1 files changed, 367 insertions, 0 deletions
diff --git a/src/backend/access/brin/brin_xlog.c b/src/backend/access/brin/brin_xlog.c
new file mode 100644
index 0000000..3519038
--- /dev/null
+++ b/src/backend/access/brin/brin_xlog.c
@@ -0,0 +1,367 @@
+/*
+ * brin_xlog.c
+ *		XLog replay routines for BRIN indexes
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/backend/access/brin/brin_xlog.c
+ */
+#include "postgres.h"
+
+#include "access/brin_page.h"
+#include "access/brin_pageops.h"
+#include "access/brin_xlog.h"
+#include "access/bufmask.h"
+#include "access/xlogutils.h"
+
+
+/*
+ * xlog replay routines
+ */
+static void
+brin_xlog_createidx(XLogReaderState *record)
+{
+	XLogRecPtr	lsn = record->EndRecPtr;
+	xl_brin_createidx *xlrec = (xl_brin_createidx *) XLogRecGetData(record);
+	Buffer		buf;
+	Page		page;
+
+	/* create the index' metapage */
+	buf = XLogInitBufferForRedo(record, 0);
+	Assert(BufferIsValid(buf));
+	page = (Page) BufferGetPage(buf);
+	brin_metapage_init(page, xlrec->pagesPerRange, xlrec->version);
+	PageSetLSN(page, lsn);
+	MarkBufferDirty(buf);
+	UnlockReleaseBuffer(buf);
+}
+
+/*
+ * Common part of an insert or update. Inserts the new tuple and updates the
+ * revmap.
+ */
+static void
+brin_xlog_insert_update(XLogReaderState *record,
+						xl_brin_insert *xlrec)
+{
+	XLogRecPtr	lsn = record->EndRecPtr;
+	Buffer		buffer;
+	BlockNumber regpgno;
+	Page		page;
+	XLogRedoAction action;
+
+	/*
+	 * If we inserted the first and only tuple on the page, re-initialize the
+	 * page from scratch.
+	 */
+	if (XLogRecGetInfo(record) & XLOG_BRIN_INIT_PAGE)
+	{
+		buffer = XLogInitBufferForRedo(record, 0);
+		page = BufferGetPage(buffer);
+		brin_page_init(page, BRIN_PAGETYPE_REGULAR);
+		action = BLK_NEEDS_REDO;
+	}
+	else
+	{
+		action = XLogReadBufferForRedo(record, 0, &buffer);
+	}
+
+	/* need this page's blkno to store in revmap */
+	regpgno = BufferGetBlockNumber(buffer);
+
+	/* insert the index item into the page */
+	if (action == BLK_NEEDS_REDO)
+	{
+		OffsetNumber offnum;
+		BrinTuple  *tuple;
+		Size		tuplen;
+
+		tuple = (BrinTuple *) XLogRecGetBlockData(record, 0, &tuplen);
+
+		Assert(tuple->bt_blkno == xlrec->heapBlk);
+
+		page = (Page) BufferGetPage(buffer);
+		offnum = xlrec->offnum;
+		if (PageGetMaxOffsetNumber(page) + 1 < offnum)
+			elog(PANIC, "brin_xlog_insert_update: invalid max offset number");
+
+		offnum = PageAddItem(page, (Item) tuple, tuplen, offnum, true, false);
+		if (offnum == InvalidOffsetNumber)
+			elog(PANIC, "brin_xlog_insert_update: failed to add tuple");
+
+		PageSetLSN(page, lsn);
+		MarkBufferDirty(buffer);
+	}
+	if (BufferIsValid(buffer))
+		UnlockReleaseBuffer(buffer);
+
+	/* update the revmap */
+	action = XLogReadBufferForRedo(record, 1, &buffer);
+	if (action == BLK_NEEDS_REDO)
+	{
+		ItemPointerData tid;
+
+		ItemPointerSet(&tid, regpgno, xlrec->offnum);
+		page = (Page) BufferGetPage(buffer);
+
+		brinSetHeapBlockItemptr(buffer, xlrec->pagesPerRange, xlrec->heapBlk,
+								tid);
+		PageSetLSN(page, lsn);
+		MarkBufferDirty(buffer);
+	}
+	if (BufferIsValid(buffer))
+		UnlockReleaseBuffer(buffer);
+
+	/* XXX no FSM updates here ... */
+}
+
+/*
+ * replay a BRIN index insertion
+ */
+static void
+brin_xlog_insert(XLogReaderState *record)
+{
+	xl_brin_insert *xlrec = (xl_brin_insert *) XLogRecGetData(record);
+
+	brin_xlog_insert_update(record, xlrec);
+}
+
+/*
+ * replay a BRIN index update
+ */
+static void
+brin_xlog_update(XLogReaderState *record)
+{
+	XLogRecPtr	lsn = record->EndRecPtr;
+	xl_brin_update *xlrec = (xl_brin_update *) XLogRecGetData(record);
+	Buffer		buffer;
+	XLogRedoAction action;
+
+	/* First remove the old tuple */
+	action = XLogReadBufferForRedo(record, 2, &buffer);
+	if (action == BLK_NEEDS_REDO)
+	{
+		Page		page;
+		OffsetNumber offnum;
+
+		page = (Page) BufferGetPage(buffer);
+
+		offnum = xlrec->oldOffnum;
+
+		PageIndexTupleDeleteNoCompact(page, offnum);
+
+		PageSetLSN(page, lsn);
+		MarkBufferDirty(buffer);
+	}
+
+	/* Then insert the new tuple and update revmap, like in an insertion. */
+	brin_xlog_insert_update(record, &xlrec->insert);
+
+	if (BufferIsValid(buffer))
+		UnlockReleaseBuffer(buffer);
+}
+
+/*
+ * Update a tuple on a single page.
+ */
+static void
+brin_xlog_samepage_update(XLogReaderState *record)
+{
+	XLogRecPtr	lsn = record->EndRecPtr;
+	xl_brin_samepage_update *xlrec;
+	Buffer		buffer;
+	XLogRedoAction action;
+
+	xlrec = (xl_brin_samepage_update *) XLogRecGetData(record);
+	action = XLogReadBufferForRedo(record, 0, &buffer);
+	if (action == BLK_NEEDS_REDO)
+	{
+		Size		tuplen;
+		BrinTuple  *brintuple;
+		Page		page;
+		OffsetNumber offnum;
+
+		brintuple = (BrinTuple *) XLogRecGetBlockData(record, 0, &tuplen);
+
+		page = (Page) BufferGetPage(buffer);
+
+		offnum = xlrec->offnum;
+
+		if (!PageIndexTupleOverwrite(page, offnum, (Item) brintuple, tuplen))
+			elog(PANIC, "brin_xlog_samepage_update: failed to replace tuple");
+
+		PageSetLSN(page, lsn);
+		MarkBufferDirty(buffer);
+	}
+	if (BufferIsValid(buffer))
+		UnlockReleaseBuffer(buffer);
+
+	/* XXX no FSM updates here ... */
+}
+
+/*
+ * Replay a revmap page extension
+ */
+static void
+brin_xlog_revmap_extend(XLogReaderState *record)
+{
+	XLogRecPtr	lsn = record->EndRecPtr;
+	xl_brin_revmap_extend *xlrec;
+	Buffer		metabuf;
+	Buffer		buf;
+	Page		page;
+	BlockNumber targetBlk;
+	XLogRedoAction action;
+
+	xlrec = (xl_brin_revmap_extend *) XLogRecGetData(record);
+
+	XLogRecGetBlockTag(record, 1, NULL, NULL, &targetBlk);
+	Assert(xlrec->targetBlk == targetBlk);
+
+	/* Update the metapage */
+	action = XLogReadBufferForRedo(record, 0, &metabuf);
+	if (action == BLK_NEEDS_REDO)
+	{
+		Page		metapg;
+		BrinMetaPageData *metadata;
+
+		metapg = BufferGetPage(metabuf);
+		metadata = (BrinMetaPageData *) PageGetContents(metapg);
+
+		Assert(metadata->lastRevmapPage == xlrec->targetBlk - 1);
+		metadata->lastRevmapPage = xlrec->targetBlk;
+
+		PageSetLSN(metapg, lsn);
+
+		/*
+		 * Set pd_lower just past the end of the metadata.  This is essential,
+		 * because without doing so, metadata will be lost if xlog.c
+		 * compresses the page.  (We must do this here because pre-v11
+		 * versions of PG did not set the metapage's pd_lower correctly, so a
+		 * pg_upgraded index might contain the wrong value.)
+		 */
+		((PageHeader) metapg)->pd_lower =
+			((char *) metadata + sizeof(BrinMetaPageData)) - (char *) metapg;
+
+		MarkBufferDirty(metabuf);
+	}
+
+	/*
+	 * Re-init the target block as a revmap page.  There's never a full- page
+	 * image here.
+	 */
+
+	buf = XLogInitBufferForRedo(record, 1);
+	page = (Page) BufferGetPage(buf);
+	brin_page_init(page, BRIN_PAGETYPE_REVMAP);
+
+	PageSetLSN(page, lsn);
+	MarkBufferDirty(buf);
+
+	UnlockReleaseBuffer(buf);
+	if (BufferIsValid(metabuf))
+		UnlockReleaseBuffer(metabuf);
+}
+
+static void
+brin_xlog_desummarize_page(XLogReaderState *record)
+{
+	XLogRecPtr	lsn = record->EndRecPtr;
+	xl_brin_desummarize *xlrec;
+	Buffer		buffer;
+	XLogRedoAction action;
+
+	xlrec = (xl_brin_desummarize *) XLogRecGetData(record);
+
+	/* Update the revmap */
+	action = XLogReadBufferForRedo(record, 0, &buffer);
+	if (action == BLK_NEEDS_REDO)
+	{
+		ItemPointerData iptr;
+
+		ItemPointerSetInvalid(&iptr);
+		brinSetHeapBlockItemptr(buffer, xlrec->pagesPerRange, xlrec->heapBlk, iptr);
+
+		PageSetLSN(BufferGetPage(buffer), lsn);
+		MarkBufferDirty(buffer);
+	}
+	if (BufferIsValid(buffer))
+		UnlockReleaseBuffer(buffer);
+
+	/* remove the leftover entry from the regular page */
+	action = XLogReadBufferForRedo(record, 1, &buffer);
+	if (action == BLK_NEEDS_REDO)
+	{
+		Page		regPg = BufferGetPage(buffer);
+
+		PageIndexTupleDeleteNoCompact(regPg, xlrec->regOffset);
+
+		PageSetLSN(regPg, lsn);
+		MarkBufferDirty(buffer);
+	}
+	if (BufferIsValid(buffer))
+		UnlockReleaseBuffer(buffer);
+}
+
+void
+brin_redo(XLogReaderState *record)
+{
+	uint8		info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
+
+	switch (info & XLOG_BRIN_OPMASK)
+	{
+		case XLOG_BRIN_CREATE_INDEX:
+			brin_xlog_createidx(record);
+			break;
+		case XLOG_BRIN_INSERT:
+			brin_xlog_insert(record);
+			break;
+		case XLOG_BRIN_UPDATE:
+			brin_xlog_update(record);
+			break;
+		case XLOG_BRIN_SAMEPAGE_UPDATE:
+			brin_xlog_samepage_update(record);
+			break;
+		case XLOG_BRIN_REVMAP_EXTEND:
+			brin_xlog_revmap_extend(record);
+			break;
+		case XLOG_BRIN_DESUMMARIZE:
+			brin_xlog_desummarize_page(record);
+			break;
+		default:
+			elog(PANIC, "brin_redo: unknown op code %u", info);
+	}
+}
+
+/*
+ * Mask a BRIN page before doing consistency checks.
+ */
+void
+brin_mask(char *pagedata, BlockNumber blkno)
+{
+	Page		page = (Page) pagedata;
+	PageHeader	pagehdr = (PageHeader) page;
+
+	mask_page_lsn_and_checksum(page);
+
+	mask_page_hint_bits(page);
+
+	/*
+	 * Regular brin pages contain unused space which needs to be masked.
+	 * Similarly for meta pages, but mask it only if pd_lower appears to have
+	 * been set correctly.
+	 */
+	if (BRIN_IS_REGULAR_PAGE(page) ||
+		(BRIN_IS_META_PAGE(page) && pagehdr->pd_lower > SizeOfPageHeaderData))
+	{
+		mask_unused_space(page);
+	}
+
+	/*
+	 * BRIN_EVACUATE_PAGE is not WAL-logged, since it's of no use in recovery.
+	 * Mask it.  See brin_start_evacuating_page() for details.
+	 */
+	BrinPageFlags(page) &= ~BRIN_EVACUATE_PAGE;
+}