diff options
| -rw-r--r-- | src/backend/utils/sort/logtape.c | 73 | ||||
| -rw-r--r-- | src/include/utils/logtape.h | 1 |
2 files changed, 47 insertions, 27 deletions
diff --git a/src/backend/utils/sort/logtape.c b/src/backend/utils/sort/logtape.c index 4f78b55fbaf..7ae160e1965 100644 --- a/src/backend/utils/sort/logtape.c +++ b/src/backend/utils/sort/logtape.c @@ -191,8 +191,8 @@ struct LogicalTapeSet Size freeBlocksLen; /* current allocated length of freeBlocks[] */ /* The array of logical tapes. */ - int nTapes; /* # of logical tapes in set */ - LogicalTape tapes[FLEXIBLE_ARRAY_MEMBER]; /* has nTapes nentries */ + int nTapes; /* # of logical tapes in set */ + LogicalTape *tapes; /* has nTapes nentries */ }; static void ltsWriteBlock(LogicalTapeSet *lts, long blocknum, void *buffer); @@ -201,6 +201,7 @@ static long ltsGetFreeBlock(LogicalTapeSet *lts); static void ltsReleaseBlock(LogicalTapeSet *lts, long blocknum); static void ltsConcatWorkerTapes(LogicalTapeSet *lts, TapeShare *shared, SharedFileSet *fileset); +static void ltsInitTape(LogicalTape *lt); static void ltsInitReadBuffer(LogicalTapeSet *lts, LogicalTape *lt); @@ -537,6 +538,27 @@ ltsConcatWorkerTapes(LogicalTapeSet *lts, TapeShare *shared, } /* + * Initialize per-tape struct. Note we allocate the I/O buffer lazily. + */ +static void +ltsInitTape(LogicalTape *lt) +{ + lt->writing = true; + lt->frozen = false; + lt->dirty = false; + lt->firstBlockNumber = -1L; + lt->curBlockNumber = -1L; + lt->nextBlockNumber = -1L; + lt->offsetBlockNumber = 0L; + lt->buffer = NULL; + lt->buffer_size = 0; + /* palloc() larger than MaxAllocSize would fail */ + lt->max_size = MaxAllocSize; + lt->pos = 0; + lt->nbytes = 0; +} + +/* * Lazily allocate and initialize the read buffer. This avoids waste when many * tapes are open at once, but not all are active between rewinding and * reading. @@ -579,15 +601,13 @@ LogicalTapeSetCreate(int ntapes, TapeShare *shared, SharedFileSet *fileset, int worker) { LogicalTapeSet *lts; - LogicalTape *lt; int i; /* * Create top-level struct including per-tape LogicalTape structs. */ Assert(ntapes > 0); - lts = (LogicalTapeSet *) palloc(offsetof(LogicalTapeSet, tapes) + - ntapes * sizeof(LogicalTape)); + lts = (LogicalTapeSet *) palloc(sizeof(LogicalTapeSet)); lts->nBlocksAllocated = 0L; lts->nBlocksWritten = 0L; lts->nHoleBlocks = 0L; @@ -596,30 +616,10 @@ LogicalTapeSetCreate(int ntapes, TapeShare *shared, SharedFileSet *fileset, lts->freeBlocks = (long *) palloc(lts->freeBlocksLen * sizeof(long)); lts->nFreeBlocks = 0; lts->nTapes = ntapes; + lts->tapes = (LogicalTape *) palloc(ntapes * sizeof(LogicalTape)); - /* - * Initialize per-tape structs. Note we allocate the I/O buffer and the - * first block for a tape only when it is first actually written to. This - * avoids wasting memory space when tuplesort.c overestimates the number - * of tapes needed. - */ for (i = 0; i < ntapes; i++) - { - lt = <s->tapes[i]; - lt->writing = true; - lt->frozen = false; - lt->dirty = false; - lt->firstBlockNumber = -1L; - lt->curBlockNumber = -1L; - lt->nextBlockNumber = -1L; - lt->offsetBlockNumber = 0L; - lt->buffer = NULL; - lt->buffer_size = 0; - /* palloc() larger than MaxAllocSize would fail */ - lt->max_size = MaxAllocSize; - lt->pos = 0; - lt->nbytes = 0; - } + ltsInitTape(<s->tapes[i]); /* * Create temp BufFile storage as required. @@ -1005,6 +1005,25 @@ LogicalTapeFreeze(LogicalTapeSet *lts, int tapenum, TapeShare *share) } /* + * Add additional tapes to this tape set. Not intended to be used when any + * tapes are frozen. + */ +void +LogicalTapeSetExtend(LogicalTapeSet *lts, int nAdditional) +{ + int i; + int nTapesOrig = lts->nTapes; + + lts->nTapes += nAdditional; + + lts->tapes = (LogicalTape *) repalloc( + lts->tapes, lts->nTapes * sizeof(LogicalTape)); + + for (i = nTapesOrig; i < lts->nTapes; i++) + ltsInitTape(<s->tapes[i]); +} + +/* * Backspace the tape a given number of bytes. (We also support a more * general seek interface, see below.) * diff --git a/src/include/utils/logtape.h b/src/include/utils/logtape.h index 695d2c00ee4..39a99174afe 100644 --- a/src/include/utils/logtape.h +++ b/src/include/utils/logtape.h @@ -67,6 +67,7 @@ extern void LogicalTapeRewindForRead(LogicalTapeSet *lts, int tapenum, extern void LogicalTapeRewindForWrite(LogicalTapeSet *lts, int tapenum); extern void LogicalTapeFreeze(LogicalTapeSet *lts, int tapenum, TapeShare *share); +extern void LogicalTapeSetExtend(LogicalTapeSet *lts, int nAdditional); extern size_t LogicalTapeBackspace(LogicalTapeSet *lts, int tapenum, size_t size); extern void LogicalTapeSeek(LogicalTapeSet *lts, int tapenum, |