Esempio n. 1
0
/*
 * dumptuples - remove tuples from memory and write to tape
 *
 * As a side effect, we must set readpos and markpos to the value
 * corresponding to "current"; otherwise, a dump would lose the current read
 * position.
 */
static void
dumptuples(Tuplestorestate *state, TuplestorePos *pos)
{
	int			i;

	for (i = 0;; i++)
	{
		if (i == pos->current)
			BufFileTell(state->myfile,
						&pos->readpos_offset);
		if (i == pos->markpos_current)
			BufFileTell(state->myfile,
						&pos->markpos_offset);
		if (i >= state->memtupcount)
			break;
		WRITETUP(state, pos, state->memtuples[i]);
	}
	state->memtupcount = 0;
}
Esempio n. 2
0
/*
 * dumptuples - remove tuples from memory and write to tape
 *
 * As a side effect, we must convert each read pointer's position from
 * "current" to file/offset format.  But eof_reached pointers don't
 * need to change state.
 */
static void
dumptuples(Tuplestorestate *state)
{
	int			i;

	for (i = 0;; i++)
	{
		TSReadPointer *readptr = state->readptrs;
		int			j;

		for (j = 0; j < state->readptrcount; readptr++, j++)
		{
			if (i == readptr->current && !readptr->eof_reached)
				BufFileTell(state->myfile,
							&readptr->file, &readptr->offset);
		}
		if (i >= state->memtupcount)
			break;
		WRITETUP(state, state->memtuples[i]);
	}
	state->memtupcount = 0;
}
Esempio n. 3
0
static void
tuplestore_puttuple_common(Tuplestorestate *state, void *tuple)
{
	TSReadPointer *readptr;
	int			i;
	ResourceOwner oldowner;

	state->tuples++;

	switch (state->status)
	{
		case TSS_INMEM:

			/*
			 * Update read pointers as needed; see API spec above.
			 */
			readptr = state->readptrs;
			for (i = 0; i < state->readptrcount; readptr++, i++)
			{
				if (readptr->eof_reached && i != state->activeptr)
				{
					readptr->eof_reached = false;
					readptr->current = state->memtupcount;
				}
			}

			/*
			 * Grow the array as needed.  Note that we try to grow the array
			 * when there is still one free slot remaining --- if we fail,
			 * there'll still be room to store the incoming tuple, and then
			 * we'll switch to tape-based operation.
			 */
			if (state->memtupcount >= state->memtupsize - 1)
			{
				(void) grow_memtuples(state);
				Assert(state->memtupcount < state->memtupsize);
			}

			/* Stash the tuple in the in-memory array */
			state->memtuples[state->memtupcount++] = tuple;

			/*
			 * Done if we still fit in available memory and have array slots.
			 */
			if (state->memtupcount < state->memtupsize && !LACKMEM(state))
				return;

			/*
			 * Nope; time to switch to tape-based operation.  Make sure that
			 * the temp file(s) are created in suitable temp tablespaces.
			 */
			PrepareTempTablespaces();

			/* associate the file with the store's resource owner */
			oldowner = CurrentResourceOwner;
			CurrentResourceOwner = state->resowner;

			state->myfile = BufFileCreateTemp(state->interXact);

			CurrentResourceOwner = oldowner;

			/*
			 * Freeze the decision about whether trailing length words will be
			 * used.  We can't change this choice once data is on tape, even
			 * though callers might drop the requirement.
			 */
			state->backward = (state->eflags & EXEC_FLAG_BACKWARD) != 0;
			state->status = TSS_WRITEFILE;
			dumptuples(state);
			break;
		case TSS_WRITEFILE:

			/*
			 * Update read pointers as needed; see API spec above. Note:
			 * BufFileTell is quite cheap, so not worth trying to avoid
			 * multiple calls.
			 */
			readptr = state->readptrs;
			for (i = 0; i < state->readptrcount; readptr++, i++)
			{
				if (readptr->eof_reached && i != state->activeptr)
				{
					readptr->eof_reached = false;
					BufFileTell(state->myfile,
								&readptr->file,
								&readptr->offset);
				}
			}

			WRITETUP(state, tuple);
			break;
		case TSS_READFILE:

			/*
			 * Switch from reading to writing.
			 */
			if (!state->readptrs[state->activeptr].eof_reached)
				BufFileTell(state->myfile,
							&state->readptrs[state->activeptr].file,
							&state->readptrs[state->activeptr].offset);
			if (BufFileSeek(state->myfile,
							state->writepos_file, state->writepos_offset,
							SEEK_SET) != 0)
				ereport(ERROR,
						(errcode_for_file_access(),
				 errmsg("could not seek in tuplestore temporary file: %m")));
			state->status = TSS_WRITEFILE;

			/*
			 * Update read pointers as needed; see API spec above.
			 */
			readptr = state->readptrs;
			for (i = 0; i < state->readptrcount; readptr++, i++)
			{
				if (readptr->eof_reached && i != state->activeptr)
				{
					readptr->eof_reached = false;
					readptr->file = state->writepos_file;
					readptr->offset = state->writepos_offset;
				}
			}

			WRITETUP(state, tuple);
			break;
		default:
			elog(ERROR, "invalid tuplestore state");
			break;
	}
}
Esempio n. 4
0
static void
tuplestore_puttuple_common(Tuplestorestate *state, TuplestorePos *pos, void *tuple)
{
	ResourceOwner oldowner;

	switch (state->status)
	{
		case TSS_INMEM:

			/*
			 * Grow the array as needed.  Note that we try to grow the array
			 * when there is still one free slot remaining --- if we fail,
			 * there'll still be room to store the incoming tuple, and then
			 * we'll switch to tape-based operation.
			 */
			if (state->memtupcount >= state->memtupsize - 1)
			{
				/*
				 * See grow_memtuples() in tuplesort.c for the rationale
				 * behind these two tests.
				 */
				if (state->availMem > (long) (state->memtupsize * sizeof(void *)) &&
					(Size) (state->memtupsize * 2) < MaxAllocSize / sizeof(void *))
				{
					FREEMEM(state, GetMemoryChunkSpace(state->memtuples));
					state->memtupsize *= 2;
					state->memtuples = (void **)
						repalloc(state->memtuples,
								 state->memtupsize * sizeof(void *));
					USEMEM(state, GetMemoryChunkSpace(state->memtuples));
				}
			}

			/* Stash the tuple in the in-memory array */
			state->memtuples[state->memtupcount++] = tuple;

			/* If eof_reached, keep read position in sync */
			if (pos->eof_reached)
				pos->current = state->memtupcount;

			/*
			 * Done if we still fit in available memory and have array slots.
			 */
			if (state->memtupcount < state->memtupsize && !LACKMEM(state))
				return;

			/*
			 * Nope; time to switch to tape-based operation.  Make sure that
			 * the temp file(s) are created in suitable temp tablespaces.
			 */
			PrepareTempTablespaces();

			/* associate the file with the store's resource owner */
			oldowner = CurrentResourceOwner;
			CurrentResourceOwner = state->resowner;

			{
				char tmpprefix[50];
				snprintf(tmpprefix, 50, "slice%d_tuplestore", currentSliceId);
				state->myfile = BufFileCreateTemp(tmpprefix, state->interXact);
			}

			CurrentResourceOwner = oldowner;

			state->status = TSS_WRITEFILE;
			dumptuples(state, pos);
			break;
		case TSS_WRITEFILE:
			WRITETUP(state, pos, tuple);
			break;
		case TSS_READFILE:

			/*
			 * Switch from reading to writing.
			 */
			if (!pos->eof_reached)
				BufFileTell(state->myfile,
							&pos->readpos_offset);
			if (BufFileSeek(state->myfile,
							pos->writepos_offset,
							SEEK_SET) != 0)
				elog(ERROR, "seek to EOF failed");
			state->status = TSS_WRITEFILE;
			WRITETUP(state, pos, tuple);
			break;
		default:
			elog(ERROR, "invalid tuplestore state");
			break;
	}
}
Esempio n. 5
0
static void
tuplestore_puttuple_common(Tuplestorestate *state, void *tuple)
{
	TSReadPointer *readptr;
	int			i;
	ResourceOwner oldowner;

	switch (state->status)
	{
		case TSS_INMEM:

			/*
			 * Update read pointers as needed; see API spec above.
			 */
			readptr = state->readptrs;
			for (i = 0; i < state->readptrcount; readptr++, i++)
			{
				if (readptr->eof_reached && i != state->activeptr)
				{
					readptr->eof_reached = false;
					readptr->current = state->memtupcount;
				}
			}

			/*
			 * Grow the array as needed.  Note that we try to grow the array
			 * when there is still one free slot remaining --- if we fail,
			 * there'll still be room to store the incoming tuple, and then
			 * we'll switch to tape-based operation.
			 */
			if (state->memtupcount >= state->memtupsize - 1)
			{
				/*
				 * See grow_memtuples() in tuplesort.c for the rationale
				 * behind these two tests.
				 */
				if (state->availMem > (long) (state->memtupsize * sizeof(void *)) &&
					(Size) (state->memtupsize * 2) < MaxAllocSize / sizeof(void *))
				{
					FREEMEM(state, GetMemoryChunkSpace(state->memtuples));
					state->memtupsize *= 2;
					state->memtuples = (void **)
						repalloc(state->memtuples,
								 state->memtupsize * sizeof(void *));
					USEMEM(state, GetMemoryChunkSpace(state->memtuples));
					if (LACKMEM(state))
						elog(ERROR, "unexpected out-of-memory situation in tuplestore");
				}
			}

			/* Stash the tuple in the in-memory array */
			state->memtuples[state->memtupcount++] = tuple;

			/*
			 * Done if we still fit in available memory and have array slots.
			 */
			if (state->memtupcount < state->memtupsize && !LACKMEM(state))
				return;

			/*
			 * Nope; time to switch to tape-based operation.  Make sure that
			 * the temp file(s) are created in suitable temp tablespaces.
			 */
			PrepareTempTablespaces();

			/* associate the file with the store's resource owner */
			oldowner = CurrentResourceOwner;
			CurrentResourceOwner = state->resowner;

			char tmpprefix[50];
			snprintf(tmpprefix, 50, "slice%d_tuplestore", currentSliceId);
			state->myfile = BufFileCreateTemp(tmpprefix, state->interXact);

			CurrentResourceOwner = oldowner;

			/*
			 * Freeze the decision about whether trailing length words will be
			 * used.  We can't change this choice once data is on tape, even
			 * though callers might drop the requirement.
			 */
			state->backward = (state->eflags & EXEC_FLAG_BACKWARD) != 0;
			state->status = TSS_WRITEFILE;
			dumptuples(state);
			break;
		case TSS_WRITEFILE:

			/*
			 * Update read pointers as needed; see API spec above. Note:
			 * BufFileTell is quite cheap, so not worth trying to avoid
			 * multiple calls.
			 */
			readptr = state->readptrs;
			for (i = 0; i < state->readptrcount; readptr++, i++)
			{
				if (readptr->eof_reached && i != state->activeptr)
				{
					readptr->eof_reached = false;
					BufFileTell(state->myfile,
								&readptr->file,
								&readptr->offset);
				}
			}

			WRITETUP(state, tuple);
			break;
		case TSS_READFILE:

			/*
			 * Switch from reading to writing.
			 */
			if (!state->readptrs[state->activeptr].eof_reached)
				BufFileTell(state->myfile,
							&state->readptrs[state->activeptr].file,
							&state->readptrs[state->activeptr].offset);
			if (BufFileSeek(state->myfile,
							state->writepos_file, state->writepos_offset,
							SEEK_SET) != 0)
				elog(ERROR, "tuplestore seek to EOF failed");
			state->status = TSS_WRITEFILE;

			/*
			 * Update read pointers as needed; see API spec above.
			 */
			readptr = state->readptrs;
			for (i = 0; i < state->readptrcount; readptr++, i++)
			{
				if (readptr->eof_reached && i != state->activeptr)
				{
					readptr->eof_reached = false;
					readptr->file = state->writepos_file;
					readptr->offset = state->writepos_offset;
				}
			}

			WRITETUP(state, tuple);
			break;
		default:
			elog(ERROR, "invalid tuplestore state");
			break;
	}
}