PostgreSQL Source Code  git master
logtape.c File Reference
#include "postgres.h"
#include <fcntl.h>
#include "storage/buffile.h"
#include "utils/builtins.h"
#include "utils/logtape.h"
#include "utils/memdebug.h"
#include "utils/memutils.h"
Include dependency graph for logtape.c:

Go to the source code of this file.

Data Structures

struct  TapeBlockTrailer
 
struct  LogicalTape
 
struct  LogicalTapeSet
 

Macros

#define TapeBlockPayloadSize   (BLCKSZ - sizeof(TapeBlockTrailer))
 
#define TapeBlockGetTrailer(buf)    ((TapeBlockTrailer *) ((char *) buf + TapeBlockPayloadSize))
 
#define TapeBlockIsLast(buf)   (TapeBlockGetTrailer(buf)->next < 0)
 
#define TapeBlockGetNBytes(buf)
 
#define TapeBlockSetNBytes(buf, nbytes)    (TapeBlockGetTrailer(buf)->next = -(nbytes))
 
#define TAPE_WRITE_PREALLOC_MIN   8
 
#define TAPE_WRITE_PREALLOC_MAX   128
 

Typedefs

typedef struct TapeBlockTrailer TapeBlockTrailer
 

Functions

static LogicalTapeltsCreateTape (LogicalTapeSet *lts)
 
static void ltsWriteBlock (LogicalTapeSet *lts, long blocknum, const void *buffer)
 
static void ltsReadBlock (LogicalTapeSet *lts, long blocknum, void *buffer)
 
static long ltsGetBlock (LogicalTapeSet *lts, LogicalTape *lt)
 
static long ltsGetFreeBlock (LogicalTapeSet *lts)
 
static long ltsGetPreallocBlock (LogicalTapeSet *lts, LogicalTape *lt)
 
static void ltsReleaseBlock (LogicalTapeSet *lts, long blocknum)
 
static void ltsInitReadBuffer (LogicalTape *lt)
 
static bool ltsReadFillBuffer (LogicalTape *lt)
 
static unsigned long left_offset (unsigned long i)
 
static unsigned long right_offset (unsigned long i)
 
static unsigned long parent_offset (unsigned long i)
 
LogicalTapeSetLogicalTapeSetCreate (bool preallocate, SharedFileSet *fileset, int worker)
 
LogicalTapeLogicalTapeImport (LogicalTapeSet *lts, int worker, TapeShare *shared)
 
void LogicalTapeSetClose (LogicalTapeSet *lts)
 
LogicalTapeLogicalTapeCreate (LogicalTapeSet *lts)
 
void LogicalTapeClose (LogicalTape *lt)
 
void LogicalTapeSetForgetFreeSpace (LogicalTapeSet *lts)
 
void LogicalTapeWrite (LogicalTape *lt, const void *ptr, size_t size)
 
void LogicalTapeRewindForRead (LogicalTape *lt, size_t buffer_size)
 
size_t LogicalTapeRead (LogicalTape *lt, void *ptr, size_t size)
 
void LogicalTapeFreeze (LogicalTape *lt, TapeShare *share)
 
size_t LogicalTapeBackspace (LogicalTape *lt, size_t size)
 
void LogicalTapeSeek (LogicalTape *lt, long blocknum, int offset)
 
void LogicalTapeTell (LogicalTape *lt, long *blocknum, int *offset)
 
long LogicalTapeSetBlocks (LogicalTapeSet *lts)
 

Macro Definition Documentation

◆ TAPE_WRITE_PREALLOC_MAX

#define TAPE_WRITE_PREALLOC_MAX   128

Definition at line 125 of file logtape.c.

◆ TAPE_WRITE_PREALLOC_MIN

#define TAPE_WRITE_PREALLOC_MIN   8

Definition at line 124 of file logtape.c.

◆ TapeBlockGetNBytes

#define TapeBlockGetNBytes (   buf)
Value:
#define TapeBlockGetTrailer(buf)
Definition: logtape.c:104
#define TapeBlockPayloadSize
Definition: logtape.c:103
#define TapeBlockIsLast(buf)
Definition: logtape.c:107
static char * buf
Definition: pg_test_fsync.c:67

Definition at line 108 of file logtape.c.

◆ TapeBlockGetTrailer

#define TapeBlockGetTrailer (   buf)     ((TapeBlockTrailer *) ((char *) buf + TapeBlockPayloadSize))

Definition at line 104 of file logtape.c.

◆ TapeBlockIsLast

#define TapeBlockIsLast (   buf)    (TapeBlockGetTrailer(buf)->next < 0)

Definition at line 107 of file logtape.c.

◆ TapeBlockPayloadSize

#define TapeBlockPayloadSize   (BLCKSZ - sizeof(TapeBlockTrailer))

Definition at line 103 of file logtape.c.

◆ TapeBlockSetNBytes

#define TapeBlockSetNBytes (   buf,
  nbytes 
)     (TapeBlockGetTrailer(buf)->next = -(nbytes))

Definition at line 111 of file logtape.c.

Typedef Documentation

◆ TapeBlockTrailer

Function Documentation

◆ left_offset()

static unsigned long left_offset ( unsigned long  i)
inlinestatic

Definition at line 337 of file logtape.c.

338 {
339  return 2 * i + 1;
340 }
int i
Definition: isn.c:73

References i.

Referenced by ltsGetFreeBlock().

◆ LogicalTapeBackspace()

size_t LogicalTapeBackspace ( LogicalTape lt,
size_t  size 
)

Definition at line 1062 of file logtape.c.

1063 {
1064  size_t seekpos = 0;
1065 
1066  Assert(lt->frozen);
1067  Assert(lt->buffer_size == BLCKSZ);
1068 
1069  if (lt->buffer == NULL)
1070  ltsInitReadBuffer(lt);
1071 
1072  /*
1073  * Easy case for seek within current block.
1074  */
1075  if (size <= (size_t) lt->pos)
1076  {
1077  lt->pos -= (int) size;
1078  return size;
1079  }
1080 
1081  /*
1082  * Not-so-easy case, have to walk back the chain of blocks. This
1083  * implementation would be pretty inefficient for long seeks, but we
1084  * really aren't doing that (a seek over one tuple is typical).
1085  */
1086  seekpos = (size_t) lt->pos; /* part within this block */
1087  while (size > seekpos)
1088  {
1089  long prev = TapeBlockGetTrailer(lt->buffer)->prev;
1090 
1091  if (prev == -1L)
1092  {
1093  /* Tried to back up beyond the beginning of tape. */
1094  if (lt->curBlockNumber != lt->firstBlockNumber)
1095  elog(ERROR, "unexpected end of tape");
1096  lt->pos = 0;
1097  return seekpos;
1098  }
1099 
1100  ltsReadBlock(lt->tapeSet, prev, lt->buffer);
1101 
1102  if (TapeBlockGetTrailer(lt->buffer)->next != lt->curBlockNumber)
1103  elog(ERROR, "broken tape, next of block %ld is %ld, expected %ld",
1104  prev,
1105  TapeBlockGetTrailer(lt->buffer)->next,
1106  lt->curBlockNumber);
1107 
1109  lt->curBlockNumber = prev;
1110  lt->nextBlockNumber = TapeBlockGetTrailer(lt->buffer)->next;
1111 
1112  seekpos += TapeBlockPayloadSize;
1113  }
1114 
1115  /*
1116  * 'seekpos' can now be greater than 'size', because it points to the
1117  * beginning the target block. The difference is the position within the
1118  * page.
1119  */
1120  lt->pos = seekpos - size;
1121  return size;
1122 }
#define ERROR
Definition: elog.h:39
Assert(fmt[strlen(fmt) - 1] !='\n')
static void ltsInitReadBuffer(LogicalTape *lt)
Definition: logtape.c:522
static void ltsReadBlock(LogicalTapeSet *lts, long blocknum, void *buffer)
Definition: logtape.c:282
while(p+4<=pend)
long curBlockNumber
Definition: logtape.c:157
char * buffer
Definition: logtape.c:164
bool frozen
Definition: logtape.c:142
long nextBlockNumber
Definition: logtape.c:158
int buffer_size
Definition: logtape.c:165
long firstBlockNumber
Definition: logtape.c:156
LogicalTapeSet * tapeSet
Definition: logtape.c:139
int nbytes
Definition: logtape.c:168

References Assert(), LogicalTape::buffer, LogicalTape::buffer_size, LogicalTape::curBlockNumber, elog(), ERROR, LogicalTape::firstBlockNumber, LogicalTape::frozen, ltsInitReadBuffer(), ltsReadBlock(), LogicalTape::nbytes, LogicalTape::nextBlockNumber, LogicalTape::pos, TapeBlockGetTrailer, TapeBlockPayloadSize, LogicalTape::tapeSet, and while().

Referenced by tuplesort_gettuple_common().

◆ LogicalTapeClose()

void LogicalTapeClose ( LogicalTape lt)

Definition at line 733 of file logtape.c.

734 {
735  if (lt->buffer)
736  pfree(lt->buffer);
737  pfree(lt);
738 }
void pfree(void *pointer)
Definition: mcxt.c:1456

References LogicalTape::buffer, and pfree().

Referenced by agg_refill_hash_table(), mergeruns(), and tuplesort_gettuple_common().

◆ LogicalTapeCreate()

LogicalTape* LogicalTapeCreate ( LogicalTapeSet lts)

Definition at line 680 of file logtape.c.

681 {
682  /*
683  * The only thing that currently prevents creating new tapes in leader is
684  * the fact that BufFiles opened using BufFileOpenShared() are read-only
685  * by definition, but that could be changed if it seemed worthwhile. For
686  * now, writing to the leader tape will raise a "Bad file descriptor"
687  * error, so tuplesort must avoid writing to the leader tape altogether.
688  */
689  if (lts->fileset && lts->worker == -1)
690  elog(ERROR, "cannot create new tapes in leader process");
691 
692  return ltsCreateTape(lts);
693 }
static LogicalTape * ltsCreateTape(LogicalTapeSet *lts)
Definition: logtape.c:696
SharedFileSet * fileset
Definition: logtape.c:190

References elog(), ERROR, LogicalTapeSet::fileset, ltsCreateTape(), and LogicalTapeSet::worker.

Referenced by hashagg_spill_init(), and selectnewtape().

◆ LogicalTapeFreeze()

void LogicalTapeFreeze ( LogicalTape lt,
TapeShare share 
)

Definition at line 981 of file logtape.c.

982 {
983  LogicalTapeSet *lts = lt->tapeSet;
984 
985  Assert(lt->writing);
986  Assert(lt->offsetBlockNumber == 0L);
987 
988  /*
989  * Completion of a write phase. Flush last partial data block, and rewind
990  * for nondestructive read.
991  */
992  if (lt->dirty)
993  {
994  /*
995  * As long as we've filled the buffer at least once, its contents are
996  * entirely defined from valgrind's point of view, even though
997  * contents beyond the current end point may be stale. But it's
998  * possible - at least in the case of a parallel sort - to sort such
999  * small amount of data that we do not fill the buffer even once. Tell
1000  * valgrind that its contents are defined, so it doesn't bleat.
1001  */
1003  lt->buffer_size - lt->nbytes);
1004 
1005  TapeBlockSetNBytes(lt->buffer, lt->nbytes);
1006  ltsWriteBlock(lt->tapeSet, lt->curBlockNumber, lt->buffer);
1007  }
1008  lt->writing = false;
1009  lt->frozen = true;
1010 
1011  /*
1012  * The seek and backspace functions assume a single block read buffer.
1013  * That's OK with current usage. A larger buffer is helpful to make the
1014  * read pattern of the backing file look more sequential to the OS, when
1015  * we're reading from multiple tapes. But at the end of a sort, when a
1016  * tape is frozen, we only read from a single tape anyway.
1017  */
1018  if (!lt->buffer || lt->buffer_size != BLCKSZ)
1019  {
1020  if (lt->buffer)
1021  pfree(lt->buffer);
1022  lt->buffer = palloc(BLCKSZ);
1023  lt->buffer_size = BLCKSZ;
1024  }
1025 
1026  /* Read the first block, or reset if tape is empty */
1027  lt->curBlockNumber = lt->firstBlockNumber;
1028  lt->pos = 0;
1029  lt->nbytes = 0;
1030 
1031  if (lt->firstBlockNumber == -1L)
1032  lt->nextBlockNumber = -1L;
1033  ltsReadBlock(lt->tapeSet, lt->curBlockNumber, lt->buffer);
1034  if (TapeBlockIsLast(lt->buffer))
1035  lt->nextBlockNumber = -1L;
1036  else
1037  lt->nextBlockNumber = TapeBlockGetTrailer(lt->buffer)->next;
1038  lt->nbytes = TapeBlockGetNBytes(lt->buffer);
1039 
1040  /* Handle extra steps when caller is to share its tapeset */
1041  if (share)
1042  {
1044  share->firstblocknumber = lt->firstBlockNumber;
1045  }
1046 }
void BufFileExportFileSet(BufFile *file)
Definition: buffile.c:394
static void ltsWriteBlock(LogicalTapeSet *lts, long blocknum, const void *buffer)
Definition: logtape.c:238
#define TapeBlockGetNBytes(buf)
Definition: logtape.c:108
#define TapeBlockSetNBytes(buf, nbytes)
Definition: logtape.c:111
void * palloc(Size size)
Definition: mcxt.c:1226
#define VALGRIND_MAKE_MEM_DEFINED(addr, size)
Definition: memdebug.h:26
BufFile * pfile
Definition: logtape.c:189
long offsetBlockNumber
Definition: logtape.c:159
bool writing
Definition: logtape.c:141
bool dirty
Definition: logtape.c:143
long firstblocknumber
Definition: logtape.h:54

References Assert(), LogicalTape::buffer, LogicalTape::buffer_size, BufFileExportFileSet(), LogicalTape::curBlockNumber, LogicalTape::dirty, LogicalTape::firstBlockNumber, TapeShare::firstblocknumber, LogicalTape::frozen, ltsReadBlock(), ltsWriteBlock(), LogicalTape::nbytes, LogicalTape::nextBlockNumber, LogicalTape::offsetBlockNumber, palloc(), LogicalTapeSet::pfile, pfree(), LogicalTape::pos, TapeBlockGetNBytes, TapeBlockGetTrailer, TapeBlockIsLast, TapeBlockSetNBytes, LogicalTape::tapeSet, VALGRIND_MAKE_MEM_DEFINED, and LogicalTape::writing.

Referenced by mergeruns(), and worker_freeze_result_tape().

◆ LogicalTapeImport()

LogicalTape* LogicalTapeImport ( LogicalTapeSet lts,
int  worker,
TapeShare shared 
)

Definition at line 609 of file logtape.c.

610 {
611  LogicalTape *lt;
612  long tapeblocks;
613  char filename[MAXPGPATH];
614  BufFile *file;
615  int64 filesize;
616 
617  lt = ltsCreateTape(lts);
618 
619  /*
620  * build concatenated view of all buffiles, remembering the block number
621  * where each source file begins.
622  */
623  pg_itoa(worker, filename);
624  file = BufFileOpenFileSet(&lts->fileset->fs, filename, O_RDONLY, false);
625  filesize = BufFileSize(file);
626 
627  /*
628  * Stash first BufFile, and concatenate subsequent BufFiles to that. Store
629  * block offset into each tape as we go.
630  */
631  lt->firstBlockNumber = shared->firstblocknumber;
632  if (lts->pfile == NULL)
633  {
634  lts->pfile = file;
635  lt->offsetBlockNumber = 0L;
636  }
637  else
638  {
639  lt->offsetBlockNumber = BufFileAppend(lts->pfile, file);
640  }
641  /* Don't allocate more for read buffer than could possibly help */
642  lt->max_size = Min(MaxAllocSize, filesize);
643  tapeblocks = filesize / BLCKSZ;
644 
645  /*
646  * Update # of allocated blocks and # blocks written to reflect the
647  * imported BufFile. Allocated/written blocks include space used by holes
648  * left between concatenated BufFiles. Also track the number of hole
649  * blocks so that we can later work backwards to calculate the number of
650  * physical blocks for instrumentation.
651  */
653 
654  lts->nBlocksAllocated = lt->offsetBlockNumber + tapeblocks;
655  lts->nBlocksWritten = lts->nBlocksAllocated;
656 
657  return lt;
658 }
long BufFileAppend(BufFile *target, BufFile *source)
Definition: buffile.c:923
BufFile * BufFileOpenFileSet(FileSet *fileset, const char *name, int mode, bool missing_ok)
Definition: buffile.c:291
int64 BufFileSize(BufFile *file)
Definition: buffile.c:884
#define Min(x, y)
Definition: c.h:993
#define MaxAllocSize
Definition: memutils.h:40
int pg_itoa(int16 i, char *a)
Definition: numutils.c:1045
#define MAXPGPATH
static char * filename
Definition: pg_dumpall.c:119
long nBlocksAllocated
Definition: logtape.c:203
long nHoleBlocks
Definition: logtape.c:205
long nBlocksWritten
Definition: logtape.c:204
int max_size
Definition: logtape.c:166

References BufFileAppend(), BufFileOpenFileSet(), BufFileSize(), filename, LogicalTapeSet::fileset, LogicalTape::firstBlockNumber, TapeShare::firstblocknumber, SharedFileSet::fs, ltsCreateTape(), LogicalTape::max_size, MaxAllocSize, MAXPGPATH, Min, LogicalTapeSet::nBlocksAllocated, LogicalTapeSet::nBlocksWritten, LogicalTapeSet::nHoleBlocks, LogicalTape::offsetBlockNumber, LogicalTapeSet::pfile, and pg_itoa().

Referenced by leader_takeover_tapes().

◆ LogicalTapeRead()

size_t LogicalTapeRead ( LogicalTape lt,
void *  ptr,
size_t  size 
)

Definition at line 928 of file logtape.c.

929 {
930  size_t nread = 0;
931  size_t nthistime;
932 
933  Assert(!lt->writing);
934 
935  if (lt->buffer == NULL)
936  ltsInitReadBuffer(lt);
937 
938  while (size > 0)
939  {
940  if (lt->pos >= lt->nbytes)
941  {
942  /* Try to load more data into buffer. */
943  if (!ltsReadFillBuffer(lt))
944  break; /* EOF */
945  }
946 
947  nthistime = lt->nbytes - lt->pos;
948  if (nthistime > size)
949  nthistime = size;
950  Assert(nthistime > 0);
951 
952  memcpy(ptr, lt->buffer + lt->pos, nthistime);
953 
954  lt->pos += nthistime;
955  ptr = (char *) ptr + nthistime;
956  size -= nthistime;
957  nread += nthistime;
958  }
959 
960  return nread;
961 }
static bool ltsReadFillBuffer(LogicalTape *lt)
Definition: logtape.c:298

References Assert(), LogicalTape::buffer, ltsInitReadBuffer(), ltsReadFillBuffer(), LogicalTape::nbytes, LogicalTape::pos, and LogicalTape::writing.

Referenced by getlen(), and hashagg_batch_read().

◆ LogicalTapeRewindForRead()

void LogicalTapeRewindForRead ( LogicalTape lt,
size_t  buffer_size 
)

Definition at line 846 of file logtape.c.

847 {
848  LogicalTapeSet *lts = lt->tapeSet;
849 
850  /*
851  * Round and cap buffer_size if needed.
852  */
853  if (lt->frozen)
854  buffer_size = BLCKSZ;
855  else
856  {
857  /* need at least one block */
858  if (buffer_size < BLCKSZ)
859  buffer_size = BLCKSZ;
860 
861  /* palloc() larger than max_size is unlikely to be helpful */
862  if (buffer_size > lt->max_size)
863  buffer_size = lt->max_size;
864 
865  /* round down to BLCKSZ boundary */
866  buffer_size -= buffer_size % BLCKSZ;
867  }
868 
869  if (lt->writing)
870  {
871  /*
872  * Completion of a write phase. Flush last partial data block, and
873  * rewind for normal (destructive) read.
874  */
875  if (lt->dirty)
876  {
877  /*
878  * As long as we've filled the buffer at least once, its contents
879  * are entirely defined from valgrind's point of view, even though
880  * contents beyond the current end point may be stale. But it's
881  * possible - at least in the case of a parallel sort - to sort
882  * such small amount of data that we do not fill the buffer even
883  * once. Tell valgrind that its contents are defined, so it
884  * doesn't bleat.
885  */
887  lt->buffer_size - lt->nbytes);
888 
889  TapeBlockSetNBytes(lt->buffer, lt->nbytes);
891  }
892  lt->writing = false;
893  }
894  else
895  {
896  /*
897  * This is only OK if tape is frozen; we rewind for (another) read
898  * pass.
899  */
900  Assert(lt->frozen);
901  }
902 
903  if (lt->buffer)
904  pfree(lt->buffer);
905 
906  /* the buffer is lazily allocated, but set the size here */
907  lt->buffer = NULL;
908  lt->buffer_size = buffer_size;
909 
910  /* free the preallocation list, and return unused block numbers */
911  if (lt->prealloc != NULL)
912  {
913  for (int i = lt->nprealloc; i > 0; i--)
914  ltsReleaseBlock(lts, lt->prealloc[i - 1]);
915  pfree(lt->prealloc);
916  lt->prealloc = NULL;
917  lt->nprealloc = 0;
918  lt->prealloc_size = 0;
919  }
920 }
static void ltsReleaseBlock(LogicalTapeSet *lts, long blocknum)
Definition: logtape.c:469
long * prealloc
Definition: logtape.c:175
int nprealloc
Definition: logtape.c:176
int prealloc_size
Definition: logtape.c:177

References Assert(), LogicalTape::buffer, LogicalTape::buffer_size, LogicalTape::curBlockNumber, LogicalTape::dirty, LogicalTape::frozen, i, ltsReleaseBlock(), ltsWriteBlock(), LogicalTape::max_size, LogicalTape::nbytes, LogicalTape::nprealloc, pfree(), LogicalTape::prealloc, LogicalTape::prealloc_size, TapeBlockSetNBytes, LogicalTape::tapeSet, VALGRIND_MAKE_MEM_DEFINED, and LogicalTape::writing.

Referenced by hashagg_spill_finish(), mergeruns(), and tuplesort_rescan().

◆ LogicalTapeSeek()

void LogicalTapeSeek ( LogicalTape lt,
long  blocknum,
int  offset 
)

Definition at line 1133 of file logtape.c.

1134 {
1135  Assert(lt->frozen);
1136  Assert(offset >= 0 && offset <= TapeBlockPayloadSize);
1137  Assert(lt->buffer_size == BLCKSZ);
1138 
1139  if (lt->buffer == NULL)
1140  ltsInitReadBuffer(lt);
1141 
1142  if (blocknum != lt->curBlockNumber)
1143  {
1144  ltsReadBlock(lt->tapeSet, blocknum, lt->buffer);
1145  lt->curBlockNumber = blocknum;
1147  lt->nextBlockNumber = TapeBlockGetTrailer(lt->buffer)->next;
1148  }
1149 
1150  if (offset > lt->nbytes)
1151  elog(ERROR, "invalid tape seek position");
1152  lt->pos = offset;
1153 }

References Assert(), LogicalTape::buffer, LogicalTape::buffer_size, LogicalTape::curBlockNumber, elog(), ERROR, LogicalTape::frozen, ltsInitReadBuffer(), ltsReadBlock(), LogicalTape::nbytes, LogicalTape::nextBlockNumber, LogicalTape::pos, TapeBlockGetTrailer, TapeBlockPayloadSize, and LogicalTape::tapeSet.

Referenced by tuplesort_restorepos().

◆ LogicalTapeSetBlocks()

long LogicalTapeSetBlocks ( LogicalTapeSet lts)

Definition at line 1183 of file logtape.c.

1184 {
1185  return lts->nBlocksWritten - lts->nHoleBlocks;
1186 }

References LogicalTapeSet::nBlocksWritten, and LogicalTapeSet::nHoleBlocks.

Referenced by hash_agg_update_metrics(), tuplesort_free(), and tuplesort_updatemax().

◆ LogicalTapeSetClose()

void LogicalTapeSetClose ( LogicalTapeSet lts)

Definition at line 667 of file logtape.c.

668 {
669  BufFileClose(lts->pfile);
670  pfree(lts->freeBlocks);
671  pfree(lts);
672 }
void BufFileClose(BufFile *file)
Definition: buffile.c:412
long * freeBlocks
Definition: logtape.c:216

References BufFileClose(), LogicalTapeSet::freeBlocks, LogicalTapeSet::pfile, and pfree().

Referenced by hashagg_reset_spill_state(), and tuplesort_free().

◆ LogicalTapeSetCreate()

LogicalTapeSet* LogicalTapeSetCreate ( bool  preallocate,
SharedFileSet fileset,
int  worker 
)

Definition at line 556 of file logtape.c.

557 {
558  LogicalTapeSet *lts;
559 
560  /*
561  * Create top-level struct including per-tape LogicalTape structs.
562  */
563  lts = (LogicalTapeSet *) palloc(sizeof(LogicalTapeSet));
564  lts->nBlocksAllocated = 0L;
565  lts->nBlocksWritten = 0L;
566  lts->nHoleBlocks = 0L;
567  lts->forgetFreeSpace = false;
568  lts->freeBlocksLen = 32; /* reasonable initial guess */
569  lts->freeBlocks = (long *) palloc(lts->freeBlocksLen * sizeof(long));
570  lts->nFreeBlocks = 0;
571  lts->enable_prealloc = preallocate;
572 
573  lts->fileset = fileset;
574  lts->worker = worker;
575 
576  /*
577  * Create temp BufFile storage as required.
578  *
579  * In leader, we hijack the BufFile of the first tape that's imported, and
580  * concatenate the BufFiles of any subsequent tapes to that. Hence don't
581  * create a BufFile here. Things are simpler for the worker case and the
582  * serial case, though. They are generally very similar -- workers use a
583  * shared fileset, whereas serial sorts use a conventional serial BufFile.
584  */
585  if (fileset && worker == -1)
586  lts->pfile = NULL;
587  else if (fileset)
588  {
589  char filename[MAXPGPATH];
590 
591  pg_itoa(worker, filename);
592  lts->pfile = BufFileCreateFileSet(&fileset->fs, filename);
593  }
594  else
595  lts->pfile = BufFileCreateTemp(false);
596 
597  return lts;
598 }
BufFile * BufFileCreateTemp(bool interXact)
Definition: buffile.c:193
BufFile * BufFileCreateFileSet(FileSet *fileset, const char *name)
Definition: buffile.c:267
long nFreeBlocks
Definition: logtape.c:217
bool forgetFreeSpace
Definition: logtape.c:215
Size freeBlocksLen
Definition: logtape.c:218
bool enable_prealloc
Definition: logtape.c:219

References BufFileCreateFileSet(), BufFileCreateTemp(), LogicalTapeSet::enable_prealloc, filename, LogicalTapeSet::fileset, LogicalTapeSet::forgetFreeSpace, LogicalTapeSet::freeBlocks, LogicalTapeSet::freeBlocksLen, SharedFileSet::fs, MAXPGPATH, LogicalTapeSet::nBlocksAllocated, LogicalTapeSet::nBlocksWritten, LogicalTapeSet::nFreeBlocks, LogicalTapeSet::nHoleBlocks, palloc(), LogicalTapeSet::pfile, pg_itoa(), and LogicalTapeSet::worker.

Referenced by hash_agg_enter_spill_mode(), inittapes(), and leader_takeover_tapes().

◆ LogicalTapeSetForgetFreeSpace()

void LogicalTapeSetForgetFreeSpace ( LogicalTapeSet lts)

Definition at line 750 of file logtape.c.

751 {
752  lts->forgetFreeSpace = true;
753 }

References LogicalTapeSet::forgetFreeSpace.

Referenced by mergeruns().

◆ LogicalTapeTell()

void LogicalTapeTell ( LogicalTape lt,
long *  blocknum,
int *  offset 
)

Definition at line 1162 of file logtape.c.

1163 {
1164  if (lt->buffer == NULL)
1165  ltsInitReadBuffer(lt);
1166 
1167  Assert(lt->offsetBlockNumber == 0L);
1168 
1169  /* With a larger buffer, 'pos' wouldn't be the same as offset within page */
1170  Assert(lt->buffer_size == BLCKSZ);
1171 
1172  *blocknum = lt->curBlockNumber;
1173  *offset = lt->pos;
1174 }

References Assert(), LogicalTape::buffer, LogicalTape::buffer_size, LogicalTape::curBlockNumber, ltsInitReadBuffer(), LogicalTape::offsetBlockNumber, and LogicalTape::pos.

Referenced by tuplesort_markpos().

◆ LogicalTapeWrite()

void LogicalTapeWrite ( LogicalTape lt,
const void *  ptr,
size_t  size 
)

Definition at line 761 of file logtape.c.

762 {
763  LogicalTapeSet *lts = lt->tapeSet;
764  size_t nthistime;
765 
766  Assert(lt->writing);
767  Assert(lt->offsetBlockNumber == 0L);
768 
769  /* Allocate data buffer and first block on first write */
770  if (lt->buffer == NULL)
771  {
772  lt->buffer = (char *) palloc(BLCKSZ);
773  lt->buffer_size = BLCKSZ;
774  }
775  if (lt->curBlockNumber == -1)
776  {
777  Assert(lt->firstBlockNumber == -1);
778  Assert(lt->pos == 0);
779 
780  lt->curBlockNumber = ltsGetBlock(lts, lt);
782 
783  TapeBlockGetTrailer(lt->buffer)->prev = -1L;
784  }
785 
786  Assert(lt->buffer_size == BLCKSZ);
787  while (size > 0)
788  {
789  if (lt->pos >= (int) TapeBlockPayloadSize)
790  {
791  /* Buffer full, dump it out */
792  long nextBlockNumber;
793 
794  if (!lt->dirty)
795  {
796  /* Hmm, went directly from reading to writing? */
797  elog(ERROR, "invalid logtape state: should be dirty");
798  }
799 
800  /*
801  * First allocate the next block, so that we can store it in the
802  * 'next' pointer of this block.
803  */
804  nextBlockNumber = ltsGetBlock(lt->tapeSet, lt);
805 
806  /* set the next-pointer and dump the current block. */
807  TapeBlockGetTrailer(lt->buffer)->next = nextBlockNumber;
809 
810  /* initialize the prev-pointer of the next block */
811  TapeBlockGetTrailer(lt->buffer)->prev = lt->curBlockNumber;
812  lt->curBlockNumber = nextBlockNumber;
813  lt->pos = 0;
814  lt->nbytes = 0;
815  }
816 
817  nthistime = TapeBlockPayloadSize - lt->pos;
818  if (nthistime > size)
819  nthistime = size;
820  Assert(nthistime > 0);
821 
822  memcpy(lt->buffer + lt->pos, ptr, nthistime);
823 
824  lt->dirty = true;
825  lt->pos += nthistime;
826  if (lt->nbytes < lt->pos)
827  lt->nbytes = lt->pos;
828  ptr = (const char *) ptr + nthistime;
829  size -= nthistime;
830  }
831 }
static long ltsGetBlock(LogicalTapeSet *lts, LogicalTape *lt)
Definition: logtape.c:358

References Assert(), LogicalTape::buffer, LogicalTape::buffer_size, LogicalTape::curBlockNumber, LogicalTape::dirty, elog(), ERROR, LogicalTape::firstBlockNumber, ltsGetBlock(), ltsWriteBlock(), LogicalTape::nbytes, LogicalTape::offsetBlockNumber, palloc(), LogicalTape::pos, TapeBlockGetTrailer, TapeBlockPayloadSize, LogicalTape::tapeSet, and LogicalTape::writing.

Referenced by hashagg_spill_tuple(), markrunend(), writetup_cluster(), writetup_datum(), writetup_heap(), and writetup_index().

◆ ltsCreateTape()

static LogicalTape * ltsCreateTape ( LogicalTapeSet lts)
static

Definition at line 696 of file logtape.c.

697 {
698  LogicalTape *lt;
699 
700  /*
701  * Create per-tape struct. Note we allocate the I/O buffer lazily.
702  */
703  lt = palloc(sizeof(LogicalTape));
704  lt->tapeSet = lts;
705  lt->writing = true;
706  lt->frozen = false;
707  lt->dirty = false;
708  lt->firstBlockNumber = -1L;
709  lt->curBlockNumber = -1L;
710  lt->nextBlockNumber = -1L;
711  lt->offsetBlockNumber = 0L;
712  lt->buffer = NULL;
713  lt->buffer_size = 0;
714  /* palloc() larger than MaxAllocSize would fail */
715  lt->max_size = MaxAllocSize;
716  lt->pos = 0;
717  lt->nbytes = 0;
718  lt->prealloc = NULL;
719  lt->nprealloc = 0;
720  lt->prealloc_size = 0;
721 
722  return lt;
723 }

References LogicalTape::buffer, LogicalTape::buffer_size, LogicalTape::curBlockNumber, LogicalTape::dirty, LogicalTape::firstBlockNumber, LogicalTape::frozen, LogicalTape::max_size, MaxAllocSize, LogicalTape::nbytes, LogicalTape::nextBlockNumber, LogicalTape::nprealloc, LogicalTape::offsetBlockNumber, palloc(), LogicalTape::pos, LogicalTape::prealloc, LogicalTape::prealloc_size, LogicalTape::tapeSet, and LogicalTape::writing.

Referenced by LogicalTapeCreate(), and LogicalTapeImport().

◆ ltsGetBlock()

static long ltsGetBlock ( LogicalTapeSet lts,
LogicalTape lt 
)
static

Definition at line 358 of file logtape.c.

359 {
360  if (lts->enable_prealloc)
361  return ltsGetPreallocBlock(lts, lt);
362  else
363  return ltsGetFreeBlock(lts);
364 }
static long ltsGetPreallocBlock(LogicalTapeSet *lts, LogicalTape *lt)
Definition: logtape.c:431
static long ltsGetFreeBlock(LogicalTapeSet *lts)
Definition: logtape.c:371

References LogicalTapeSet::enable_prealloc, ltsGetFreeBlock(), and ltsGetPreallocBlock().

Referenced by LogicalTapeWrite().

◆ ltsGetFreeBlock()

static long ltsGetFreeBlock ( LogicalTapeSet lts)
static

Definition at line 371 of file logtape.c.

372 {
373  long *heap = lts->freeBlocks;
374  long blocknum;
375  long heapsize;
376  long holeval;
377  unsigned long holepos;
378 
379  /* freelist empty; allocate a new block */
380  if (lts->nFreeBlocks == 0)
381  return lts->nBlocksAllocated++;
382 
383  /* easy if heap contains one element */
384  if (lts->nFreeBlocks == 1)
385  {
386  lts->nFreeBlocks--;
387  return lts->freeBlocks[0];
388  }
389 
390  /* remove top of minheap */
391  blocknum = heap[0];
392 
393  /* we'll replace it with end of minheap array */
394  holeval = heap[--lts->nFreeBlocks];
395 
396  /* sift down */
397  holepos = 0; /* holepos is where the "hole" is */
398  heapsize = lts->nFreeBlocks;
399  while (true)
400  {
401  unsigned long left = left_offset(holepos);
402  unsigned long right = right_offset(holepos);
403  unsigned long min_child;
404 
405  if (left < heapsize && right < heapsize)
406  min_child = (heap[left] < heap[right]) ? left : right;
407  else if (left < heapsize)
408  min_child = left;
409  else if (right < heapsize)
410  min_child = right;
411  else
412  break;
413 
414  if (heap[min_child] >= holeval)
415  break;
416 
417  heap[holepos] = heap[min_child];
418  holepos = min_child;
419  }
420  heap[holepos] = holeval;
421 
422  return blocknum;
423 }
static unsigned long right_offset(unsigned long i)
Definition: logtape.c:343
static unsigned long left_offset(unsigned long i)
Definition: logtape.c:337

References LogicalTapeSet::freeBlocks, left_offset(), LogicalTapeSet::nBlocksAllocated, LogicalTapeSet::nFreeBlocks, and right_offset().

Referenced by ltsGetBlock(), and ltsGetPreallocBlock().

◆ ltsGetPreallocBlock()

static long ltsGetPreallocBlock ( LogicalTapeSet lts,
LogicalTape lt 
)
static

Definition at line 431 of file logtape.c.

432 {
433  /* sorted in descending order, so return the last element */
434  if (lt->nprealloc > 0)
435  return lt->prealloc[--lt->nprealloc];
436 
437  if (lt->prealloc == NULL)
438  {
440  lt->prealloc = (long *) palloc(sizeof(long) * lt->prealloc_size);
441  }
442  else if (lt->prealloc_size < TAPE_WRITE_PREALLOC_MAX)
443  {
444  /* when the preallocation list runs out, double the size */
445  lt->prealloc_size *= 2;
448  lt->prealloc = (long *) repalloc(lt->prealloc,
449  sizeof(long) * lt->prealloc_size);
450  }
451 
452  /* refill preallocation list */
453  lt->nprealloc = lt->prealloc_size;
454  for (int i = lt->nprealloc; i > 0; i--)
455  {
456  lt->prealloc[i - 1] = ltsGetFreeBlock(lts);
457 
458  /* verify descending order */
459  Assert(i == lt->nprealloc || lt->prealloc[i - 1] > lt->prealloc[i]);
460  }
461 
462  return lt->prealloc[--lt->nprealloc];
463 }
#define TAPE_WRITE_PREALLOC_MIN
Definition: logtape.c:124
#define TAPE_WRITE_PREALLOC_MAX
Definition: logtape.c:125
void * repalloc(void *pointer, Size size)
Definition: mcxt.c:1476

References Assert(), i, ltsGetFreeBlock(), LogicalTape::nprealloc, palloc(), LogicalTape::prealloc, LogicalTape::prealloc_size, repalloc(), TAPE_WRITE_PREALLOC_MAX, and TAPE_WRITE_PREALLOC_MIN.

Referenced by ltsGetBlock().

◆ ltsInitReadBuffer()

static void ltsInitReadBuffer ( LogicalTape lt)
static

Definition at line 522 of file logtape.c.

523 {
524  Assert(lt->buffer_size > 0);
525  lt->buffer = palloc(lt->buffer_size);
526 
527  /* Read the first block, or reset if tape is empty */
529  lt->pos = 0;
530  lt->nbytes = 0;
531  ltsReadFillBuffer(lt);
532 }

References Assert(), LogicalTape::buffer, LogicalTape::buffer_size, LogicalTape::firstBlockNumber, ltsReadFillBuffer(), LogicalTape::nbytes, LogicalTape::nextBlockNumber, palloc(), and LogicalTape::pos.

Referenced by LogicalTapeBackspace(), LogicalTapeRead(), LogicalTapeSeek(), and LogicalTapeTell().

◆ ltsReadBlock()

static void ltsReadBlock ( LogicalTapeSet lts,
long  blocknum,
void *  buffer 
)
static

Definition at line 282 of file logtape.c.

283 {
284  if (BufFileSeekBlock(lts->pfile, blocknum) != 0)
285  ereport(ERROR,
287  errmsg("could not seek to block %ld of temporary file",
288  blocknum)));
289  BufFileReadExact(lts->pfile, buffer, BLCKSZ);
290 }
void BufFileReadExact(BufFile *file, void *ptr, size_t size)
Definition: buffile.c:654
int BufFileSeekBlock(BufFile *file, long blknum)
Definition: buffile.c:851
int errcode_for_file_access(void)
Definition: elog.c:881
int errmsg(const char *fmt,...)
Definition: elog.c:1069
#define ereport(elevel,...)
Definition: elog.h:149

References BufFileReadExact(), BufFileSeekBlock(), ereport, errcode_for_file_access(), errmsg(), ERROR, and LogicalTapeSet::pfile.

Referenced by LogicalTapeBackspace(), LogicalTapeFreeze(), LogicalTapeSeek(), and ltsReadFillBuffer().

◆ ltsReadFillBuffer()

static bool ltsReadFillBuffer ( LogicalTape lt)
static

Definition at line 298 of file logtape.c.

299 {
300  lt->pos = 0;
301  lt->nbytes = 0;
302 
303  do
304  {
305  char *thisbuf = lt->buffer + lt->nbytes;
306  long datablocknum = lt->nextBlockNumber;
307 
308  /* Fetch next block number */
309  if (datablocknum == -1L)
310  break; /* EOF */
311  /* Apply worker offset, needed for leader tapesets */
312  datablocknum += lt->offsetBlockNumber;
313 
314  /* Read the block */
315  ltsReadBlock(lt->tapeSet, datablocknum, thisbuf);
316  if (!lt->frozen)
317  ltsReleaseBlock(lt->tapeSet, datablocknum);
319 
320  lt->nbytes += TapeBlockGetNBytes(thisbuf);
321  if (TapeBlockIsLast(thisbuf))
322  {
323  lt->nextBlockNumber = -1L;
324  /* EOF */
325  break;
326  }
327  else
328  lt->nextBlockNumber = TapeBlockGetTrailer(thisbuf)->next;
329 
330  /* Advance to next block, if we have buffer space left */
331  } while (lt->buffer_size - lt->nbytes > BLCKSZ);
332 
333  return (lt->nbytes > 0);
334 }

References LogicalTape::buffer, LogicalTape::buffer_size, LogicalTape::curBlockNumber, LogicalTape::frozen, ltsReadBlock(), ltsReleaseBlock(), LogicalTape::nbytes, LogicalTape::nextBlockNumber, LogicalTape::offsetBlockNumber, LogicalTape::pos, TapeBlockGetNBytes, TapeBlockGetTrailer, TapeBlockIsLast, and LogicalTape::tapeSet.

Referenced by LogicalTapeRead(), and ltsInitReadBuffer().

◆ ltsReleaseBlock()

static void ltsReleaseBlock ( LogicalTapeSet lts,
long  blocknum 
)
static

Definition at line 469 of file logtape.c.

470 {
471  long *heap;
472  unsigned long holepos;
473 
474  /*
475  * Do nothing if we're no longer interested in remembering free space.
476  */
477  if (lts->forgetFreeSpace)
478  return;
479 
480  /*
481  * Enlarge freeBlocks array if full.
482  */
483  if (lts->nFreeBlocks >= lts->freeBlocksLen)
484  {
485  /*
486  * If the freelist becomes very large, just return and leak this free
487  * block.
488  */
489  if (lts->freeBlocksLen * 2 * sizeof(long) > MaxAllocSize)
490  return;
491 
492  lts->freeBlocksLen *= 2;
493  lts->freeBlocks = (long *) repalloc(lts->freeBlocks,
494  lts->freeBlocksLen * sizeof(long));
495  }
496 
497  /* create a "hole" at end of minheap array */
498  heap = lts->freeBlocks;
499  holepos = lts->nFreeBlocks;
500  lts->nFreeBlocks++;
501 
502  /* sift up to insert blocknum */
503  while (holepos != 0)
504  {
505  unsigned long parent = parent_offset(holepos);
506 
507  if (heap[parent] < blocknum)
508  break;
509 
510  heap[holepos] = heap[parent];
511  holepos = parent;
512  }
513  heap[holepos] = blocknum;
514 }
static unsigned long parent_offset(unsigned long i)
Definition: logtape.c:349

References LogicalTapeSet::forgetFreeSpace, LogicalTapeSet::freeBlocks, LogicalTapeSet::freeBlocksLen, MaxAllocSize, LogicalTapeSet::nFreeBlocks, parent_offset(), and repalloc().

Referenced by LogicalTapeRewindForRead(), and ltsReadFillBuffer().

◆ ltsWriteBlock()

static void ltsWriteBlock ( LogicalTapeSet lts,
long  blocknum,
const void *  buffer 
)
static

Definition at line 238 of file logtape.c.

239 {
240  /*
241  * BufFile does not support "holes", so if we're about to write a block
242  * that's past the current end of file, fill the space between the current
243  * end of file and the target block with zeros.
244  *
245  * This can happen either when tapes preallocate blocks; or for the last
246  * block of a tape which might not have been flushed.
247  *
248  * Note that BufFile concatenation can leave "holes" in BufFile between
249  * worker-owned block ranges. These are tracked for reporting purposes
250  * only. We never read from nor write to these hole blocks, and so they
251  * are not considered here.
252  */
253  while (blocknum > lts->nBlocksWritten)
254  {
255  PGIOAlignedBlock zerobuf;
256 
257  MemSet(zerobuf.data, 0, sizeof(zerobuf));
258 
259  ltsWriteBlock(lts, lts->nBlocksWritten, zerobuf.data);
260  }
261 
262  /* Write the requested block */
263  if (BufFileSeekBlock(lts->pfile, blocknum) != 0)
264  ereport(ERROR,
266  errmsg("could not seek to block %ld of temporary file",
267  blocknum)));
268  BufFileWrite(lts->pfile, buffer, BLCKSZ);
269 
270  /* Update nBlocksWritten, if we extended the file */
271  if (blocknum == lts->nBlocksWritten)
272  lts->nBlocksWritten++;
273 }
void BufFileWrite(BufFile *file, const void *ptr, size_t size)
Definition: buffile.c:676
#define MemSet(start, val, len)
Definition: c.h:1009
char data[BLCKSZ]
Definition: c.h:1150

References BufFileSeekBlock(), BufFileWrite(), PGIOAlignedBlock::data, ereport, errcode_for_file_access(), errmsg(), ERROR, MemSet, LogicalTapeSet::nBlocksWritten, and LogicalTapeSet::pfile.

Referenced by LogicalTapeFreeze(), LogicalTapeRewindForRead(), and LogicalTapeWrite().

◆ parent_offset()

static unsigned long parent_offset ( unsigned long  i)
inlinestatic

Definition at line 349 of file logtape.c.

350 {
351  return (i - 1) / 2;
352 }

References i.

Referenced by ltsReleaseBlock().

◆ right_offset()

static unsigned long right_offset ( unsigned long  i)
inlinestatic

Definition at line 343 of file logtape.c.

344 {
345  return 2 * i + 2;
346 }

References i.

Referenced by ltsGetFreeBlock().