/*
* __wt_btree_stat_init --
* Initialize the Btree statistics.
*/
int
__wt_btree_stat_init(WT_SESSION_IMPL *session, uint32_t flags)
{
WT_BM *bm;
WT_BTREE *btree;
WT_DECL_RET;
WT_DSRC_STATS *stats;
WT_PAGE *page;
btree = S2BT(session);
bm = btree->bm;
stats = &btree->dhandle->stats;
WT_RET(bm->stat(bm, session, stats));
WT_STAT_SET(stats, btree_fixed_len, btree->bitcnt);
WT_STAT_SET(stats, btree_maximum_depth, btree->maximum_depth);
WT_STAT_SET(stats, btree_maxintlitem, btree->maxintlitem);
WT_STAT_SET(stats, btree_maxintlpage, btree->maxintlpage);
WT_STAT_SET(stats, btree_maxleafitem, btree->maxleafitem);
WT_STAT_SET(stats, btree_maxleafpage, btree->maxleafpage);
page = NULL;
if (LF_ISSET(WT_STATISTICS_FAST))
return (0);
while ((ret = __wt_tree_walk(session, &page, 0)) == 0 && page != NULL)
WT_RET(__stat_page(session, page, stats));
return (ret == WT_NOTFOUND ? 0 : ret);
}
/*
* __wt_rec_track_wrapup_err --
* Resolve the page's list of tracked objects after an error occurs.
*/
int
__wt_rec_track_wrapup_err(WT_SESSION_IMPL *session, WT_PAGE *page)
{
WT_BM *bm;
WT_DECL_RET;
WT_PAGE_MODIFY *mod;
WT_PAGE_TRACK *track;
uint32_t i;
bm = session->btree->bm;
/*
* After a failed reconciliation of a page, discard entries added in the
* current reconciliation, their information is incorrect, additionally,
* clear the in-use flag in preparation for the next reconciliation.
*/
mod = page->modify;
for (track = mod->track, i = 0; i < mod->track_entries; ++track, ++i)
if (F_ISSET(track, WT_TRK_JUST_ADDED)) {
/*
* The in-use flag is used to avoid discarding backing
* blocks: if an object is both just-added and in-use,
* we allocated the blocks on this run, and we want to
* discard them on error.
*/
if (F_ISSET(track, WT_TRK_INUSE))
WT_TRET(bm->free(bm, session,
track->addr.addr, track->addr.size));
__wt_free(session, track->addr.addr);
memset(track, 0, sizeof(*track));
} else
F_CLR(track, WT_TRK_INUSE);
return (ret);
}
/*
* __meta_track_apply --
* Apply the changes in a metadata tracking record.
*/
static int
__meta_track_apply(WT_SESSION_IMPL *session, WT_META_TRACK *trk)
{
WT_BM *bm;
WT_BTREE *btree;
WT_DECL_RET;
switch (trk->op) {
case WT_ST_EMPTY: /* Unused slot */
break;
case WT_ST_CHECKPOINT: /* Checkpoint, see above */
btree = trk->dhandle->handle;
bm = btree->bm;
WT_WITH_DHANDLE(session, trk->dhandle,
ret = bm->checkpoint_resolve(bm, session));
break;
case WT_ST_DROP_COMMIT:
if ((ret =
__wt_block_manager_drop(session, trk->a, false)) != 0)
__wt_err(session, ret,
"metadata remove dropped file %s", trk->a);
break;
case WT_ST_LOCK:
WT_WITH_DHANDLE(session, trk->dhandle,
ret = __wt_session_release_btree(session));
break;
case WT_ST_FILEOP:
case WT_ST_REMOVE:
case WT_ST_SET:
break;
}
__meta_track_clear(session, trk);
return (ret);
}
/*
* __wt_btree_stat_init --
* Initialize the Btree statistics.
*/
int
__wt_btree_stat_init(WT_SESSION_IMPL *session, WT_CURSOR_STAT *cst)
{
WT_BM *bm;
WT_BTREE *btree;
WT_DSRC_STATS **stats;
btree = S2BT(session);
bm = btree->bm;
stats = btree->dhandle->stats;
WT_RET(bm->stat(bm, session, stats[0]));
WT_STAT_SET(session, stats, btree_fixed_len, btree->bitcnt);
WT_STAT_SET(session, stats, btree_maximum_depth, btree->maximum_depth);
WT_STAT_SET(session, stats, btree_maxintlkey, btree->maxintlkey);
WT_STAT_SET(session, stats, btree_maxintlpage, btree->maxintlpage);
WT_STAT_SET(session, stats, btree_maxleafkey, btree->maxleafkey);
WT_STAT_SET(session, stats, btree_maxleafpage, btree->maxleafpage);
WT_STAT_SET(session, stats, btree_maxleafvalue, btree->maxleafvalue);
WT_STAT_SET(session, stats, cache_bytes_inuse,
__wt_btree_bytes_inuse(session));
if (F_ISSET(cst, WT_STAT_TYPE_CACHE_WALK))
__wt_curstat_cache_walk(session);
if (F_ISSET(cst, WT_STAT_TYPE_TREE_WALK))
WT_RET(__stat_tree_walk(session));
return (0);
}
/*
* __wt_compact_page_skip --
* Return if the block-manager wants us to re-write this page.
*/
int
__wt_compact_page_skip(
WT_SESSION_IMPL *session, WT_PAGE *parent, WT_REF *ref, int *skipp)
{
WT_BM *bm;
uint32_t addr_size;
const uint8_t *addr;
bm = S2BT(session)->bm;
/*
* There's one compaction test we do before we read the page, to see
* if the block-manager thinks it useful to rewrite the page. If a
* rewrite won't help, we don't want to do I/O for nothing. For that
* reason, this check is done in a call from inside the tree-walking
* routine.
*
* Ignore everything but on-disk pages, we've already done a pass over
* the in-memory pages.
*/
if (ref->state != WT_REF_DISK) {
*skipp = 1;
return (0);
}
__wt_get_addr(parent, ref, &addr, &addr_size);
if (addr == NULL) {
*skipp = 1;
return (0);
}
return (bm->compact_page_skip(bm, session, addr, addr_size, skipp));
}
/*
* __wt_compact_page_skip --
* Return if compaction requires we read this page.
*/
int
__wt_compact_page_skip(WT_SESSION_IMPL *session, WT_REF *ref, bool *skipp)
{
WT_BM *bm;
size_t addr_size;
u_int type;
const uint8_t *addr;
*skipp = false; /* Default to reading. */
type = 0; /* Keep compiler quiet. */
bm = S2BT(session)->bm;
/*
* We aren't holding a hazard pointer, so we can't look at the page
* itself, all we can look at is the WT_REF information. If there's no
* address, the page isn't on disk, but we have to read internal pages
* to walk the tree regardless; throw up our hands and read it.
*/
__wt_ref_info(ref, &addr, &addr_size, &type);
if (addr == NULL)
return (0);
/*
* Internal pages must be read to walk the tree; ask the block-manager
* if it's useful to rewrite leaf pages, don't do the I/O if a rewrite
* won't help.
*/
return (type == WT_CELL_ADDR_INT ? 0 :
bm->compact_page_skip(bm, session, addr, addr_size, skipp));
}
/*
* __compact_end --
* End object compaction.
*/
static int
__compact_end(WT_SESSION_IMPL *session)
{
WT_BM *bm;
bm = S2BT(session)->bm;
return (bm->compact_end(bm, session));
}
/*
* __wt_compact --
* Compact a file.
*/
int
__wt_compact(WT_SESSION_IMPL *session, const char *cfg[])
{
WT_BM *bm;
WT_CONFIG_ITEM cval;
WT_DECL_RET;
WT_PAGE *page;
int trigger, skip;
bm = S2BT(session)->bm;
WT_DSTAT_INCR(session, session_compact);
WT_RET(__wt_config_gets(session, cfg, "trigger", &cval));
trigger = (int)cval.val;
/* Check if compaction might be useful. */
WT_RET(bm->compact_skip(bm, session, trigger, &skip));
if (skip)
return (0);
/*
* Walk the cache reviewing in-memory pages to see if they need to be
* re-written. This requires looking at page reconciliation results,
* which means the page cannot be reconciled at the same time as it's
* being reviewed for compaction. The underlying functions ensure we
* don't collide with page eviction, but we need to make sure we don't
* collide with checkpoints either, they are the other operation that
* can reconcile a page.
*/
__wt_spin_lock(session, &S2C(session)->metadata_lock);
WT_RET(__wt_bt_cache_op(session, NULL, WT_SYNC_COMPACT));
__wt_spin_unlock(session, &S2C(session)->metadata_lock);
/*
* Walk the tree, reviewing on-disk pages to see if they need to be
* re-written.
*/
for (page = NULL;;) {
WT_RET(__wt_tree_walk(session, &page, WT_TREE_COMPACT));
if (page == NULL)
break;
/*
* The only pages returned by the tree walk function are pages
* we want to re-write; mark the page and tree dirty.
*/
if ((ret = __wt_page_modify_init(session, page)) != 0) {
WT_TRET(__wt_page_release(session, page));
WT_RET(ret);
}
__wt_page_and_tree_modify_set(session, page);
WT_DSTAT_INCR(session, btree_compact_rewrite);
}
return (0);
}
/*
* __ovfl_reuse_wrapup_err --
* Resolve the page's overflow reuse list after an error occurs.
*/
static int
__ovfl_reuse_wrapup_err(WT_SESSION_IMPL *session, WT_PAGE *page)
{
WT_BM *bm;
WT_DECL_RET;
WT_OVFL_REUSE **e, **head, *reuse;
size_t decr;
int i;
bm = S2BT(session)->bm;
head = page->modify->ovfl_track->ovfl_reuse;
/*
* Discard any overflow records that were just added, freeing underlying
* blocks.
*
* First, walk the overflow reuse lists (except for the lowest one),
* fixing up skiplist links.
*/
for (i = WT_SKIP_MAXDEPTH - 1; i > 0; --i)
for (e = &head[i]; (reuse = *e) != NULL;) {
if (!F_ISSET(reuse, WT_OVFL_REUSE_JUST_ADDED)) {
e = &reuse->next[i];
continue;
}
*e = reuse->next[i];
}
/*
* Second, discard any overflow record with a just-added flag, clear the
* flags for the next run.
*/
decr = 0;
for (e = &head[0]; (reuse = *e) != NULL;) {
if (!F_ISSET(reuse, WT_OVFL_REUSE_JUST_ADDED)) {
F_CLR(reuse, WT_OVFL_REUSE_INUSE);
e = &reuse->next[0];
continue;
}
*e = reuse->next[0];
if (WT_VERBOSE_ISSET(session, WT_VERB_OVERFLOW))
WT_RET(
__ovfl_reuse_verbose(session, page, reuse, "free"));
WT_TRET(bm->free(
bm, session, WT_OVFL_REUSE_ADDR(reuse), reuse->addr_size));
decr += WT_OVFL_SIZE(reuse, WT_OVFL_REUSE);
__wt_free(session, reuse);
}
if (decr != 0)
__wt_cache_page_inmem_decr(session, page, decr);
return (0);
}
/*
* __compact_rewrite --
* Return if a page needs to be re-written.
*/
static int
__compact_rewrite(WT_SESSION_IMPL *session, WT_REF *ref, bool *skipp)
{
WT_BM *bm;
WT_DECL_RET;
WT_PAGE *page;
WT_PAGE_MODIFY *mod;
size_t addr_size;
const uint8_t *addr;
*skipp = true; /* Default skip. */
bm = S2BT(session)->bm;
page = ref->page;
mod = page->modify;
/*
* Ignore the root: it may not have a replacement address, and besides,
* if anything else gets written, so will it.
*/
if (__wt_ref_is_root(ref))
return (0);
/* Ignore currently dirty pages, they will be written regardless. */
if (__wt_page_is_modified(page))
return (0);
/*
* If the page is clean, test the original addresses.
* If the page is a 1-to-1 replacement, test the replacement addresses.
* Ignore empty pages, they get merged into the parent.
*/
if (mod == NULL || mod->rec_result == 0) {
WT_RET(__wt_ref_info(session, ref, &addr, &addr_size, NULL));
if (addr == NULL)
return (0);
WT_RET(
bm->compact_page_skip(bm, session, addr, addr_size, skipp));
} else if (mod->rec_result == WT_PM_REC_REPLACE) {
/*
* The page's modification information can change underfoot if
* the page is being reconciled, serialize with reconciliation.
*/
WT_RET(__wt_fair_lock(session, &page->page_lock));
ret = bm->compact_page_skip(bm, session,
mod->mod_replace.addr, mod->mod_replace.size, skipp);
WT_TRET(__wt_fair_unlock(session, &page->page_lock));
WT_RET(ret);
}
return (0);
}
/*
* __wt_btree_stat_init --
* Initialize the Btree statistics.
*/
int
__wt_btree_stat_init(WT_SESSION_IMPL *session, WT_CURSOR_STAT *cst)
{
WT_BM *bm;
WT_BTREE *btree;
WT_DECL_RET;
WT_DSRC_STATS **stats;
WT_REF *next_walk;
btree = S2BT(session);
bm = btree->bm;
stats = btree->dhandle->stats;
WT_RET(bm->stat(bm, session, stats[0]));
WT_STAT_SET(session, stats, btree_fixed_len, btree->bitcnt);
WT_STAT_SET(session, stats, btree_maximum_depth, btree->maximum_depth);
WT_STAT_SET(session, stats, btree_maxintlkey, btree->maxintlkey);
WT_STAT_SET(session, stats, btree_maxintlpage, btree->maxintlpage);
WT_STAT_SET(session, stats, btree_maxleafkey, btree->maxleafkey);
WT_STAT_SET(session, stats, btree_maxleafpage, btree->maxleafpage);
WT_STAT_SET(session, stats, btree_maxleafvalue, btree->maxleafvalue);
/* Everything else is really, really expensive. */
if (!F_ISSET(cst, WT_CONN_STAT_ALL))
return (0);
/*
* Clear the statistics we're about to count.
*/
WT_STAT_SET(session, stats, btree_column_deleted, 0);
WT_STAT_SET(session, stats, btree_column_fix, 0);
WT_STAT_SET(session, stats, btree_column_internal, 0);
WT_STAT_SET(session, stats, btree_column_rle, 0);
WT_STAT_SET(session, stats, btree_column_variable, 0);
WT_STAT_SET(session, stats, btree_entries, 0);
WT_STAT_SET(session, stats, btree_overflow, 0);
WT_STAT_SET(session, stats, btree_row_internal, 0);
WT_STAT_SET(session, stats, btree_row_leaf, 0);
next_walk = NULL;
while ((ret = __wt_tree_walk(
session, &next_walk, 0)) == 0 && next_walk != NULL) {
WT_WITH_PAGE_INDEX(session,
ret = __stat_page(session, next_walk->page, stats));
WT_RET(ret);
}
return (ret == WT_NOTFOUND ? 0 : ret);
}
/*
* __wt_addr_string --
* Load a buffer with a printable, nul-terminated representation of an
* address.
*/
const char *
__wt_addr_string(
WT_SESSION_IMPL *session, WT_ITEM *buf, const uint8_t *addr, uint32_t size)
{
WT_BM *bm;
bm = S2BT(session)->bm;
if (addr == NULL) {
buf->data = "[NoAddr]";
buf->size = WT_STORE_SIZE(strlen("[NoAddr]"));
} else if (bm->addr_string(bm, session, buf, addr, size) != 0) {
buf->data = "[Error]";
buf->size = WT_STORE_SIZE(strlen("[Error]"));
}
return (buf->data);
}
/*
* __wt_ovfl_discard --
* Discard an on-page overflow value, and reset the page's cell.
*/
int
__wt_ovfl_discard(WT_SESSION_IMPL *session, WT_CELL *cell)
{
WT_BM *bm;
WT_BTREE *btree;
WT_CELL_UNPACK *unpack, _unpack;
WT_DECL_RET;
btree = S2BT(session);
bm = btree->bm;
unpack = &_unpack;
__wt_cell_unpack(cell, unpack);
/*
* Finally remove overflow key/value objects, called when reconciliation
* finishes after successfully writing a page.
*
* Keys must have already been instantiated and value objects must have
* already been cached (if they might potentially still be read by any
* running transaction).
*
* Acquire the overflow lock to avoid racing with a thread reading the
* backing overflow blocks.
*/
WT_RET(__wt_writelock(session, btree->ovfl_lock));
switch (unpack->raw) {
case WT_CELL_KEY_OVFL:
__wt_cell_type_reset(session,
unpack->cell, WT_CELL_KEY_OVFL, WT_CELL_KEY_OVFL_RM);
break;
case WT_CELL_VALUE_OVFL:
__wt_cell_type_reset(session,
unpack->cell, WT_CELL_VALUE_OVFL, WT_CELL_VALUE_OVFL_RM);
break;
WT_ILLEGAL_VALUE(session);
}
WT_TRET(__wt_writeunlock(session, btree->ovfl_lock));
/* Free the backing disk blocks. */
WT_TRET(bm->free(bm, session, unpack->data, unpack->size));
return (ret);
}
/*
* __wt_debug_addr --
* Read and dump a disk page in debugging mode, using an addr/size pair.
*/
int
__wt_debug_addr(WT_SESSION_IMPL *session,
const uint8_t *addr, size_t addr_size, const char *ofile)
{
WT_BM *bm;
WT_DECL_ITEM(buf);
WT_DECL_RET;
bm = S2BT(session)->bm;
WT_RET(__wt_scr_alloc(session, 1024, &buf));
WT_ERR(bm->read(bm, session, buf, addr, addr_size));
ret = __wt_debug_disk(session, buf->mem, ofile);
err: __wt_scr_free(session, &buf);
return (ret);
}
/*
* __wt_addr_string --
* Load a buffer with a printable, nul-terminated representation of an
* address.
*/
const char *
__wt_addr_string(WT_SESSION_IMPL *session,
const uint8_t *addr, size_t addr_size, WT_ITEM *buf)
{
WT_BM *bm;
WT_BTREE *btree;
btree = S2BT_SAFE(session);
if (addr == NULL) {
buf->data = "[NoAddr]";
buf->size = strlen("[NoAddr]");
} else if (btree == NULL || (bm = btree->bm) == NULL ||
bm->addr_string(bm, session, buf, addr, addr_size) != 0) {
buf->data = "[Error]";
buf->size = strlen("[Error]");
}
return (buf->data);
}
/*
* __cursor_size_chk --
* Return if an inserted item is too large.
*/
static inline int
__cursor_size_chk(WT_SESSION_IMPL *session, WT_ITEM *kv)
{
WT_BM *bm;
WT_BTREE *btree;
WT_DECL_RET;
size_t size;
btree = S2BT(session);
bm = btree->bm;
if (btree->type == BTREE_COL_FIX) {
/* Fixed-size column-stores take a single byte. */
if (kv->size != 1)
WT_RET_MSG(session, EINVAL,
"item size of %" WT_SIZET_FMT " does not match "
"fixed-length file requirement of 1 byte",
kv->size);
return (0);
}
/* Don't waste effort, 1GB is always cool. */
if (kv->size <= WT_GIGABYTE)
return (0);
/*
* There are two checks: what we are willing to store in the tree, and
* what the block manager can actually write.
*/
if (kv->size > WT_BTREE_MAX_OBJECT_SIZE)
ret = EINVAL;
else {
size = kv->size;
ret = bm->write_size(bm, session, &size);
}
if (ret != 0)
WT_RET_MSG(session, ret,
"item size of %" WT_SIZET_FMT " exceeds the maximum "
"supported size",
kv->size);
return (0);
}
/*
* __wt_block_manager_open --
* Open a file.
*/
int
__wt_block_manager_open(WT_SESSION_IMPL *session,
const char *filename, const char *cfg[], int forced_salvage, WT_BM **bmp)
{
WT_BM *bm;
WT_DECL_RET;
*bmp = NULL;
WT_RET(__wt_calloc_def(session, 1, &bm));
__bm_method_set(bm, 0);
WT_ERR(__wt_block_open(
session, filename, cfg, forced_salvage, &bm->block));
*bmp = bm;
return (0);
err: WT_TRET(bm->close(bm, session));
return (ret);
}
/*
* __wt_block_manager_open --
* Open a file.
*/
int
__wt_block_manager_open(WT_SESSION_IMPL *session,
const char *filename, const char *cfg[],
bool forced_salvage, bool readonly, uint32_t allocsize, WT_BM **bmp)
{
WT_BM *bm;
WT_DECL_RET;
*bmp = NULL;
WT_RET(__wt_calloc_one(session, &bm));
__bm_method_set(bm, false);
WT_ERR(__wt_block_open(session, filename, cfg,
forced_salvage, readonly, allocsize, &bm->block));
*bmp = bm;
return (0);
err: WT_TRET(bm->close(bm, session));
return (ret);
}
/*将多余的文件空间compact到合适的位置,如果ref在compact范围内，返回skip = 1,表示文件空间不能进行compact*/
static int __compact_rewrite(WT_SESSION_IMPL* session, WT_REF* ref, int* skipp)
{
WT_BM *bm;
WT_DECL_RET;
WT_PAGE *page;
WT_PAGE_MODIFY *mod;
size_t addr_size;
const uint8_t *addr;
*skipp = 1;
bm = S2BT(session)->bm;
page = ref->page;
mod = page->modify;
/*root page是不能被compact*/
if (__wt_ref_is_root(ref))
return 0;
/*ref指向的是个脏页，不进行compact*/
if (__wt_page_is_modified(page))
return (0);
/*假如page一已经被清空的，直接判断是否可以它的block空间compact*/
if (mod == NULL || F_ISSET(mod, WT_PM_REC_MASK) == 0) {
WT_RET(__wt_ref_info(session, ref, &addr, &addr_size, NULL));
if (addr == NULL)
return (0);
WT_RET(bm->compact_page_skip(bm, session, addr, addr_size, skipp));
}
else if (F_ISSET(mod, WT_PM_REC_MASK) == WT_PM_REC_REPLACE){ /*如果page空间是替换，那么进行替换block的compact操作判断*/
WT_PAGE_LOCK(session, page);
ret = bm->compact_page_skip(bm, session, mod->mod_replace.addr, mod->mod_replace.size, skipp);
WT_PAGE_UNLOCK(session, page);
WT_RET(ret);
}
return 0;
}
/*在读取ref对应的page时，检查它是否需要compact*/
int __wt_compact_page_skip(WT_SESSION_IMPL* session, WT_REF* ref, int* skipp)
{
WT_BM *bm;
size_t addr_size;
u_int type;
const uint8_t *addr;
*skipp = 0;
type = 0;
bm = S2BT(session)->bm;
/*
* We aren't holding a hazard pointer, so we can't look at the page
* itself, all we can look at is the WT_REF information. If there's no
* address, the page isn't on disk, but we have to read internal pages
* to walk the tree regardless; throw up our hands and read it.
*/
WT_RET(__wt_ref_info(session, ref, &addr, &addr_size, &type));
if (addr == NULL)
return 0;
return (type == WT_CELL_ADDR_INT ? 0 : bm->compact_page_skip(bm, session, addr, addr_size, skipp));
}
/*
* __wt_bt_write --
* Write a buffer into a block, returning the block's addr/size and
* checksum.
*/
int
__wt_bt_write(WT_SESSION_IMPL *session, WT_ITEM *buf,
uint8_t *addr, size_t *addr_sizep, bool checkpoint, bool compressed)
{
WT_BM *bm;
WT_BTREE *btree;
WT_ITEM *ip;
WT_DECL_ITEM(tmp);
WT_DECL_RET;
WT_PAGE_HEADER *dsk;
size_t dst_len, len, result_len, size, src_len;
int compression_failed; /* Extension API, so not a bool. */
uint8_t *dst, *src;
bool data_cksum;
btree = S2BT(session);
bm = btree->bm;
/* Checkpoint calls are different than standard calls. */
WT_ASSERT(session,
(!checkpoint && addr != NULL && addr_sizep != NULL) ||
(checkpoint && addr == NULL && addr_sizep == NULL));
#ifdef HAVE_DIAGNOSTIC
/*
* We're passed a table's disk image. Decompress if necessary and
* verify the image. Always check the in-memory length for accuracy.
*/
dsk = buf->mem;
if (compressed) {
WT_ERR(__wt_scr_alloc(session, dsk->mem_size, &tmp));
memcpy(tmp->mem, buf->data, WT_BLOCK_COMPRESS_SKIP);
WT_ERR(btree->compressor->decompress(
btree->compressor, &session->iface,
(uint8_t *)buf->data + WT_BLOCK_COMPRESS_SKIP,
buf->size - WT_BLOCK_COMPRESS_SKIP,
(uint8_t *)tmp->data + WT_BLOCK_COMPRESS_SKIP,
tmp->memsize - WT_BLOCK_COMPRESS_SKIP,
&result_len));
WT_ASSERT(session,
dsk->mem_size == result_len + WT_BLOCK_COMPRESS_SKIP);
tmp->size = (uint32_t)result_len + WT_BLOCK_COMPRESS_SKIP;
ip = tmp;
} else {
WT_ASSERT(session, dsk->mem_size == buf->size);
ip = buf;
}
WT_ERR(__wt_verify_dsk(session, "[write-check]", ip));
__wt_scr_free(session, &tmp);
#endif
/*
* Optionally stream-compress the data, but don't compress blocks that
* are already as small as they're going to get.
*/
if (btree->compressor == NULL ||
btree->compressor->compress == NULL || compressed)
ip = buf;
else if (buf->size <= btree->allocsize) {
ip = buf;
WT_STAT_FAST_DATA_INCR(session, compress_write_too_small);
} else {
/* Skip the header bytes of the source data. */
src = (uint8_t *)buf->mem + WT_BLOCK_COMPRESS_SKIP;
src_len = buf->size - WT_BLOCK_COMPRESS_SKIP;
/*
* Compute the size needed for the destination buffer. We only
* allocate enough memory for a copy of the original by default,
* if any compressed version is bigger than the original, we
* won't use it. However, some compression engines (snappy is
* one example), may need more memory because they don't stop
* just because there's no more memory into which to compress.
*/
if (btree->compressor->pre_size == NULL)
len = src_len;
else
WT_ERR(btree->compressor->pre_size(btree->compressor,
&session->iface, src, src_len, &len));
size = len + WT_BLOCK_COMPRESS_SKIP;
WT_ERR(bm->write_size(bm, session, &size));
WT_ERR(__wt_scr_alloc(session, size, &tmp));
/* Skip the header bytes of the destination data. */
dst = (uint8_t *)tmp->mem + WT_BLOCK_COMPRESS_SKIP;
dst_len = len;
compression_failed = 0;
WT_ERR(btree->compressor->compress(btree->compressor,
&session->iface,
src, src_len,
dst, dst_len,
&result_len, &compression_failed));
result_len += WT_BLOCK_COMPRESS_SKIP;
/*
* If compression fails, or doesn't gain us at least one unit of
* allocation, fallback to the original version. This isn't
* unexpected: if compression doesn't work for some chunk of
* data for some reason (noting likely additional format/header
* information which compressed output requires), it just means
* the uncompressed version is as good as it gets, and that's
* what we use.
*/
if (compression_failed ||
buf->size / btree->allocsize <=
result_len / btree->allocsize) {
ip = buf;
WT_STAT_FAST_DATA_INCR(session, compress_write_fail);
} else {
compressed = true;
WT_STAT_FAST_DATA_INCR(session, compress_write);
/*
* Copy in the skipped header bytes, set the final data
* size.
*/
memcpy(tmp->mem, buf->mem, WT_BLOCK_COMPRESS_SKIP);
tmp->size = result_len;
ip = tmp;
}
}
dsk = ip->mem;
/* If the buffer is compressed, set the flag. */
if (compressed)
F_SET(dsk, WT_PAGE_COMPRESSED);
/*
* We increment the block's write generation so it's easy to identify
* newer versions of blocks during salvage. (It's common in WiredTiger,
* at least for the default block manager, for multiple blocks to be
* internally consistent with identical first and last keys, so we need
* a way to know the most recent state of the block. We could check
* which leaf is referenced by a valid internal page, but that implies
* salvaging internal pages, which I don't want to do, and it's not
* as good anyway, because the internal page may not have been written
* after the leaf page was updated. So, write generations it is.
*
* Nothing is locked at this point but two versions of a page with the
* same generation is pretty unlikely, and if we did, they're going to
* be roughly identical for the purposes of salvage, anyway.
*/
dsk->write_gen = ++btree->write_gen;
/*
* Checksum the data if the buffer isn't compressed or checksums are
* configured.
*/
switch (btree->checksum) {
case CKSUM_ON:
data_cksum = true;
break;
case CKSUM_OFF:
data_cksum = false;
break;
case CKSUM_UNCOMPRESSED:
default:
data_cksum = !compressed;
break;
}
/* Call the block manager to write the block. */
WT_ERR(checkpoint ?
bm->checkpoint(bm, session, ip, btree->ckpt, data_cksum) :
bm->write(bm, session, ip, addr, addr_sizep, data_cksum));
WT_STAT_FAST_CONN_INCR(session, cache_write);
WT_STAT_FAST_DATA_INCR(session, cache_write);
WT_STAT_FAST_CONN_INCRV(session, cache_bytes_write, dsk->mem_size);
WT_STAT_FAST_DATA_INCRV(session, cache_bytes_write, dsk->mem_size);
err: __wt_scr_free(session, &tmp);
return (ret);
}
/*
* __wt_bt_read --
* Read a cookie referenced block into a buffer.
*/
int
__wt_bt_read(WT_SESSION_IMPL *session,
WT_ITEM *buf, const uint8_t *addr, size_t addr_size)
{
WT_BM *bm;
WT_BTREE *btree;
WT_DECL_ITEM(etmp);
WT_DECL_ITEM(tmp);
WT_DECL_RET;
WT_ENCRYPTOR *encryptor;
WT_ITEM *ip;
const WT_PAGE_HEADER *dsk;
const char *fail_msg;
size_t result_len;
btree = S2BT(session);
bm = btree->bm;
fail_msg = NULL; /* -Wuninitialized */
/*
* If anticipating a compressed or encrypted block, read into a scratch
* buffer and decompress into the caller's buffer. Else, read directly
* into the caller's buffer.
*/
if (btree->compressor == NULL && btree->kencryptor == NULL) {
WT_RET(bm->read(bm, session, buf, addr, addr_size));
dsk = buf->data;
ip = NULL;
} else {
WT_RET(__wt_scr_alloc(session, 0, &tmp));
WT_ERR(bm->read(bm, session, tmp, addr, addr_size));
dsk = tmp->data;
ip = tmp;
}
/*
* If the block is encrypted, copy the skipped bytes of the original
* image into place, then decrypt.
*/
if (F_ISSET(dsk, WT_PAGE_ENCRYPTED)) {
if (btree->kencryptor == NULL ||
(encryptor = btree->kencryptor->encryptor) == NULL ||
encryptor->decrypt == NULL) {
fail_msg =
"encrypted block in file for which no encryption "
"configured";
goto corrupt;
}
WT_ERR(__wt_scr_alloc(session, 0, &etmp));
if ((ret = __wt_decrypt(session,
encryptor, WT_BLOCK_ENCRYPT_SKIP, ip, etmp)) != 0) {
fail_msg = "block decryption failed";
goto corrupt;
}
ip = etmp;
dsk = ip->data;
} else if (btree->kencryptor != NULL) {
fail_msg =
"unencrypted block in file for which encryption configured";
goto corrupt;
}
if (F_ISSET(dsk, WT_PAGE_COMPRESSED)) {
if (btree->compressor == NULL ||
btree->compressor->decompress == NULL) {
fail_msg =
"compressed block in file for which no compression "
"configured";
goto corrupt;
}
/*
* Size the buffer based on the in-memory bytes we're expecting
* from decompression.
*/
WT_ERR(__wt_buf_initsize(session, buf, dsk->mem_size));
/*
* Note the source length is NOT the number of compressed bytes,
* it's the length of the block we just read (minus the skipped
* bytes). We don't store the number of compressed bytes: some
* compression engines need that length stored externally, they
* don't have markers in the stream to signal the end of the
* compressed bytes. Those engines must store the compressed
* byte length somehow, see the snappy compression extension for
* an example.
*/
memcpy(buf->mem, ip->data, WT_BLOCK_COMPRESS_SKIP);
ret = btree->compressor->decompress(
btree->compressor, &session->iface,
(uint8_t *)ip->data + WT_BLOCK_COMPRESS_SKIP,
tmp->size - WT_BLOCK_COMPRESS_SKIP,
(uint8_t *)buf->mem + WT_BLOCK_COMPRESS_SKIP,
dsk->mem_size - WT_BLOCK_COMPRESS_SKIP, &result_len);
/*
* If checksums were turned off because we're depending on the
* decompression to fail on any corrupted data, we'll end up
* here after corruption happens. If we're salvaging the file,
* it's OK, otherwise it's really, really bad.
*/
if (ret != 0 ||
result_len != dsk->mem_size - WT_BLOCK_COMPRESS_SKIP) {
fail_msg = "block decryption failed";
goto corrupt;
}
} else
/*
* If we uncompressed above, the page is in the correct buffer.
* If we get here the data may be in the wrong buffer and the
* buffer may be the wrong size. If needed, get the page
* into the destination buffer.
*/
if (ip != NULL)
WT_ERR(__wt_buf_set(
session, buf, ip->data, dsk->mem_size));
/* If the handle is a verify handle, verify the physical page. */
if (F_ISSET(btree, WT_BTREE_VERIFY)) {
if (tmp == NULL)
WT_ERR(__wt_scr_alloc(session, 0, &tmp));
WT_ERR(bm->addr_string(bm, session, tmp, addr, addr_size));
WT_ERR(__wt_verify_dsk(session, tmp->data, buf));
}
WT_STAT_FAST_CONN_INCR(session, cache_read);
WT_STAT_FAST_DATA_INCR(session, cache_read);
if (F_ISSET(dsk, WT_PAGE_COMPRESSED))
WT_STAT_FAST_DATA_INCR(session, compress_read);
WT_STAT_FAST_CONN_INCRV(session, cache_bytes_read, dsk->mem_size);
WT_STAT_FAST_DATA_INCRV(session, cache_bytes_read, dsk->mem_size);
if (0) {
corrupt: if (ret == 0)
ret = WT_ERROR;
if (!F_ISSET(btree, WT_BTREE_VERIFY) &&
!F_ISSET(session, WT_SESSION_QUIET_CORRUPT_FILE)) {
__wt_err(session, ret, "%s", fail_msg);
ret = __wt_illegal_value(session, btree->dhandle->name);
}
}
err: __wt_scr_free(session, &tmp);
__wt_scr_free(session, &etmp);
return (ret);
}
/*
* __verify_tree --
* Verify a tree, recursively descending through it in depth-first fashion.
* The page argument was physically verified (so we know it's correctly formed),
* and the in-memory version built. Our job is to check logical relationships
* in the page and in the tree.
*/
static int
__verify_tree(WT_SESSION_IMPL *session, WT_REF *ref, WT_VSTUFF *vs)
{
WT_BM *bm;
WT_CELL *cell;
WT_CELL_UNPACK *unpack, _unpack;
WT_COL *cip;
WT_DECL_RET;
WT_PAGE *page;
WT_REF *child_ref;
uint64_t recno;
uint32_t entry, i;
bool found;
bm = S2BT(session)->bm;
page = ref->page;
unpack = &_unpack;
WT_CLEAR(*unpack); /* -Wuninitialized */
WT_RET(__wt_verbose(session, WT_VERB_VERIFY, "%s %s",
__wt_page_addr_string(session, ref, vs->tmp1),
__wt_page_type_string(page->type)));
/* Optionally dump the address. */
if (vs->dump_address)
WT_RET(__wt_msg(session, "%s %s",
__wt_page_addr_string(session, ref, vs->tmp1),
__wt_page_type_string(page->type)));
/* Track the shape of the tree. */
if (WT_PAGE_IS_INTERNAL(page))
++vs->depth_internal[
WT_MIN(vs->depth, WT_ELEMENTS(vs->depth_internal) - 1)];
else
++vs->depth_leaf[
WT_MIN(vs->depth, WT_ELEMENTS(vs->depth_internal) - 1)];
/*
* The page's physical structure was verified when it was read into
* memory by the read server thread, and then the in-memory version
* of the page was built. Now we make sure the page and tree are
* logically consistent.
*
* !!!
* The problem: (1) the read server has to build the in-memory version
* of the page because the read server is the thread that flags when
* any thread can access the page in the tree; (2) we can't build the
* in-memory version of the page until the physical structure is known
* to be OK, so the read server has to verify at least the physical
* structure of the page; (3) doing complete page verification requires
* reading additional pages (for example, overflow keys imply reading
* overflow pages in order to test the key's order in the page); (4)
* the read server cannot read additional pages because it will hang
* waiting on itself. For this reason, we split page verification
* into a physical verification, which allows the in-memory version
* of the page to be built, and then a subsequent logical verification
* which happens here.
*
* Report progress occasionally.
*/
#define WT_VERIFY_PROGRESS_INTERVAL 100
if (++vs->fcnt % WT_VERIFY_PROGRESS_INTERVAL == 0)
WT_RET(__wt_progress(session, NULL, vs->fcnt));
#ifdef HAVE_DIAGNOSTIC
/* Optionally dump the blocks or page in debugging mode. */
if (vs->dump_blocks)
WT_RET(__wt_debug_disk(session, page->dsk, NULL));
if (vs->dump_pages)
WT_RET(__wt_debug_page(session, page, NULL));
#endif
/*
* Column-store key order checks: check the page's record number and
* then update the total record count.
*/
switch (page->type) {
case WT_PAGE_COL_FIX:
recno = page->pg_fix_recno;
goto recno_chk;
case WT_PAGE_COL_INT:
recno = page->pg_intl_recno;
goto recno_chk;
case WT_PAGE_COL_VAR:
recno = page->pg_var_recno;
recno_chk: if (recno != vs->record_total + 1)
WT_RET_MSG(session, WT_ERROR,
"page at %s has a starting record of %" PRIu64
" when the expected starting record is %" PRIu64,
__wt_page_addr_string(session, ref, vs->tmp1),
recno, vs->record_total + 1);
break;
}
switch (page->type) {
case WT_PAGE_COL_FIX:
vs->record_total += page->pg_fix_entries;
break;
case WT_PAGE_COL_VAR:
recno = 0;
WT_COL_FOREACH(page, cip, i)
if ((cell = WT_COL_PTR(page, cip)) == NULL)
++recno;
else {
__wt_cell_unpack(cell, unpack);
recno += __wt_cell_rle(unpack);
}
vs->record_total += recno;
break;
}
/*
* Row-store leaf page key order check: it's a depth-first traversal,
* the first key on this page should be larger than any key previously
* seen.
*/
switch (page->type) {
case WT_PAGE_ROW_LEAF:
WT_RET(__verify_row_leaf_key_order(session, ref, vs));
break;
}
/* If it's not the root page, unpack the parent cell. */
if (!__wt_ref_is_root(ref)) {
__wt_cell_unpack(ref->addr, unpack);
/* Compare the parent cell against the page type. */
switch (page->type) {
case WT_PAGE_COL_FIX:
if (unpack->raw != WT_CELL_ADDR_LEAF_NO)
goto celltype_err;
break;
case WT_PAGE_COL_VAR:
if (unpack->raw != WT_CELL_ADDR_LEAF &&
unpack->raw != WT_CELL_ADDR_LEAF_NO)
goto celltype_err;
break;
case WT_PAGE_ROW_LEAF:
if (unpack->raw != WT_CELL_ADDR_DEL &&
unpack->raw != WT_CELL_ADDR_LEAF &&
unpack->raw != WT_CELL_ADDR_LEAF_NO)
goto celltype_err;
break;
case WT_PAGE_COL_INT:
case WT_PAGE_ROW_INT:
if (unpack->raw != WT_CELL_ADDR_INT)
celltype_err: WT_RET_MSG(session, WT_ERROR,
"page at %s, of type %s, is referenced in "
"its parent by a cell of type %s",
__wt_page_addr_string(
session, ref, vs->tmp1),
__wt_page_type_string(page->type),
__wt_cell_type_string(unpack->raw));
break;
}
}
/*
* Check overflow pages. We check overflow cells separately from other
* tests that walk the page as it's simpler, and I don't care much how
* fast table verify runs.
*/
switch (page->type) {
case WT_PAGE_COL_VAR:
case WT_PAGE_ROW_INT:
case WT_PAGE_ROW_LEAF:
WT_RET(__verify_overflow_cell(session, ref, &found, vs));
if (__wt_ref_is_root(ref) || page->type == WT_PAGE_ROW_INT)
break;
/*
* Object if a leaf-no-overflow address cell references a page
* with overflow keys, but don't object if a leaf address cell
* references a page without overflow keys. Reconciliation
* doesn't guarantee every leaf page without overflow items will
* be a leaf-no-overflow type.
*/
if (found && unpack->raw == WT_CELL_ADDR_LEAF_NO)
WT_RET_MSG(session, WT_ERROR,
"page at %s, of type %s and referenced in its "
"parent by a cell of type %s, contains overflow "
"items",
__wt_page_addr_string(session, ref, vs->tmp1),
__wt_page_type_string(page->type),
__wt_cell_type_string(WT_CELL_ADDR_LEAF_NO));
break;
}
/* Check tree connections and recursively descend the tree. */
switch (page->type) {
case WT_PAGE_COL_INT:
/* For each entry in an internal page, verify the subtree. */
entry = 0;
WT_INTL_FOREACH_BEGIN(session, page, child_ref) {
/*
* It's a depth-first traversal: this entry's starting
* record number should be 1 more than the total records
* reviewed to this point.
*/
++entry;
if (child_ref->key.recno != vs->record_total + 1) {
WT_RET_MSG(session, WT_ERROR,
"the starting record number in entry %"
PRIu32 " of the column internal page at "
"%s is %" PRIu64 " and the expected "
"starting record number is %" PRIu64,
entry,
__wt_page_addr_string(
session, child_ref, vs->tmp1),
child_ref->key.recno,
vs->record_total + 1);
}
/* Verify the subtree. */
++vs->depth;
WT_RET(__wt_page_in(session, child_ref, 0));
ret = __verify_tree(session, child_ref, vs);
WT_TRET(__wt_page_release(session, child_ref, 0));
--vs->depth;
WT_RET(ret);
__wt_cell_unpack(child_ref->addr, unpack);
WT_RET(bm->verify_addr(
bm, session, unpack->data, unpack->size));
} WT_INTL_FOREACH_END;
break;
case WT_PAGE_ROW_INT:
/* For each entry in an internal page, verify the subtree. */
entry = 0;
WT_INTL_FOREACH_BEGIN(session, page, child_ref) {
/*
* It's a depth-first traversal: this entry's starting
* key should be larger than the largest key previously
* reviewed.
*
* The 0th key of any internal page is magic, and we
* can't test against it.
*/
++entry;
if (entry != 1)
WT_RET(__verify_row_int_key_order(
session, page, child_ref, entry, vs));
/* Verify the subtree. */
++vs->depth;
WT_RET(__wt_page_in(session, child_ref, 0));
ret = __verify_tree(session, child_ref, vs);
WT_TRET(__wt_page_release(session, child_ref, 0));
--vs->depth;
WT_RET(ret);
__wt_cell_unpack(child_ref->addr, unpack);
WT_RET(bm->verify_addr(
bm, session, unpack->data, unpack->size));
} WT_INTL_FOREACH_END;
/*
* __wt_verify --
* Verify a file.
*/
int
__wt_verify(WT_SESSION_IMPL *session, const char *cfg[])
{
WT_BM *bm;
WT_BTREE *btree;
WT_CKPT *ckptbase, *ckpt;
WT_DECL_RET;
WT_VSTUFF *vs, _vstuff;
size_t root_addr_size;
uint8_t root_addr[WT_BTREE_MAX_ADDR_COOKIE];
bool bm_start, quit;
btree = S2BT(session);
bm = btree->bm;
ckptbase = NULL;
bm_start = false;
WT_CLEAR(_vstuff);
vs = &_vstuff;
WT_ERR(__wt_scr_alloc(session, 0, &vs->max_key));
WT_ERR(__wt_scr_alloc(session, 0, &vs->max_addr));
WT_ERR(__wt_scr_alloc(session, 0, &vs->tmp1));
WT_ERR(__wt_scr_alloc(session, 0, &vs->tmp2));
WT_ERR(__wt_scr_alloc(session, 0, &vs->tmp3));
WT_ERR(__wt_scr_alloc(session, 0, &vs->tmp4));
/* Check configuration strings. */
WT_ERR(__verify_config(session, cfg, vs));
/* Optionally dump specific block offsets. */
WT_ERR(__verify_config_offsets(session, cfg, &quit));
if (quit)
goto done;
/* Get a list of the checkpoints for this file. */
WT_ERR(
__wt_meta_ckptlist_get(session, btree->dhandle->name, &ckptbase));
/* Inform the underlying block manager we're verifying. */
WT_ERR(bm->verify_start(bm, session, ckptbase, cfg));
bm_start = true;
/* Loop through the file's checkpoints, verifying each one. */
WT_CKPT_FOREACH(ckptbase, ckpt) {
WT_ERR(__wt_verbose(session, WT_VERB_VERIFY,
"%s: checkpoint %s", btree->dhandle->name, ckpt->name));
/* Fake checkpoints require no work. */
if (F_ISSET(ckpt, WT_CKPT_FAKE))
continue;
/* House-keeping between checkpoints. */
__verify_checkpoint_reset(vs);
if (WT_VRFY_DUMP(vs))
WT_ERR(__wt_msg(session, "%s: checkpoint %s",
btree->dhandle->name, ckpt->name));
/* Load the checkpoint. */
WT_ERR(bm->checkpoint_load(bm, session,
ckpt->raw.data, ckpt->raw.size,
root_addr, &root_addr_size, true));
/*
* Ignore trees with no root page.
* Verify, then discard the checkpoint from the cache.
*/
if (root_addr_size != 0 &&
(ret = __wt_btree_tree_open(
session, root_addr, root_addr_size)) == 0) {
if (WT_VRFY_DUMP(vs))
WT_ERR(__wt_msg(session, "Root: %s %s",
__wt_addr_string(session,
root_addr, root_addr_size, vs->tmp1),
__wt_page_type_string(
btree->root.page->type)));
WT_WITH_PAGE_INDEX(session,
ret = __verify_tree(session, &btree->root, vs));
WT_TRET(__wt_cache_op(session, WT_SYNC_DISCARD));
}
/* Unload the checkpoint. */
WT_TRET(bm->checkpoint_unload(bm, session));
WT_ERR(ret);
/* Display the tree shape. */
if (vs->dump_shape)
WT_ERR(__verify_tree_shape(session, vs));
}
/*
* __ovfl_reuse_wrapup --
* Resolve the page's overflow reuse list after a page is written.
*/
static int
__ovfl_reuse_wrapup(WT_SESSION_IMPL *session, WT_PAGE *page)
{
WT_BM *bm;
WT_OVFL_REUSE **e, **head, *reuse;
size_t decr;
int i;
bm = S2BT(session)->bm;
head = page->modify->ovfl_track->ovfl_reuse;
/*
* Discard any overflow records that aren't in-use, freeing underlying
* blocks.
*
* First, walk the overflow reuse lists (except for the lowest one),
* fixing up skiplist links.
*/
for (i = WT_SKIP_MAXDEPTH - 1; i > 0; --i)
for (e = &head[i]; (reuse = *e) != NULL;) {
if (F_ISSET(reuse, WT_OVFL_REUSE_INUSE)) {
e = &reuse->next[i];
continue;
}
*e = reuse->next[i];
}
/*
* Second, discard any overflow record without an in-use flag, clear
* the flags for the next run.
*
* As part of the pass through the lowest level, figure out how much
* space we added/subtracted from the page, and update its footprint.
* We don't get it exactly correct because we don't know the depth of
* the skiplist here, but it's close enough, and figuring out the
* memory footprint change in the reconciliation wrapup code means
* fewer atomic updates and less code overall.
*/
decr = 0;
for (e = &head[0]; (reuse = *e) != NULL;) {
if (F_ISSET(reuse, WT_OVFL_REUSE_INUSE)) {
F_CLR(reuse,
WT_OVFL_REUSE_INUSE | WT_OVFL_REUSE_JUST_ADDED);
e = &reuse->next[0];
continue;
}
*e = reuse->next[0];
WT_ASSERT(session, !F_ISSET(reuse, WT_OVFL_REUSE_JUST_ADDED));
if (WT_VERBOSE_ISSET(session, WT_VERB_OVERFLOW))
WT_RET(
__ovfl_reuse_verbose(session, page, reuse, "free"));
WT_RET(bm->free(
bm, session, WT_OVFL_REUSE_ADDR(reuse), reuse->addr_size));
decr += WT_OVFL_SIZE(reuse, WT_OVFL_REUSE);
__wt_free(session, reuse);
}
if (decr != 0)
__wt_cache_page_inmem_decr(session, page, decr);
return (0);
}
/*
* __wt_compact --
* Compact a file.
*/
int
__wt_compact(WT_SESSION_IMPL *session, const char *cfg[])
{
WT_BM *bm;
WT_BTREE *btree;
WT_DECL_RET;
WT_REF *ref;
bool block_manager_begin, skip;
WT_UNUSED(cfg);
btree = S2BT(session);
bm = btree->bm;
ref = NULL;
block_manager_begin = false;
WT_STAT_FAST_DATA_INCR(session, session_compact);
/*
* Check if compaction might be useful -- the API layer will quit trying
* to compact the data source if we make no progress, set a flag if the
* block layer thinks compaction is possible.
*/
WT_RET(bm->compact_skip(bm, session, &skip));
if (skip)
return (0);
/*
* Reviewing in-memory pages requires looking at page reconciliation
* results, because we care about where the page is stored now, not
* where the page was stored when we first read it into the cache.
* We need to ensure we don't race with page reconciliation as it's
* writing the page modify information.
*
* There are three ways we call reconciliation: checkpoints, threads
* writing leaf pages (usually in preparation for a checkpoint or if
* closing a file), and eviction.
*
* We're holding the schema lock which serializes with checkpoints.
*/
WT_ASSERT(session, F_ISSET(session, WT_SESSION_LOCKED_SCHEMA));
/*
* Get the tree handle's flush lock which blocks threads writing leaf
* pages.
*/
__wt_spin_lock(session, &btree->flush_lock);
/* Start compaction. */
WT_ERR(bm->compact_start(bm, session));
block_manager_begin = true;
/* Walk the tree reviewing pages to see if they should be re-written. */
for (;;) {
/*
* Pages read for compaction aren't "useful"; don't update the
* read generation of pages already in memory, and if a page is
* read, set its generation to a low value so it is evicted
* quickly.
*/
WT_ERR(__wt_tree_walk(session, &ref,
WT_READ_COMPACT | WT_READ_NO_GEN | WT_READ_WONT_NEED));
if (ref == NULL)
break;
WT_ERR(__compact_rewrite(session, ref, &skip));
if (skip)
continue;
session->compact_state = WT_COMPACT_SUCCESS;
/* Rewrite the page: mark the page and tree dirty. */
WT_ERR(__wt_page_modify_init(session, ref->page));
__wt_page_modify_set(session, ref->page);
WT_STAT_FAST_DATA_INCR(session, btree_compact_rewrite);
}
err:
if (ref != NULL)
WT_TRET(__wt_page_release(session, ref, 0));
if (block_manager_begin)
WT_TRET(bm->compact_end(bm, session));
/* Unblock threads writing leaf pages. */
__wt_spin_unlock(session, &btree->flush_lock);
return (ret);
}
/*
* __wt_bt_read --
* Read a cookie referenced block into a buffer.
*/
int
__wt_bt_read(WT_SESSION_IMPL *session,
WT_ITEM *buf, const uint8_t *addr, size_t addr_size)
{
WT_BM *bm;
WT_BTREE *btree;
WT_DECL_ITEM(tmp);
WT_DECL_RET;
const WT_PAGE_HEADER *dsk;
size_t result_len;
btree = S2BT(session);
bm = btree->bm;
/*
* If anticipating a compressed block, read into a scratch buffer and
* decompress into the caller's buffer. Else, read directly into the
* caller's buffer.
*/
if (btree->compressor == NULL) {
WT_RET(bm->read(bm, session, buf, addr, addr_size));
dsk = buf->data;
} else {
WT_RET(__wt_scr_alloc(session, 0, &tmp));
WT_ERR(bm->read(bm, session, tmp, addr, addr_size));
dsk = tmp->data;
}
/*
* If the block is compressed, copy the skipped bytes of the original
* image into place, then decompress.
*/
if (F_ISSET(dsk, WT_PAGE_COMPRESSED)) {
if (btree->compressor == NULL ||
btree->compressor->decompress == NULL)
WT_ERR_MSG(session, WT_ERROR,
"read compressed block where no compression engine "
"configured");
/*
* We're allocating the exact number of bytes we're expecting
* from decompression.
*/
WT_ERR(__wt_buf_initsize(session, buf, dsk->mem_size));
/*
* Note the source length is NOT the number of compressed bytes,
* it's the length of the block we just read (minus the skipped
* bytes). We don't store the number of compressed bytes: some
* compression engines need that length stored externally, they
* don't have markers in the stream to signal the end of the
* compressed bytes. Those engines must store the compressed
* byte length somehow, see the snappy compression extension for
* an example.
*/
memcpy(buf->mem, tmp->data, WT_BLOCK_COMPRESS_SKIP);
ret = btree->compressor->decompress(
btree->compressor, &session->iface,
(uint8_t *)tmp->data + WT_BLOCK_COMPRESS_SKIP,
tmp->size - WT_BLOCK_COMPRESS_SKIP,
(uint8_t *)buf->mem + WT_BLOCK_COMPRESS_SKIP,
dsk->mem_size - WT_BLOCK_COMPRESS_SKIP, &result_len);
/*
* If checksums were turned off because we're depending on the
* decompression to fail on any corrupted data, we'll end up
* here after corruption happens. If we're salvaging the file,
* it's OK, otherwise it's really, really bad.
*/
if (ret != 0 ||
result_len != dsk->mem_size - WT_BLOCK_COMPRESS_SKIP)
WT_ERR(
F_ISSET(btree, WT_BTREE_VERIFY) ||
F_ISSET(session, WT_SESSION_SALVAGE_CORRUPT_OK) ?
WT_ERROR :
__wt_illegal_value(session, btree->dhandle->name));
} else
if (btree->compressor == NULL)
buf->size = dsk->mem_size;
else
/*
* We guessed wrong: there was a compressor, but this
* block was not compressed, and now the page is in the
* wrong buffer and the buffer may be of the wrong size.
* This should be rare, but happens with small blocks
* that aren't worth compressing.
*/
WT_ERR(__wt_buf_set(
session, buf, tmp->data, dsk->mem_size));
/* If the handle is a verify handle, verify the physical page. */
if (F_ISSET(btree, WT_BTREE_VERIFY)) {
if (tmp == NULL)
WT_ERR(__wt_scr_alloc(session, 0, &tmp));
WT_ERR(bm->addr_string(bm, session, tmp, addr, addr_size));
WT_ERR(__wt_verify_dsk(session, (const char *)tmp->data, buf));
}
WT_STAT_FAST_CONN_INCR(session, cache_read);
WT_STAT_FAST_DATA_INCR(session, cache_read);
if (F_ISSET(dsk, WT_PAGE_COMPRESSED))
WT_STAT_FAST_DATA_INCR(session, compress_read);
WT_STAT_FAST_CONN_INCRV(session, cache_bytes_read, dsk->mem_size);
WT_STAT_FAST_DATA_INCRV(session, cache_bytes_read, dsk->mem_size);
err: __wt_scr_free(session, &tmp);
return (ret);
}
/*
* __compact_rewrite --
* Return if a page needs to be re-written.
*/
static int
__compact_rewrite(WT_SESSION_IMPL *session, WT_REF *ref, bool *skipp)
{
WT_BM *bm;
WT_DECL_RET;
WT_MULTI *multi;
WT_PAGE *page;
WT_PAGE_MODIFY *mod;
size_t addr_size;
uint32_t i;
const uint8_t *addr;
*skipp = true; /* Default skip. */
bm = S2BT(session)->bm;
page = ref->page;
mod = page->modify;
/*
* Ignore the root: it may not have a replacement address, and besides,
* if anything else gets written, so will it.
*/
if (__wt_ref_is_root(ref))
return (0);
/* Ignore currently dirty pages, they will be written regardless. */
if (__wt_page_is_modified(page))
return (0);
/*
* If the page is clean, test the original addresses.
* If the page is a replacement, test the replacement addresses.
* Ignore empty pages, they get merged into the parent.
*/
if (mod == NULL || mod->rec_result == 0) {
__wt_ref_info(ref, &addr, &addr_size, NULL);
if (addr == NULL)
return (0);
return (
bm->compact_page_skip(bm, session, addr, addr_size, skipp));
}
/*
* The page's modification information can change underfoot if the page
* is being reconciled, serialize with reconciliation.
*/
if (mod->rec_result == WT_PM_REC_REPLACE ||
mod->rec_result == WT_PM_REC_MULTIBLOCK)
WT_RET(__wt_fair_lock(session, &page->page_lock));
if (mod->rec_result == WT_PM_REC_REPLACE)
ret = bm->compact_page_skip(bm, session,
mod->mod_replace.addr, mod->mod_replace.size, skipp);
if (mod->rec_result == WT_PM_REC_MULTIBLOCK)
for (multi = mod->mod_multi,
i = 0; i < mod->mod_multi_entries; ++multi, ++i) {
if (multi->disk_image != NULL)
continue;
if ((ret = bm->compact_page_skip(bm, session,
multi->addr.addr, multi->addr.size, skipp)) != 0)
break;
if (!*skipp)
break;
}
if (mod->rec_result == WT_PM_REC_REPLACE ||
mod->rec_result == WT_PM_REC_MULTIBLOCK)
WT_TRET(__wt_fair_unlock(session, &page->page_lock));
return (ret);
}
/*
* __verify_dsk_row --
* Walk a WT_PAGE_ROW_INT or WT_PAGE_ROW_LEAF disk page and verify it.
*/
static int
__verify_dsk_row(
WT_SESSION_IMPL *session, const char *tag, const WT_PAGE_HEADER *dsk)
{
WT_BM *bm;
WT_BTREE *btree;
WT_CELL *cell;
WT_CELL_UNPACK *unpack, _unpack;
WT_DECL_ITEM(current);
WT_DECL_ITEM(last_ovfl);
WT_DECL_ITEM(last_pfx);
WT_DECL_RET;
WT_ITEM *last;
enum { FIRST, WAS_KEY, WAS_VALUE } last_cell_type;
void *huffman;
uint32_t cell_num, cell_type, i, key_cnt, prefix;
uint8_t *end;
int cmp;
btree = S2BT(session);
bm = btree->bm;
unpack = &_unpack;
huffman = dsk->type == WT_PAGE_ROW_INT ? NULL : btree->huffman_key;
WT_ERR(__wt_scr_alloc(session, 0, ¤t));
WT_ERR(__wt_scr_alloc(session, 0, &last_pfx));
WT_ERR(__wt_scr_alloc(session, 0, &last_ovfl));
last = last_ovfl;
end = (uint8_t *)dsk + dsk->mem_size;
last_cell_type = FIRST;
cell_num = 0;
key_cnt = 0;
WT_CELL_FOREACH(btree, dsk, cell, unpack, i) {
++cell_num;
/* Carefully unpack the cell. */
if (__wt_cell_unpack_safe(cell, unpack, end) != 0) {
ret = __err_cell_corrupted(session, cell_num, tag);
goto err;
}
/* Check the raw and collapsed cell types. */
WT_ERR(__err_cell_type(
session, cell_num, tag, unpack->raw, dsk->type));
WT_ERR(__err_cell_type(
session, cell_num, tag, unpack->type, dsk->type));
cell_type = unpack->type;
/*
* Check ordering relationships between the WT_CELL entries.
* For row-store internal pages, check for:
* two values in a row,
* two keys in a row,
* a value as the first cell on a page.
* For row-store leaf pages, check for:
* two values in a row,
* a value as the first cell on a page.
*/
switch (cell_type) {
case WT_CELL_KEY:
case WT_CELL_KEY_OVFL:
++key_cnt;
switch (last_cell_type) {
case FIRST:
case WAS_VALUE:
break;
case WAS_KEY:
if (dsk->type == WT_PAGE_ROW_LEAF)
break;
WT_ERR_VRFY(session,
"cell %" PRIu32 " on page at %s is the "
"first of two adjacent keys",
cell_num - 1, tag);
}
last_cell_type = WAS_KEY;
break;
case WT_CELL_ADDR_DEL:
case WT_CELL_ADDR_INT:
case WT_CELL_ADDR_LEAF:
case WT_CELL_ADDR_LEAF_NO:
case WT_CELL_VALUE:
case WT_CELL_VALUE_OVFL:
switch (last_cell_type) {
case FIRST:
WT_ERR_VRFY(session,
"page at %s begins with a value", tag);
case WAS_KEY:
break;
case WAS_VALUE:
WT_ERR_VRFY(session,
"cell %" PRIu32 " on page at %s is the "
"first of two adjacent values",
cell_num - 1, tag);
}
last_cell_type = WAS_VALUE;
break;
}
/* Check if any referenced item has a valid address. */
switch (cell_type) {
case WT_CELL_ADDR_DEL:
case WT_CELL_ADDR_INT:
case WT_CELL_ADDR_LEAF:
case WT_CELL_ADDR_LEAF_NO:
case WT_CELL_KEY_OVFL:
case WT_CELL_VALUE_OVFL:
if (!bm->addr_valid(bm,
session, unpack->data, unpack->size))
goto eof;
break;
}
/*
* Remaining checks are for key order and prefix compression.
* If this cell isn't a key, we're done, move to the next cell.
* If this cell is an overflow item, instantiate the key and
* compare it with the last key. Otherwise, we have to deal with
* prefix compression.
*/
switch (cell_type) {
case WT_CELL_KEY:
break;
case WT_CELL_KEY_OVFL:
WT_ERR(__wt_dsk_cell_data_ref(
session, dsk->type, unpack, current));
goto key_compare;
default:
/* Not a key -- continue with the next cell. */
continue;
}
/*
* Prefix compression checks.
*
* Confirm the first non-overflow key on a page has a zero
* prefix compression count.
*/
prefix = unpack->prefix;
if (last_pfx->size == 0 && prefix != 0)
WT_ERR_VRFY(session,
"the %" PRIu32 " key on page at %s is the first "
"non-overflow key on the page and has a non-zero "
"prefix compression value",
cell_num, tag);
/* Confirm the prefix compression count is possible. */
if (cell_num > 1 && prefix > last->size)
WT_ERR_VRFY(session,
"key %" PRIu32 " on page at %s has a prefix "
"compression count of %" PRIu32 ", larger than "
"the length of the previous key, %" WT_SIZET_FMT,
cell_num, tag, prefix, last->size);
/*
* If Huffman decoding required, unpack the cell to build the
* key, then resolve the prefix. Else, we can do it faster
* internally because we don't have to shuffle memory around as
* much.
*/
if (huffman != NULL) {
WT_ERR(__wt_dsk_cell_data_ref(
session, dsk->type, unpack, current));
/*
* If there's a prefix, make sure there's enough buffer
* space, then shift the decoded data past the prefix
* and copy the prefix into place. Take care with the
* pointers: current->data may be pointing inside the
* buffer.
*/
if (prefix != 0) {
WT_ERR(__wt_buf_grow(
session, current, prefix + current->size));
memmove((uint8_t *)current->mem + prefix,
current->data, current->size);
memcpy(current->mem, last->data, prefix);
current->data = current->mem;
current->size += prefix;
}
} else {
/*
* Get the cell's data/length and make sure we have
* enough buffer space.
*/
WT_ERR(__wt_buf_init(
session, current, prefix + unpack->size));
/* Copy the prefix then the data into place. */
if (prefix != 0)
memcpy(current->mem, last->data, prefix);
memcpy((uint8_t *)current->mem + prefix, unpack->data,
unpack->size);
current->size = prefix + unpack->size;
}
key_compare: /*
* Compare the current key against the last key.
*
* Be careful about the 0th key on internal pages: we only store
* the first byte and custom collators may not be able to handle
* truncated keys.
*/
if ((dsk->type == WT_PAGE_ROW_INT && cell_num > 3) ||
(dsk->type != WT_PAGE_ROW_INT && cell_num > 1)) {
WT_ERR(__wt_compare(
session, btree->collator, last, current, &cmp));
if (cmp >= 0)
WT_ERR_VRFY(session,
"the %" PRIu32 " and %" PRIu32 " keys on "
"page at %s are incorrectly sorted",
cell_num - 2, cell_num, tag);
}
/*
* Swap the buffers: last always references the last key entry,
* last_pfx and last_ovfl reference the last prefix-compressed
* and last overflow key entries. Current gets pointed to the
* buffer we're not using this time around, which is where the
* next key goes.
*/
last = current;
if (cell_type == WT_CELL_KEY) {
current = last_pfx;
last_pfx = last;
} else {
current = last_ovfl;
last_ovfl = last;
}
WT_ASSERT(session, last != current);
}
/*
* __meta_track_apply --
* Apply the changes in a metadata tracking record.
*/
static int
__meta_track_apply(WT_SESSION_IMPL *session, WT_META_TRACK *trk, int unroll)
{
WT_BM *bm;
WT_BTREE *btree;
WT_DECL_RET;
int tret;
/*
* Unlock handles and complete checkpoints regardless of whether we are
* unrolling.
*/
if (!unroll && trk->op != WT_ST_CHECKPOINT && trk->op != WT_ST_LOCK)
goto free;
switch (trk->op) {
case WT_ST_EMPTY: /* Unused slot */
break;
case WT_ST_CHECKPOINT: /* Checkpoint, see above */
if (!unroll) {
btree = trk->dhandle->handle;
bm = btree->bm;
WT_WITH_DHANDLE(session, trk->dhandle,
WT_TRET(bm->checkpoint_resolve(bm, session)));
}
break;
case WT_ST_LOCK: /* Handle lock, see above */
if (unroll && trk->created)
F_SET(trk->dhandle, WT_DHANDLE_DISCARD);
WT_WITH_DHANDLE(session, trk->dhandle,
WT_TRET(__wt_session_release_btree(session)));
break;
case WT_ST_FILEOP: /* File operation */
/*
* For renames, both a and b are set.
* For creates, a is NULL.
* For removes, b is NULL.
*/
if (trk->a != NULL && trk->b != NULL &&
(tret = __wt_rename(session,
trk->b + strlen("file:"),
trk->a + strlen("file:"))) != 0) {
__wt_err(session, tret,
"metadata unroll rename %s to %s",
trk->b, trk->a);
WT_TRET(tret);
} else if (trk->a == NULL) {
if ((tret = __wt_remove(session,
trk->b + strlen("file:"))) != 0) {
__wt_err(session, tret,
"metadata unroll create %s",
trk->b);
WT_TRET(tret);
}
}
/*
* We can't undo removes yet: that would imply
* some kind of temporary rename and remove in
* roll forward.
*/
break;
case WT_ST_REMOVE: /* Remove trk.a */
if ((tret = __wt_metadata_remove(session, trk->a)) != 0) {
__wt_err(session, tret,
"metadata unroll remove: %s",
trk->a);
WT_TRET(tret);
}
break;
case WT_ST_SET: /* Set trk.a to trk.b */
if ((tret = __wt_metadata_update(
session, trk->a, trk->b)) != 0) {
__wt_err(session, tret,
"metadata unroll update %s to %s",
trk->a, trk->b);
WT_TRET(tret);
}
break;
WT_ILLEGAL_VALUE(session);
}
free: trk->op = WT_ST_EMPTY;
__wt_free(session, trk->a);
__wt_free(session, trk->b);
trk->dhandle = NULL;
return (ret);
}