int64 indtuples; /* total number of tuples indexed */
MemoryContext tmpCtx; /* temporary memory context reset after each
* tuple */
- char data[BLCKSZ]; /* cached page */
+ PGAlignedBlock data; /* cached page */
int count; /* number of tuples in cached page */
} BloomBuildState;
state = GenericXLogStart(index);
page = GenericXLogRegisterBuffer(state, buffer, GENERIC_XLOG_FULL_IMAGE);
- memcpy(page, buildstate->data, BLCKSZ);
+ memcpy(page, buildstate->data.data, BLCKSZ);
GenericXLogFinish(state);
UnlockReleaseBuffer(buffer);
}
static void
initCachedPage(BloomBuildState *buildstate)
{
- memset(buildstate->data, 0, BLCKSZ);
- BloomInitPage(buildstate->data, 0);
+ memset(buildstate->data.data, 0, BLCKSZ);
+ BloomInitPage(buildstate->data.data, 0);
buildstate->count = 0;
}
itup = BloomFormTuple(&buildstate->blstate, &htup->t_self, values, isnull);
/* Try to add next item to cached page */
- if (BloomPageAddItem(&buildstate->blstate, buildstate->data, itup))
+ if (BloomPageAddItem(&buildstate->blstate, buildstate->data.data, itup))
{
/* Next item was added successfully */
buildstate->count++;
initCachedPage(buildstate);
- if (!BloomPageAddItem(&buildstate->blstate, buildstate->data, itup))
+ if (!BloomPageAddItem(&buildstate->blstate, buildstate->data.data, itup))
{
/* We shouldn't be here since we're inserting to the empty page */
elog(ERROR, "could not add new bloom tuple to empty page");
PREWARM_BUFFER
} PrewarmType;
-static char blockbuffer[BLCKSZ];
+static PGAlignedBlock blockbuffer;
/*
* pg_prewarm(regclass, mode text, fork text,
for (block = first_block; block <= last_block; ++block)
{
CHECK_FOR_INTERRUPTS();
- smgrread(rel->rd_smgr, forkNumber, block, blockbuffer);
+ smgrread(rel->rd_smgr, forkNumber, block, blockbuffer.data);
++blocks_done;
}
}
Page lpage = PageGetTempPageCopy(BufferGetPage(origbuf));
Page rpage = PageGetTempPageCopy(BufferGetPage(origbuf));
Size pageSize = PageGetPageSize(lpage);
- char tupstore[2 * BLCKSZ];
+ PGAlignedBlock tupstore[2]; /* could need 2 pages' worth of tuples */
entryPreparePage(btree, lpage, off, insertData, updateblkno);
* one after another in a temporary workspace.
*/
maxoff = PageGetMaxOffsetNumber(lpage);
- ptr = tupstore;
+ ptr = tupstore[0].data;
for (i = FirstOffsetNumber; i <= maxoff; i++)
{
if (i == off)
GinInitPage(rpage, GinPageGetOpaque(lpage)->flags, pageSize);
GinInitPage(lpage, GinPageGetOpaque(rpage)->flags, pageSize);
- ptr = tupstore;
+ ptr = tupstore[0].data;
maxoff++;
lsize = 0;
size = 0;
OffsetNumber l,
off;
- char *workspace;
+ PGAlignedBlock workspace;
char *ptr;
- /* workspace could be a local array; we use palloc for alignment */
- workspace = palloc(BLCKSZ);
-
START_CRIT_SECTION();
GinInitBuffer(buffer, GIN_LIST);
off = FirstOffsetNumber;
- ptr = workspace;
+ ptr = workspace.data;
for (i = 0; i < ntuples; i++)
{
XLogRegisterData((char *) &data, sizeof(ginxlogInsertListPage));
XLogRegisterBuffer(0, buffer, REGBUF_WILL_INIT);
- XLogRegisterBufData(0, workspace, size);
+ XLogRegisterBufData(0, workspace.data, size);
recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_INSERT_LISTPAGE);
PageSetLSN(page, recptr);
END_CRIT_SECTION();
- pfree(workspace);
-
return freesize;
}
_hash_alloc_buckets(Relation rel, BlockNumber firstblock, uint32 nblocks)
{
BlockNumber lastblock;
- char zerobuf[BLCKSZ];
+ PGAlignedBlock zerobuf;
lastblock = firstblock + nblocks - 1;
if (lastblock < firstblock || lastblock == InvalidBlockNumber)
return false;
- MemSet(zerobuf, 0, sizeof(zerobuf));
+ MemSet(zerobuf.data, 0, sizeof(zerobuf));
RelationOpenSmgr(rel);
- smgrextend(rel->rd_smgr, MAIN_FORKNUM, lastblock, zerobuf, false);
+ smgrextend(rel->rd_smgr, MAIN_FORKNUM, lastblock, zerobuf.data, false);
return true;
}
HeapTuple *heaptuples;
int i;
int ndone;
- char *scratch = NULL;
+ PGAlignedBlock scratch;
Page page;
bool needwal;
Size saveFreeSpace;
heaptuples[i] = heap_prepare_insert(relation, tuples[i],
xid, cid, options);
- /*
- * Allocate some memory to use for constructing the WAL record. Using
- * palloc() within a critical section is not safe, so we allocate this
- * beforehand.
- */
- if (needwal)
- scratch = palloc(BLCKSZ);
-
/*
* We're about to do the actual inserts -- but check for conflict first,
* to minimize the possibility of having to roll back work we've just
uint8 info = XLOG_HEAP2_MULTI_INSERT;
char *tupledata;
int totaldatalen;
- char *scratchptr = scratch;
+ char *scratchptr = scratch.data;
bool init;
int bufflags = 0;
scratchptr += datalen;
}
totaldatalen = scratchptr - tupledata;
- Assert((scratchptr - scratch) < BLCKSZ);
+ Assert((scratchptr - scratch.data) < BLCKSZ);
if (need_tuple_data)
xlrec->flags |= XLH_INSERT_CONTAINS_NEW_TUPLE;
bufflags |= REGBUF_KEEP_DATA;
XLogBeginInsert();
- XLogRegisterData((char *) xlrec, tupledata - scratch);
+ XLogRegisterData((char *) xlrec, tupledata - scratch.data);
XLogRegisterBuffer(0, buffer, REGBUF_STANDARD | bufflags);
XLogRegisterBufData(0, tupledata, totaldatalen);
vm_extend(Relation rel, BlockNumber vm_nblocks)
{
BlockNumber vm_nblocks_now;
- Page pg;
+ PGAlignedBlock pg;
- pg = (Page) palloc(BLCKSZ);
- PageInit(pg, BLCKSZ, 0);
+ PageInit((Page) pg.data, BLCKSZ, 0);
/*
* We use the relation extension lock to lock out other backends trying to
/* Now extend the file */
while (vm_nblocks_now < vm_nblocks)
{
- PageSetChecksumInplace(pg, vm_nblocks_now);
+ PageSetChecksumInplace((Page) pg.data, vm_nblocks_now);
smgrextend(rel->rd_smgr, VISIBILITYMAP_FORKNUM, vm_nblocks_now,
- (char *) pg, false);
+ pg.data, false);
vm_nblocks_now++;
}
rel->rd_smgr->smgr_vm_nblocks = vm_nblocks_now;
UnlockRelationForExtension(rel, ExclusiveLock);
-
- pfree(pg);
}
/* State of generic xlog record construction */
struct GenericXLogState
{
- /*
- * page's images. Should be first in this struct to have MAXALIGN'ed
- * images addresses, because some code working with pages directly aligns
- * addresses, not offsets from beginning of page
- */
- char images[MAX_GENERIC_XLOG_PAGES * BLCKSZ];
+ /* Info about each page, see above */
PageData pages[MAX_GENERIC_XLOG_PAGES];
bool isLogged;
+ /* Page images (properly aligned) */
+ PGAlignedBlock images[MAX_GENERIC_XLOG_PAGES];
};
static void writeFragment(PageData *pageData, OffsetNumber offset,
#ifdef WAL_DEBUG
if (XLOG_DEBUG)
{
- char tmp[BLCKSZ];
+ PGAlignedBlock tmp;
- memcpy(tmp, curpage, BLCKSZ);
- applyPageRedo(tmp, pageData->delta, pageData->deltaLen);
- if (memcmp(tmp, targetpage, targetLower) != 0 ||
- memcmp(tmp + targetUpper, targetpage + targetUpper,
+ memcpy(tmp.data, curpage, BLCKSZ);
+ applyPageRedo(tmp.data, pageData->delta, pageData->deltaLen);
+ if (memcmp(tmp.data, targetpage, targetLower) != 0 ||
+ memcmp(tmp.data + targetUpper, targetpage + targetUpper,
BLCKSZ - targetUpper) != 0)
elog(ERROR, "result of generic xlog apply does not match");
}
for (i = 0; i < MAX_GENERIC_XLOG_PAGES; i++)
{
- state->pages[i].image = state->images + BLCKSZ * i;
+ state->pages[i].image = state->images[i].data;
state->pages[i].buffer = InvalidBuffer;
}
{
char path[MAXPGPATH];
char tmppath[MAXPGPATH];
- char zbuffer_raw[XLOG_BLCKSZ + MAXIMUM_ALIGNOF];
- char *zbuffer;
+ PGAlignedXLogBlock zbuffer;
XLogSegNo installed_segno;
XLogSegNo max_segno;
int fd;
* fsync below) that all the indirect blocks are down on disk. Therefore,
* fdatasync(2) or O_DSYNC will be sufficient to sync future writes to the
* log file.
- *
- * Note: ensure the buffer is reasonably well-aligned; this may save a few
- * cycles transferring data to the kernel.
*/
- zbuffer = (char *) MAXALIGN(zbuffer_raw);
- memset(zbuffer, 0, XLOG_BLCKSZ);
+ memset(zbuffer.data, 0, XLOG_BLCKSZ);
for (nbytes = 0; nbytes < XLogSegSize; nbytes += XLOG_BLCKSZ)
{
errno = 0;
- if ((int) write(fd, zbuffer, XLOG_BLCKSZ) != (int) XLOG_BLCKSZ)
+ if ((int) write(fd, zbuffer.data, XLOG_BLCKSZ) != (int) XLOG_BLCKSZ)
{
int save_errno = errno;
{
char path[MAXPGPATH];
char tmppath[MAXPGPATH];
- char buffer[XLOG_BLCKSZ];
+ PGAlignedXLogBlock buffer;
int srcfd;
int fd;
int nbytes;
* zeros.
*/
if (nread < sizeof(buffer))
- memset(buffer, 0, sizeof(buffer));
+ memset(buffer.data, 0, sizeof(buffer));
if (nread > 0)
{
if (nread > sizeof(buffer))
nread = sizeof(buffer);
errno = 0;
- if (read(srcfd, buffer, nread) != nread)
+ if (read(srcfd, buffer.data, nread) != nread)
{
if (errno != 0)
ereport(ERROR,
}
}
errno = 0;
- if ((int) write(fd, buffer, sizeof(buffer)) != (int) sizeof(buffer))
+ if ((int) write(fd, buffer.data, sizeof(buffer)) != (int) sizeof(buffer))
{
int save_errno = errno;
int32 len;
int32 extra_bytes = 0;
char *source;
- char tmp[BLCKSZ];
+ PGAlignedBlock tmp;
if (hole_length != 0)
{
/* must skip the hole */
- source = tmp;
+ source = tmp.data;
memcpy(source, page, hole_offset);
memcpy(source + hole_offset,
page + (hole_offset + hole_length),
if (lsn <= RedoRecPtr)
{
int flags;
- char copied_buffer[BLCKSZ];
+ PGAlignedBlock copied_buffer;
char *origdata = (char *) BufferGetBlock(buffer);
RelFileNode rnode;
ForkNumber forkno;
uint16 lower = ((PageHeader) page)->pd_lower;
uint16 upper = ((PageHeader) page)->pd_upper;
- memcpy(copied_buffer, origdata, lower);
- memcpy(copied_buffer + upper, origdata + upper, BLCKSZ - upper);
+ memcpy(copied_buffer.data, origdata, lower);
+ memcpy(copied_buffer.data + upper, origdata + upper, BLCKSZ - upper);
}
else
- memcpy(copied_buffer, origdata, BLCKSZ);
+ memcpy(copied_buffer.data, origdata, BLCKSZ);
XLogBeginInsert();
flags |= REGBUF_STANDARD;
BufferGetTag(buffer, &rnode, &forkno, &blkno);
- XLogRegisterBlock(0, &rnode, forkno, blkno, copied_buffer, flags);
+ XLogRegisterBlock(0, &rnode, forkno, blkno, copied_buffer.data, flags);
recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI_FOR_HINT);
}
{
DecodedBkpBlock *bkpb;
char *ptr;
- char tmp[BLCKSZ];
+ PGAlignedBlock tmp;
if (!record->blocks[block_id].in_use)
return false;
if (bkpb->bimg_info & BKPIMAGE_IS_COMPRESSED)
{
/* If a backup block image is compressed, decompress it */
- if (pglz_decompress(ptr, bkpb->bimg_len, tmp,
+ if (pglz_decompress(ptr, bkpb->bimg_len, tmp.data,
BLCKSZ - bkpb->hole_length) < 0)
{
report_invalid_record(record, "invalid compressed image at %X/%X, block %d",
block_id);
return false;
}
- ptr = tmp;
+ ptr = tmp.data;
}
/* generate page, taking into account hole if necessary */
copy_relation_data(SMgrRelation src, SMgrRelation dst,
ForkNumber forkNum, char relpersistence)
{
- char *buf;
+ PGAlignedBlock buf;
Page page;
bool use_wal;
bool copying_initfork;
BlockNumber nblocks;
BlockNumber blkno;
- /*
- * palloc the buffer so that it's MAXALIGN'd. If it were just a local
- * char[] array, the compiler might align it on any byte boundary, which
- * can seriously hurt transfer speed to and from the kernel; not to
- * mention possibly making log_newpage's accesses to the page header fail.
- */
- buf = (char *) palloc(BLCKSZ);
- page = (Page) buf;
+ page = (Page) buf.data;
/*
* The init fork for an unlogged relation in many respects has to be
/* If we got a cancel signal during the copy of the data, quit */
CHECK_FOR_INTERRUPTS();
- smgrread(src, forkNum, blkno, buf);
+ smgrread(src, forkNum, blkno, buf.data);
if (!PageIsVerified(page, blkno))
ereport(ERROR,
* rel, because there's no need for smgr to schedule an fsync for this
* write; we'll do it ourselves below.
*/
- smgrextend(dst, forkNum, blkno, buf, true);
+ smgrextend(dst, forkNum, blkno, buf.data, true);
}
- pfree(buf);
-
/*
* If the rel is WAL-logged, must fsync before commit. We use heap_sync
* to ensure that the toast table gets fsync'd too. (For a temp or
bytesleft = histfilelen;
while (bytesleft > 0)
{
- char rbuf[BLCKSZ];
+ PGAlignedBlock rbuf;
int nread;
- nread = read(fd, rbuf, sizeof(rbuf));
+ nread = read(fd, rbuf.data, sizeof(rbuf));
if (nread <= 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not read file \"%s\": %m",
path)));
- pq_sendbytes(&buf, rbuf, nread);
+ pq_sendbytes(&buf, rbuf.data, nread);
bytesleft -= nread;
}
CloseTransientFile(fd);
off_t curOffset; /* offset part of current pos */
int pos; /* next read/write position in buffer */
int nbytes; /* total # of valid bytes in buffer */
- char buffer[BLCKSZ];
+ PGAlignedBlock buffer;
};
static BufFile *makeBufFile(File firstfile);
/*
* Read whatever we can get, up to a full bufferload.
*/
- file->nbytes = FileRead(thisfile, file->buffer, sizeof(file->buffer));
+ file->nbytes = FileRead(thisfile, file->buffer.data, sizeof(file->buffer));
if (file->nbytes < 0)
file->nbytes = 0;
file->offsets[file->curFile] += file->nbytes;
return; /* seek failed, give up */
file->offsets[file->curFile] = file->curOffset;
}
- bytestowrite = FileWrite(thisfile, file->buffer + wpos, bytestowrite);
+ bytestowrite = FileWrite(thisfile, file->buffer.data + wpos, bytestowrite);
if (bytestowrite <= 0)
return; /* failed to write */
file->offsets[file->curFile] += bytestowrite;
nthistime = size;
Assert(nthistime > 0);
- memcpy(ptr, file->buffer + file->pos, nthistime);
+ memcpy(ptr, file->buffer.data + file->pos, nthistime);
file->pos += nthistime;
ptr = (void *) ((char *) ptr + nthistime);
nthistime = size;
Assert(nthistime > 0);
- memcpy(file->buffer + file->pos, ptr, nthistime);
+ memcpy(file->buffer.data + file->pos, ptr, nthistime);
file->dirty = true;
file->pos += nthistime;
fsm_extend(Relation rel, BlockNumber fsm_nblocks)
{
BlockNumber fsm_nblocks_now;
- Page pg;
+ PGAlignedBlock pg;
- pg = (Page) palloc(BLCKSZ);
- PageInit(pg, BLCKSZ, 0);
+ PageInit((Page) pg.data, BLCKSZ, 0);
/*
* We use the relation extension lock to lock out other backends trying to
while (fsm_nblocks_now < fsm_nblocks)
{
- PageSetChecksumInplace(pg, fsm_nblocks_now);
+ PageSetChecksumInplace((Page) pg.data, fsm_nblocks_now);
smgrextend(rel->rd_smgr, FSM_FORKNUM, fsm_nblocks_now,
- (char *) pg, false);
+ pg.data, false);
fsm_nblocks_now++;
}
rel->rd_smgr->smgr_fsm_nblocks = fsm_nblocks_now;
UnlockRelationForExtension(rel, ExclusiveLock);
-
- pfree(pg);
}
/*
int f;
char fn[MAXPGPATH];
struct stat statbuf;
- char *zerobuf;
+ PGAlignedXLogBlock zerobuf;
int bytes;
XLogSegNo segno;
}
/* New, empty, file. So pad it to 16Mb with zeroes */
- zerobuf = pg_malloc0(XLOG_BLCKSZ);
+ memset(zerobuf.data, 0, XLOG_BLCKSZ);
for (bytes = 0; bytes < XLogSegSize; bytes += XLOG_BLCKSZ)
{
errno = 0;
- if (write(f, zerobuf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
+ if (write(f, zerobuf.data, XLOG_BLCKSZ) != XLOG_BLCKSZ)
{
/* if write didn't set errno, assume problem is no disk space */
if (errno == 0)
fprintf(stderr,
_("%s: could not pad transaction log file \"%s\": %s\n"),
progname, fn, strerror(errno));
- free(zerobuf);
close(f);
unlink(fn);
return false;
}
}
- free(zerobuf);
if (lseek(f, SEEK_SET, 0) != 0)
{
static void
WriteEmptyXLOG(void)
{
- char *buffer;
+ PGAlignedXLogBlock buffer;
XLogPageHeader page;
XLogLongPageHeader longpage;
XLogRecord *record;
int nbytes;
char *recptr;
- /* Use malloc() to ensure buffer is MAXALIGNED */
- buffer = (char *) pg_malloc(XLOG_BLCKSZ);
- page = (XLogPageHeader) buffer;
- memset(buffer, 0, XLOG_BLCKSZ);
+ memset(buffer.data, 0, XLOG_BLCKSZ);
/* Set up the XLOG page header */
+ page = (XLogPageHeader) buffer.data;
page->xlp_magic = XLOG_PAGE_MAGIC;
page->xlp_info = XLP_LONG_HEADER;
page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
}
errno = 0;
- if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
+ if (write(fd, buffer.data, XLOG_BLCKSZ) != XLOG_BLCKSZ)
{
/* if write didn't set errno, assume problem is no disk space */
if (errno == 0)
}
/* Fill the rest of the file with zeroes */
- memset(buffer, 0, XLOG_BLCKSZ);
+ memset(buffer.data, 0, XLOG_BLCKSZ);
for (nbytes = XLOG_BLCKSZ; nbytes < XLogSegSize; nbytes += XLOG_BLCKSZ)
{
errno = 0;
- if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
+ if (write(fd, buffer.data, XLOG_BLCKSZ) != XLOG_BLCKSZ)
{
if (errno == 0)
errno = ENOSPC;
static void
rewind_copy_file_range(const char *path, off_t begin, off_t end, bool trunc)
{
- char buf[BLCKSZ];
+ PGAlignedBlock buf;
char srcpath[MAXPGPATH];
int srcfd;
else
len = end - begin;
- readlen = read(srcfd, buf, len);
+ readlen = read(srcfd, buf.data, len);
if (readlen < 0)
pg_fatal("could not read file \"%s\": %s\n",
else if (readlen == 0)
pg_fatal("unexpected EOF while reading file \"%s\"\n", srcpath);
- write_target_range(buf, begin, readlen);
+ write_target_range(buf.data, begin, readlen);
begin += readlen;
}
{
int src_fd;
int dst_fd;
- char *buffer;
- char *new_vmbuf;
+ PGAlignedBlock buffer;
+ PGAlignedBlock new_vmbuf;
ssize_t totalBytesRead = 0;
ssize_t src_filesize;
int rewriteVmBytesPerPage;
/* Save old file size */
src_filesize = statbuf.st_size;
- /*
- * Malloc the work buffers, rather than making them local arrays, to
- * ensure adequate alignment.
- */
- buffer = (char *) pg_malloc(BLCKSZ);
- new_vmbuf = (char *) pg_malloc(BLCKSZ);
-
/*
* Turn each visibility map page into 2 pages one by one. Each new page
* has the same page header as the old one. If the last section of the
PageHeaderData pageheader;
bool old_lastblk;
- if ((bytesRead = read(src_fd, buffer, BLCKSZ)) != BLCKSZ)
+ if ((bytesRead = read(src_fd, buffer.data, BLCKSZ)) != BLCKSZ)
{
if (bytesRead < 0)
pg_fatal("error while copying relation \"%s.%s\": could not read file \"%s\": %s\n",
old_lastblk = (totalBytesRead == src_filesize);
/* Save the page header data */
- memcpy(&pageheader, buffer, SizeOfPageHeaderData);
+ memcpy(&pageheader, buffer.data, SizeOfPageHeaderData);
/*
* These old_* variables point to old visibility map page. old_cur
* old block. old_break is the end+1 position on the old page for the
* data that will be transferred to the current new page.
*/
- old_cur = buffer + SizeOfPageHeaderData;
- old_blkend = buffer + bytesRead;
+ old_cur = buffer.data + SizeOfPageHeaderData;
+ old_blkend = buffer.data + bytesRead;
old_break = old_cur + rewriteVmBytesPerPage;
while (old_break <= old_blkend)
bool old_lastpart;
/* First, copy old page header to new page */
- memcpy(new_vmbuf, &pageheader, SizeOfPageHeaderData);
+ memcpy(new_vmbuf.data, &pageheader, SizeOfPageHeaderData);
/* Rewriting the last part of the last old page? */
old_lastpart = old_lastblk && (old_break == old_blkend);
- new_cur = new_vmbuf + SizeOfPageHeaderData;
+ new_cur = new_vmbuf.data + SizeOfPageHeaderData;
/* Process old page bytes one by one, and turn it into new page. */
while (old_cur < old_break)
/* Set new checksum for visibility map page, if enabled */
if (new_cluster.controldata.data_checksum_version != 0)
- ((PageHeader) new_vmbuf)->pd_checksum =
- pg_checksum_page(new_vmbuf, new_blkno);
+ ((PageHeader) new_vmbuf.data)->pd_checksum =
+ pg_checksum_page(new_vmbuf.data, new_blkno);
errno = 0;
- if (write(dst_fd, new_vmbuf, BLCKSZ) != BLCKSZ)
+ if (write(dst_fd, new_vmbuf.data, BLCKSZ) != BLCKSZ)
{
/* if write didn't set errno, assume problem is no disk space */
if (errno == 0)
}
/* Clean up */
- pg_free(buffer);
- pg_free(new_vmbuf);
close(dst_fd);
close(src_fd);
}
* ----------------------------------------------------------------
*/
+/*
+ * Use this, not "char buf[BLCKSZ]", to declare a field or local variable
+ * holding a page buffer, if that page might be accessed as a page and not
+ * just a string of bytes. Otherwise the variable might be under-aligned,
+ * causing problems on alignment-picky hardware. (In some places, we use
+ * this to declare buffers even though we only pass them to read() and
+ * write(), because copying to/from aligned buffers is usually faster than
+ * using unaligned buffers.) We include both "double" and "int64" in the
+ * union to ensure that the compiler knows the value must be MAXALIGN'ed
+ * (cf. configure's computation of MAXIMUM_ALIGNOF).
+ */
+typedef union PGAlignedBlock
+{
+ char data[BLCKSZ];
+ double force_align_d;
+ int64 force_align_i64;
+} PGAlignedBlock;
+
+/* Same, but for an XLOG_BLCKSZ-sized buffer */
+typedef union PGAlignedXLogBlock
+{
+ char data[XLOG_BLCKSZ];
+ double force_align_d;
+ int64 force_align_i64;
+} PGAlignedXLogBlock;
+
/* msb for char */
#define HIGHBIT (0x80)
#define IS_HIGHBIT_SET(ch) ((unsigned char)(ch) & HIGHBIT)
projects / postgresql.git / commitdiff