ISAR/libmdbx
3
0
Fork 0
mirror of https://github.com/isar/libmdbx.git synced 2025-01-01 23:54:12 +08:00
Code Issues Packages Projects Releases Wiki Activity

mdbx: account freelist-backlog while shrinking DB.

Browse Source 
Change-Id: I8b211f281483e7cb6344ef99c571f3516d16f61d
This commit is contained in:
Leo Yuriev 2018-01-07 22:31:34 +03:00
parent 7812476518
commit f10f5b376f
1 changed files with 12 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
src/mdbx.c
View File

@ -2982,12 +2982,17 @@ static __inline int mdbx_backlog_size(MDBX_txn *txn) {
return reclaimed + txn->mt_loose_count + txn->mt_end_pgno - txn->mt_next_pgno;
}
static __inline int mdbx_backlog_extragap(MDBX_env *env) {
/* LY: extra page(s) for b-tree rebalancing */
return (env->me_flags & MDBX_LIFORECLAIM) ? 2 : 1;
}
/* LY: Prepare a backlog of pages to modify FreeDB itself,
* while reclaiming is prohibited. It should be enough to prevent search
* in mdbx_page_alloc() during a deleting, when freeDB tree is unbalanced. */
static int mdbx_prep_backlog(MDBX_txn *txn, MDBX_cursor *mc) {
/* LY: extra page(s) for b-tree rebalancing */
const int extra = (txn->mt_env->me_flags & MDBX_LIFORECLAIM) ? 2 : 1;
const int extra = mdbx_backlog_extragap(txn->mt_env);
if (mdbx_backlog_size(txn) < mc->mc_db->md_depth + extra) {
int rc = mdbx_cursor_touch(mc);
@ -4108,13 +4113,17 @@ static int mdbx_sync_locked(MDBX_env *env, unsigned flags,
/* Windows is unable shrinking a mapped file */
#else
/* LY: check conditions to shrink datafile */
const pgno_t backlog_gap =
pending->mm_dbs[FREE_DBI].md_depth + mdbx_backlog_extragap(env);
pgno_t shrink = 0;
if ((flags & MDBX_SHRINK_ALLOWED) && pending->mm_geo.shrink &&
pending->mm_geo.now - pending->mm_geo.next > pending->mm_geo.shrink) {
pending->mm_geo.now - pending->mm_geo.next >
pending->mm_geo.shrink + backlog_gap) {
const pgno_t aligner =
pending->mm_geo.grow ? pending->mm_geo.grow : pending->mm_geo.shrink;
const pgno_t with_backlog_gap = pending->mm_geo.next + backlog_gap;
const pgno_t aligned = pgno_align2os_pgno(
env, pending->mm_geo.next + aligner - pending->mm_geo.next % aligner);
env, with_backlog_gap + aligner - with_backlog_gap % aligner);
const pgno_t bottom =
(aligned > pending->mm_geo.lower) ? aligned : pending->mm_geo.lower;
if (pending->mm_geo.now > bottom) {