Commit 27ab75ef authored by Howard Chu's avatar Howard Chu
Browse files

Re-use old pages

parent 661d4f80
CC = gcc
W = -W -Wall -Wno-unused-parameter -Wcast-qual -Wbad-function-cast
CFLAGS = -pthread -O2 -g $(W) $(XCFLAGS)
OPT = -O2 -g
CFLAGS = -pthread $(OPT) $(W) $(XCFLAGS)
LDLIBS = -lssl
all: mtest mdb_stat
......@@ -11,8 +12,8 @@ clean:
test: all
./mtest && ./mdb_stat testdb
mdb_stat: mdb_stat.o mdb.o
mtest: mtest.o mdb.o
mdb_stat: mdb_stat.o mdb.o idl.o
mtest: mtest.o mdb.o idl.o
%: %.o mdb.o
$(CC) $(CFLAGS) $(LDFLAGS) $^ $(LDLIBS) -o $@
......
/* Lifted from OpenLDAP back-bdb/idl.c */
#include <strings.h>
#include <sys/types.h>
#include <assert.h>
#include "idl.h"
typedef ulong pgno_t;
/* Sort the IDLs from highest to lowest */
#define IDL_CMP(x,y) ( x > y ? -1 : ( x < y ? 1 : 0 ) )
unsigned mdb_idl_search( ID *ids, ID id )
{
/*
* binary search of id in ids
* if found, returns position of id
* if not found, returns first position greater than id
*/
unsigned base = 0;
unsigned cursor = 0;
int val = 0;
unsigned n = ids[0];
while( 0 < n ) {
int pivot = n >> 1;
cursor = base + pivot;
val = IDL_CMP( id, ids[cursor + 1] );
if( val < 0 ) {
n = pivot;
} else if ( val > 0 ) {
base = cursor + 1;
n -= pivot + 1;
} else {
return cursor + 1;
}
}
if( val > 0 ) {
return cursor + 2;
} else {
return cursor + 1;
}
}
int mdb_idl_insert( ID *ids, ID id )
{
unsigned x;
if (MDB_IDL_IS_RANGE( ids )) {
/* if already in range, treat as a dup */
if (id >= MDB_IDL_FIRST(ids) && id <= MDB_IDL_LAST(ids))
return -1;
if (id < MDB_IDL_FIRST(ids))
ids[1] = id;
else if (id > MDB_IDL_LAST(ids))
ids[2] = id;
return 0;
}
x = mdb_idl_search( ids, id );
assert( x > 0 );
if( x < 1 ) {
/* internal error */
return -2;
}
if ( x <= ids[0] && ids[x] == id ) {
/* duplicate */
return -1;
}
if ( ++ids[0] >= MDB_IDL_DB_MAX ) {
if( id < ids[1] ) {
ids[1] = id;
ids[2] = ids[ids[0]-1];
} else if ( ids[ids[0]-1] < id ) {
ids[2] = id;
} else {
ids[2] = ids[ids[0]-1];
}
ids[0] = NOID;
} else {
/* insert id */
AC_MEMCPY( &ids[x+1], &ids[x], (ids[0]-x) * sizeof(ID) );
ids[x] = id;
}
return 0;
}
/* idl.h - ldap bdb back-end ID list header file */
/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
* Copyright 2000-2011 The OpenLDAP Foundation.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted only as authorized by the OpenLDAP
* Public License.
*
* A copy of this license is available in the file LICENSE in the
* top-level directory of the distribution or, alternatively, at
* <http://www.OpenLDAP.org/license.html>.
*/
#ifndef _MDB_IDL_H_
#define _MDB_IDL_H_
#define AC_MEMCPY(dst,src,size) bcopy(src,dst,size)
#define ID unsigned long
#define NOID ((ID)~0)
/* IDL sizes - likely should be even bigger
* limiting factors: sizeof(ID), thread stack size
*/
#define MDB_IDL_LOGN 16 /* DB_SIZE is 2^16, UM_SIZE is 2^17 */
#define MDB_IDL_DB_SIZE (1<<MDB_IDL_LOGN)
#define MDB_IDL_UM_SIZE (1<<(MDB_IDL_LOGN+1))
#define MDB_IDL_UM_SIZEOF (MDB_IDL_UM_SIZE * sizeof(ID))
#define MDB_IDL_DB_MAX (MDB_IDL_DB_SIZE-1)
#define MDB_IDL_UM_MAX (MDB_IDL_UM_SIZE-1)
#define MDB_IDL_IS_RANGE(ids) ((ids)[0] == NOID)
#define MDB_IDL_RANGE_SIZE (3)
#define MDB_IDL_RANGE_SIZEOF (MDB_IDL_RANGE_SIZE * sizeof(ID))
#define MDB_IDL_SIZEOF(ids) ((MDB_IDL_IS_RANGE(ids) \
? MDB_IDL_RANGE_SIZE : ((ids)[0]+1)) * sizeof(ID))
#define MDB_IDL_RANGE_FIRST(ids) ((ids)[1])
#define MDB_IDL_RANGE_LAST(ids) ((ids)[2])
#define MDB_IDL_RANGE( ids, f, l ) \
do { \
(ids)[0] = NOID; \
(ids)[1] = (f); \
(ids)[2] = (l); \
} while(0)
#define MDB_IDL_ZERO(ids) \
do { \
(ids)[0] = 0; \
(ids)[1] = 0; \
(ids)[2] = 0; \
} while(0)
#define MDB_IDL_IS_ZERO(ids) ( (ids)[0] == 0 )
#define MDB_IDL_IS_ALL( range, ids ) ( (ids)[0] == NOID \
&& (ids)[1] <= (range)[1] && (range)[2] <= (ids)[2] )
#define MDB_IDL_CPY( dst, src ) (AC_MEMCPY( dst, src, MDB_IDL_SIZEOF( src ) ))
#define MDB_IDL_ID( bdb, ids, id ) MDB_IDL_RANGE( ids, id, ((bdb)->bi_lastid) )
#define MDB_IDL_ALL( bdb, ids ) MDB_IDL_RANGE( ids, 1, ((bdb)->bi_lastid) )
#define MDB_IDL_FIRST( ids ) ( ids[1] )
#define MDB_IDL_LAST( ids ) ( MDB_IDL_IS_RANGE(ids) \
? ids[2] : ids[ids[0]] )
#define MDB_IDL_N( ids ) ( MDB_IDL_IS_RANGE(ids) \
? (ids[2]-ids[1])+1 : ids[0] )
int mdb_idl_insert( ID *ids, ID id );
#endif
......@@ -24,6 +24,7 @@
#include <pthread.h>
#include "mdb.h"
#include "idl.h"
#ifndef DEBUG
#define DEBUG 1
......@@ -124,6 +125,8 @@ typedef struct MDB_page { /* represents a page of storage */
#define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
#define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
#define OVPAGES(size, psize) (PAGEHDRSZ + size + psize - 1) / psize;
typedef struct MDB_meta { /* meta (footer) page content */
uint32_t mm_magic;
uint32_t mm_version;
......@@ -149,6 +152,12 @@ typedef struct MDB_dpage {
SIMPLEQ_HEAD(dirty_queue, MDB_dpage);
typedef struct MDB_oldpages {
struct MDB_oldpages *mo_next;
ulong mo_txnid;
pgno_t mo_pages[1]; /* dynamic */
} MDB_oldpages;
typedef struct MDB_pageparent {
MDB_page *mp_page;
MDB_page *mp_parent;
......@@ -199,7 +208,9 @@ struct MDB_txn {
pgno_t mt_next_pgno; /* next unallocated page */
pgno_t mt_first_pgno;
ulong mt_txnid;
ulong mt_oldest;
MDB_env *mt_env;
pgno_t *mt_free_pgs; /* this is an IDL */
union {
struct dirty_queue *dirty_queue; /* modified pages */
MDB_reader *reader;
......@@ -243,6 +254,8 @@ struct MDB_env {
size_t me_mapsize;
off_t me_size; /* current file size */
pthread_key_t me_txkey; /* thread-key for readers */
MDB_oldpages *me_pghead;
MDB_oldpages *me_pgtail;
};
#define NODESIZE offsetof(MDB_node, mn_data)
......@@ -375,6 +388,40 @@ static MDB_dpage *
mdb_newpage(MDB_txn *txn, MDB_page *parent, unsigned int parent_idx, int num)
{
MDB_dpage *dp;
pgno_t pgno = P_INVALID;
if (txn->mt_env->me_pghead) {
ulong oldest = txn->mt_txnid - 2;
int i;
for (i=0; i<txn->mt_env->me_txns->mt_numreaders; i++) {
if (txn->mt_env->me_txns->mt_readers[i].mr_txnid < oldest)
oldest = txn->mt_env->me_txns->mt_readers[i].mr_txnid;
}
if (oldest > txn->mt_env->me_pghead->mo_txnid) {
MDB_oldpages *mop = txn->mt_env->me_pghead;
txn->mt_oldest = oldest;
if (num > 1) {
/* FIXME */
;
} else {
/* peel pages off tail, so we only have to truncate the list */
pgno = MDB_IDL_LAST(mop->mo_pages);
if (MDB_IDL_IS_RANGE(mop->mo_pages)) {
mop->mo_pages[2]++;
if (mop->mo_pages[2] > mop->mo_pages[1])
mop->mo_pages[0] = 0;
} else {
mop->mo_pages[0]--;
}
if (MDB_IDL_IS_ZERO(mop->mo_pages)) {
txn->mt_env->me_pghead = mop->mo_next;
if (!txn->mt_env->me_pghead)
txn->mt_env->me_pgtail = NULL;
free(mop);
}
}
}
}
if ((dp = malloc(txn->mt_env->me_meta.mm_stat.ms_psize * num + sizeof(MDB_dhead))) == NULL)
return NULL;
......@@ -382,8 +429,12 @@ mdb_newpage(MDB_txn *txn, MDB_page *parent, unsigned int parent_idx, int num)
dp->h.md_parent = parent;
dp->h.md_pi = parent_idx;
SIMPLEQ_INSERT_TAIL(txn->mt_u.dirty_queue, dp, h.md_next);
dp->p.mp_pgno = txn->mt_next_pgno;
txn->mt_next_pgno += num;
if (pgno == P_INVALID) {
dp->p.mp_pgno = txn->mt_next_pgno;
txn->mt_next_pgno += num;
} else {
dp->p.mp_pgno = pgno;
}
return dp;
}
......@@ -400,9 +451,10 @@ mdb_touch(MDB_txn *txn, MDB_pageparent *pp)
if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
MDB_dpage *dp;
DPRINTF("touching page %lu -> %lu", mp->mp_pgno, txn->mt_next_pgno);
if ((dp = mdb_newpage(txn, pp->mp_parent, pp->mp_pi, 1)) == NULL)
return ENOMEM;
DPRINTF("touched page %lu -> %lu", mp->mp_pgno, dp->p.mp_pgno);
mdb_idl_insert(txn->mt_free_pgs, mp->mp_pgno);
pgno = dp->p.mp_pgno;
bcopy(mp, &dp->p, txn->mt_env->me_meta.mm_stat.ms_psize);
mp = &dp->p;
......@@ -451,6 +503,13 @@ mdb_txn_begin(MDB_env *env, int rdonly, MDB_txn **ret)
pthread_mutex_lock(&env->me_txns->mt_wmutex);
env->me_txns->mt_txnid++;
txn->mt_free_pgs = malloc(MDB_IDL_UM_SIZEOF);
if (txn->mt_free_pgs == NULL) {
free(txn->mt_u.dirty_queue);
free(txn);
return ENOMEM;
}
txn->mt_free_pgs[0] = 0;
}
txn->mt_txnid = env->me_txns->mt_txnid;
if (rdonly) {
......@@ -512,22 +571,32 @@ mdb_txn_abort(MDB_txn *txn)
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
txn->mt_u.reader->mr_txnid = 0;
} else {
/* Discard all dirty pages.
/* Discard all dirty pages. Return any re-used pages
* to the free list.
*/
MDB_IDL_ZERO(txn->mt_free_pgs);
while (!SIMPLEQ_EMPTY(txn->mt_u.dirty_queue)) {
dp = SIMPLEQ_FIRST(txn->mt_u.dirty_queue);
SIMPLEQ_REMOVE_HEAD(txn->mt_u.dirty_queue, h.md_next);
if (dp->p.mp_pgno <= env->me_meta.mm_last_pg)
mdb_idl_insert(txn->mt_free_pgs, dp->p.mp_pgno);
free(dp);
}
#if 0
DPRINTF("releasing write lock on txn %p", txn);
txn->bt->txn = NULL;
if (flock(txn->bt->fd, LOCK_UN) != 0) {
DPRINTF("failed to unlock fd %d: %s",
txn->bt->fd, strerror(errno));
/* put back to head of free list */
if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) {
MDB_oldpages *mop;
mop = malloc(sizeof(MDB_oldpages) + MDB_IDL_SIZEOF(txn->mt_free_pgs) - sizeof(pgno_t));
mop->mo_next = env->me_pghead;
mop->mo_txnid = txn->mt_oldest - 1;
if (!env->me_pghead) {
env->me_pgtail = mop;
}
env->me_pghead = mop;
bcopy(txn->mt_free_pgs, mop->mo_pages, MDB_IDL_SIZEOF(txn->mt_free_pgs));
}
#endif
free(txn->mt_free_pgs);
free(txn->mt_u.dirty_queue);
env->me_txn = NULL;
pthread_mutex_unlock(&env->me_txns->mt_wmutex);
......@@ -636,7 +705,25 @@ mdb_txn_commit(MDB_txn *txn)
return n;
}
env->me_txn = NULL;
/* add to tail of free list */
if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) {
MDB_oldpages *mop;
mop = malloc(sizeof(MDB_oldpages) + MDB_IDL_SIZEOF(txn->mt_free_pgs) - sizeof(pgno_t));
mop->mo_next = NULL;
if (env->me_pghead) {
env->me_pgtail->mo_next = mop;
} else {
env->me_pghead = mop;
}
env->me_pgtail = mop;
bcopy(txn->mt_free_pgs, mop->mo_pages, MDB_IDL_SIZEOF(txn->mt_free_pgs));
mop->mo_txnid = txn->mt_txnid;
}
pthread_mutex_unlock(&env->me_txns->mt_wmutex);
free(txn->mt_free_pgs);
free(txn->mt_u.dirty_queue);
free(txn);
txn = NULL;
......@@ -751,7 +838,7 @@ mdbenv_write_meta(MDB_txn *txn)
meta.mm_txnid = txn->mt_txnid;
off = 0;
if (env->me_metatoggle)
if (!env->me_metatoggle)
off = env->me_meta.mm_stat.ms_psize;
off += PAGEHDRSZ;
......@@ -1093,17 +1180,19 @@ mdbenv_get_page(MDB_env *env, pgno_t pgno)
{
MDB_page *p = NULL;
MDB_txn *txn = env->me_txn;
int found = 0;
if (txn && pgno >= txn->mt_first_pgno &&
!SIMPLEQ_EMPTY(txn->mt_u.dirty_queue)) {
if (txn && !SIMPLEQ_EMPTY(txn->mt_u.dirty_queue)) {
MDB_dpage *dp;
SIMPLEQ_FOREACH(dp, txn->mt_u.dirty_queue, h.md_next) {
if (dp->p.mp_pgno == pgno) {
p = &dp->p;
found = 1;
break;
}
}
} else {
}
if (!found) {
p = (MDB_page *)(env->me_map + env->me_meta.mm_stat.ms_psize * pgno);
}
return p;
......@@ -1528,10 +1617,10 @@ mdbenv_new_page(MDB_env *env, uint32_t flags, int num)
assert(env != NULL);
assert(env->me_txn != NULL);
DPRINTF("allocating new mpage %lu, page size %u",
env->me_txn->mt_next_pgno, env->me_meta.mm_stat.ms_psize);
if ((dp = mdb_newpage(env->me_txn, NULL, 0, num)) == NULL)
return NULL;
DPRINTF("allocated new mpage %lu, page size %u",
dp->p.mp_pgno, env->me_meta.mm_stat.ms_psize);
dp->p.mp_flags = flags | P_DIRTY;
dp->p.mp_lower = PAGEHDRSZ;
dp->p.mp_upper = env->me_meta.mm_stat.ms_psize;
......@@ -1603,8 +1692,7 @@ mdb_add_node(MDB_db *db, MDB_page *mp, indx_t indx,
/* Data already on overflow page. */
node_size += sizeof(pgno_t);
} else if (data->mv_size >= db->md_env->me_meta.mm_stat.ms_psize / MDB_MINKEYS) {
int ovpages = PAGEHDRSZ + data->mv_size + db->md_env->me_meta.mm_stat.ms_psize - 1;
ovpages /= db->md_env->me_meta.mm_stat.ms_psize;
int ovpages = OVPAGES(data->mv_size, db->md_env->me_meta.mm_stat.ms_psize);
/* Put data on overflow page. */
DPRINTF("data size is %zu, put on overflow page",
data->mv_size);
......@@ -2056,6 +2144,18 @@ mdb_del(MDB_db *bt, MDB_txn *txn,
return rc;
mdb_del_node(bt, mpp.mp_page, ki);
/* add overflow pages to free list */
if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
int i, ovpages;
pgno_t pg;
bcopy(NODEDATA(leaf), &pg, sizeof(pg));
ovpages = OVPAGES(NODEDSZ(leaf), bt->md_env->me_meta.mm_stat.ms_psize);
for (i=0; i<ovpages; i++) {
mdb_idl_insert(txn->mt_free_pgs, pg);
pg++;
}
}
bt->md_env->me_meta.mm_stat.ms_entries--;
rc = mdb_rebalance(bt, &mpp);
if (rc != MDB_SUCCESS)
......
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