From rsync-cvs at lists.samba.org Sun Aug 14 21:45:06 2016 From: rsync-cvs at lists.samba.org (Rsync CVS commit messages) Date: Sun, 14 Aug 2016 23:45:06 +0200 (CEST) Subject: [SCM] The rsync repository. - branch master updated Message-ID: The branch, master has been updated via 6e3b210 xattrs: maintain a hashtable in order to speed up find_matching_xattr() via cc29b94 hashtable: add hashlittle() from lookup3.c, by Bob Jenkins via 6eb71be xattrs: introduce a rsync_xa_list struct as layer between two nested item_lists via 39d7e3e xattrs: let rsync_xal_store() return ndx. via ac97bc1 xattrs: add const to empty_xattr from 31e93c3 Makefile: rounding.h generation requires proto.h via rsync.h https://git.samba.org/?p=rsync.git;a=shortlog;h=master - Log ----------------------------------------------------------------- commit 6e3b2102bc2c7df42aa4961a6460eae954c95af2 Author: Stefan Metzmacher Date: Fri Jul 22 19:46:46 2016 +0200 xattrs: maintain a hashtable in order to speed up find_matching_xattr() As a testcase I've used one directory on gpfs with 1000000 files, each with an xattr called 'name$i' having a value of 'value$i'. So we also have 1000000 unique xattrs. The source and dest directories are already in sync before. So the rsync command is basically a noop, just verifying that everything is already in sync. The results before this patchset are: [gpfs]# time rsync -a -P -X -q source-xattr/ dest-with-xattr/ real 8m46.191s user 6m29.016s sys 0m24.883s [gpfs]# time rsync -a -P -q source-xattr/ dest-without-xattr/ real 1m58.462s user 0m0.957s sys 0m11.801s With the patchset I got: [gpfs]# time /gpfs/rsync.install/bin/rsync -a -P -X -q source-xattr/ dest-with-xattr/ real 2m4.150s user 0m1.917s sys 0m17.077s [gpfs]# time /gpfs/rsync.install/bin/rsync -a -P -q source-xattr/ dest-without-xattr/ real 1m59.534s user 0m0.924s sys 0m11.599s It means the time in userspace dropped from 6m29.016s down to 0m1.917s! Without -X we get ~ 0m0.9s with or without the patch. Part of a patchset for bug 5324. commit cc29b94d0f3ae5d8f96dd0daaf282ed9a73bfe73 Author: Stefan Metzmacher Date: Fri Jul 22 18:35:18 2016 +0200 hashtable: add hashlittle() from lookup3.c, by Bob Jenkins Part of a patchset for bug 5324. commit 6eb71beaffb365c8f3b3d0db3ab7123026ee423e Author: Stefan Metzmacher Date: Fri Jul 22 18:32:04 2016 +0200 xattrs: introduce a rsync_xa_list struct as layer between two nested item_lists We have the global 'item_list rsync_xal_l', this maintains an array of rsync_xa_list structure, one per file. Each rsync_xa_list structure maintains an array of rsync_xa structure, while each represent a single xattr with name and value. Part of a patchset for bug 5324. commit 39d7e3ec255a15ed6da035a009abc2a1c0a3d856 Author: Stefan Metzmacher Date: Fri Jul 22 18:14:40 2016 +0200 xattrs: let rsync_xal_store() return ndx. Part of a patchset for bug 5324. commit ac97bc14f623fe5027423aa0a6acd3a8c1124e99 Author: Stefan Metzmacher Date: Fri Jul 22 14:43:27 2016 +0200 xattrs: add const to empty_xattr Part of a patchset for bug 5324. ----------------------------------------------------------------------- Summary of changes: hashtable.c | 302 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ xattrs.c | 207 ++++++++++++++++++++++++++++++++++------- 2 files changed, 475 insertions(+), 34 deletions(-) Changeset truncated at 500 lines: diff --git a/hashtable.c b/hashtable.c index f0fbe51..238db08 100644 --- a/hashtable.c +++ b/hashtable.c @@ -170,3 +170,305 @@ void *hashtable_find(struct hashtable *tbl, int64 key, int allocate_if_missing) tbl->entries++; return node; } + +#ifndef WORDS_BIGENDIAN +# define HASH_LITTLE_ENDIAN 1 +# define HASH_BIG_ENDIAN 0 +#else +# define HASH_LITTLE_ENDIAN 0 +# define HASH_BIG_ENDIAN 1 +#endif + +/* + ------------------------------------------------------------------------------- + lookup3.c, by Bob Jenkins, May 2006, Public Domain. + + These are functions for producing 32-bit hashes for hash table lookup. + hash_word(), hashlittle(), hashlittle2(), hashbig(), mix(), and final() + are externally useful functions. Routines to test the hash are included + if SELF_TEST is defined. You can use this free for any purpose. It's in + the public domain. It has no warranty. + + You probably want to use hashlittle(). hashlittle() and hashbig() + hash byte arrays. hashlittle() is is faster than hashbig() on + little-endian machines. Intel and AMD are little-endian machines. + On second thought, you probably want hashlittle2(), which is identical to + hashlittle() except it returns two 32-bit hashes for the price of one. + You could implement hashbig2() if you wanted but I haven't bothered here. + + If you want to find a hash of, say, exactly 7 integers, do + a = i1; b = i2; c = i3; + mix(a,b,c); + a += i4; b += i5; c += i6; + mix(a,b,c); + a += i7; + final(a,b,c); + then use c as the hash value. If you have a variable length array of + 4-byte integers to hash, use hash_word(). If you have a byte array (like + a character string), use hashlittle(). If you have several byte arrays, or + a mix of things, see the comments above hashlittle(). + + Why is this so big? I read 12 bytes at a time into 3 4-byte integers, + then mix those integers. This is fast (you can do a lot more thorough + mixing with 12*3 instructions on 3 integers than you can with 3 instructions + on 1 byte), but shoehorning those bytes into integers efficiently is messy. +*/ + +#define hashsize(n) ((uint32_t)1<<(n)) +#define hashmask(n) (hashsize(n)-1) +#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k)))) + +/* + ------------------------------------------------------------------------------- + mix -- mix 3 32-bit values reversibly. + + This is reversible, so any information in (a,b,c) before mix() is + still in (a,b,c) after mix(). + + If four pairs of (a,b,c) inputs are run through mix(), or through + mix() in reverse, there are at least 32 bits of the output that + are sometimes the same for one pair and different for another pair. + This was tested for: + * pairs that differed by one bit, by two bits, in any combination + of top bits of (a,b,c), or in any combination of bottom bits of + (a,b,c). + * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed + the output delta to a Gray code (a^(a>>1)) so a string of 1's (as + is commonly produced by subtraction) look like a single 1-bit + difference. + * the base values were pseudorandom, all zero but one bit set, or + all zero plus a counter that starts at zero. + + Some k values for my "a-=c; a^=rot(c,k); c+=b;" arrangement that + satisfy this are + 4 6 8 16 19 4 + 9 15 3 18 27 15 + 14 9 3 7 17 3 + Well, "9 15 3 18 27 15" didn't quite get 32 bits diffing + for "differ" defined as + with a one-bit base and a two-bit delta. I + used http://burtleburtle.net/bob/hash/avalanche.html to choose + the operations, constants, and arrangements of the variables. + + This does not achieve avalanche. There are input bits of (a,b,c) + that fail to affect some output bits of (a,b,c), especially of a. The + most thoroughly mixed value is c, but it doesn't really even achieve + avalanche in c. + + This allows some parallelism. Read-after-writes are good at doubling + the number of bits affected, so the goal of mixing pulls in the opposite + direction as the goal of parallelism. I did what I could. Rotates + seem to cost as much as shifts on every machine I could lay my hands + on, and rotates are much kinder to the top and bottom bits, so I used + rotates. + ------------------------------------------------------------------------------- +*/ +#define mix(a,b,c) \ +{ \ + a -= c; a ^= rot(c, 4); c += b; \ + b -= a; b ^= rot(a, 6); a += c; \ + c -= b; c ^= rot(b, 8); b += a; \ + a -= c; a ^= rot(c,16); c += b; \ + b -= a; b ^= rot(a,19); a += c; \ + c -= b; c ^= rot(b, 4); b += a; \ +} + +/* + ------------------------------------------------------------------------------- + final -- final mixing of 3 32-bit values (a,b,c) into c + + Pairs of (a,b,c) values differing in only a few bits will usually + produce values of c that look totally different. This was tested for + * pairs that differed by one bit, by two bits, in any combination + of top bits of (a,b,c), or in any combination of bottom bits of + (a,b,c). + * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed + the output delta to a Gray code (a^(a>>1)) so a string of 1's (as + is commonly produced by subtraction) look like a single 1-bit + difference. + * the base values were pseudorandom, all zero but one bit set, or + all zero plus a counter that starts at zero. + + These constants passed: + 14 11 25 16 4 14 24 + 12 14 25 16 4 14 24 + and these came close: + 4 8 15 26 3 22 24 + 10 8 15 26 3 22 24 + 11 8 15 26 3 22 24 + ------------------------------------------------------------------------------- +*/ +#define final(a,b,c) \ +{ \ + c ^= b; c -= rot(b,14); \ + a ^= c; a -= rot(c,11); \ + b ^= a; b -= rot(a,25); \ + c ^= b; c -= rot(b,16); \ + a ^= c; a -= rot(c,4); \ + b ^= a; b -= rot(a,14); \ + c ^= b; c -= rot(b,24); \ +} + + +/* + ------------------------------------------------------------------------------- + hashlittle() -- hash a variable-length key into a 32-bit value + k : the key (the unaligned variable-length array of bytes) + length : the length of the key, counting by bytes + val2 : IN: can be any 4-byte value OUT: second 32 bit hash. + Returns a 32-bit value. Every bit of the key affects every bit of + the return value. Two keys differing by one or two bits will have + totally different hash values. Note that the return value is better + mixed than val2, so use that first. + + The best hash table sizes are powers of 2. There is no need to do + mod a prime (mod is sooo slow!). If you need less than 32 bits, + use a bitmask. For example, if you need only 10 bits, do + h = (h & hashmask(10)); + In which case, the hash table should have hashsize(10) elements. + + If you are hashing n strings (uint8_t **)k, do it like this: + for (i=0, h=0; i 12) + { + a += k[0]; + b += k[1]; + c += k[2]; + mix(a,b,c); + length -= 12; + k += 3; + } + + /*----------------------------- handle the last (probably partial) block */ + k8 = (const uint8_t *)k; + switch(length) + { + case 12: c+=k[2]; b+=k[1]; a+=k[0]; break; + case 11: c+=((uint32_t)k8[10])<<16; /* fall through */ + case 10: c+=((uint32_t)k8[9])<<8; /* fall through */ + case 9 : c+=k8[8]; /* fall through */ + case 8 : b+=k[1]; a+=k[0]; break; + case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */ + case 6 : b+=((uint32_t)k8[5])<<8; /* fall through */ + case 5 : b+=k8[4]; /* fall through */ + case 4 : a+=k[0]; break; + case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */ + case 2 : a+=((uint32_t)k8[1])<<8; /* fall through */ + case 1 : a+=k8[0]; break; + case 0 : return c; + } + } else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) { + const uint16_t *k = (const uint16_t *)key; /* read 16-bit chunks */ + const uint8_t *k8; + + /*--------------- all but last block: aligned reads and different mixing */ + while (length > 12) + { + a += k[0] + (((uint32_t)k[1])<<16); + b += k[2] + (((uint32_t)k[3])<<16); + c += k[4] + (((uint32_t)k[5])<<16); + mix(a,b,c); + length -= 12; + k += 6; + } + + /*----------------------------- handle the last (probably partial) block */ + k8 = (const uint8_t *)k; + switch(length) + { + case 12: c+=k[4]+(((uint32_t)k[5])<<16); + b+=k[2]+(((uint32_t)k[3])<<16); + a+=k[0]+(((uint32_t)k[1])<<16); + break; + case 11: c+=((uint32_t)k8[10])<<16; /* fall through */ + case 10: c+=k[4]; + b+=k[2]+(((uint32_t)k[3])<<16); + a+=k[0]+(((uint32_t)k[1])<<16); + break; + case 9 : c+=k8[8]; /* fall through */ + case 8 : b+=k[2]+(((uint32_t)k[3])<<16); + a+=k[0]+(((uint32_t)k[1])<<16); + break; + case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */ + case 6 : b+=k[2]; + a+=k[0]+(((uint32_t)k[1])<<16); + break; + case 5 : b+=k8[4]; /* fall through */ + case 4 : a+=k[0]+(((uint32_t)k[1])<<16); + break; + case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */ + case 2 : a+=k[0]; + break; + case 1 : a+=k8[0]; + break; + case 0 : return c; /* zero length requires no mixing */ + } + + } else { /* need to read the key one byte at a time */ + const uint8_t *k = (const uint8_t *)key; + + /*--------------- all but the last block: affect some 32 bits of (a,b,c) */ + while (length > 12) + { + a += k[0]; + a += ((uint32_t)k[1])<<8; + a += ((uint32_t)k[2])<<16; + a += ((uint32_t)k[3])<<24; + b += k[4]; + b += ((uint32_t)k[5])<<8; + b += ((uint32_t)k[6])<<16; + b += ((uint32_t)k[7])<<24; + c += k[8]; + c += ((uint32_t)k[9])<<8; + c += ((uint32_t)k[10])<<16; + c += ((uint32_t)k[11])<<24; + mix(a,b,c); + length -= 12; + k += 12; + } + + /*-------------------------------- last block: affect all 32 bits of (c) */ + switch(length) /* all the case statements fall through */ + { + case 12: c+=((uint32_t)k[11])<<24; + case 11: c+=((uint32_t)k[10])<<16; + case 10: c+=((uint32_t)k[9])<<8; + case 9 : c+=k[8]; + case 8 : b+=((uint32_t)k[7])<<24; + case 7 : b+=((uint32_t)k[6])<<16; + case 6 : b+=((uint32_t)k[5])<<8; + case 5 : b+=k[4]; + case 4 : a+=((uint32_t)k[3])<<24; + case 3 : a+=((uint32_t)k[2])<<16; + case 2 : a+=((uint32_t)k[1])<<8; + case 1 : a+=k[0]; + break; + case 0 : return c; + } + } + + final(a,b,c); + return c; +} diff --git a/xattrs.c b/xattrs.c index 0658afb..b105392 100644 --- a/xattrs.c +++ b/xattrs.c @@ -79,11 +79,28 @@ typedef struct { int num; } rsync_xa; +struct _rsync_xa_list; + +typedef struct _rsync_xa_list_ref { + struct _rsync_xa_list_ref *next; + int ndx; +} rsync_xa_list_ref; + +typedef struct _rsync_xa_list { + int ndx; + int64 key; + item_list xa_items; +} rsync_xa_list; + static size_t namebuf_len = 0; static char *namebuf = NULL; -static item_list empty_xattr = EMPTY_ITEM_LIST; +static const rsync_xa_list empty_xa_list = { + .xa_items = EMPTY_ITEM_LIST, +}; +static const item_list empty_xattr = EMPTY_ITEM_LIST; static item_list rsync_xal_l = EMPTY_ITEM_LIST; +static struct hashtable *rsync_xal_h = NULL; static size_t prior_xattr_count = (size_t)-1; @@ -360,17 +377,58 @@ int copy_xattrs(const char *source, const char *dest) return 0; } -static int find_matching_xattr(item_list *xalp) +static int64 xattr_lookup_hash(const item_list *xalp) +{ + const rsync_xa *rxas = xalp->items; + size_t i; + int64 key = hashlittle(&xalp->count, sizeof xalp->count); + + for (i = 0; i < xalp->count; i++) { + key += hashlittle(rxas[i].name, rxas[i].name_len); + if (rxas[i].datum_len > MAX_FULL_DATUM) + key += hashlittle(rxas[i].datum, MAX_DIGEST_LEN); + else + key += hashlittle(rxas[i].datum, rxas[i].datum_len); + } + + if (key == 0) { + /* This is very unlikely, but we should never + * return 0 as hashtable_find() doesn't like it. */ + return 1; + } + + return key; +} + +static int find_matching_xattr(const item_list *xalp) { - size_t i, j; - item_list *lst = rsync_xal_l.items; + const struct ht_int64_node *node; + const rsync_xa_list_ref *ref; + int64 key; - for (i = 0; i < rsync_xal_l.count; i++) { - rsync_xa *rxas1 = lst[i].items; - rsync_xa *rxas2 = xalp->items; + if (rsync_xal_h == NULL) + return -1; + + key = xattr_lookup_hash(xalp); + + node = hashtable_find(rsync_xal_h, key, 0); + if (node == NULL) + return -1; + + if (node->data == NULL) + return -1; + + for (ref = node->data; ref != NULL; ref = ref->next) { + const rsync_xa_list *ptr = rsync_xal_l.items; + const rsync_xa *rxas1; + const rsync_xa *rxas2 = xalp->items; + size_t j; + + ptr += ref->ndx; + rxas1 = ptr->xa_items.items; /* Wrong number of elements? */ - if (lst[i].count != xalp->count) + if (ptr->xa_items.count != xalp->count) continue; /* any elements different? */ for (j = 0; j < xalp->count; j++) { @@ -391,23 +449,61 @@ static int find_matching_xattr(item_list *xalp) } /* no differences found. This is The One! */ if (j == xalp->count) - return i; + return ref->ndx; } return -1; } /* Store *xalp on the end of rsync_xal_l */ -static void rsync_xal_store(item_list *xalp) +static int rsync_xal_store(item_list *xalp) { - item_list *new_lst = EXPAND_ITEM_LIST(&rsync_xal_l, item_list, RSYNC_XAL_LIST_INITIAL); + struct ht_int64_node *node; + int ndx = rsync_xal_l.count; /* pre-incremented count */ + rsync_xa_list *new_list = EXPAND_ITEM_LIST(&rsync_xal_l, rsync_xa_list, RSYNC_XAL_LIST_INITIAL); + rsync_xa_list_ref *new_ref; /* Since the following call starts a new list, we know it will hold the * entire initial-count, not just enough space for one new item. */ - *new_lst = empty_xattr; - (void)EXPAND_ITEM_LIST(new_lst, rsync_xa, xalp->count); - memcpy(new_lst->items, xalp->items, xalp->count * sizeof (rsync_xa)); - new_lst->count = xalp->count; + *new_list = empty_xa_list; + (void)EXPAND_ITEM_LIST(&new_list->xa_items, rsync_xa, xalp->count); + memcpy(new_list->xa_items.items, xalp->items, xalp->count * sizeof (rsync_xa)); + new_list->xa_items.count = xalp->count; xalp->count = 0; + + new_list->ndx = ndx; + new_list->key = xattr_lookup_hash(&new_list->xa_items); + + if (rsync_xal_h == NULL) + rsync_xal_h = hashtable_create(512, 1); + if (rsync_xal_h == NULL) + out_of_memory("rsync_xal_h hashtable_create()"); + + node = hashtable_find(rsync_xal_h, new_list->key, 1); + if (node == NULL) + out_of_memory("rsync_xal_h hashtable_find()"); + + new_ref = new0(rsync_xa_list_ref); + if (new_ref == NULL) + out_of_memory("new0(rsync_xa_list_ref)"); + + new_ref->ndx = ndx; + + if (node->data != NULL) { + rsync_xa_list_ref *ref = node->data; + + while (ref != NULL) { + if (ref->next != NULL) { + ref = ref->next; + continue; + } + + ref->next = new_ref; + break; + } + } else + node->data = new_ref; + + return ndx; } /* Send the make_xattr()-generated xattr list for this flist entry. */ @@ -454,8 +550,7 @@ int send_xattr(int f, stat_x *sxp) else write_bigbuf(f, rxa->datum, rxa->datum_len); } - ndx = rsync_xal_l.count; /* pre-incremented count */ - rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */ + ndx = rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */ } return ndx; @@ -466,7 +561,8 @@ int send_xattr(int f, stat_x *sxp) * need so that send_xattr_request() can tell the sender about them. */ int xattr_diff(struct file_struct *file, stat_x *sxp, int find_all) { - item_list *lst = rsync_xal_l.items; + const rsync_xa_list *glst = rsync_xal_l.items; + const item_list *lst; rsync_xa *snd_rxa, *rec_rxa; int snd_cnt, rec_cnt; int cmp, same, xattrs_equal = 1; @@ -479,9 +575,10 @@ int xattr_diff(struct file_struct *file, stat_x *sxp, int find_all) -- The rsync repository.