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checkpoint - moving overflow page headers

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Moving headers outside of overflow page.
mdb.master3
Howard Chu 7 years ago
parent c7ef535aa9
commit f0f985fa93
3 changed files with 153 additions and 79 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 191
      libraries/liblmdb/mdb.c
  2. 31
      libraries/liblmdb/midl.c
  3. 6
      libraries/liblmdb/midl.h

191
libraries/liblmdb/mdb.c
Unescape View File

@ -942,8 +942,9 @@ enum {
* sorted #mp_ptrs[] entries referring to them. Exception: #P_LEAF2 pages
* omit mp_ptrs and pack sorted #MDB_DUPFIXED values after the page header.
*
* #P_OVERFLOW records occupy one or more contiguous pages where only the
* first has a page header. They hold the real data of #F_BIGDATA nodes.
* #P_OVERFLOW records occupy one or more contiguous pages that contain
* pure data with no page header. They hold the real data of #F_BIGDATA nodes,
* and the node stores what would have gone in a page header.
*
* #P_SUBP sub-pages are small leaf "pages" with duplicate data.
* A node with flag #F_DUPDATA but not #F_SUBDATA contains a sub-page.
@ -954,15 +955,15 @@ enum {
* Each non-metapage up to #MDB_meta.%mm_last_pg is reachable exactly once
* in the snapshot: Either used by a database or listed in a freeDB record.
*/
typedef struct MDB_page {
typedef struct MDB_page_header {
#define mp_pgno mp_p.p_pgno
#define mp_next mp_p.p_next
union {
pgno_t p_pgno; /**< page number */
struct MDB_page *p_next; /**< for in-memory list of freed pages */
} mp_p;
txnid_t mp_txnid; /**< txnid that committed this page, unused in meta pages */
uint16_t mp_pad; /**< key size if this is a LEAF2 page */
} mh_p;
txnid_t mh_txnid; /**< txnid that committed this page, unused in meta pages */
uint16_t mh_pad; /**< key size if this is a LEAF2 page */
/** @defgroup mdb_page Page Flags
* @ingroup internal
* Flags for the page headers.
@ -975,10 +976,11 @@ typedef struct MDB_page {
#define P_DIRTY 0x10 /**< dirty page, also set for #P_SUBP pages */
#define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */
#define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */
#define P_DIRTY_OVF 0x2000 /**< page has dirty overflow nodes */
#define P_LOOSE 0x4000 /**< page was dirtied then freed, can be reused */
#define P_KEEP 0x8000 /**< leave this page alone during spill */
/** @} */
uint16_t mp_flags; /**< @ref mdb_page */
uint16_t mh_flags; /**< @ref mdb_page */
#define mp_lower mp_pb.pb.pb_lower
#define mp_upper mp_pb.pb.pb_upper
#define mp_pages mp_pb.pb_pages
@ -988,12 +990,21 @@ typedef struct MDB_page {
indx_t pb_upper; /**< upper bound of free space */
} pb;
uint32_t pb_pages; /**< number of overflow pages */
} mp_pb;
} mh_pb;
} MDB_page_header;
typedef struct MDB_page {
MDB_page_header mp_hdr;
#define mp_p mp_hdr.mh_p
#define mp_txnid mp_hdr.mh_txnid
#define mp_pad mp_hdr.mh_pad
#define mp_flags mp_hdr.mh_flags
#define mp_pb mp_hdr.mh_pb
indx_t mp_ptrs[1]; /**< dynamic size */
} MDB_page;
/** Size of the page header, excluding dynamic data at the end */
#define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
#define PAGEHDRSZ sizeof(MDB_page_header)
/** Address of first usable data byte in a page, after the header */
#define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
@ -1026,6 +1037,19 @@ typedef struct MDB_page {
/** Test if a page is a sub page */
#define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP)
/** Header for overflow pages, stored in an F_BIGDATA node */
typedef struct MDB_ovpage {
pgno_t op_pgno;
txnid_t op_txnid;
mdb_size_t op_pages;
} MDB_ovpage;
/** Header for a dirty overflow page in memory */
typedef struct MDB_dovpage {
MDB_page_header mp_hdr;
void *mp_ptr;
} MDB_dovpage;
/** The number of overflow pages needed to store the given size. */
#define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
@ -1044,7 +1068,7 @@ typedef struct MDB_page {
* order in case some accesses can be optimized to 32-bit word access.
*
* Leaf node flags describe node contents. #F_BIGDATA says the node's
* data part is the page number of an overflow page with actual data.
* data part is an MDB_ovpage struct pointing to a page with actual data.
* #F_DUPDATA and #F_SUBDATA can be combined giving duplicate data in
* a sub-page/sub-database, and named databases (just #F_SUBDATA).
*/
@ -1276,6 +1300,8 @@ struct MDB_txn {
/** For read txns: This thread/txn's reader table slot, or NULL. */
MDB_reader *reader;
} mt_u;
/** The sorted list of dirty overflow pages. */
MDB_ID2L mt_dirty_ovs;
/** Array of records for each DB known in the environment. */
MDB_dbx *mt_dbxs;
/** Array of MDB_db records for each known DB */
@ -1553,7 +1579,7 @@ typedef struct MDB_ntxn {
#define TXN_DBI_CHANGED(txn, dbi) \
((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi])
static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
static int mdb_page_alloc(MDB_cursor *mc, int num, int ov, MDB_page **mp);
static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
static int mdb_page_touch(MDB_cursor *mc);
@ -1871,7 +1897,7 @@ mdb_page_list(MDB_page *mp)
total += nsize;
} else {
if (F_ISSET(node->mn_flags, F_BIGDATA))
nsize += sizeof(pgno_t);
nsize += sizeof(MDB_ovpage);
else
nsize += NODEDSZ(node);
total += nsize;
@ -2409,7 +2435,7 @@ mdb_find_oldest(MDB_txn *txn)
/** Add a page to the txn's dirty list */
static void
mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
mdb_page_dirty(MDB_txn *txn, MDB_page *mp, int ov)
{
MDB_ID2 mid;
int rc, (*insert)(MDB_ID2L, MDB_ID2 *);
@ -2421,10 +2447,14 @@ mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
}
mid.mid = mp->mp_pgno;
mid.mptr = mp;
if (ov) {
rc = mdb_mid2l_insert(txn->mt_dirty_ovs, &mid);
} else {
rc = insert(txn->mt_u.dirty_list, &mid);
mdb_tassert(txn, rc == 0);
txn->mt_dirty_room--;
}
mdb_tassert(txn, rc == 0);
}
/** Allocate page numbers and memory for writing. Maintain me_pglast,
* me_pghead and mt_next_pgno. Set #MDB_TXN_ERROR on failure.
@ -2444,7 +2474,7 @@ mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
* @return 0 on success, non-zero on failure.
*/
static int
mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
mdb_page_alloc(MDB_cursor *mc, int num, int ov, MDB_page **mp)
{
#ifdef MDB_PARANOID /* Seems like we can ignore this now */
/* Get at most <Max_retries> more freeDB records once me_pghead
@ -2467,6 +2497,17 @@ mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
MDB_cursor_op op;
MDB_cursor m2;
int found_old = 0;
MDB_dovpage *dph = NULL;
if (ov) {
if (!txn->mt_dirty_ovs) {
txn->mt_dirty_ovs = mdb_mid2l_alloc(16);
if (!txn->mt_dirty_ovs)
return ENOMEM;
} else if (mdb_mid2l_need(&txn->mt_dirty_ovs, txn->mt_dirty_ovs[0].mid + 1))
return ENOMEM;
dph = malloc(sizeof(MDB_dovpage));
}
/* If there are any loose pages, just use them */
if (num == 1 && txn->mt_loose_pgs) {
@ -2474,6 +2515,11 @@ mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);
txn->mt_loose_count--;
DPRINTF(("db %d use loose page %"Yu, DDBI(mc), np->mp_pgno));
if (ov) {
dph->mp_hdr = np->mp_hdr;
dph->mp_ptr = np;
np = (MDB_page *)dph;
}
*mp = np;
return MDB_SUCCESS;
}
@ -2627,12 +2673,19 @@ search_done:
}
np->mp_pgno = pgno;
np->mp_txnid = txn->mt_txnid;
mdb_page_dirty(txn, np);
if (ov) {
dph->mp_hdr = np->mp_hdr;
dph->mp_ptr = np;
np = (MDB_page *)dph;
}
mdb_page_dirty(txn, np, ov);
*mp = np;
return MDB_SUCCESS;
fail:
if (dph)
free(dph);
txn->mt_flags |= MDB_TXN_ERROR;
return rc;
}
@ -2670,7 +2723,7 @@ mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
* mp wasn't spilled.
*/
static int
mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
mdb_page_unspill(MDB_txn *txn, MDB_page *mp, int num, int ov, MDB_page **ret)
{
MDB_env *env = txn->mt_env;
const MDB_txn *tx2;
@ -2683,20 +2736,15 @@ mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
x = mdb_midl_search(tx2->mt_spill_pgs, pn);
if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
MDB_page *np;
int num;
if (txn->mt_dirty_room == 0)
return MDB_TXN_FULL;
if (IS_OVERFLOW(mp))
num = mp->mp_pages;
else
num = 1;
if (env->me_flags & MDB_WRITEMAP) {
np = mp;
} else {
np = mdb_page_malloc(txn, num, 1);
if (!np)
return ENOMEM;
if (num > 1)
if (ov)
memcpy(np, mp, num * env->me_psize);
else
mdb_page_copy(np, mp, env->me_psize);
@ -2714,7 +2762,8 @@ mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
* page remains spilled until child commits
*/
mdb_page_dirty(txn, np);
mdb_page_dirty(txn, np, ov);
if (!ov)
np->mp_flags |= P_DIRTY;
*ret = np;
break;
@ -2740,14 +2789,14 @@ mdb_page_touch(MDB_cursor *mc)
if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
if (txn->mt_flags & MDB_TXN_SPILLS) {
np = NULL;
rc = mdb_page_unspill(txn, mp, &np);
rc = mdb_page_unspill(txn, mp, 1, 0, &np);
if (rc)
goto fail;
if (np)
goto done;
}
if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
(rc = mdb_page_alloc(mc, 1, &np)))
(rc = mdb_page_alloc(mc, 1, 0, &np)))
goto fail;
pgno = np->mp_pgno;
DPRINTF(("touched db %d page %"Yu" -> %"Yu, DDBI(mc),
@ -3099,6 +3148,7 @@ mdb_txn_renew0(MDB_txn *txn)
txn->mt_free_pgs = env->me_free_pgs;
txn->mt_free_pgs[0] = 0;
txn->mt_spill_pgs = NULL;
txn->mt_dirty_ovs = NULL;
env->me_txn = txn;
memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned int));
}
@ -3223,6 +3273,7 @@ mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
txn->mt_dirty_room = parent->mt_dirty_room;
txn->mt_u.dirty_list[0].mid = 0;
txn->mt_spill_pgs = NULL;
txn->mt_dirty_ovs = NULL;
txn->mt_next_pgno = parent->mt_next_pgno;
parent->mt_flags |= MDB_TXN_HAS_CHILD;
parent->mt_child = txn;
@ -3383,6 +3434,7 @@ mdb_txn_end(MDB_txn *txn, unsigned mode)
env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
mdb_midl_free(txn->mt_free_pgs);
mdb_midl_free(txn->mt_spill_pgs);
mdb_mid2l_free(txn->mt_dirty_ovs);
free(txn->mt_u.dirty_list);
}
@ -6843,7 +6895,7 @@ static int
mdb_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data)
{
MDB_page *omp; /* overflow page */
pgno_t pgno;
MDB_ovpage ovp;
int rc;
if (MC_OVPG(mc)) {
@ -6858,13 +6910,10 @@ mdb_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data)
/* Read overflow data.
*/
memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
memcpy(&ovp, NODEDATA(leaf), sizeof(ovp));
{
#if MDB_RPAGE_CACHE
int dpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
#endif
if ((rc = MDB_PAGE_GET(mc, pgno, dpages, &omp, NULL)) != 0) {
DPRINTF(("read overflow page %"Yu" failed", pgno));
if ((rc = MDB_PAGE_GET(mc, ovp.op_pgno, ovp.op_pages, &omp, NULL)) != 0) {
DPRINTF(("read overflow page %"Yu" failed", ovp.op_pgno));
return rc;
}
}
@ -7932,7 +7981,7 @@ prep_subDB:
dummy.md_entries = NUMKEYS(fp);
xdata.mv_size = sizeof(MDB_db);
xdata.mv_data = &dummy;
if ((rc = mdb_page_alloc(mc, 1, &mp)))
if ((rc = mdb_page_alloc(mc, 1, 0, &mp)))
return rc;
offset = env->me_psize - olddata.mv_size;
flags |= F_DUPDATA|F_SUBDATA;
@ -7968,26 +8017,27 @@ current:
/* overflow page overwrites need special handling */
if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
MDB_page *omp;
pgno_t pg;
MDB_ovpage ovp;
int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
memcpy(&pg, olddata.mv_data, sizeof(pg));
if ((rc2 = MDB_PAGE_GET(mc, pg, dpages, &omp, &level)) != 0)
memcpy(&ovp, olddata.mv_data, sizeof(ovp));
if ((rc2 = MDB_PAGE_GET(mc, ovp.op_pgno, ovp.op_pages, &omp, &level)) != 0)
return rc2;
ovpages = omp->mp_pages;
ovpages = ovp.op_pages;
/* Is the ov page large enough? */
if (ovpages >= dpages) {
/* Did we dirty it in this txn? */
if (!(omp->mp_flags & P_DIRTY) &&
(level || (env->me_flags & MDB_WRITEMAP)))
{
rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
rc = mdb_page_unspill(mc->mc_txn, omp, ovpages, 1, &omp);
if (rc)
return rc;
level = 0; /* dirty in this txn or clean */
}
/* Is it dirty? */
if (omp->mp_flags & P_DIRTY) {
if (ovp.op_txnid == mc->mc_txn->mt_txnid) {
/* yes, overwrite it. Note in this case we don't
* bother to try shrinking the page if the new data
* is smaller than the overflow threshold.
@ -7999,7 +8049,7 @@ current:
MDB_ID2 id2;
if (!np)
return ENOMEM;
id2.mid = pg;
id2.mid = ovp.op_pgno;
id2.mptr = np;
/* Note - this page is already counted in parent's dirty_room */
rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
@ -8013,12 +8063,10 @@ current:
* Copy end of page, adjusting alignment so
* compiler may copy words instead of bytes.
*/
off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
off = data->mv_size & -sizeof(size_t);
memcpy((size_t *)((char *)np + off),
(size_t *)((char *)omp + off), sz - off);
sz = PAGEHDRSZ;
}
memcpy(np, omp, sz); /* Copy beginning of page */
omp = np;
}
SETDSZ(leaf, data->mv_size);
@ -8269,13 +8317,13 @@ mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
/* add overflow pages to free list */
if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
MDB_page *omp;
pgno_t pg;
MDB_ovpage ovp;
memcpy(&pg, NODEDATA(leaf), sizeof(pg));
memcpy(&ovp, NODEDATA(leaf), sizeof(ovp));
/* note we don't care about page count here since
* we're just adding pgno to the freelist anyway
*/
if ((rc = MDB_PAGE_GET(mc, pg, 1, &omp, NULL)) ||
if ((rc = MDB_PAGE_GET(mc, ovp.op_pgno, 1, &omp, NULL)) ||
(rc = mdb_ovpage_free(mc, omp)))
goto fail;
}
@ -8303,7 +8351,7 @@ mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
MDB_page *np;
int rc;
if ((rc = mdb_page_alloc(mc, num, &np)))
if ((rc = mdb_page_alloc(mc, num, flags & P_OVERFLOW, &np)))
return rc;
DPRINTF(("allocated new mpage %"Yu", page size %u",
np->mp_pgno, mc->mc_txn->mt_env->me_psize));
@ -8435,7 +8483,7 @@ mdb_node_add(MDB_cursor *mc, indx_t indx,
mdb_cassert(mc, key && data);
if (F_ISSET(flags, F_BIGDATA)) {
/* Data already on overflow page. */
node_size += sizeof(pgno_t);
node_size += sizeof(MDB_ovpage);
} else if (node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax) {
int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
int rc;
@ -8486,14 +8534,13 @@ update:
ndata = NODEDATA(node);
if (ofp == NULL) {
if (F_ISSET(flags, F_BIGDATA))
memcpy(ndata, data->mv_data, sizeof(pgno_t));
memcpy(ndata, data->mv_data, sizeof(MDB_ovpage));
else if (F_ISSET(flags, MDB_RESERVE))
data->mv_data = ndata;
else
memcpy(ndata, data->mv_data, data->mv_size);
} else {
memcpy(ndata, &ofp->mp_pgno, sizeof(pgno_t));
ndata = METADATA(ofp);
ndata = ((MDB_dovpage *)ofp)->mp_ptr;
if (F_ISSET(flags, MDB_RESERVE))
data->mv_data = ndata;
else
@ -8546,7 +8593,7 @@ mdb_node_del(MDB_cursor *mc, int ksize)
sz = NODESIZE + node->mn_ksize;
if (IS_LEAF(mp)) {
if (F_ISSET(node->mn_flags, F_BIGDATA))
sz += sizeof(pgno_t);
sz += sizeof(MDB_ovpage);
else
sz += NODEDSZ(node);
}
@ -9901,7 +9948,7 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
if (IS_LEAF(mp)) {
if (F_ISSET(node->mn_flags, F_BIGDATA))
psize += sizeof(pgno_t);
psize += sizeof(MDB_ovpage);
else
psize += NODEDSZ(node);
}
@ -10338,9 +10385,7 @@ mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
ni = NODEPTR(mp, i);
if (ni->mn_flags & F_BIGDATA) {
MDB_page *omp;
pgno_t pg;
size_t dsize;
int dpages;
MDB_ovpage ovp;
/* Need writable leaf */
if (mp != leaf) {
@ -10349,12 +10394,9 @@ mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
mp = leaf;
ni = NODEPTR(mp, i);
}
dsize = NODEDSZ(ni);
dpages = OVPAGES(dsize, my->mc_env->me_psize);
memcpy(&pg, NODEDATA(ni), sizeof(pg));
memcpy(NODEDATA(ni), &my->mc_next_pgno, sizeof(pgno_t));
rc = MDB_PAGE_GET(&mc, pg, dpages, &omp, NULL);
memcpy(&ovp, NODEDATA(ni), sizeof(ovp));
rc = MDB_PAGE_GET(&mc, ovp.op_pgno, ovp.op_pages, &omp, NULL);
if (rc)
goto done;
if (my->mc_wlen[toggle] >= MDB_WBUF) {
@ -10365,12 +10407,13 @@ mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
}
mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
memcpy(mo, omp, my->mc_env->me_psize);
mo->mp_pgno = my->mc_next_pgno;
mo->mp_txnid = 1;
my->mc_next_pgno += omp->mp_pages;
ovp.op_pgno = my->mc_next_pgno;
ovp.op_txnid = 1;
memcpy(NODEDATA(ni), &ovp, sizeof(ovp));
my->mc_next_pgno += ovp.op_pages;
my->mc_wlen[toggle] += my->mc_env->me_psize;
if (dpages > 1) {
my->mc_olen[toggle] = my->mc_env->me_psize * (dpages - 1);
if (ovp.op_pages > 1) {
my->mc_olen[toggle] = my->mc_env->me_psize * (ovp.op_pages - 1);
my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize;
rc = mdb_env_cthr_toggle(my, 1);
if (rc)
@ -11089,19 +11132,13 @@ mdb_drop0(MDB_cursor *mc, int subs)
for (i=0; i<n; i++) {
ni = NODEPTR(mp, i);
if (ni->mn_flags & F_BIGDATA) {
MDB_page *omp;
pgno_t pg;
memcpy(&pg, NODEDATA(ni), sizeof(pg));
/* page count is irrelevant here */
rc = MDB_PAGE_GET(mc, pg, 1, &omp, NULL);
if (rc != 0)
goto done;
mdb_cassert(mc, IS_OVERFLOW(omp));
MDB_ovpage ovp;
memcpy(&ovp, NODEDATA(ni), sizeof(ovp));
rc = mdb_midl_append_range(&txn->mt_free_pgs,
pg, omp->mp_pages);
ovp.op_pgno, ovp.op_pages);
if (rc)
goto done;
mc->mc_db->md_overflow_pages -= omp->mp_pages;
mc->mc_db->md_overflow_pages -= ovp.op_pages;
if (!mc->mc_db->md_overflow_pages && !subs)
break;
} else if (subs && (ni->mn_flags & F_SUBDATA)) {

31
libraries/liblmdb/midl.c
Unescape View File

@ -355,6 +355,37 @@ int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id )
return 0;
}
MDB_ID2L mdb_mid2l_alloc(int num)
{
MDB_ID2L ids = malloc((num+2) * sizeof(MDB_ID2));
if (ids) {
ids->mid = num;
ids++;
ids->mid = 0;
}
return ids;
}
void mdb_mid2l_free(MDB_ID2L ids)
{
if (ids)
free(ids-1);
}
int mdb_mid2l_need( MDB_ID2L *idp, unsigned num )
{
MDB_ID2L ids = *idp;
num += ids[0].mid;
if (num > ids[-1].mid) {
num = (num + num/4 + (256 + 2)) & -256;
if (!(ids = realloc(ids-1, num * sizeof(MDB_ID2))))
return ENOMEM;
ids[0].mid = num - 2;
*idp = ids+1;
}
return 0;
}
#if MDB_RPAGE_CACHE
unsigned mdb_mid3l_search( MDB_ID3L ids, MDB_ID id )
{

6
libraries/liblmdb/midl.h
Unescape View File

@ -178,6 +178,12 @@ int mdb_mid2l_insert( MDB_ID2L ids, MDB_ID2 *id );
*/
int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id );
MDB_ID2L mdb_mid2l_alloc(int num);
void mdb_mid2l_free(MDB_ID2L ids);
int mdb_mid2l_need( MDB_ID2L *idp, unsigned num );
#if MDB_RPAGE_CACHE
typedef struct MDB_ID3 {
MDB_ID mid; /**< The ID */

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