1 #define _LARGEFILE64_SOURCE 1
3 #include "../../config/config.h"
11 #include <sys/types.h>
17 #ifdef HAVE_LINUX_FS_H
20 #ifdef HAVE_SYS_IOCTL_H
21 #include <sys/ioctl.h>
24 static int istty2 = 0;
26 // Probably we should use autoconf or something and set HAVE_PY_GETARGCARGV...
27 #if __WIN32__ || __CYGWIN__
29 // There's no 'ps' on win32 anyway, and Py_GetArgcArgv() isn't available.
30 static void unpythonize_argv(void) { }
32 #else // not __WIN32__
34 // For some reason this isn't declared in Python.h
35 extern void Py_GetArgcArgv(int *argc, char ***argv);
37 static void unpythonize_argv(void)
42 Py_GetArgcArgv(&argc, &argv);
44 for (i = 0; i < argc-1; i++)
46 if (argv[i] + strlen(argv[i]) + 1 != argv[i+1])
48 // The argv block doesn't work the way we expected; it's unsafe
54 arge = argv[argc-1] + strlen(argv[argc-1]) + 1;
56 if (strstr(argv[0], "python") && argv[1] == argv[0] + strlen(argv[0]) + 1)
60 p = strrchr(argv[1], '/');
66 memmove(argv[0], p, len);
67 memset(arge - diff, 0, diff);
68 for (i = 0; i < argc; i++)
69 argv[i] = argv[i+1] ? argv[i+1]-diff : NULL;
74 #endif // not __WIN32__ or __CYGWIN__
77 static PyObject *selftest(PyObject *self, PyObject *args)
79 if (!PyArg_ParseTuple(args, ""))
82 return Py_BuildValue("i", !bupsplit_selftest());
86 static PyObject *blobbits(PyObject *self, PyObject *args)
88 if (!PyArg_ParseTuple(args, ""))
90 return Py_BuildValue("i", BUP_BLOBBITS);
94 static PyObject *splitbuf(PyObject *self, PyObject *args)
96 unsigned char *buf = NULL;
97 int len = 0, out = 0, bits = -1;
99 if (!PyArg_ParseTuple(args, "t#", &buf, &len))
101 out = bupsplit_find_ofs(buf, len, &bits);
102 if (out) assert(bits >= BUP_BLOBBITS);
103 return Py_BuildValue("ii", out, bits);
107 static PyObject *bitmatch(PyObject *self, PyObject *args)
109 unsigned char *buf1 = NULL, *buf2 = NULL;
110 int len1 = 0, len2 = 0;
113 if (!PyArg_ParseTuple(args, "t#t#", &buf1, &len1, &buf2, &len2))
117 for (byte = 0; byte < len1 && byte < len2; byte++)
119 int b1 = buf1[byte], b2 = buf2[byte];
122 for (bit = 0; bit < 8; bit++)
123 if ( (b1 & (0x80 >> bit)) != (b2 & (0x80 >> bit)) )
129 return Py_BuildValue("i", byte*8 + bit);
133 static PyObject *firstword(PyObject *self, PyObject *args)
135 unsigned char *buf = NULL;
139 if (!PyArg_ParseTuple(args, "t#", &buf, &len))
145 v = ntohl(*(uint32_t *)buf);
146 return PyLong_FromUnsignedLong(v);
150 #define BLOOM2_HEADERLEN 16
157 static void to_bloom_address_bitmask4(const bits40_t *buf,
158 const int nbits, uint64_t *v, unsigned char *bitmask)
163 mask = (1<<nbits) - 1;
164 raw = (((uint64_t)ntohl(buf->high)) << 8) | buf->low;
165 bit = (raw >> (37-nbits)) & 0x7;
166 *v = (raw >> (40-nbits)) & mask;
170 static void to_bloom_address_bitmask5(const uint32_t *buf,
171 const int nbits, uint32_t *v, unsigned char *bitmask)
176 mask = (1<<nbits) - 1;
178 bit = (raw >> (29-nbits)) & 0x7;
179 *v = (raw >> (32-nbits)) & mask;
183 #define BLOOM_SET_BIT(name, address, itype, otype) \
184 static void name(unsigned char *bloom, const void *buf, const int nbits)\
186 unsigned char bitmask;\
188 address((itype *)buf, nbits, &v, &bitmask);\
189 bloom[BLOOM2_HEADERLEN+v] |= bitmask;\
191 BLOOM_SET_BIT(bloom_set_bit4, to_bloom_address_bitmask4, bits40_t, uint64_t)
192 BLOOM_SET_BIT(bloom_set_bit5, to_bloom_address_bitmask5, uint32_t, uint32_t)
195 #define BLOOM_GET_BIT(name, address, itype, otype) \
196 static int name(const unsigned char *bloom, const void *buf, const int nbits)\
198 unsigned char bitmask;\
200 address((itype *)buf, nbits, &v, &bitmask);\
201 return bloom[BLOOM2_HEADERLEN+v] & bitmask;\
203 BLOOM_GET_BIT(bloom_get_bit4, to_bloom_address_bitmask4, bits40_t, uint64_t)
204 BLOOM_GET_BIT(bloom_get_bit5, to_bloom_address_bitmask5, uint32_t, uint32_t)
207 static PyObject *bloom_add(PyObject *self, PyObject *args)
209 unsigned char *sha = NULL, *bloom = NULL;
211 int len = 0, blen = 0, nbits = 0, k = 0;
213 if (!PyArg_ParseTuple(args, "w#s#ii", &bloom, &blen, &sha, &len, &nbits, &k))
216 if (blen < 16+(1<<nbits) || len % 20 != 0)
223 for (end = sha + len; sha < end; sha += 20/k)
224 bloom_set_bit5(bloom, sha, nbits);
230 for (end = sha + len; sha < end; sha += 20/k)
231 bloom_set_bit4(bloom, sha, nbits);
237 return Py_BuildValue("i", len/20);
240 static PyObject *bloom_contains(PyObject *self, PyObject *args)
242 unsigned char *sha = NULL, *bloom = NULL;
243 int len = 0, blen = 0, nbits = 0, k = 0;
247 if (!PyArg_ParseTuple(args, "t#s#ii", &bloom, &blen, &sha, &len, &nbits, &k))
257 for (steps = 1, end = sha + 20; sha < end; sha += 20/k, steps++)
258 if (!bloom_get_bit5(bloom, sha, nbits))
259 return Py_BuildValue("Oi", Py_None, steps);
265 for (steps = 1, end = sha + 20; sha < end; sha += 20/k, steps++)
266 if (!bloom_get_bit4(bloom, sha, nbits))
267 return Py_BuildValue("Oi", Py_None, steps);
272 return Py_BuildValue("ii", 1, k);
276 static uint32_t _extract_bits(unsigned char *buf, int nbits)
280 mask = (1<<nbits) - 1;
281 v = ntohl(*(uint32_t *)buf);
282 v = (v >> (32-nbits)) & mask;
285 static PyObject *extract_bits(PyObject *self, PyObject *args)
287 unsigned char *buf = NULL;
288 int len = 0, nbits = 0;
290 if (!PyArg_ParseTuple(args, "t#i", &buf, &len, &nbits))
296 return PyLong_FromUnsignedLong(_extract_bits(buf, nbits));
301 unsigned char bytes[20];
313 static int _cmp_sha(const struct sha *sha1, const struct sha *sha2)
316 for (i = 0; i < sizeof(struct sha); i++)
317 if (sha1->bytes[i] != sha2->bytes[i])
318 return sha1->bytes[i] - sha2->bytes[i];
323 static void _fix_idx_order(struct idx **idxs, int *last_i)
326 int low, mid, high, c = 0;
329 if (idxs[*last_i]->cur >= idxs[*last_i]->end)
331 idxs[*last_i] = NULL;
344 mid = (low + high) / 2;
345 c = _cmp_sha(idx->cur, idxs[mid]->cur);
357 memmove(&idxs[mid+1], &idxs[mid], (*last_i-mid)*sizeof(struct idx *));
362 static uint32_t _get_idx_i(struct idx *idx)
364 if (idx->cur_name == NULL)
365 return idx->name_base;
366 return ntohl(*idx->cur_name) + idx->name_base;
369 #define MIDX4_HEADERLEN 12
371 static PyObject *merge_into(PyObject *self, PyObject *args)
373 PyObject *ilist = NULL;
374 unsigned char *fmap = NULL;
375 struct sha *sha_ptr, *sha_start = NULL;
376 uint32_t *table_ptr, *name_ptr, *name_start;
377 struct idx **idxs = NULL;
378 int flen = 0, bits = 0, i;
379 uint32_t total, count, prefix;
383 if (!PyArg_ParseTuple(args, "w#iIO", &fmap, &flen, &bits, &total, &ilist))
386 num_i = PyList_Size(ilist);
387 idxs = (struct idx **)PyMem_Malloc(num_i * sizeof(struct idx *));
389 for (i = 0; i < num_i; i++)
391 long len, sha_ofs, name_map_ofs;
392 idxs[i] = (struct idx *)PyMem_Malloc(sizeof(struct idx));
393 PyObject *itup = PyList_GetItem(ilist, i);
394 if (!PyArg_ParseTuple(itup, "t#llli", &idxs[i]->map, &idxs[i]->bytes,
395 &len, &sha_ofs, &name_map_ofs, &idxs[i]->name_base))
397 idxs[i]->cur = (struct sha *)&idxs[i]->map[sha_ofs];
398 idxs[i]->end = &idxs[i]->cur[len];
400 idxs[i]->cur_name = (uint32_t *)&idxs[i]->map[name_map_ofs];
402 idxs[i]->cur_name = NULL;
404 table_ptr = (uint32_t *)&fmap[MIDX4_HEADERLEN];
405 sha_start = sha_ptr = (struct sha *)&table_ptr[1<<bits];
406 name_start = name_ptr = (uint32_t *)&sha_ptr[total];
415 if (count % 102424 == 0 && istty2)
416 fprintf(stderr, "midx: writing %.2f%% (%d/%d)\r",
417 count*100.0/total, count, total);
419 new_prefix = _extract_bits((unsigned char *)idx->cur, bits);
420 while (prefix < new_prefix)
421 table_ptr[prefix++] = htonl(count);
422 memcpy(sha_ptr++, idx->cur, sizeof(struct sha));
423 *name_ptr++ = htonl(_get_idx_i(idx));
425 if (idx->cur_name != NULL)
427 _fix_idx_order(idxs, &last_i);
430 while (prefix < (1<<bits))
431 table_ptr[prefix++] = htonl(count);
432 assert(count == total);
433 assert(prefix == (1<<bits));
434 assert(sha_ptr == sha_start+count);
435 assert(name_ptr == name_start+count);
438 return PyLong_FromUnsignedLong(count);
441 // This function should technically be macro'd out if it's going to be used
442 // more than ocasionally. As of this writing, it'll actually never be called
443 // in real world bup scenarios (because our packs are < MAX_INT bytes).
444 static uint64_t htonll(uint64_t value)
446 static const int endian_test = 42;
448 if (*(char *)&endian_test == endian_test) // LSB-MSB
449 return ((uint64_t)htonl(value & 0xFFFFFFFF) << 32) | htonl(value >> 32);
450 return value; // already in network byte order MSB-LSB
453 #define PACK_IDX_V2_HEADERLEN 8
454 #define FAN_ENTRIES 256
456 static PyObject *write_idx(PyObject *self, PyObject *args)
458 PyObject *pf = NULL, *idx = NULL;
461 unsigned char *fmap = NULL;
465 int i, j, ofs64_count;
466 uint32_t *fan_ptr, *crc_ptr, *ofs_ptr;
469 if (!PyArg_ParseTuple(args, "Ow#OI", &pf, &fmap, &flen, &idx, &total))
472 fan_ptr = (uint32_t *)&fmap[PACK_IDX_V2_HEADERLEN];
473 sha_ptr = (struct sha *)&fan_ptr[FAN_ENTRIES];
474 crc_ptr = (uint32_t *)&sha_ptr[total];
475 ofs_ptr = (uint32_t *)&crc_ptr[total];
476 f = PyFile_AsFile(pf);
480 for (i = 0; i < FAN_ENTRIES; ++i)
483 part = PyList_GET_ITEM(idx, i);
485 plen = PyList_GET_SIZE(part);
487 *fan_ptr++ = htonl(count);
488 for (j = 0; j < plen; ++j)
490 unsigned char *sha = NULL;
494 if (!PyArg_ParseTuple(PyList_GET_ITEM(part, j), "t#IK",
495 &sha, &sha_len, &crc, &ofs))
497 if (sha_len != sizeof(struct sha))
499 memcpy(sha_ptr++, sha, sizeof(struct sha));
500 *crc_ptr++ = htonl(crc);
501 if (ofs > 0x7fffffff)
503 uint64_t nofs = htonll(ofs);
504 if (fwrite(&nofs, sizeof(uint64_t), 1, f) != 1)
505 return PyErr_SetFromErrno(PyExc_OSError);
506 ofs = 0x80000000 | ofs64_count++;
508 *ofs_ptr++ = htonl((uint32_t)ofs);
511 return PyLong_FromUnsignedLong(count);
515 // I would have made this a lower-level function that just fills in a buffer
516 // with random values, and then written those values from python. But that's
517 // about 20% slower in my tests, and since we typically generate random
518 // numbers for benchmarking other parts of bup, any slowness in generating
519 // random bytes will make our benchmarks inaccurate. Plus nobody wants
520 // pseudorandom bytes much except for this anyway.
521 static PyObject *write_random(PyObject *self, PyObject *args)
523 uint32_t buf[1024/4];
524 int fd = -1, seed = 0, verbose = 0;
526 long long len = 0, kbytes = 0, written = 0;
528 if (!PyArg_ParseTuple(args, "iLii", &fd, &len, &seed, &verbose))
533 for (kbytes = 0; kbytes < len/1024; kbytes++)
536 for (i = 0; i < sizeof(buf)/sizeof(buf[0]); i++)
538 ret = write(fd, buf, sizeof(buf));
542 if (ret < (int)sizeof(buf))
544 if (verbose && kbytes/1024 > 0 && !(kbytes%1024))
545 fprintf(stderr, "Random: %lld Mbytes\r", kbytes/1024);
548 // handle non-multiples of 1024
552 for (i = 0; i < sizeof(buf)/sizeof(buf[0]); i++)
554 ret = write(fd, buf, len % 1024);
561 fprintf(stderr, "Random: %lld Mbytes, done.\n", kbytes/1024);
562 return Py_BuildValue("L", written);
566 static PyObject *random_sha(PyObject *self, PyObject *args)
568 static int seeded = 0;
569 uint32_t shabuf[20/4];
574 assert(sizeof(shabuf) == 20);
579 if (!PyArg_ParseTuple(args, ""))
582 memset(shabuf, 0, sizeof(shabuf));
583 for (i=0; i < 20/4; i++)
584 shabuf[i] = random();
585 return Py_BuildValue("s#", shabuf, 20);
589 static PyObject *open_noatime(PyObject *self, PyObject *args)
591 char *filename = NULL;
592 int attrs, attrs_noatime, fd;
593 if (!PyArg_ParseTuple(args, "s", &filename))
600 attrs |= O_LARGEFILE;
602 attrs_noatime = attrs;
604 attrs_noatime |= O_NOATIME;
606 fd = open(filename, attrs_noatime);
607 if (fd < 0 && errno == EPERM)
609 // older Linux kernels would return EPERM if you used O_NOATIME
610 // and weren't the file's owner. This pointless restriction was
611 // relaxed eventually, but we have to handle it anyway.
612 // (VERY old kernels didn't recognized O_NOATIME, but they would
613 // just harmlessly ignore it, so this branch won't trigger)
614 fd = open(filename, attrs);
617 return PyErr_SetFromErrnoWithFilename(PyExc_OSError, filename);
618 return Py_BuildValue("i", fd);
622 static PyObject *fadvise_done(PyObject *self, PyObject *args)
626 if (!PyArg_ParseTuple(args, "iL", &fd, &ofs))
628 #ifdef POSIX_FADV_DONTNEED
629 posix_fadvise(fd, 0, ofs, POSIX_FADV_DONTNEED);
631 return Py_BuildValue("");
635 #ifdef FS_IOC_GETFLAGS
636 static PyObject *bup_get_linux_file_attr(PyObject *self, PyObject *args)
643 if (!PyArg_ParseTuple(args, "s", &path))
646 fd = open(path, O_RDONLY | O_NONBLOCK | O_LARGEFILE | O_NOFOLLOW);
648 return PyErr_SetFromErrnoWithFilename(PyExc_OSError, path);
651 rc = ioctl(fd, FS_IOC_GETFLAGS, &attr);
655 return PyErr_SetFromErrnoWithFilename(PyExc_OSError, path);
659 return Py_BuildValue("k", attr);
661 #endif /* def FS_IOC_GETFLAGS */
664 #ifdef FS_IOC_SETFLAGS
665 static PyObject *bup_set_linux_file_attr(PyObject *self, PyObject *args)
672 if (!PyArg_ParseTuple(args, "sk", &path, &attr))
675 fd = open(path, O_RDONLY | O_NONBLOCK | O_LARGEFILE | O_NOFOLLOW);
677 return PyErr_SetFromErrnoWithFilename(PyExc_OSError, path);
679 rc = ioctl(fd, FS_IOC_SETFLAGS, &attr);
683 return PyErr_SetFromErrnoWithFilename(PyExc_OSError, path);
687 return Py_BuildValue("O", Py_None);
689 #endif /* def FS_IOC_SETFLAGS */
692 #ifdef HAVE_UTIMENSAT
693 #if defined(_ATFILE_SOURCE) \
694 || _XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
695 #define HAVE_BUP_UTIMENSAT 1
697 static PyObject *bup_utimensat(PyObject *self, PyObject *args)
699 int rc, dirfd, flags;
701 long access, access_ns, modification, modification_ns;
702 struct timespec ts[2];
704 if (!PyArg_ParseTuple(args, "is((ll)(ll))i",
708 &modification, &modification_ns,
714 PyErr_SetString(PyExc_ValueError, "access time is NaN");
717 else if (isinf(access))
719 PyErr_SetString(PyExc_ValueError, "access time is infinite");
722 else if (isnan(modification))
724 PyErr_SetString(PyExc_ValueError, "modification time is NaN");
727 else if (isinf(modification))
729 PyErr_SetString(PyExc_ValueError, "modification time is infinite");
733 if (isnan(access_ns))
735 PyErr_SetString(PyExc_ValueError, "access time ns is NaN");
738 else if (isinf(access_ns))
740 PyErr_SetString(PyExc_ValueError, "access time ns is infinite");
743 else if (isnan(modification_ns))
745 PyErr_SetString(PyExc_ValueError, "modification time ns is NaN");
748 else if (isinf(modification_ns))
750 PyErr_SetString(PyExc_ValueError, "modification time ns is infinite");
754 ts[0].tv_sec = access;
755 ts[0].tv_nsec = access_ns;
756 ts[1].tv_sec = modification;
757 ts[1].tv_nsec = modification_ns;
759 rc = utimensat(dirfd, path, ts, flags);
761 return PyErr_SetFromErrnoWithFilename(PyExc_OSError, path);
763 return Py_BuildValue("O", Py_None);
766 #endif /* defined(_ATFILE_SOURCE)
767 || _XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L */
768 #endif /* HAVE_UTIMENSAT */
770 static PyObject *stat_struct_to_py(const struct stat *st)
772 /* Enforce the current timespec nanosecond range expectations. */
773 if (st->st_atim.tv_nsec < 0 || st->st_atim.tv_nsec > 999999999)
775 PyErr_SetString(PyExc_ValueError, "invalid atime timespec nanoseconds");
778 if (st->st_mtim.tv_nsec < 0 || st->st_mtim.tv_nsec > 999999999)
780 PyErr_SetString(PyExc_ValueError, "invalid mtime timespec nanoseconds");
783 if (st->st_ctim.tv_nsec < 0 || st->st_ctim.tv_nsec > 999999999)
785 PyErr_SetString(PyExc_ValueError, "invalid ctime timespec nanoseconds");
789 return Py_BuildValue("kkkkkkkk(Ll)(Ll)(Ll)",
790 (unsigned long) st->st_mode,
791 (unsigned long) st->st_ino,
792 (unsigned long) st->st_dev,
793 (unsigned long) st->st_nlink,
794 (unsigned long) st->st_uid,
795 (unsigned long) st->st_gid,
796 (unsigned long) st->st_rdev,
797 (unsigned long) st->st_size,
798 (long long) st->st_atime,
799 (long) st->st_atim.tv_nsec,
800 (long long) st->st_mtime,
801 (long) st->st_mtim.tv_nsec,
802 (long long) st->st_ctime,
803 (long) st->st_ctim.tv_nsec);
807 static PyObject *bup_stat(PyObject *self, PyObject *args)
812 if (!PyArg_ParseTuple(args, "s", &filename))
816 rc = stat(filename, &st);
818 return PyErr_SetFromErrnoWithFilename(PyExc_OSError, filename);
819 return stat_struct_to_py(&st);
823 static PyObject *bup_lstat(PyObject *self, PyObject *args)
828 if (!PyArg_ParseTuple(args, "s", &filename))
832 rc = lstat(filename, &st);
834 return PyErr_SetFromErrnoWithFilename(PyExc_OSError, filename);
835 return stat_struct_to_py(&st);
839 static PyObject *bup_fstat(PyObject *self, PyObject *args)
843 if (!PyArg_ParseTuple(args, "i", &fd))
849 return PyErr_SetFromErrno(PyExc_OSError);
850 return stat_struct_to_py(&st);
854 static PyMethodDef helper_methods[] = {
855 { "selftest", selftest, METH_VARARGS,
856 "Check that the rolling checksum rolls correctly (for unit tests)." },
857 { "blobbits", blobbits, METH_VARARGS,
858 "Return the number of bits in the rolling checksum." },
859 { "splitbuf", splitbuf, METH_VARARGS,
860 "Split a list of strings based on a rolling checksum." },
861 { "bitmatch", bitmatch, METH_VARARGS,
862 "Count the number of matching prefix bits between two strings." },
863 { "firstword", firstword, METH_VARARGS,
864 "Return an int corresponding to the first 32 bits of buf." },
865 { "bloom_contains", bloom_contains, METH_VARARGS,
866 "Check if a bloom filter of 2^nbits bytes contains an object" },
867 { "bloom_add", bloom_add, METH_VARARGS,
868 "Add an object to a bloom filter of 2^nbits bytes" },
869 { "extract_bits", extract_bits, METH_VARARGS,
870 "Take the first 'nbits' bits from 'buf' and return them as an int." },
871 { "merge_into", merge_into, METH_VARARGS,
872 "Merges a bunch of idx and midx files into a single midx." },
873 { "write_idx", write_idx, METH_VARARGS,
874 "Write a PackIdxV2 file from an idx list of lists of tuples" },
875 { "write_random", write_random, METH_VARARGS,
876 "Write random bytes to the given file descriptor" },
877 { "random_sha", random_sha, METH_VARARGS,
878 "Return a random 20-byte string" },
879 { "open_noatime", open_noatime, METH_VARARGS,
880 "open() the given filename for read with O_NOATIME if possible" },
881 { "fadvise_done", fadvise_done, METH_VARARGS,
882 "Inform the kernel that we're finished with earlier parts of a file" },
883 #ifdef FS_IOC_GETFLAGS
884 { "get_linux_file_attr", bup_get_linux_file_attr, METH_VARARGS,
885 "Return the Linux attributes for the given file." },
887 #ifdef FS_IOC_SETFLAGS
888 { "set_linux_file_attr", bup_set_linux_file_attr, METH_VARARGS,
889 "Set the Linux attributes for the given file." },
891 #ifdef HAVE_BUP_UTIMENSAT
892 { "utimensat", bup_utimensat, METH_VARARGS,
893 "Change file timestamps with nanosecond precision." },
895 { "stat", bup_stat, METH_VARARGS,
896 "Extended version of stat." },
897 { "lstat", bup_lstat, METH_VARARGS,
898 "Extended version of lstat." },
899 { "fstat", bup_fstat, METH_VARARGS,
900 "Extended version of fstat." },
901 { NULL, NULL, 0, NULL }, // sentinel
905 PyMODINIT_FUNC init_helpers(void)
908 PyObject *m = Py_InitModule("_helpers", helper_methods);
911 #ifdef HAVE_BUP_UTIMENSAT
912 PyModule_AddObject(m, "AT_FDCWD", Py_BuildValue("i", AT_FDCWD));
913 PyModule_AddObject(m, "AT_SYMLINK_NOFOLLOW",
914 Py_BuildValue("i", AT_SYMLINK_NOFOLLOW));
916 e = getenv("BUP_FORCE_TTY");
917 istty2 = isatty(2) || (atoi(e ? e : "0") & 2);