revs))
+ die(_("failed to setup revision walk"));
+
+ while ((c = get_revision(info->revs))) {
+ struct object_id *oid = get_commit_tree_oid(c);
+ struct tree *t = lookup_tree(info->revs->repo, oid);
+ commits_nr++;
+
+ if (t)
+ oid_array_append(&root_tree_list->oids, oid);
+ else
+ warning("could not find tree %s", oid_to_hex(oid));
+ }
+
+ trace2_data_intmax("path-walk", ctx.repo, "commits", commits_nr);
+ trace2_region_leave("path-walk", "commit-walk", info->revs->repo);
+
+ string_list_append(&ctx.path_stack, root_path);
+
+ trace2_region_enter("path-walk", "path-walk", info->revs->repo);
+ while (!ret && ctx.path_stack.nr) {
+ char *path = ctx.path_stack.items[ctx.path_stack.nr - 1].string;
+ ctx.path_stack.nr--;
+ paths_nr++;
+
+ ret = walk_path(&ctx, path);
+
+ free(path);
+ }
+ trace2_data_intmax("path-walk", ctx.repo, "paths", paths_nr);
+ trace2_region_leave("path-walk", "path-walk", info->revs->repo);
+
+ clear_strmap(&ctx.paths_to_lists);
+ string_list_clear(&ctx.path_stack, 0);
+ return ret;
+}
new file mode 100644
@@ -0,0 +1,43 @@
+/*
+ * path-walk.h : Methods and structures for walking the object graph in batches
+ * by the paths that can reach those objects.
+ */
+#include "object.h" /* Required for 'enum object_type'. */
+
+struct rev_info;
+struct oid_array;
+
+/**
+ * The type of a function pointer for the method that is called on a list of
+ * objects reachable at a given path.
+ */
+typedef int (*path_fn)(const char *path,
+ struct oid_array *oids,
+ enum object_type type,
+ void *data);
+
+struct path_walk_info {
+ /**
+ * revs provides the definitions for the commit walk, including
+ * which commits are UNINTERESTING or not.
+ */
+ struct rev_info *revs;
+
+ /**
+ * The caller wishes to execute custom logic on objects reachable at a
+ * given path. Every reachable object will be visited exactly once, and
+ * the first path to see an object wins. This may not be a stable choice.
+ */
+ path_fn path_fn;
+ void *path_fn_data;
+};
+
+#define PATH_WALK_INFO_INIT { 0 }
+
+/**
+ * Given the configuration of 'info', walk the commits based on 'info->revs' and
+ * call 'info->path_fn' on each discovered path.
+ *
+ * Returns nonzero on an error.
+ */
+int walk_objects_by_path(struct path_walk_info *info);