dir: convert struct untracked_cache_dir to object_id
[gitweb.git] / packfile.c
index 7c1a2519fcb9c45aacf5481811bc26f44736de59..b7bc4eab17c736345b3757a7ad656ff4da8a9c94 100644 (file)
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "list.h"
 #include "pack.h"
+#include "repository.h"
 #include "dir.h"
 #include "mergesort.h"
 #include "packfile.h"
@@ -13,6 +14,7 @@
 #include "tag.h"
 #include "tree-walk.h"
 #include "tree.h"
+#include "object-store.h"
 
 char *odb_pack_name(struct strbuf *buf,
                    const unsigned char *sha1,
@@ -44,8 +46,6 @@ static unsigned int pack_open_fds;
 static unsigned int pack_max_fds;
 static size_t peak_pack_mapped;
 static size_t pack_mapped;
-struct packed_git *packed_git;
-LIST_HEAD(packed_git_mru);
 
 #define SZ_FMT PRIuMAX
 static inline uintmax_t sz_fmt(size_t s) { return s; }
@@ -84,6 +84,7 @@ static int check_packed_git_idx(const char *path, struct packed_git *p)
        uint32_t version, nr, i, *index;
        int fd = git_open(path);
        struct stat st;
+       const unsigned int hashsz = the_hash_algo->rawsz;
 
        if (fd < 0)
                return -1;
@@ -92,7 +93,7 @@ static int check_packed_git_idx(const char *path, struct packed_git *p)
                return -1;
        }
        idx_size = xsize_t(st.st_size);
-       if (idx_size < 4 * 256 + 20 + 20) {
+       if (idx_size < 4 * 256 + hashsz + hashsz) {
                close(fd);
                return error("index file %s is too small", path);
        }
@@ -129,11 +130,11 @@ static int check_packed_git_idx(const char *path, struct packed_git *p)
                /*
                 * Total size:
                 *  - 256 index entries 4 bytes each
-                *  - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
-                *  - 20-byte SHA1 of the packfile
-                *  - 20-byte SHA1 file checksum
+                *  - 24-byte entries * nr (object ID + 4-byte offset)
+                *  - hash of the packfile
+                *  - file checksum
                 */
-               if (idx_size != 4*256 + nr * 24 + 20 + 20) {
+               if (idx_size != 4*256 + nr * (hashsz + 4) + hashsz + hashsz) {
                        munmap(idx_map, idx_size);
                        return error("wrong index v1 file size in %s", path);
                }
@@ -142,16 +143,16 @@ static int check_packed_git_idx(const char *path, struct packed_git *p)
                 * Minimum size:
                 *  - 8 bytes of header
                 *  - 256 index entries 4 bytes each
-                *  - 20-byte sha1 entry * nr
+                *  - object ID entry * nr
                 *  - 4-byte crc entry * nr
                 *  - 4-byte offset entry * nr
-                *  - 20-byte SHA1 of the packfile
-                *  - 20-byte SHA1 file checksum
+                *  - hash of the packfile
+                *  - file checksum
                 * And after the 4-byte offset table might be a
                 * variable sized table containing 8-byte entries
                 * for offsets larger than 2^31.
                 */
-               unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
+               unsigned long min_size = 8 + 4*256 + nr*(hashsz + 4 + 4) + hashsz + hashsz;
                unsigned long max_size = min_size;
                if (nr)
                        max_size += (nr - 1)*8;
@@ -245,7 +246,7 @@ static int unuse_one_window(struct packed_git *current)
 
        if (current)
                scan_windows(current, &lru_p, &lru_w, &lru_l);
-       for (p = packed_git; p; p = p->next)
+       for (p = the_repository->objects->packed_git; p; p = p->next)
                scan_windows(p, &lru_p, &lru_w, &lru_l);
        if (lru_p) {
                munmap(lru_w->base, lru_w->len);
@@ -311,11 +312,11 @@ static void close_pack(struct packed_git *p)
        close_pack_index(p);
 }
 
-void close_all_packs(void)
+void close_all_packs(struct raw_object_store *o)
 {
        struct packed_git *p;
 
-       for (p = packed_git; p; p = p->next)
+       for (p = o->packed_git; p; p = p->next)
                if (p->do_not_close)
                        die("BUG: want to close pack marked 'do-not-close'");
                else
@@ -383,7 +384,7 @@ static int close_one_pack(void)
        struct pack_window *mru_w = NULL;
        int accept_windows_inuse = 1;
 
-       for (p = packed_git; p; p = p->next) {
+       for (p = the_repository->objects->packed_git; p; p = p->next) {
                if (p->pack_fd == -1)
                        continue;
                find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
@@ -444,10 +445,11 @@ static int open_packed_git_1(struct packed_git *p)
 {
        struct stat st;
        struct pack_header hdr;
-       unsigned char sha1[20];
-       unsigned char *idx_sha1;
+       unsigned char hash[GIT_MAX_RAWSZ];
+       unsigned char *idx_hash;
        long fd_flag;
        ssize_t read_result;
+       const unsigned hashsz = the_hash_algo->rawsz;
 
        if (!p->index_data && open_pack_index(p))
                return error("packfile %s index unavailable", p->pack_name);
@@ -507,15 +509,15 @@ static int open_packed_git_1(struct packed_git *p)
                             " while index indicates %"PRIu32" objects",
                             p->pack_name, ntohl(hdr.hdr_entries),
                             p->num_objects);
-       if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
+       if (lseek(p->pack_fd, p->pack_size - hashsz, SEEK_SET) == -1)
                return error("end of packfile %s is unavailable", p->pack_name);
-       read_result = read_in_full(p->pack_fd, sha1, sizeof(sha1));
+       read_result = read_in_full(p->pack_fd, hash, hashsz);
        if (read_result < 0)
                return error_errno("error reading from %s", p->pack_name);
-       if (read_result != sizeof(sha1))
+       if (read_result != hashsz)
                return error("packfile %s signature is unavailable", p->pack_name);
-       idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
-       if (hashcmp(sha1, idx_sha1))
+       idx_hash = ((unsigned char *)p->index_data) + p->index_size - hashsz * 2;
+       if (hashcmp(hash, idx_hash))
                return error("packfile %s does not match index", p->pack_name);
        return 0;
 }
@@ -530,7 +532,7 @@ static int open_packed_git(struct packed_git *p)
 
 static int in_window(struct pack_window *win, off_t offset)
 {
-       /* We must promise at least 20 bytes (one hash) after the
+       /* We must promise at least one full hash after the
         * offset is available from this window, otherwise the offset
         * is not actually in this window and a different window (which
         * has that one hash excess) must be used.  This is to support
@@ -538,7 +540,7 @@ static int in_window(struct pack_window *win, off_t offset)
         */
        off_t win_off = win->offset;
        return win_off <= offset
-               && (offset + 20) <= (win_off + win->len);
+               && (offset + the_hash_algo->rawsz) <= (win_off + win->len);
 }
 
 unsigned char *use_pack(struct packed_git *p,
@@ -555,7 +557,7 @@ unsigned char *use_pack(struct packed_git *p,
         */
        if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
                die("packfile %s cannot be accessed", p->pack_name);
-       if (offset > (p->pack_size - 20))
+       if (offset > (p->pack_size - the_hash_algo->rawsz))
                die("offset beyond end of packfile (truncated pack?)");
        if (offset < 0)
                die(_("offset before end of packfile (broken .idx?)"));
@@ -675,18 +677,19 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
        p->pack_size = st.st_size;
        p->pack_local = local;
        p->mtime = st.st_mtime;
-       if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
+       if (path_len < the_hash_algo->hexsz ||
+           get_sha1_hex(path + path_len - the_hash_algo->hexsz, p->sha1))
                hashclr(p->sha1);
        return p;
 }
 
-void install_packed_git(struct packed_git *pack)
+void install_packed_git(struct repository *r, struct packed_git *pack)
 {
        if (pack->pack_fd != -1)
                pack_open_fds++;
 
-       pack->next = packed_git;
-       packed_git = pack;
+       pack->next = r->objects->packed_git;
+       r->objects->packed_git = pack;
 }
 
 void (*report_garbage)(unsigned seen_bits, const char *path);
@@ -735,7 +738,7 @@ static void report_pack_garbage(struct string_list *list)
        report_helper(list, seen_bits, first, list->nr);
 }
 
-static void prepare_packed_git_one(char *objdir, int local)
+static void prepare_packed_git_one(struct repository *r, char *objdir, int local)
 {
        struct strbuf path = STRBUF_INIT;
        size_t dirnamelen;
@@ -768,7 +771,8 @@ static void prepare_packed_git_one(char *objdir, int local)
                base_len = path.len;
                if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
                        /* Don't reopen a pack we already have. */
-                       for (p = packed_git; p; p = p->next) {
+                       for (p = r->objects->packed_git; p;
+                            p = p->next) {
                                size_t len;
                                if (strip_suffix(p->pack_name, ".pack", &len) &&
                                    len == base_len &&
@@ -781,7 +785,7 @@ static void prepare_packed_git_one(char *objdir, int local)
                             * corresponding .pack file that we can map.
                             */
                            (p = add_packed_git(path.buf, path.len, local)) != NULL)
-                               install_packed_git(p);
+                               install_packed_git(r, p);
                }
 
                if (!report_garbage)
@@ -802,8 +806,7 @@ static void prepare_packed_git_one(char *objdir, int local)
        strbuf_release(&path);
 }
 
-static int approximate_object_count_valid;
-
+static void prepare_packed_git(struct repository *r);
 /*
  * Give a fast, rough count of the number of objects in the repository. This
  * ignores loose objects completely. If you have a lot of them, then either
@@ -813,19 +816,20 @@ static int approximate_object_count_valid;
  */
 unsigned long approximate_object_count(void)
 {
-       static unsigned long count;
-       if (!approximate_object_count_valid) {
+       if (!the_repository->objects->approximate_object_count_valid) {
+               unsigned long count;
                struct packed_git *p;
 
-               prepare_packed_git();
+               prepare_packed_git(the_repository);
                count = 0;
-               for (p = packed_git; p; p = p->next) {
+               for (p = the_repository->objects->packed_git; p; p = p->next) {
                        if (open_pack_index(p))
                                continue;
                        count += p->num_objects;
                }
+               the_repository->objects->approximate_object_count = count;
        }
-       return count;
+       return the_repository->objects->approximate_object_count;
 }
 
 static void *get_next_packed_git(const void *p)
@@ -866,43 +870,55 @@ static int sort_pack(const void *a_, const void *b_)
        return -1;
 }
 
-static void rearrange_packed_git(void)
+static void rearrange_packed_git(struct repository *r)
 {
-       packed_git = llist_mergesort(packed_git, get_next_packed_git,
-                                    set_next_packed_git, sort_pack);
+       r->objects->packed_git = llist_mergesort(
+               r->objects->packed_git, get_next_packed_git,
+               set_next_packed_git, sort_pack);
 }
 
-static void prepare_packed_git_mru(void)
+static void prepare_packed_git_mru(struct repository *r)
 {
        struct packed_git *p;
 
-       INIT_LIST_HEAD(&packed_git_mru);
+       INIT_LIST_HEAD(&r->objects->packed_git_mru);
 
-       for (p = packed_git; p; p = p->next)
-               list_add_tail(&p->mru, &packed_git_mru);
+       for (p = r->objects->packed_git; p; p = p->next)
+               list_add_tail(&p->mru, &r->objects->packed_git_mru);
 }
 
-static int prepare_packed_git_run_once = 0;
-void prepare_packed_git(void)
+static void prepare_packed_git(struct repository *r)
 {
        struct alternate_object_database *alt;
 
-       if (prepare_packed_git_run_once)
+       if (r->objects->packed_git_initialized)
                return;
-       prepare_packed_git_one(get_object_directory(), 1);
-       prepare_alt_odb();
-       for (alt = alt_odb_list; alt; alt = alt->next)
-               prepare_packed_git_one(alt->path, 0);
-       rearrange_packed_git();
-       prepare_packed_git_mru();
-       prepare_packed_git_run_once = 1;
+       prepare_packed_git_one(r, r->objects->objectdir, 1);
+       prepare_alt_odb(r);
+       for (alt = r->objects->alt_odb_list; alt; alt = alt->next)
+               prepare_packed_git_one(r, alt->path, 0);
+       rearrange_packed_git(r);
+       prepare_packed_git_mru(r);
+       r->objects->packed_git_initialized = 1;
+}
+
+void reprepare_packed_git(struct repository *r)
+{
+       r->objects->approximate_object_count_valid = 0;
+       r->objects->packed_git_initialized = 0;
+       prepare_packed_git(r);
+}
+
+struct packed_git *get_packed_git(struct repository *r)
+{
+       prepare_packed_git(r);
+       return r->objects->packed_git;
 }
 
-void reprepare_packed_git(void)
+struct list_head *get_packed_git_mru(struct repository *r)
 {
-       approximate_object_count_valid = 0;
-       prepare_packed_git_run_once = 0;
-       prepare_packed_git();
+       prepare_packed_git(r);
+       return &r->objects->packed_git_mru;
 }
 
 unsigned long unpack_object_header_buffer(const unsigned char *buf,
@@ -1013,9 +1029,10 @@ const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
        struct packed_git *p;
        unsigned i;
 
-       for (p = packed_git; p; p = p->next)
+       for (p = the_repository->objects->packed_git; p; p = p->next)
                for (i = 0; i < p->num_bad_objects; i++)
-                       if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
+                       if (!hashcmp(sha1,
+                                    p->bad_object_sha1 + the_hash_algo->rawsz * i))
                                return p;
        return NULL;
 }
@@ -1053,7 +1070,7 @@ static off_t get_delta_base(struct packed_git *p,
        } else if (type == OBJ_REF_DELTA) {
                /* The base entry _must_ be in the same pack */
                base_offset = find_pack_entry_one(base_info, p);
-               *curpos += 20;
+               *curpos += the_hash_algo->rawsz;
        } else
                die("I am totally screwed");
        return base_offset;
@@ -1095,13 +1112,13 @@ static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
 {
        int type;
        struct revindex_entry *revidx;
-       const unsigned char *sha1;
+       struct object_id oid;
        revidx = find_pack_revindex(p, obj_offset);
        if (!revidx)
                return OBJ_BAD;
-       sha1 = nth_packed_object_sha1(p, revidx->nr);
-       mark_bad_packed_object(p, sha1);
-       type = sha1_object_info(sha1, NULL);
+       nth_packed_object_oid(&oid, p, revidx->nr);
+       mark_bad_packed_object(p, oid.hash);
+       type = oid_object_info(&oid, NULL);
        if (type <= OBJ_NONE)
                return OBJ_BAD;
        return type;
@@ -1452,7 +1469,7 @@ struct unpack_entry_stack_ent {
        unsigned long size;
 };
 
-static void *read_object(const unsigned char *sha1, enum object_type *type,
+static void *read_object(const struct object_id *oid, enum object_type *type,
                         unsigned long *size)
 {
        struct object_info oi = OBJECT_INFO_INIT;
@@ -1461,7 +1478,7 @@ static void *read_object(const unsigned char *sha1, enum object_type *type,
        oi.sizep = size;
        oi.contentp = &content;
 
-       if (sha1_object_info_extended(sha1, &oi, 0) < 0)
+       if (oid_object_info_extended(oid, &oi, 0) < 0)
                return NULL;
        return content;
 }
@@ -1501,11 +1518,11 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
                        struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
                        off_t len = revidx[1].offset - obj_offset;
                        if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
-                               const unsigned char *sha1 =
-                                       nth_packed_object_sha1(p, revidx->nr);
+                               struct object_id oid;
+                               nth_packed_object_oid(&oid, p, revidx->nr);
                                error("bad packed object CRC for %s",
-                                     sha1_to_hex(sha1));
-                               mark_bad_packed_object(p, sha1);
+                                     oid_to_hex(&oid));
+                               mark_bad_packed_object(p, oid.hash);
                                data = NULL;
                                goto out;
                        }
@@ -1588,16 +1605,16 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
                         * of a corrupted pack, and is better than failing outright.
                         */
                        struct revindex_entry *revidx;
-                       const unsigned char *base_sha1;
+                       struct object_id base_oid;
                        revidx = find_pack_revindex(p, obj_offset);
                        if (revidx) {
-                               base_sha1 = nth_packed_object_sha1(p, revidx->nr);
+                               nth_packed_object_oid(&base_oid, p, revidx->nr);
                                error("failed to read delta base object %s"
                                      " at offset %"PRIuMAX" from %s",
-                                     sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
+                                     oid_to_hex(&base_oid), (uintmax_t)obj_offset,
                                      p->pack_name);
-                               mark_bad_packed_object(p, base_sha1);
-                               base = read_object(base_sha1, &type, &base_size);
+                               mark_bad_packed_object(p, base_oid.hash);
+                               base = read_object(&base_oid, &type, &base_size);
                                external_base = base;
                        }
                }
@@ -1654,10 +1671,35 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
        return data;
 }
 
+int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32_t *result)
+{
+       const unsigned char *index_fanout = p->index_data;
+       const unsigned char *index_lookup;
+       const unsigned int hashsz = the_hash_algo->rawsz;
+       int index_lookup_width;
+
+       if (!index_fanout)
+               BUG("bsearch_pack called without a valid pack-index");
+
+       index_lookup = index_fanout + 4 * 256;
+       if (p->index_version == 1) {
+               index_lookup_width = hashsz + 4;
+               index_lookup += 4;
+       } else {
+               index_lookup_width = hashsz;
+               index_fanout += 8;
+               index_lookup += 8;
+       }
+
+       return bsearch_hash(oid->hash, (const uint32_t*)index_fanout,
+                           index_lookup, index_lookup_width, result);
+}
+
 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
                                            uint32_t n)
 {
        const unsigned char *index = p->index_data;
+       const unsigned int hashsz = the_hash_algo->rawsz;
        if (!index) {
                if (open_pack_index(p))
                        return NULL;
@@ -1667,10 +1709,10 @@ const unsigned char *nth_packed_object_sha1(struct packed_git *p,
                return NULL;
        index += 4 * 256;
        if (p->index_version == 1) {
-               return index + 24 * n + 4;
+               return index + (hashsz + 4) * n + 4;
        } else {
                index += 8;
-               return index + 20 * n;
+               return index + hashsz * n;
        }
 }
 
@@ -1702,12 +1744,13 @@ void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
 {
        const unsigned char *index = p->index_data;
+       const unsigned int hashsz = the_hash_algo->rawsz;
        index += 4 * 256;
        if (p->index_version == 1) {
-               return ntohl(*((uint32_t *)(index + 24 * n)));
+               return ntohl(*((uint32_t *)(index + (hashsz + 4) * n)));
        } else {
                uint32_t off;
-               index += 8 + p->num_objects * (20 + 4);
+               index += 8 + p->num_objects * (hashsz + 4);
                off = ntohl(*((uint32_t *)(index + 4 * n)));
                if (!(off & 0x80000000))
                        return off;
@@ -1720,30 +1763,17 @@ off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
 off_t find_pack_entry_one(const unsigned char *sha1,
                                  struct packed_git *p)
 {
-       const uint32_t *level1_ofs = p->index_data;
        const unsigned char *index = p->index_data;
-       unsigned stride;
+       struct object_id oid;
        uint32_t result;
 
        if (!index) {
                if (open_pack_index(p))
                        return 0;
-               level1_ofs = p->index_data;
-               index = p->index_data;
-       }
-       if (p->index_version > 1) {
-               level1_ofs += 2;
-               index += 8;
-       }
-       index += 4 * 256;
-       if (p->index_version > 1) {
-               stride = 20;
-       } else {
-               stride = 24;
-               index += 4;
        }
 
-       if (bsearch_hash(sha1, level1_ofs, index, stride, &result))
+       hashcpy(oid.hash, sha1);
+       if (bsearch_pack(&oid, p, &result))
                return nth_packed_object_offset(p, result);
        return 0;
 }
@@ -1782,7 +1812,7 @@ struct packed_git *find_sha1_pack(const unsigned char *sha1,
 
 }
 
-static int fill_pack_entry(const unsigned char *sha1,
+static int fill_pack_entry(const struct object_id *oid,
                           struct pack_entry *e,
                           struct packed_git *p)
 {
@@ -1791,11 +1821,12 @@ static int fill_pack_entry(const unsigned char *sha1,
        if (p->num_bad_objects) {
                unsigned i;
                for (i = 0; i < p->num_bad_objects; i++)
-                       if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
+                       if (!hashcmp(oid->hash,
+                                    p->bad_object_sha1 + the_hash_algo->rawsz * i))
                                return 0;
        }
 
-       offset = find_pack_entry_one(sha1, p);
+       offset = find_pack_entry_one(oid->hash, p);
        if (!offset)
                return 0;
 
@@ -1810,36 +1841,31 @@ static int fill_pack_entry(const unsigned char *sha1,
                return 0;
        e->offset = offset;
        e->p = p;
-       hashcpy(e->sha1, sha1);
        return 1;
 }
 
-/*
- * Iff a pack file contains the object named by sha1, return true and
- * store its location to e.
- */
-int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
+int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
 {
        struct list_head *pos;
 
-       prepare_packed_git();
-       if (!packed_git)
+       prepare_packed_git(r);
+       if (!r->objects->packed_git)
                return 0;
 
-       list_for_each(pos, &packed_git_mru) {
+       list_for_each(pos, &r->objects->packed_git_mru) {
                struct packed_git *p = list_entry(pos, struct packed_git, mru);
-               if (fill_pack_entry(sha1, e, p)) {
-                       list_move(&p->mru, &packed_git_mru);
+               if (fill_pack_entry(oid, e, p)) {
+                       list_move(&p->mru, &r->objects->packed_git_mru);
                        return 1;
                }
        }
        return 0;
 }
 
-int has_sha1_pack(const unsigned char *sha1)
+int has_object_pack(const struct object_id *oid)
 {
        struct pack_entry e;
-       return find_pack_entry(sha1, &e);
+       return find_pack_entry(the_repository, oid, &e);
 }
 
 int has_pack_index(const unsigned char *sha1)
@@ -1875,8 +1901,8 @@ int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
        int r = 0;
        int pack_errors = 0;
 
-       prepare_packed_git();
-       for (p = packed_git; p; p = p->next) {
+       prepare_packed_git(the_repository);
+       for (p = the_repository->objects->packed_git; p; p = p->next) {
                if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
                        continue;
                if ((flags & FOR_EACH_OBJECT_PROMISOR_ONLY) &&
@@ -1907,7 +1933,7 @@ static int add_promisor_object(const struct object_id *oid,
 
        /*
         * If this is a tree, commit, or tag, the objects it refers
-        * to are also promisor objects. (Blobs refer to no objects.)
+        * to are also promisor objects. (Blobs refer to no objects->)
         */
        if (obj->type == OBJ_TREE) {
                struct tree *tree = (struct tree *)obj;