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mariadb/newbrt/cachetable.c
Bradley C. Kuszmaul 4db5b5063c Did 
{{{
svn merge -r4556:4568 https://svn.tokutek.com/tokudb/tokudb.906
}}}
to incorporate the hash improvements.

Addresses #906.


git-svn-id: file:///svn/tokudb@4596 c7de825b-a66e-492c-adef-691d508d4ae1
2008-06-17 17:05:19 +00:00

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28 KiB
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/* -*- mode: C; c-basic-offset: 4 -*- */
#ident "Copyright (c) 2007, 2008 Tokutek Inc. All rights reserved."
#include "cachetable.h"
#include "hashfun.h"
#include "memory.h"
#include "toku_assert.h"
#include "brt-internal.h"
#include "log_header.h"
#include <malloc.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
//#define TRACE_CACHETABLE
#ifdef TRACE_CACHETABLE
#define WHEN_TRACE_CT(x) x
#else
#define WHEN_TRACE_CT(x) ((void)0)
#endif
typedef struct ctpair *PAIR;
struct ctpair {
enum typ_tag tag;
long long pinned;
long size;
char dirty;
CACHEKEY key;
void *value;
PAIR next,prev; // In LRU list.
PAIR hash_chain;
CACHEFILE cachefile;
CACHETABLE_FLUSH_FUNC_T flush_callback;
CACHETABLE_FETCH_FUNC_T fetch_callback;
void *extraargs;
int verify_flag; /* Used in verify_cachetable() */
LSN modified_lsn; // What was the LSN when modified (undefined if not dirty)
LSN written_lsn; // What was the LSN when written (we need to get this information when we fetch)
u_int32_t fullhash;
};
// The cachetable is as close to an ENV as we get.
struct cachetable {
enum typ_tag tag;
u_int32_t n_in_table;
u_int32_t table_size;
PAIR *table;
PAIR head,tail; // of LRU list. head is the most recently used. tail is least recently used.
CACHEFILE cachefiles;
long size_current, size_limit;
LSN lsn_of_checkpoint; // the most recent checkpoint in the log.
TOKULOGGER logger;
};
struct fileid {
dev_t st_dev; /* device and inode are enough to uniquely identify a file in unix. */
ino_t st_ino;
};
struct cachefile {
CACHEFILE next;
u_int32_t header_fullhash;
u_int64_t refcount; /* CACHEFILEs are shared. Use a refcount to decide when to really close it.
* The reference count is one for every open DB.
* Plus one for every commit/rollback record. (It would be harder to keep a count for every open transaction,
* because then we'd have to figure out if the transaction was already counted. If we simply use a count for
* every record in the transaction, we'll be ok. Hence we use a 64-bit counter to make sure we don't run out.
*/
int fd; /* Bug: If a file is opened read-only, then it is stuck in read-only. If it is opened read-write, then subsequent writers can write to it too. */
CACHETABLE cachetable;
struct fileid fileid;
FILENUM filenum;
char *fname;
};
int toku_create_cachetable(CACHETABLE *result, long size_limit, LSN initial_lsn, TOKULOGGER logger) {
{
static int did_mallopt = 0;
if (!did_mallopt) {
mallopt(M_MMAP_THRESHOLD, 1024*64); // 64K and larger should be malloced with mmap().
did_mallopt = 1;
}
}
TAGMALLOC(CACHETABLE, t);
u_int32_t i;
t->n_in_table = 0;
t->table_size = 4;
MALLOC_N(t->table_size, t->table);
assert(t->table);
t->head = t->tail = 0;
for (i=0; i<t->table_size; i++) {
t->table[i]=0;
}
t->cachefiles = 0;
t->size_current = 0;
t->size_limit = size_limit;
t->lsn_of_checkpoint = initial_lsn;
t->logger = logger;
*result = t;
return 0;
}
// What cachefile goes with particular fd?
int toku_cachefile_of_filenum (CACHETABLE t, FILENUM filenum, CACHEFILE *cf) {
CACHEFILE extant;
for (extant = t->cachefiles; extant; extant=extant->next) {
if (extant->filenum.fileid==filenum.fileid) {
*cf = extant;
return 0;
}
}
return ENOENT;
}
// If something goes wrong, close the fd. After this, the caller shouldn't close the fd, but instead should close the cachefile.
int toku_cachetable_openfd (CACHEFILE *cf, CACHETABLE t, int fd, const char *fname) {
int r;
CACHEFILE extant;
static FILENUM next_filenum_to_use={0};
struct stat statbuf;
struct fileid fileid;
memset(&fileid, 0, sizeof(fileid));
r=fstat(fd, &statbuf);
if (r != 0) { r=errno; close(fd); }
fileid.st_dev = statbuf.st_dev;
fileid.st_ino = statbuf.st_ino;
for (extant = t->cachefiles; extant; extant=extant->next) {
if (memcmp(&extant->fileid, &fileid, sizeof(fileid))==0) {
r = close(fd);
assert(r == 0);
extant->refcount++;
*cf = extant;
return 0;
}
}
try_again:
for (extant = t->cachefiles; extant; extant=extant->next) {
if (next_filenum_to_use.fileid==extant->filenum.fileid) {
next_filenum_to_use.fileid++;
goto try_again;
}
}
{
CACHEFILE MALLOC(newcf);
newcf->filenum.fileid = next_filenum_to_use.fileid++;
newcf->header_fullhash = toku_cachetable_hash(newcf, 0);
newcf->next = t->cachefiles;
newcf->refcount = 1;
newcf->fd = fd;
newcf->cachetable = t;
newcf->fileid = fileid;
newcf->fname = fname ? toku_strdup(fname) : 0;
t->cachefiles = newcf;
*cf = newcf;
return 0;
}
}
int toku_cachetable_openf (CACHEFILE *cf, CACHETABLE t, const char *fname, int flags, mode_t mode) {
int fd = open(fname, flags, mode);
if (fd<0) return errno;
return toku_cachetable_openfd (cf, t, fd, fname);
}
static CACHEFILE remove_cf_from_list (CACHEFILE cf, CACHEFILE list) {
if (list==0) return 0;
else if (list==cf) {
return list->next;
} else {
list->next = remove_cf_from_list(cf, list->next);
return list;
}
}
static int cachefile_flush_and_remove (CACHEFILE cf);
// Increment the reference count
void toku_cachefile_refup (CACHEFILE cf) {
cf->refcount++;
}
int toku_cachefile_close (CACHEFILE *cfp, TOKULOGGER logger) {
CACHEFILE cf = *cfp;
assert(cf->refcount>0);
cf->refcount--;
if (cf->refcount==0) {
int r;
if ((r = cachefile_flush_and_remove(cf))) return r;
r = close(cf->fd);
assert(r == 0);
cf->fd = -1;
cf->cachetable->cachefiles = remove_cf_from_list(cf, cf->cachetable->cachefiles);
if (logger) {
assert(cf->fname);
BYTESTRING bs = {.len=strlen(cf->fname), .data=cf->fname};
r = toku_log_cfclose(logger, 0, 0, bs, cf->filenum);
}
if (cf->fname)
toku_free(cf->fname);
toku_free(cf);
*cfp=0;
return r;
} else {
*cfp=0;
return 0;
}
}
int toku_cachetable_assert_all_unpinned (CACHETABLE t) {
u_int32_t i;
int some_pinned=0;
for (i=0; i<t->table_size; i++) {
PAIR p;
for (p=t->table[i]; p; p=p->hash_chain) {
assert(p->pinned>=0);
if (p->pinned) {
printf("%s:%d pinned: %lld (%p)\n", __FILE__, __LINE__, p->key, p->value);
some_pinned=1;
}
}
}
return some_pinned;
}
int toku_cachefile_count_pinned (CACHEFILE cf, int print_them) {
u_int32_t i;
int n_pinned=0;
CACHETABLE t = cf->cachetable;
for (i=0; i<t->table_size; i++) {
PAIR p;
for (p=t->table[i]; p; p=p->hash_chain) {
assert(p->pinned>=0);
if (p->pinned && p->cachefile==cf) {
if (print_them) printf("%s:%d pinned: %lld (%p)\n", __FILE__, __LINE__, p->key, p->value);
n_pinned++;
}
}
}
return n_pinned;
}
#if 0
unsigned int ct_hash_longlong (unsigned long long l) {
unsigned int r = hash_key((unsigned char*)&l, 8);
printf("%lld --> %d --> %d\n", l, r, r%64);
return r;
}
#endif
// This hash function comes from Jenkins: http://burtleburtle.net/bob/c/lookup3.c
// The idea here is to mix the bits thoroughly so that we don't have to do modulo by a prime number.
// Instead we can use a bitmask on a table of size power of two.
// This hash function does yield improved performance on ./db-benchmark-test-tokudb and ./scanscan
static inline u_int32_t rot(u_int32_t x, u_int32_t k) {
return (x<<k) | (x>>(32-k));
}
static inline u_int32_t final (u_int32_t a, u_int32_t b, u_int32_t 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);
return c;
}
u_int32_t toku_cachetable_hash (CACHEFILE cachefile, CACHEKEY key)
// Effect: Return a 32-bit hash key. The hash key shall be suitable for using with bitmasking for a table of size power-of-two.
{
return final(cachefile->filenum.fileid, (u_int32_t)(key>>32), (u_int32_t)key);
}
#if 0
static unsigned int hashit (CACHETABLE t, CACHEKEY key, CACHEFILE cachefile) {
assert(0==(t->table_size & (t->table_size -1))); // make sure table is power of two
return (toku_cachetable_hash(key,cachefile))&(t->table_size-1);
}
#endif
static void cachetable_rehash (CACHETABLE t, u_int32_t newtable_size) {
// printf("rehash %p %d %d %d\n", t, primeindexdelta, t->n_in_table, t->table_size);
assert(newtable_size>=4 && ((newtable_size & (newtable_size-1))==0));
PAIR *newtable = toku_calloc(newtable_size, sizeof(*t->table));
u_int32_t i;
//printf("%s:%d newtable_size=%d\n", __FILE__, __LINE__, newtable_size);
assert(newtable!=0);
u_int32_t oldtable_size = t->table_size;
t->table_size=newtable_size;
for (i=0; i<newtable_size; i++) newtable[i]=0;
for (i=0; i<oldtable_size; i++) {
PAIR p;
while ((p=t->table[i])!=0) {
unsigned int h = p->fullhash&(newtable_size-1);
t->table[i] = p->hash_chain;
p->hash_chain = newtable[h];
newtable[h] = p;
}
}
toku_free(t->table);
// printf("Freed\n");
t->table=newtable;
//printf("Done growing or shrinking\n");
}
static void lru_remove (CACHETABLE t, PAIR p) {
if (p->next) {
p->next->prev = p->prev;
} else {
assert(t->tail==p);
t->tail = p->prev;
}
if (p->prev) {
p->prev->next = p->next;
} else {
assert(t->head==p);
t->head = p->next;
}
p->prev = p->next = 0;
}
static void lru_add_to_list (CACHETABLE t, PAIR p) {
// requires that touch_me is not currently in the table.
assert(p->prev==0);
p->prev = 0;
p->next = t->head;
if (t->head) {
t->head->prev = p;
} else {
assert(!t->tail);
t->tail = p;
}
t->head = p;
}
static void lru_touch (CACHETABLE t, PAIR p) {
lru_remove(t,p);
lru_add_to_list(t,p);
}
static PAIR remove_from_hash_chain (PAIR remove_me, PAIR list) {
if (remove_me==list) return list->hash_chain;
list->hash_chain = remove_from_hash_chain(remove_me, list->hash_chain);
return list;
}
// Predicate to determine if a node must be renamed. Nodes are renamed on the time they are written
// after a checkpoint.
// Thus we need to rename it if it is dirty,
// if it has been modified within the current checkpoint regime (hence non-strict inequality)
// and the last time it was written was in a previous checkpoint regime (strict inequality)
static BOOL need_to_rename_p (CACHETABLE t, PAIR p) {
return (p->dirty
&& p->modified_lsn.lsn>=t->lsn_of_checkpoint.lsn // nonstrict
&& p->written_lsn.lsn < t->lsn_of_checkpoint.lsn); // strict
}
static void flush_and_remove (CACHETABLE t, PAIR remove_me, int write_me) {
lru_remove(t, remove_me);
//printf("flush_callback(%lld,%p)\n", remove_me->key, remove_me->value);
WHEN_TRACE_CT(printf("%s:%d CT flush_callback(%lld, %p, dirty=%d, 0)\n", __FILE__, __LINE__, remove_me->key, remove_me->value, remove_me->dirty && write_me));
//printf("%s:%d TAG=%x p=%p\n", __FILE__, __LINE__, remove_me->tag, remove_me);
//printf("%s:%d dirty=%d\n", __FILE__, __LINE__, remove_me->dirty);
remove_me->flush_callback(remove_me->cachefile, remove_me->key, remove_me->value, remove_me->size, remove_me->dirty && write_me, 0,
t->lsn_of_checkpoint, need_to_rename_p(t, remove_me));
assert(t->n_in_table>0);
t->n_in_table--;
// Remove it from the hash chain.
{
unsigned int h = remove_me->fullhash&(t->table_size-1);
t->table[h] = remove_from_hash_chain (remove_me, t->table[h]);
}
t->size_current -= remove_me->size;
toku_free(remove_me);
}
static unsigned long toku_maxrss=0;
unsigned long toku_get_maxrss(void) __attribute__((__visibility__("default")));
unsigned long toku_get_maxrss(void) {
return toku_maxrss;
}
static unsigned long check_maxrss (void) __attribute__((__unused__));
static unsigned long check_maxrss (void) {
pid_t pid = getpid();
char fname[100];
snprintf(fname, sizeof(fname), "/proc/%u/statm", pid);
FILE *f = fopen(fname, "r");
unsigned long ignore, rss;
fscanf(f, "%lu %lu", &ignore, &rss);
fclose(f);
if (toku_maxrss<rss) toku_maxrss=rss;
return rss;
}
static int maybe_flush_some (CACHETABLE t, long size __attribute__((unused))) {
int r = 0;
again:
// if (t->n_in_table >= t->table_size) {
if (size + t->size_current > t->size_limit) {
{
unsigned long rss __attribute__((__unused__)) = check_maxrss();
//printf("this-size=%.6fMB projected size = %.2fMB limit=%2.fMB rss=%2.fMB\n", size/(1024.0*1024.0), (size+t->size_current)/(1024.0*1024.0), t->size_limit/(1024.0*1024.0), rss/256.0);
//struct mallinfo m = mallinfo();
//printf(" arena=%d hblks=%d hblkhd=%d\n", m.arena, m.hblks, m.hblkhd);
}
/* Try to remove one. */
PAIR remove_me;
for (remove_me = t->tail; remove_me; remove_me = remove_me->prev) {
if (!remove_me->pinned) {
flush_and_remove(t, remove_me, 1);
goto again;
}
}
/* All were pinned. */
//printf("All are pinned\n");
return 0; // Don't indicate an error code. Instead let memory get overfull.
}
if ((4 * t->n_in_table < t->table_size) && t->table_size > 4)
cachetable_rehash(t, t->table_size/2);
return r;
}
static int cachetable_insert_at(CACHEFILE cachefile, u_int32_t fullhash, CACHEKEY key, void *value, long size,
cachetable_flush_func_t flush_callback,
cachetable_fetch_func_t fetch_callback,
void *extraargs, int dirty,
LSN written_lsn) {
TAGMALLOC(PAIR, p);
p->fullhash = fullhash;
p->pinned = 1;
p->dirty = dirty;
p->size = size;
//printf("%s:%d p=%p dirty=%d\n", __FILE__, __LINE__, p, p->dirty);
p->key = key;
p->value = value;
p->next = p->prev = 0;
p->cachefile = cachefile;
p->flush_callback = flush_callback;
p->fetch_callback = fetch_callback;
p->extraargs = extraargs;
p->modified_lsn.lsn = 0;
p->written_lsn = written_lsn;
p->fullhash = fullhash;
CACHETABLE ct = cachefile->cachetable;
lru_add_to_list(ct, p);
u_int32_t h = fullhash & (ct->table_size-1);
p->hash_chain = ct->table[h];
ct->table[h] = p;
ct->n_in_table++;
ct->size_current += size;
if (ct->n_in_table > ct->table_size) {
cachetable_rehash(ct, ct->table_size*2);
}
return 0;
}
enum { hash_histogram_max = 100 };
static unsigned long long hash_histogram[hash_histogram_max];
void print_hash_histogram (void) __attribute__((__visibility__("default")));
void print_hash_histogram (void) {
int i;
for (i=0; i<hash_histogram_max; i++)
if (hash_histogram[i]) printf("%d:%lld ", i, hash_histogram[i]);
printf("\n");
}
void note_hash_count (int count) {
if (count>=hash_histogram_max) count=hash_histogram_max-1;
hash_histogram[count]++;
}
int toku_cachetable_put(CACHEFILE cachefile, CACHEKEY key, u_int32_t fullhash, void*value, long size,
cachetable_flush_func_t flush_callback, cachetable_fetch_func_t fetch_callback, void *extraargs) {
WHEN_TRACE_CT(printf("%s:%d CT cachetable_put(%lld)=%p\n", __FILE__, __LINE__, key, value));
int count=0;
{
PAIR p;
for (p=cachefile->cachetable->table[fullhash&(cachefile->cachetable->table_size-1)]; p; p=p->hash_chain) {
count++;
if (p->key==key && p->cachefile==cachefile) {
note_hash_count(count);
// Semantically, these two asserts are not strictly right. After all, when are two functions eq?
// In practice, the functions better be the same.
assert(p->flush_callback==flush_callback);
assert(p->fetch_callback==fetch_callback);
p->pinned++; /* Already present. But increment the pin count. */
return -1; /* Already present. */
}
}
}
int r;
note_hash_count(count);
if ((r=maybe_flush_some(cachefile->cachetable, size))) return r;
// flushing could change the table size, but wont' change the fullhash
r = cachetable_insert_at(cachefile, fullhash, key, value, size, flush_callback, fetch_callback, extraargs, 1, ZERO_LSN);
return r;
}
int toku_cachetable_get_and_pin(CACHEFILE cachefile, CACHEKEY key, u_int32_t fullhash, void**value, long *sizep,
cachetable_flush_func_t flush_callback, cachetable_fetch_func_t fetch_callback, void *extraargs) {
CACHETABLE t = cachefile->cachetable;
int tsize __attribute__((__unused__)) = t->table_size;
PAIR p;
int count=0;
for (p=t->table[fullhash&(t->table_size-1)]; p; p=p->hash_chain) {
count++;
if (p->key==key && p->cachefile==cachefile) {
note_hash_count(count);
*value = p->value;
if (sizep) *sizep = p->size;
p->pinned++;
lru_touch(t,p);
WHEN_TRACE_CT(printf("%s:%d cachtable_get_and_pin(%lld)--> %p\n", __FILE__, __LINE__, key, *value));
return 0;
}
}
note_hash_count(count);
int r;
// Note. hashit(t,key) may have changed as a result of flushing. But fullhash won't have changed.
{
void *toku_value;
long size = 1; // compat
LSN written_lsn;
WHEN_TRACE_CT(printf("%s:%d CT: fetch_callback(%lld...)\n", __FILE__, __LINE__, key));
if ((r=fetch_callback(cachefile, key, fullhash, &toku_value, &size, extraargs, &written_lsn))) {
return r;
}
cachetable_insert_at(cachefile, fullhash, key, toku_value, size, flush_callback, fetch_callback, extraargs, 0, written_lsn);
*value = toku_value;
if (sizep)
*sizep = size;
// maybe_flush_some(t, size);
}
if ((r=maybe_flush_some(t, 0))) return r;
WHEN_TRACE_CT(printf("%s:%d did fetch: cachtable_get_and_pin(%lld)--> %p\n", __FILE__, __LINE__, key, *value));
return 0;
}
int toku_cachetable_maybe_get_and_pin (CACHEFILE cachefile, CACHEKEY key, u_int32_t fullhash, void**value) {
CACHETABLE t = cachefile->cachetable;
PAIR p;
int count = 0;
for (p=t->table[fullhash&(t->table_size-1)]; p; p=p->hash_chain) {
count++;
if (p->key==key && p->cachefile==cachefile) {
note_hash_count(count);
*value = p->value;
p->pinned++;
lru_touch(t,p);
//printf("%s:%d cachetable_maybe_get_and_pin(%lld)--> %p\n", __FILE__, __LINE__, key, *value);
return 0;
}
}
note_hash_count(count);
return -1;
}
int toku_cachetable_unpin(CACHEFILE cachefile, CACHEKEY key, u_int32_t fullhash, int dirty, long size) {
CACHETABLE t = cachefile->cachetable;
PAIR p;
WHEN_TRACE_CT(printf("%s:%d unpin(%lld)", __FILE__, __LINE__, key));
//printf("%s:%d is dirty now=%d\n", __FILE__, __LINE__, dirty);
int count = 0;
//assert(fullhash == toku_cachetable_hash(cachefile, key));
for (p=t->table[fullhash&(t->table_size-1)]; p; p=p->hash_chain) {
count++;
if (p->key==key && p->cachefile==cachefile) {
note_hash_count(count);
assert(p->pinned>0);
p->pinned--;
p->dirty |= dirty;
if (size != 0) {
t->size_current -= p->size;
p->size = size;
t->size_current += p->size;
}
WHEN_TRACE_CT(printf("[count=%lld]\n", p->pinned));
{
int r;
if ((r=maybe_flush_some(t, 0))) return r;
}
return 0;
}
}
note_hash_count(count);
return 0;
}
// effect: Move an object from one key to another key.
// requires: The object is pinned in the table
int toku_cachetable_rename (CACHEFILE cachefile, CACHEKEY oldkey, CACHEKEY newkey) {
CACHETABLE t = cachefile->cachetable;
PAIR *ptr_to_p,p;
int count = 0;
u_int32_t fullhash = toku_cachetable_hash(cachefile, oldkey);
for (ptr_to_p = &t->table[fullhash&(t->table_size-1)], p = *ptr_to_p;
p;
ptr_to_p = &p->hash_chain, p = *ptr_to_p) {
count++;
if (p->key==oldkey && p->cachefile==cachefile) {
note_hash_count(count);
*ptr_to_p = p->hash_chain;
p->key = newkey;
u_int32_t new_fullhash = toku_cachetable_hash(cachefile, newkey);
u_int32_t nh = new_fullhash&(t->table_size-1);
p->fullhash = new_fullhash;
p->hash_chain = t->table[nh];
t->table[nh] = p;
return 0;
}
}
note_hash_count(count);
return -1;
}
static int cachetable_flush (CACHETABLE t) {
u_int32_t i;
for (i=0; i<t->table_size; i++) {
PAIR p;
while ((p = t->table[i]))
flush_and_remove(t, p, 1); // Must be careful, since flush_and_remove kills the linked list.
}
return 0;
}
void toku_cachefile_verify (CACHEFILE cf) {
toku_cachetable_verify(cf->cachetable);
}
void toku_cachetable_verify (CACHETABLE t) {
// First clear all the verify flags by going through the hash chains
{
u_int32_t i;
for (i=0; i<t->table_size; i++) {
PAIR p;
for (p=t->table[i]; p; p=p->hash_chain) {
p->verify_flag=0;
}
}
}
// Now go through the LRU chain, make sure everything in the LRU chain is hashed, and set the verify flag.
{
PAIR p;
for (p=t->head; p; p=p->next) {
assert(p->verify_flag==0);
PAIR p2;
u_int32_t fullhash = p->fullhash;
//assert(fullhash==toku_cachetable_hash(p->cachefile, p->key));
for (p2=t->table[fullhash&(t->table_size-1)]; p2; p2=p2->hash_chain) {
if (p2==p) {
/* found it */
goto next;
}
}
fprintf(stderr, "Something in the LRU chain is not hashed\n");
assert(0);
next:
p->verify_flag = 1;
}
}
// Now make sure everything in the hash chains has the verify_flag set to 1.
{
u_int32_t i;
for (i=0; i<t->table_size; i++) {
PAIR p;
for (p=t->table[i]; p; p=p->hash_chain) {
assert(p->verify_flag);
}
}
}
}
static void assert_cachefile_is_flushed_and_removed (CACHEFILE cf) {
CACHETABLE t = cf->cachetable;
u_int32_t i;
// Check it two ways
// First way: Look through all the hash chains
for (i=0; i<t->table_size; i++) {
PAIR p;
for (p=t->table[i]; p; p=p->hash_chain) {
assert(p->cachefile!=cf);
}
}
// Second way: Look through the LRU list.
{
PAIR p;
for (p=t->head; p; p=p->next) {
assert(p->cachefile!=cf);
}
}
}
static int cachefile_flush_and_remove (CACHEFILE cf) {
u_int32_t i;
CACHETABLE t = cf->cachetable;
for (i=0; i<t->table_size; i++) {
PAIR p;
again:
p = t->table[i];
while (p) {
if (p->cachefile==cf) {
flush_and_remove(t, p, 1); // Must be careful, since flush_and_remove kills the linked list.
goto again;
} else {
p=p->hash_chain;
}
}
}
assert_cachefile_is_flushed_and_removed(cf);
if ((4 * t->n_in_table < t->table_size) && (t->table_size>4))
cachetable_rehash(t, t->table_size/2);
return 0;
}
/* Require that it all be flushed. */
int toku_cachetable_close (CACHETABLE *tp) {
CACHETABLE t=*tp;
u_int32_t i;
int r;
if ((r=cachetable_flush(t))) return r;
for (i=0; i<t->table_size; i++) {
if (t->table[i]) return -1;
}
toku_free(t->table);
toku_free(t);
*tp = 0;
return 0;
}
int toku_cachetable_remove (CACHEFILE cachefile, CACHEKEY key, int write_me) {
/* Removing something already present is OK. */
CACHETABLE t = cachefile->cachetable;
PAIR p;
int count = 0;
u_int32_t fullhash = toku_cachetable_hash(cachefile, key);
for (p=t->table[fullhash&(t->table_size-1)]; p; p=p->hash_chain) {
count++;
if (p->key==key && p->cachefile==cachefile) {
flush_and_remove(t, p, write_me);
if ((4 * t->n_in_table < t->table_size) && (t->table_size>4))
cachetable_rehash(t, t->table_size/2);
goto done;
}
}
done:
note_hash_count(count);
return 0;
}
#if 0
static void flush_and_keep (PAIR flush_me) {
if (flush_me->dirty) {
WHEN_TRACE_CT(printf("%s:%d CT flush_callback(%lld, %p, dirty=1, 0)\n", __FILE__, __LINE__, flush_me->key, flush_me->value));
flush_me->flush_callback(flush_me->cachefile, flush_me->key, flush_me->value, flush_me->size, 1, 1);
flush_me->dirty=0;
}
}
static int cachetable_fsync_pairs (CACHETABLE t, PAIR p) {
if (p) {
int r = cachetable_fsync_pairs(t, p->hash_chain);
if (r!=0) return r;
flush_and_keep(p);
}
return 0;
}
int cachetable_fsync (CACHETABLE t) {
int i;
int r;
for (i=0; i<t->table_size; i++) {
r=cachetable_fsync_pairs(t, t->table[i]);
if (r!=0) return r;
}
return 0;
}
#endif
#if 0
int cachefile_pwrite (CACHEFILE cf, const void *buf, size_t count, off_t offset) {
ssize_t r = pwrite(cf->fd, buf, count, offset);
if (r==-1) return errno;
assert((size_t)r==count);
return 0;
}
int cachefile_pread (CACHEFILE cf, void *buf, size_t count, off_t offset) {
ssize_t r = pread(cf->fd, buf, count, offset);
if (r==-1) return errno;
if (r==0) return -1; /* No error for EOF ??? */
assert((size_t)r==count);
return 0;
}
#endif
int toku_cachefile_fd (CACHEFILE cf) {
return cf->fd;
}
/* debug functions */
void toku_cachetable_print_state (CACHETABLE ct) {
u_int32_t i;
for (i=0; i<ct->table_size; i++) {
PAIR p = ct->table[i];
if (p != 0) {
printf("t[%d]=", i);
for (p=ct->table[i]; p; p=p->hash_chain) {
printf(" {%lld, %p, dirty=%d, pin=%lld, size=%ld}", p->key, p->cachefile, p->dirty, p->pinned, p->size);
}
printf("\n");
}
}
}
void toku_cachetable_get_state (CACHETABLE ct, int *num_entries_ptr, int *hash_size_ptr, long *size_current_ptr, long *size_limit_ptr) {
if (num_entries_ptr)
*num_entries_ptr = ct->n_in_table;
if (hash_size_ptr)
*hash_size_ptr = ct->table_size;
if (size_current_ptr)
*size_current_ptr = ct->size_current;
if (size_limit_ptr)
*size_limit_ptr = ct->size_limit;
}
int toku_cachetable_get_key_state (CACHETABLE ct, CACHEKEY key, CACHEFILE cf, void **value_ptr,
int *dirty_ptr, long long *pin_ptr, long *size_ptr) {
PAIR p;
int count = 0;
u_int32_t fullhash = toku_cachetable_hash(cf, key);
for (p = ct->table[fullhash&(ct->table_size-1)]; p; p = p->hash_chain) {
count++;
if (p->key == key) {
note_hash_count(count);
if (value_ptr)
*value_ptr = p->value;
if (dirty_ptr)
*dirty_ptr = p->dirty;
if (pin_ptr)
*pin_ptr = p->pinned;
if (size_ptr)
*size_ptr = p->size;
return 0;
}
}
note_hash_count(count);
return 1;
}
int toku_cachetable_checkpoint (CACHETABLE ct) {
// Single threaded checkpoint.
// In future: for multithreaded checkpoint we should not proceed if the previous checkpoint has not finished.
// Requires: Everything is unpinned. (In the multithreaded version we have to wait for things to get unpinned and then
// grab them (or else the unpinner has to do something.)
// Algorithm: Write a checkpoint record to the log, noting the LSN of that record.
// Note the LSN of the previous checkpoint (stored in lsn_of_checkpoint)
// For every (unpinnned) dirty node in which the LSN is newer than the prev checkpoint LSN:
// flush the node (giving it a new nodeid, and fixing up the downpointer in the parent)
// Watch out since evicting the node modifies the hash table.
//?? This is a skeleton. It compiles, but doesn't do anything reasonable yet.
//?? log_the_checkpoint();
int n_saved=0;
int n_in_table = ct->n_in_table;
struct save_something {
CACHEFILE cf;
DISKOFF key;
void *value;
long size;
LSN modified_lsn;
CACHETABLE_FLUSH_FUNC_T flush_callback;
} *MALLOC_N(n_in_table, info);
{
PAIR pair;
for (pair=ct->head; pair; pair=pair->next) {
assert(!pair->pinned);
if (pair->dirty && pair->modified_lsn.lsn>ct->lsn_of_checkpoint.lsn) {
//?? /save_something_about_the_pair(); // This read-only so it doesn't modify the table.
n_saved++;
}
}
}
{
int i;
for (i=0; i<n_saved; i++) {
info[i].flush_callback(info[i].cf, info[i].key, info[i].value, info[i].size, 1, 1, info[i].modified_lsn, 0);
}
}
toku_free(info);
return 0;
}
TOKULOGGER toku_cachefile_logger (CACHEFILE cf) {
return cf->cachetable->logger;
}
FILENUM toku_cachefile_filenum (CACHEFILE cf) {
return cf->filenum;
}
u_int32_t toku_cachefile_fullhash_of_header (CACHEFILE cachefile) {
return cachefile->header_fullhash;
}
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