Datum
btint82cmp(PG_FUNCTION_ARGS)
{
	int64		a = PG_GETARG_INT64(0);
	int16		b = PG_GETARG_INT16(1);

	if (a > b)
		PG_RETURN_INT32(A_GREATER_THAN_B);
	else if (a == b)
		PG_RETURN_INT32(0);
	else
		PG_RETURN_INT32(A_LESS_THAN_B);
}

Datum
int8div(PG_FUNCTION_ARGS)
{
	int64		arg1 = PG_GETARG_INT64(0);
	int64		arg2 = PG_GETARG_INT64(1);
	int64		result;

	if (arg2 == 0)
	{
		ereport(ERROR,
				(errcode(ERRCODE_DIVISION_BY_ZERO),
				 errmsg("division by zero")));
		/* ensure compiler realizes we mustn't reach the division (gcc bug) */
		PG_RETURN_NULL();
	}

	/*
	 * INT64_MIN / -1 is problematic, since the result can't be represented on
	 * a two's-complement machine.  Some machines produce INT64_MIN, some
	 * produce zero, some throw an exception.  We can dodge the problem by
	 * recognizing that division by -1 is the same as negation.
	 */
	if (arg2 == -1)
	{
		result = -arg1;
		/* overflow check (needed for INT64_MIN) */
		if (arg1 != 0 && SAMESIGN(result, arg1))
			ereport(ERROR,
					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
					 errmsg("bigint out of range")));
		PG_RETURN_INT64(result);
	}

	/* No overflow is possible */

	result = arg1 / arg2;

	PG_RETURN_INT64(result);
}

Datum
btint82cmp(PG_FUNCTION_ARGS)
{
	int64		a = PG_GETARG_INT64(0);
	int16		b = PG_GETARG_INT16(1);

	if (a > b)
		PG_RETURN_INT32(1);
	else if (a == b)
		PG_RETURN_INT32(0);
	else
		PG_RETURN_INT32(-1);
}

/*
 * pg_advisory_unlock_shared(int8) - release share lock on an int8 key
 *
 * Returns true if successful, false if lock was not held
 */
Datum
pg_advisory_unlock_shared_int8(PG_FUNCTION_ARGS)
{
	int64		key = PG_GETARG_INT64(0);
	LOCKTAG		tag;
	bool		res;

	SET_LOCKTAG_INT64(tag, key);

	res = LockRelease(&tag, ShareLock, true);

	PG_RETURN_BOOL(res);
}

/*
 * Read a section of a file, returning it as bytea
 */
Datum
pg_read_binary_file(PG_FUNCTION_ARGS)
{
	text	   *filename_t = PG_GETARG_TEXT_P(0);
	int64		seek_offset = PG_GETARG_INT64(1);
	int64		bytes_to_read = PG_GETARG_INT64(2);
	char	   *filename;

	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to read files"))));

	filename = convert_and_check_filename(filename_t);

	if (bytes_to_read < 0)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("requested length cannot be negative")));

	PG_RETURN_BYTEA_P(read_binary_file(filename, seek_offset, bytes_to_read));
}

Datum
btint48cmp(PG_FUNCTION_ARGS)
{
	int32		a = PG_GETARG_INT32(0);
	int64		b = PG_GETARG_INT64(1);

	if (a > b)
		PG_RETURN_INT32(1);
	else if (a == b)
		PG_RETURN_INT32(0);
	else
		PG_RETURN_INT32(-1);
}

/*
 * pg_try_advisory_lock_shared(int8) - acquire share lock on an int8 key, no wait
 *
 * Returns true if successful, false if lock not available
 */
Datum
pg_try_advisory_lock_shared_int8(PG_FUNCTION_ARGS)
{
	int64		key = PG_GETARG_INT64(0);
	LOCKTAG		tag;
	LockAcquireResult res;

	SET_LOCKTAG_INT64(tag, key);

	res = LockAcquire(&tag, ShareLock, true, true);

	PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
}

/*
 * pg_advisory_xact_lock_shared(int8) - acquire xact scoped
 * share lock on an int8 key
 */
Datum
pg_advisory_xact_lock_shared_int8(PG_FUNCTION_ARGS)
{
	int64		key = PG_GETARG_INT64(0);
	LOCKTAG		tag;

	PreventAdvisoryLocksInParallelMode();
	SET_LOCKTAG_INT64(tag, key);

	(void) LockAcquire(&tag, ShareLock, false, false);

	PG_RETURN_VOID();
}

/*
 * Visibility map information for a single block of a relation, plus the
 * page-level information for the same block.
 */
Datum
pg_visibility(PG_FUNCTION_ARGS)
{
    Oid			relid = PG_GETARG_OID(0);
    int64		blkno = PG_GETARG_INT64(1);
    int32		mapbits;
    Relation	rel;
    Buffer		vmbuffer = InvalidBuffer;
    Buffer		buffer;
    Page		page;
    TupleDesc	tupdesc;
    Datum		values[3];
    bool		nulls[3];

    rel = relation_open(relid, AccessShareLock);

    if (blkno < 0 || blkno > MaxBlockNumber)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("invalid block number")));

    tupdesc = pg_visibility_tupdesc(false, true);
    MemSet(nulls, 0, sizeof(nulls));

    mapbits = (int32) visibilitymap_get_status(rel, blkno, &vmbuffer);
    if (vmbuffer != InvalidBuffer)
        ReleaseBuffer(vmbuffer);
    values[0] = BoolGetDatum((mapbits & VISIBILITYMAP_ALL_VISIBLE) != 0);
    values[1] = BoolGetDatum((mapbits & VISIBILITYMAP_ALL_FROZEN) != 0);

    /* Here we have to explicitly check rel size ... */
    if (blkno < RelationGetNumberOfBlocks(rel))
    {
        buffer = ReadBuffer(rel, blkno);
        LockBuffer(buffer, BUFFER_LOCK_SHARE);

        page = BufferGetPage(buffer);
        values[2] = BoolGetDatum(PageIsAllVisible(page));

        UnlockReleaseBuffer(buffer);
    }
    else
    {
        /* As with the vismap, silently return 0 for pages past EOF */
        values[2] = BoolGetDatum(false);
    }

    relation_close(rel, AccessShareLock);

    PG_RETURN_DATUM(HeapTupleGetDatum(heap_form_tuple(tupdesc, values, nulls)));
}

/*
 * Read a section of a file, returning it as text
 *
 * This function is kept to support adminpack 1.0.
 */
Datum
pg_read_file(PG_FUNCTION_ARGS)
{
	text	   *filename_t = PG_GETARG_TEXT_PP(0);
	int64		seek_offset = 0;
	int64		bytes_to_read = -1;
	bool		missing_ok = false;
	char	   *filename;
	text	   *result;

	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to read files with adminpack 1.0"),
				  errhint("Consider using pg_file_read(), which is part of core, instead."))));

	/* handle optional arguments */
	if (PG_NARGS() >= 3)
	{
		seek_offset = PG_GETARG_INT64(1);
		bytes_to_read = PG_GETARG_INT64(2);

		if (bytes_to_read < 0)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
					 errmsg("requested length cannot be negative")));
	}
	if (PG_NARGS() >= 4)
		missing_ok = PG_GETARG_BOOL(3);

	filename = convert_and_check_filename(filename_t);

	result = read_text_file(filename, seek_offset, bytes_to_read, missing_ok);
	if (result)
		PG_RETURN_TEXT_P(result);
	else
		PG_RETURN_NULL();
}

Datum
linterp_int64(PG_FUNCTION_ARGS)
{
	float8 y0;
	float8 y1;
	float8 p;
	float8 r;
	int64 result;
	bool eq_bounds = false;
	bool eq_abscissas = false;
	
	/* Common */
	p = linterp_abscissa(fcinfo, &eq_bounds, &eq_abscissas);
	
	/* Ordinate type specific code*/
	y0 = (float8)PG_GETARG_INT64(2);
	y1 = (float8)PG_GETARG_INT64(4);
	
	if ( eq_bounds )
	{
		if ( eq_abscissas && y0 == y1 )
			r = y0;
		else 
			PG_RETURN_NULL();
	}
	else 
	{
		r = round(y0+p*(y1-y0));
		if ( r < LONG_MIN || r > LONG_MAX )
			ereport(ERROR,
					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
					 errmsg("value \"%f\" is out of range for type bigint", r)));
	}

	result = (int64)r;

	PG_RETURN_INT64(result);
}

/*
 * worker_apply_inter_shard_ddl_command extends table, index, or constraint names in
 * the given DDL command. The function then applies this extended DDL command
 * against the database.
 */
Datum
worker_apply_inter_shard_ddl_command(PG_FUNCTION_ARGS)
{
	uint64 leftShardId = PG_GETARG_INT64(0);
	text *leftShardSchemaNameText = PG_GETARG_TEXT_P(1);
	uint64 rightShardId = PG_GETARG_INT64(2);
	text *rightShardSchemaNameText = PG_GETARG_TEXT_P(3);
	text *ddlCommandText = PG_GETARG_TEXT_P(4);

	char *leftShardSchemaName = text_to_cstring(leftShardSchemaNameText);
	char *rightShardSchemaName = text_to_cstring(rightShardSchemaNameText);
	const char *ddlCommand = text_to_cstring(ddlCommandText);
	Node *ddlCommandNode = ParseTreeNode(ddlCommand);

	/* extend names in ddl command and apply extended command */
	RelayEventExtendNamesForInterShardCommands(ddlCommandNode, leftShardId,
											   leftShardSchemaName, rightShardId,
											   rightShardSchemaName);
	ProcessUtility(ddlCommandNode, ddlCommand, PROCESS_UTILITY_TOPLEVEL, NULL,
				   None_Receiver, NULL);

	PG_RETURN_VOID();
}

/*
 * pg_advisory_unlock(int8) - release exclusive lock on an int8 key
 *
 * Returns true if successful, false if lock was not held
*/
Datum
pg_advisory_unlock_int8(PG_FUNCTION_ARGS)
{
	int64		key = PG_GETARG_INT64(0);
	LOCKTAG		tag;
	bool		res;

	PreventAdvisoryLocksInParallelMode();
	SET_LOCKTAG_INT64(tag, key);

	res = LockRelease(&tag, ExclusiveLock, true);

	PG_RETURN_BOOL(res);
}

/**
 * Put the given file in a cache, so that subsequent reads becomes faster.
 * There is no need to uncache files later, as this happens automatically.
 */
Datum cache_file(PG_FUNCTION_ARGS)
{
	if ( PG_ARGISNULL(0) )
		ereport(ERROR, (errcode( ERRCODE_RAISE_EXCEPTION ),	errmsg("NULL argument not allowed")));

	int64 id = PG_GETARG_INT64(0);

	// WARNING:
	// Do not use any postgres functionality within this macro
	// It will cause a resource leak.
	HANDLE_EXCEPTIONS(cacheFile(id));

	PG_RETURN_NULL();
}

/* int8abs()
 * Absolute value
 */
Datum
int8abs(PG_FUNCTION_ARGS)
{
    int64		arg1 = PG_GETARG_INT64(0);
    int64		result;

    result = (arg1 < 0) ? -arg1 : arg1;
    /* overflow check (needed for INT64_MIN) */
    if (result < 0)
        ereport(ERROR,
                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                 errmsg("bigint out of range")));
    PG_RETURN_INT64(result);
}

/* int8out()
 */
Datum
int8out(PG_FUNCTION_ARGS)
{
	int64		val = PG_GETARG_INT64(0);
	char	   *result;
	int			len;
	char		buf[MAXINT8LEN + 1];

	if ((len = snprintf(buf, MAXINT8LEN, INT64_FORMAT, val)) < 0)
		elog(ERROR, "could not format int8");

	result = pstrdup(buf);
	PG_RETURN_CSTRING(result);
}

Datum
int8um(PG_FUNCTION_ARGS)
{
    int64		arg = PG_GETARG_INT64(0);
    int64		result;

    result = -arg;
    /* overflow check (needed for INT64_MIN) */
    if (arg != 0 && SAMESIGN(result, arg))
        ereport(ERROR,
                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                 errmsg("bigint out of range")));
    PG_RETURN_INT64(result);
}

/*
 * pg_try_advisory_xact_lock_shared(int8) - acquire xact scoped
 * share lock on an int8 key, no wait
 *
 * Returns true if successful, false if lock not available
 */
Datum
pg_try_advisory_xact_lock_shared_int8(PG_FUNCTION_ARGS)
{
	int64		key = PG_GETARG_INT64(0);
	LOCKTAG		tag;
	LockAcquireResult res;

	PreventAdvisoryLocksInParallelMode();
	SET_LOCKTAG_INT64(tag, key);

	res = LockAcquire(&tag, ShareLock, false, true);

	PG_RETURN_BOOL(res != LOCKACQUIRE_NOT_AVAIL);
}

Datum
setval_mirror(PG_FUNCTION_ARGS)
{
	Oid			relid = PG_GETARG_OID(0);
	int64		next = PG_GETARG_INT64(1);
	int64		result;

	result = DatumGetInt64(DirectFunctionCall2(setval_oid,
											   ObjectIdGetDatum(relid),
											   Int64GetDatum(next)));

	saveSequenceUpdate(relid, result, true);

	PG_RETURN_INT64(result);
}

Datum
int8dec(PG_FUNCTION_ARGS)
{
	int64		arg = PG_GETARG_INT64(0);
	int64		result;

	result = arg - 1;
	/* Overflow check */
	if (result > 0 && arg < 0)
		ereport(ERROR,
				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
				 errmsg("bigint out of range")));

	PG_RETURN_INT64(result);
}