diff options
Diffstat (limited to 'src/backend/access/nbtree/nbtsort.c')
| -rw-r--r-- | src/backend/access/nbtree/nbtsort.c | 103 |
1 files changed, 57 insertions, 46 deletions
diff --git a/src/backend/access/nbtree/nbtsort.c b/src/backend/access/nbtree/nbtsort.c index e9224a485a..2aca6bf7cf 100644 --- a/src/backend/access/nbtree/nbtsort.c +++ b/src/backend/access/nbtree/nbtsort.c @@ -6,7 +6,7 @@ * * We use tuplesort.c to sort the given index tuples into order. * Then we scan the index tuples in order and build the btree pages - * for each level. We load source tuples into leaf-level pages. + * for each level. We load source tuples into leaf-level pages. * Whenever we fill a page at one level, we add a link to it to its * parent level (starting a new parent level if necessary). When * done, we write out each final page on each level, adding it to @@ -35,7 +35,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtsort.c,v 1.59 2001/01/24 19:42:49 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtsort.c,v 1.60 2001/03/22 03:59:15 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -57,7 +57,7 @@ struct BTSpool }; /* - * Status record for a btree page being built. We have one of these + * Status record for a btree page being built. We have one of these * for each active tree level. * * The reason we need to store a copy of the minimum key is that we'll @@ -73,11 +73,13 @@ typedef struct BTPageState { Buffer btps_buf; /* current buffer & page */ Page btps_page; - BTItem btps_minkey; /* copy of minimum key (first item) on page */ + BTItem btps_minkey; /* copy of minimum key (first item) on + * page */ OffsetNumber btps_lastoff; /* last item offset loaded */ int btps_level; /* tree level (0 = leaf) */ - Size btps_full; /* "full" if less than this much free space */ - struct BTPageState *btps_next; /* link to parent level, if any */ + Size btps_full; /* "full" if less than this much free + * space */ + struct BTPageState *btps_next; /* link to parent level, if any */ } BTPageState; @@ -92,7 +94,7 @@ static void _bt_blnewpage(Relation index, Buffer *buf, Page *page, int flags); static BTPageState *_bt_pagestate(Relation index, int flags, int level); static void _bt_slideleft(Relation index, Buffer buf, Page page); static void _bt_sortaddtup(Page page, Size itemsize, - BTItem btitem, OffsetNumber itup_off); + BTItem btitem, OffsetNumber itup_off); static void _bt_buildadd(Relation index, BTPageState *state, BTItem bti); static void _bt_uppershutdown(Relation index, BTPageState *state); static void _bt_load(Relation index, BTSpool *btspool, BTSpool *btspool2); @@ -162,7 +164,7 @@ _bt_leafbuild(BTSpool *btspool, BTSpool *btspool2) ShowUsage(); ResetUsage(); } -#endif /* BTREE_BUILD_STATS */ +#endif /* BTREE_BUILD_STATS */ tuplesort_performsort(btspool->sortstate); if (btspool2) @@ -269,9 +271,9 @@ _bt_sortaddtup(Page page, OffsetNumber itup_off) { BTPageOpaque opaque = (BTPageOpaque) PageGetSpecialPointer(page); - BTItemData truncitem; + BTItemData truncitem; - if (! P_ISLEAF(opaque) && itup_off == P_FIRSTKEY) + if (!P_ISLEAF(opaque) && itup_off == P_FIRSTKEY) { memcpy(&truncitem, btitem, sizeof(BTItemData)); truncitem.bti_itup.t_info = sizeof(BTItemData); @@ -290,7 +292,7 @@ _bt_sortaddtup(Page page, * We must be careful to observe the page layout conventions of nbtsearch.c: * - rightmost pages start data items at P_HIKEY instead of at P_FIRSTKEY. * - on non-leaf pages, the key portion of the first item need not be - * stored, we should store only the link. + * stored, we should store only the link. * * A leaf page being built looks like: * @@ -347,11 +349,12 @@ _bt_buildadd(Relation index, BTPageState *state, BTItem bti) */ if (btisz > (PageGetPageSize(npage) - sizeof(PageHeaderData) - MAXALIGN(sizeof(BTPageOpaqueData))) / 3 - sizeof(ItemIdData)) elog(ERROR, "btree: index item size %lu exceeds maximum %ld", - (unsigned long)btisz, - (PageGetPageSize(npage) - sizeof(PageHeaderData) - MAXALIGN(sizeof(BTPageOpaqueData))) /3 - sizeof(ItemIdData)); + (unsigned long) btisz, + (PageGetPageSize(npage) - sizeof(PageHeaderData) - MAXALIGN(sizeof(BTPageOpaqueData))) / 3 - sizeof(ItemIdData)); if (pgspc < btisz || pgspc < state->btps_full) { + /* * Item won't fit on this page, or we feel the page is full enough * already. Finish off the page and write it out. @@ -388,9 +391,9 @@ _bt_buildadd(Relation index, BTPageState *state, BTItem bti) ((PageHeader) opage)->pd_lower -= sizeof(ItemIdData); /* - * Link the old buffer into its parent, using its minimum key. - * If we don't have a parent, we have to create one; - * this adds a new btree level. + * Link the old buffer into its parent, using its minimum key. If + * we don't have a parent, we have to create one; this adds a new + * btree level. */ if (state->btps_next == (BTPageState *) NULL) { @@ -405,8 +408,8 @@ _bt_buildadd(Relation index, BTPageState *state, BTItem bti) /* * Save a copy of the minimum key for the new page. We have to - * copy it off the old page, not the new one, in case we are - * not at leaf level. + * copy it off the old page, not the new one, in case we are not + * at leaf level. */ state->btps_minkey = _bt_formitem(&(obti->bti_itup)); @@ -414,13 +417,13 @@ _bt_buildadd(Relation index, BTPageState *state, BTItem bti) * Set the sibling links for both pages, and parent links too. * * It's not necessary to set the parent link at all, because it's - * only used for handling concurrent root splits, but we may as well - * do it as a debugging aid. Note we set new page's link as well - * as old's, because if the new page turns out to be the last of - * the level, _bt_uppershutdown won't change it. The links may be - * out of date by the time the build finishes, but that's OK; they - * need only point to a left-sibling of the true parent. See the - * README file for more info. + * only used for handling concurrent root splits, but we may as + * well do it as a debugging aid. Note we set new page's link as + * well as old's, because if the new page turns out to be the last + * of the level, _bt_uppershutdown won't change it. The links may + * be out of date by the time the build finishes, but that's OK; + * they need only point to a left-sibling of the true parent. See + * the README file for more info. */ { BTPageOpaque oopaque = (BTPageOpaque) PageGetSpecialPointer(opage); @@ -434,7 +437,7 @@ _bt_buildadd(Relation index, BTPageState *state, BTItem bti) } /* - * Write out the old page. We never want to see it again, so we + * Write out the old page. We never want to see it again, so we * can give up our lock (if we had one; most likely BuildingBtree * is set, so we aren't locking). */ @@ -449,8 +452,8 @@ _bt_buildadd(Relation index, BTPageState *state, BTItem bti) /* * If the new item is the first for its page, stash a copy for later. * Note this will only happen for the first item on a level; on later - * pages, the first item for a page is copied from the prior page - * in the code above. + * pages, the first item for a page is copied from the prior page in + * the code above. */ if (last_off == P_HIKEY) { @@ -493,8 +496,8 @@ _bt_uppershutdown(Relation index, BTPageState *state) * * If we're at the top, it's the root, so attach it to the metapage. * Otherwise, add an entry for it to its parent using its minimum - * key. This may cause the last page of the parent level to split, - * but that's not a problem -- we haven't gotten to it yet. + * key. This may cause the last page of the parent level to + * split, but that's not a problem -- we haven't gotten to it yet. */ if (s->btps_next == (BTPageState *) NULL) { @@ -513,7 +516,7 @@ _bt_uppershutdown(Relation index, BTPageState *state) /* * This is the rightmost page, so the ItemId array needs to be - * slid back one slot. Then we can dump out the page. + * slid back one slot. Then we can dump out the page. */ _bt_slideleft(index, s->btps_buf, s->btps_page); _bt_wrtbuf(index, s->btps_buf); @@ -529,22 +532,29 @@ _bt_load(Relation index, BTSpool *btspool, BTSpool *btspool2) { BTPageState *state = NULL; bool merge = (btspool2 != NULL); - BTItem bti, bti2 = NULL; - bool should_free, should_free2, load1; + BTItem bti, + bti2 = NULL; + bool should_free, + should_free2, + load1; TupleDesc tupdes = RelationGetDescr(index); - int i, keysz = RelationGetNumberOfAttributes(index); + int i, + keysz = RelationGetNumberOfAttributes(index); ScanKey indexScanKey = NULL; if (merge) { + /* - * Another BTSpool for dead tuples exists. - * Now we have to merge btspool and btspool2. - */ - ScanKey entry; - Datum attrDatum1, attrDatum2; - bool isFirstNull, isSecondNull; - int32 compare; + * Another BTSpool for dead tuples exists. Now we have to merge + * btspool and btspool2. + */ + ScanKey entry; + Datum attrDatum1, + attrDatum2; + bool isFirstNull, + isSecondNull; + int32 compare; /* the preparation of merge */ bti = (BTItem) tuplesort_getindextuple(btspool->sortstate, true, &should_free); @@ -552,7 +562,7 @@ _bt_load(Relation index, BTSpool *btspool, BTSpool *btspool2) indexScanKey = _bt_mkscankey_nodata(index); for (;;) { - load1 = true; /* load BTSpool next ? */ + load1 = true; /* load BTSpool next ? */ if (NULL == bti2) { if (NULL == bti) @@ -564,8 +574,8 @@ _bt_load(Relation index, BTSpool *btspool, BTSpool *btspool2) for (i = 1; i <= keysz; i++) { entry = indexScanKey + i - 1; - attrDatum1 = index_getattr((IndexTuple)bti, i, tupdes, &isFirstNull); - attrDatum2 = index_getattr((IndexTuple)bti2, i, tupdes, &isSecondNull); + attrDatum1 = index_getattr((IndexTuple) bti, i, tupdes, &isFirstNull); + attrDatum2 = index_getattr((IndexTuple) bti2, i, tupdes, &isSecondNull); if (isFirstNull) { if (!isSecondNull) @@ -586,7 +596,7 @@ _bt_load(Relation index, BTSpool *btspool, BTSpool *btspool2) } else if (compare < 0) break; - } + } } } else @@ -613,7 +623,8 @@ _bt_load(Relation index, BTSpool *btspool, BTSpool *btspool2) } _bt_freeskey(indexScanKey); } - else /* merge is unnecessary */ + else +/* merge is unnecessary */ { while (bti = (BTItem) tuplesort_getindextuple(btspool->sortstate, true, &should_free), bti != (BTItem) NULL) { |