Esempio n. 1
0
/* function subhandler */
Datum
PLy_exec_function(FunctionCallInfo fcinfo, PLyProcedure *proc)
{
	Datum		rv;
	PyObject   *volatile plargs = NULL;
	PyObject   *volatile plrv = NULL;
	FuncCallContext *volatile funcctx = NULL;
	PLySRFState *volatile srfstate = NULL;
	ErrorContextCallback plerrcontext;

	/*
	 * If the function is called recursively, we must push outer-level
	 * arguments into the stack.  This must be immediately before the PG_TRY
	 * to ensure that the corresponding pop happens.
	 */
	PLy_global_args_push(proc);

	PG_TRY();
	{
		if (proc->is_setof)
		{
			/* First Call setup */
			if (SRF_IS_FIRSTCALL())
			{
				funcctx = SRF_FIRSTCALL_INIT();
				srfstate = (PLySRFState *)
					MemoryContextAllocZero(funcctx->multi_call_memory_ctx,
										   sizeof(PLySRFState));
				/* Immediately register cleanup callback */
				srfstate->callback.func = plpython_srf_cleanup_callback;
				srfstate->callback.arg = (void *) srfstate;
				MemoryContextRegisterResetCallback(funcctx->multi_call_memory_ctx,
												   &srfstate->callback);
				funcctx->user_fctx = (void *) srfstate;
			}
			/* Every call setup */
			funcctx = SRF_PERCALL_SETUP();
			Assert(funcctx != NULL);
			srfstate = (PLySRFState *) funcctx->user_fctx;
		}

		if (srfstate == NULL || srfstate->iter == NULL)
		{
			/*
			 * Non-SETOF function or first time for SETOF function: build
			 * args, then actually execute the function.
			 */
			plargs = PLy_function_build_args(fcinfo, proc);
			plrv = PLy_procedure_call(proc, "args", plargs);
			Assert(plrv != NULL);
		}
		else
		{
			/*
			 * Second or later call for a SETOF function: restore arguments in
			 * globals dict to what they were when we left off.  We must do
			 * this in case multiple evaluations of the same SETOF function
			 * are interleaved.  It's a bit annoying, since the iterator may
			 * not look at the arguments at all, but we have no way to know
			 * that.  Fortunately this isn't terribly expensive.
			 */
			if (srfstate->savedargs)
				PLy_function_restore_args(proc, srfstate->savedargs);
			srfstate->savedargs = NULL; /* deleted by restore_args */
		}

		/*
		 * If it returns a set, call the iterator to get the next return item.
		 * We stay in the SPI context while doing this, because PyIter_Next()
		 * calls back into Python code which might contain SPI calls.
		 */
		if (proc->is_setof)
		{
			if (srfstate->iter == NULL)
			{
				/* first time -- do checks and setup */
				ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;

				if (!rsi || !IsA(rsi, ReturnSetInfo) ||
					(rsi->allowedModes & SFRM_ValuePerCall) == 0)
				{
					ereport(ERROR,
							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
							 errmsg("unsupported set function return mode"),
							 errdetail("PL/Python set-returning functions only support returning one value per call.")));
				}
				rsi->returnMode = SFRM_ValuePerCall;

				/* Make iterator out of returned object */
				srfstate->iter = PyObject_GetIter(plrv);

				Py_DECREF(plrv);
				plrv = NULL;

				if (srfstate->iter == NULL)
					ereport(ERROR,
							(errcode(ERRCODE_DATATYPE_MISMATCH),
							 errmsg("returned object cannot be iterated"),
							 errdetail("PL/Python set-returning functions must return an iterable object.")));
			}

			/* Fetch next from iterator */
			plrv = PyIter_Next(srfstate->iter);
			if (plrv == NULL)
			{
				/* Iterator is exhausted or error happened */
				bool		has_error = (PyErr_Occurred() != NULL);

				Py_DECREF(srfstate->iter);
				srfstate->iter = NULL;

				if (has_error)
					PLy_elog(ERROR, "error fetching next item from iterator");

				/* Pass a null through the data-returning steps below */
				Py_INCREF(Py_None);
				plrv = Py_None;
			}
			else
			{
				/*
				 * This won't be last call, so save argument values.  We do
				 * this again each time in case the iterator is changing those
				 * values.
				 */
				srfstate->savedargs = PLy_function_save_args(proc);
			}
		}

		/*
		 * Disconnect from SPI manager and then create the return values datum
		 * (if the input function does a palloc for it this must not be
		 * allocated in the SPI memory context because SPI_finish would free
		 * it).
		 */
		if (SPI_finish() != SPI_OK_FINISH)
			elog(ERROR, "SPI_finish failed");

		plerrcontext.callback = plpython_return_error_callback;
		plerrcontext.previous = error_context_stack;
		error_context_stack = &plerrcontext;

		/*
		 * If the function is declared to return void, the Python return value
		 * must be None. For void-returning functions, we also treat a None
		 * return value as a special "void datum" rather than NULL (as is the
		 * case for non-void-returning functions).
		 */
		if (proc->result.out.d.typoid == VOIDOID)
		{
			if (plrv != Py_None)
				ereport(ERROR,
						(errcode(ERRCODE_DATATYPE_MISMATCH),
						 errmsg("PL/Python function with return type \"void\" did not return None")));

			fcinfo->isnull = false;
			rv = (Datum) 0;
		}
		else if (plrv == Py_None)
		{
			fcinfo->isnull = true;

			/*
			 * In a SETOF function, the iteration-ending null isn't a real
			 * value; don't pass it through the input function, which might
			 * complain.
			 */
			if (srfstate && srfstate->iter == NULL)
				rv = (Datum) 0;
			else if (proc->result.is_rowtype < 1)
				rv = InputFunctionCall(&proc->result.out.d.typfunc,
									   NULL,
									   proc->result.out.d.typioparam,
									   -1);
			else
				/* Tuple as None */
				rv = (Datum) NULL;
		}
		else if (proc->result.is_rowtype >= 1)
		{
			TupleDesc	desc;

			/* make sure it's not an unnamed record */
			Assert((proc->result.out.d.typoid == RECORDOID &&
					proc->result.out.d.typmod != -1) ||
				   (proc->result.out.d.typoid != RECORDOID &&
					proc->result.out.d.typmod == -1));

			desc = lookup_rowtype_tupdesc(proc->result.out.d.typoid,
										  proc->result.out.d.typmod);

			rv = PLyObject_ToCompositeDatum(&proc->result, desc, plrv);
			fcinfo->isnull = (rv == (Datum) NULL);

			ReleaseTupleDesc(desc);
		}
		else
		{
			fcinfo->isnull = false;
			rv = (proc->result.out.d.func) (&proc->result.out.d, -1, plrv);
		}
	}
	PG_CATCH();
	{
		/* Pop old arguments from the stack if they were pushed above */
		PLy_global_args_pop(proc);

		Py_XDECREF(plargs);
		Py_XDECREF(plrv);

		/*
		 * If there was an error within a SRF, the iterator might not have
		 * been exhausted yet.  Clear it so the next invocation of the
		 * function will start the iteration again.  (This code is probably
		 * unnecessary now; plpython_srf_cleanup_callback should take care of
		 * cleanup.  But it doesn't hurt anything to do it here.)
		 */
		if (srfstate)
		{
			Py_XDECREF(srfstate->iter);
			srfstate->iter = NULL;
			/* And drop any saved args; we won't need them */
			if (srfstate->savedargs)
				PLy_function_drop_args(srfstate->savedargs);
			srfstate->savedargs = NULL;
		}

		PG_RE_THROW();
	}
	PG_END_TRY();

	error_context_stack = plerrcontext.previous;

	/* Pop old arguments from the stack if they were pushed above */
	PLy_global_args_pop(proc);

	Py_XDECREF(plargs);
	Py_DECREF(plrv);

	if (srfstate)
	{
		/* We're in a SRF, exit appropriately */
		if (srfstate->iter == NULL)
		{
			/* Iterator exhausted, so we're done */
			SRF_RETURN_DONE(funcctx);
		}
		else if (fcinfo->isnull)
			SRF_RETURN_NEXT_NULL(funcctx);
		else
			SRF_RETURN_NEXT(funcctx, rv);
	}

	/* Plain function, just return the Datum value (possibly null) */
	return rv;
}
Esempio n. 2
0
Datum ta_f( PG_FUNCTION_ARGS)
{

	// Declare for TA
	TA_RetCode retCode;
	TA_Real *closePrice = NULL;
	TA_Real *out;

	TA_Integer outBeg;
	TA_Integer outNbElement;

	// Declare for postgres
	FuncCallContext *funcctx;
	int call_cntr;
	int max_calls;
	Datum *result = NULL;
	int dim;
	int z;
	ArrayType *ur = PG_GETARG_ARRAYTYPE_P(0);

	if (array_contains_nulls(ur))
	{
		ereport(ERROR,
				( errcode(ERRCODE_ARRAY_ELEMENT_ERROR), errmsg("cannot work with arrays containing NULLs") ));
	}

	dim = ARRNELEMS(ur);
	closePrice = ARRPTR(ur);

	if (SRF_IS_FIRSTCALL())
	{
		MemoryContext oldcontext;

		funcctx = SRF_FIRSTCALL_INIT();
		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
		/* One-time setup code appears here: */
		retCode = TA_Initialize();
		if (retCode != TA_SUCCESS)
		{
			ereport(ERROR,
					( errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("Cannot initialize TA-Lib (%d)!\n", retCode) ));
		}

		out = palloc(dim * sizeof(TA_Real));

		retCode = TA_MA(0, dim - 1, &closePrice[0], 5, TA_MAType_SMA, &outBeg,
				&outNbElement, &out[0]);

		result = palloc(outNbElement * sizeof(Datum));

		// Error log for debugging
		/*
		ereport(NOTICE,
				(errmsg("dims %d,  outBeg: %d, outNbElement %d\n", dim, outBeg, outNbElement)));
		*/
		for (z = 0; z < dim; z++)
		{
			// Error log for debugging
			//ereport(NOTICE, (errmsg("z: %d, out[z]: %5.1f", z, out[z])));
			if(z > outBeg-1) {
				result[z] = Float8GetDatum(out[z-outBeg]);
				continue;
			}
			result[z] = NULL;
		}
		TA_Shutdown();

		funcctx->max_calls = dim;
		funcctx->user_fctx = result;
		MemoryContextSwitchTo(oldcontext);
	}

	/* stuff done on every call of the function */
	funcctx = SRF_PERCALL_SETUP();

	call_cntr = funcctx->call_cntr;
	max_calls = funcctx->max_calls;

	if (call_cntr < max_calls)
	{
		if(((Datum *) funcctx->user_fctx)[call_cntr]) {
			SRF_RETURN_NEXT(funcctx, ((Datum *) funcctx->user_fctx)[call_cntr]);
		}
		SRF_RETURN_NEXT_NULL(funcctx);
	}
	SRF_RETURN_DONE(funcctx);
}