Adding upstream version 1:2.39.2.upstream/1%2.39.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 316 insertions, 0 deletions

diff --git a/tmp-objdir.c b/tmp-objdir.c
new file mode 100644
index 0000000..2a2012e
--- /dev/null
+++ b/tmp-objdir.c
@@ -0,0 +1,316 @@
+#include "cache.h"
+#include "tmp-objdir.h"
+#include "chdir-notify.h"
+#include "dir.h"
+#include "sigchain.h"
+#include "string-list.h"
+#include "strbuf.h"
+#include "strvec.h"
+#include "quote.h"
+#include "object-store.h"
+
+struct tmp_objdir {
+	struct strbuf path;
+	struct strvec env;
+	struct object_directory *prev_odb;
+	int will_destroy;
+};
+
+/*
+ * Allow only one tmp_objdir at a time in a running process, which simplifies
+ * our atexit cleanup routines.  It's doubtful callers will ever need
+ * more than one, and we can expand later if so.  You can have many such
+ * tmp_objdirs simultaneously in many processes, of course.
+ */
+static struct tmp_objdir *the_tmp_objdir;
+
+static void tmp_objdir_free(struct tmp_objdir *t)
+{
+	strbuf_release(&t->path);
+	strvec_clear(&t->env);
+	free(t);
+}
+
+int tmp_objdir_destroy(struct tmp_objdir *t)
+{
+	int err;
+
+	if (!t)
+		return 0;
+
+	if (t == the_tmp_objdir)
+		the_tmp_objdir = NULL;
+
+	if (t->prev_odb)
+		restore_primary_odb(t->prev_odb, t->path.buf);
+
+	err = remove_dir_recursively(&t->path, 0);
+
+	tmp_objdir_free(t);
+
+	return err;
+}
+
+static void remove_tmp_objdir(void)
+{
+	tmp_objdir_destroy(the_tmp_objdir);
+}
+
+void tmp_objdir_discard_objects(struct tmp_objdir *t)
+{
+	remove_dir_recursively(&t->path, REMOVE_DIR_KEEP_TOPLEVEL);
+}
+
+/*
+ * These env_* functions are for setting up the child environment; the
+ * "replace" variant overrides the value of any existing variable with that
+ * "key". The "append" variant puts our new value at the end of a list,
+ * separated by PATH_SEP (which is what separate values in
+ * GIT_ALTERNATE_OBJECT_DIRECTORIES).
+ */
+static void env_append(struct strvec *env, const char *key, const char *val)
+{
+	struct strbuf quoted = STRBUF_INIT;
+	const char *old;
+
+	/*
+	 * Avoid quoting if it's not necessary, for maximum compatibility
+	 * with older parsers which don't understand the quoting.
+	 */
+	if (*val == '"' || strchr(val, PATH_SEP)) {
+		strbuf_addch(&quoted, '"');
+		quote_c_style(val, &quoted, NULL, 1);
+		strbuf_addch(&quoted, '"');
+		val = quoted.buf;
+	}
+
+	old = getenv(key);
+	if (!old)
+		strvec_pushf(env, "%s=%s", key, val);
+	else
+		strvec_pushf(env, "%s=%s%c%s", key, old, PATH_SEP, val);
+
+	strbuf_release(&quoted);
+}
+
+static void env_replace(struct strvec *env, const char *key, const char *val)
+{
+	strvec_pushf(env, "%s=%s", key, val);
+}
+
+static int setup_tmp_objdir(const char *root)
+{
+	char *path;
+	int ret = 0;
+
+	path = xstrfmt("%s/pack", root);
+	ret = mkdir(path, 0777);
+	free(path);
+
+	return ret;
+}
+
+struct tmp_objdir *tmp_objdir_create(const char *prefix)
+{
+	static int installed_handlers;
+	struct tmp_objdir *t;
+
+	if (the_tmp_objdir)
+		BUG("only one tmp_objdir can be used at a time");
+
+	t = xcalloc(1, sizeof(*t));
+	strbuf_init(&t->path, 0);
+	strvec_init(&t->env);
+
+	/*
+	 * Use a string starting with tmp_ so that the builtin/prune.c code
+	 * can recognize any stale objdirs left behind by a crash and delete
+	 * them.
+	 */
+	strbuf_addf(&t->path, "%s/tmp_objdir-%s-XXXXXX", get_object_directory(), prefix);
+
+	if (!mkdtemp(t->path.buf)) {
+		/* free, not destroy, as we never touched the filesystem */
+		tmp_objdir_free(t);
+		return NULL;
+	}
+
+	the_tmp_objdir = t;
+	if (!installed_handlers) {
+		atexit(remove_tmp_objdir);
+		installed_handlers++;
+	}
+
+	if (setup_tmp_objdir(t->path.buf)) {
+		tmp_objdir_destroy(t);
+		return NULL;
+	}
+
+	env_append(&t->env, ALTERNATE_DB_ENVIRONMENT,
+		   absolute_path(get_object_directory()));
+	env_replace(&t->env, DB_ENVIRONMENT, absolute_path(t->path.buf));
+	env_replace(&t->env, GIT_QUARANTINE_ENVIRONMENT,
+		    absolute_path(t->path.buf));
+
+	return t;
+}
+
+/*
+ * Make sure we copy packfiles and their associated metafiles in the correct
+ * order. All of these ends_with checks are slightly expensive to do in
+ * the midst of a sorting routine, but in practice it shouldn't matter.
+ * We will have a relatively small number of packfiles to order, and loose
+ * objects exit early in the first line.
+ */
+static int pack_copy_priority(const char *name)
+{
+	if (!starts_with(name, "pack"))
+		return 0;
+	if (ends_with(name, ".keep"))
+		return 1;
+	if (ends_with(name, ".pack"))
+		return 2;
+	if (ends_with(name, ".rev"))
+		return 3;
+	if (ends_with(name, ".idx"))
+		return 4;
+	return 5;
+}
+
+static int pack_copy_cmp(const char *a, const char *b)
+{
+	return pack_copy_priority(a) - pack_copy_priority(b);
+}
+
+static int read_dir_paths(struct string_list *out, const char *path)
+{
+	DIR *dh;
+	struct dirent *de;
+
+	dh = opendir(path);
+	if (!dh)
+		return -1;
+
+	while ((de = readdir(dh)))
+		if (de->d_name[0] != '.')
+			string_list_append(out, de->d_name);
+
+	closedir(dh);
+	return 0;
+}
+
+static int migrate_paths(struct strbuf *src, struct strbuf *dst);
+
+static int migrate_one(struct strbuf *src, struct strbuf *dst)
+{
+	struct stat st;
+
+	if (stat(src->buf, &st) < 0)
+		return -1;
+	if (S_ISDIR(st.st_mode)) {
+		if (!mkdir(dst->buf, 0777)) {
+			if (adjust_shared_perm(dst->buf))
+				return -1;
+		} else if (errno != EEXIST)
+			return -1;
+		return migrate_paths(src, dst);
+	}
+	return finalize_object_file(src->buf, dst->buf);
+}
+
+static int migrate_paths(struct strbuf *src, struct strbuf *dst)
+{
+	size_t src_len = src->len, dst_len = dst->len;
+	struct string_list paths = STRING_LIST_INIT_DUP;
+	int i;
+	int ret = 0;
+
+	if (read_dir_paths(&paths, src->buf) < 0)
+		return -1;
+	paths.cmp = pack_copy_cmp;
+	string_list_sort(&paths);
+
+	for (i = 0; i < paths.nr; i++) {
+		const char *name = paths.items[i].string;
+
+		strbuf_addf(src, "/%s", name);
+		strbuf_addf(dst, "/%s", name);
+
+		ret |= migrate_one(src, dst);
+
+		strbuf_setlen(src, src_len);
+		strbuf_setlen(dst, dst_len);
+	}
+
+	string_list_clear(&paths, 0);
+	return ret;
+}
+
+int tmp_objdir_migrate(struct tmp_objdir *t)
+{
+	struct strbuf src = STRBUF_INIT, dst = STRBUF_INIT;
+	int ret;
+
+	if (!t)
+		return 0;
+
+	if (t->prev_odb) {
+		if (the_repository->objects->odb->will_destroy)
+			BUG("migrating an ODB that was marked for destruction");
+		restore_primary_odb(t->prev_odb, t->path.buf);
+		t->prev_odb = NULL;
+	}
+
+	strbuf_addbuf(&src, &t->path);
+	strbuf_addstr(&dst, get_object_directory());
+
+	ret = migrate_paths(&src, &dst);
+
+	strbuf_release(&src);
+	strbuf_release(&dst);
+
+	tmp_objdir_destroy(t);
+	return ret;
+}
+
+const char **tmp_objdir_env(const struct tmp_objdir *t)
+{
+	if (!t)
+		return NULL;
+	return t->env.v;
+}
+
+void tmp_objdir_add_as_alternate(const struct tmp_objdir *t)
+{
+	add_to_alternates_memory(t->path.buf);
+}
+
+void tmp_objdir_replace_primary_odb(struct tmp_objdir *t, int will_destroy)
+{
+	if (t->prev_odb)
+		BUG("the primary object database is already replaced");
+	t->prev_odb = set_temporary_primary_odb(t->path.buf, will_destroy);
+	t->will_destroy = will_destroy;
+}
+
+struct tmp_objdir *tmp_objdir_unapply_primary_odb(void)
+{
+	if (!the_tmp_objdir || !the_tmp_objdir->prev_odb)
+		return NULL;
+
+	restore_primary_odb(the_tmp_objdir->prev_odb, the_tmp_objdir->path.buf);
+	the_tmp_objdir->prev_odb = NULL;
+	return the_tmp_objdir;
+}
+
+void tmp_objdir_reapply_primary_odb(struct tmp_objdir *t, const char *old_cwd,
+		const char *new_cwd)
+{
+	char *path;
+
+	path = reparent_relative_path(old_cwd, new_cwd, t->path.buf);
+	strbuf_reset(&t->path);
+	strbuf_addstr(&t->path, path);
+	free(path);
+	tmp_objdir_replace_primary_odb(t, t->will_destroy);
+}