Golang encoding.EncodeNullDescending函数代码示例

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本文整理汇总了Golang中github.com/cockroachdb/cockroach/util/encoding.EncodeNullDescending函数的典型用法代码示例。如果您正苦于以下问题：Golang EncodeNullDescending函数的具体用法？Golang EncodeNullDescending怎么用？Golang EncodeNullDescending使用的例子？那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。

在下文中一共展示了EncodeNullDescending函数的4个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于我们的系统推荐出更棒的Golang代码示例。

示例1: encodeStartConstraintDescending

func encodeStartConstraintDescending(
	spans []span, c *parser.ComparisonExpr) {
	switch c.Operator {
	case parser.Is:
		// An IS NULL expressions allows us to constrain the start of the range
		// to begin at NULL.
		if c.Right != parser.DNull {
			panic(fmt.Sprintf("expected NULL operand for IS operator, found %v", c.Right))
		}
		for i := range spans {
			spans[i].start = encoding.EncodeNullDescending(spans[i].start)
		}
	case parser.NE:
		panic("'!=' operators should have been transformed to 'IS NOT NULL'")
	case parser.LE, parser.EQ:
		datum := c.Right.(parser.Datum)
		key, pErr := encodeTableKey(nil, datum, encoding.Descending)
		if pErr != nil {
			panic(pErr)
		}
		// Append the constraint to all of the existing spans.
		for i := range spans {
			spans[i].start = append(spans[i].start, key...)
		}
	case parser.LT:
		// A "<" constraint is the last start constraint. Since the constraint
		// is exclusive and the start key is inclusive, we're going to apply
		// a .PrefixEnd(). Note that a "<" is usually transformed to a "<=".
		datum := c.Right.(parser.Datum)
		key, pErr := encodeTableKey(nil, datum, encoding.Descending)
		if pErr != nil {
			panic(pErr)
		}
		// Append the constraint to all of the existing spans.
		for i := range spans {
			spans[i].start = append(spans[i].start, key...)
			spans[i].start = spans[i].start.PrefixEnd()
		}

	default:
		panic(fmt.Sprintf("unexpected operator: %s", c))
	}
}

开发者ID:petermattis，项目名称:cockroach，代码行数:43，代码来源:index_selection.go

示例2: encodeStartConstraintDescending

func encodeStartConstraintDescending(
	spans []span, c *parser.ComparisonExpr) {
	switch c.Operator {
	case parser.Is:
		// An IS NULL expressions allows us to constrain the start of the range
		// to begin at NULL.
		if c.Right != parser.DNull {
			panic("Expected NULL operand for IS operator.")
		}
		for i := range spans {
			spans[i].start = encoding.EncodeNullDescending(spans[i].start)
		}
	case parser.LE, parser.EQ:
		if datum, ok := c.Right.(parser.Datum); ok {
			key, pErr := encodeTableKey(nil, datum, encoding.Descending)
			if pErr != nil {
				panic(pErr)
			}
			// Append the constraint to all of the existing spans.
			for i := range spans {
				spans[i].start = append(spans[i].start, key...)
			}
		}
	case parser.LT:
		// A "<" constraint is the last start constraint. Since the constraint
		// is exclusive and the start key is inclusive, we're going to apply
		// a .PrefixEnd().
		if datum, ok := c.Right.(parser.Datum); ok {
			key, pErr := encodeTableKey(nil, datum, encoding.Descending)
			if pErr != nil {
				panic(pErr)
			}
			// Append the constraint to all of the existing spans.
			for i := range spans {
				spans[i].start = append(spans[i].start, key...)
				spans[i].start = spans[i].start.PrefixEnd()
			}
		}
	default:
		panic(fmt.Errorf("unexpected operator: %s", c.String()))
	}
}

开发者ID:surpass，项目名称:cockroach，代码行数:42，代码来源:select.go

示例3: EncodeTableKey

// EncodeTableKey encodes `val` into `b` and returns the new buffer.
func EncodeTableKey(b []byte, val parser.Datum, dir encoding.Direction) ([]byte, error) {
	if (dir != encoding.Ascending) && (dir != encoding.Descending) {
		return nil, util.Errorf("invalid direction: %d", dir)
	}

	if val == parser.DNull {
		if dir == encoding.Ascending {
			return encoding.EncodeNullAscending(b), nil
		}
		return encoding.EncodeNullDescending(b), nil
	}

	switch t := val.(type) {
	case *parser.DBool:
		var x int64
		if *t {
			x = 1
		} else {
			x = 0
		}
		if dir == encoding.Ascending {
			return encoding.EncodeVarintAscending(b, x), nil
		}
		return encoding.EncodeVarintDescending(b, x), nil
	case *parser.DInt:
		if dir == encoding.Ascending {
			return encoding.EncodeVarintAscending(b, int64(*t)), nil
		}
		return encoding.EncodeVarintDescending(b, int64(*t)), nil
	case *parser.DFloat:
		if dir == encoding.Ascending {
			return encoding.EncodeFloatAscending(b, float64(*t)), nil
		}
		return encoding.EncodeFloatDescending(b, float64(*t)), nil
	case *parser.DDecimal:
		if dir == encoding.Ascending {
			return encoding.EncodeDecimalAscending(b, &t.Dec), nil
		}
		return encoding.EncodeDecimalDescending(b, &t.Dec), nil
	case *parser.DString:
		if dir == encoding.Ascending {
			return encoding.EncodeStringAscending(b, string(*t)), nil
		}
		return encoding.EncodeStringDescending(b, string(*t)), nil
	case *parser.DBytes:
		if dir == encoding.Ascending {
			return encoding.EncodeStringAscending(b, string(*t)), nil
		}
		return encoding.EncodeStringDescending(b, string(*t)), nil
	case *parser.DDate:
		if dir == encoding.Ascending {
			return encoding.EncodeVarintAscending(b, int64(*t)), nil
		}
		return encoding.EncodeVarintDescending(b, int64(*t)), nil
	case *parser.DTimestamp:
		if dir == encoding.Ascending {
			return encoding.EncodeTimeAscending(b, t.Time), nil
		}
		return encoding.EncodeTimeDescending(b, t.Time), nil
	case *parser.DTimestampTZ:
		if dir == encoding.Ascending {
			return encoding.EncodeTimeAscending(b, t.Time), nil
		}
		return encoding.EncodeTimeDescending(b, t.Time), nil
	case *parser.DInterval:
		if dir == encoding.Ascending {
			return encoding.EncodeDurationAscending(b, t.Duration)
		}
		return encoding.EncodeDurationDescending(b, t.Duration)
	case *parser.DTuple:
		for _, datum := range *t {
			var err error
			b, err = EncodeTableKey(b, datum, dir)
			if err != nil {
				return nil, err
			}
		}
		return b, nil
	}
	return nil, util.Errorf("unable to encode table key: %T", val)
}

开发者ID:GitGoldie，项目名称:cockroach，代码行数:82，代码来源:table.go

示例4: encodeTableKey

// Encodes `val` into `b` and returns the new buffer.
func encodeTableKey(b []byte, val parser.Datum, dir encoding.Direction) ([]byte, *roachpb.Error) {
	if (dir != encoding.Ascending) && (dir != encoding.Descending) {
		return nil, roachpb.NewErrorf("invalid direction: %d", dir)
	}

	if val == parser.DNull {
		if dir == encoding.Ascending {
			return encoding.EncodeNullAscending(b), nil
		}
		return encoding.EncodeNullDescending(b), nil
	}

	switch t := val.(type) {
	case parser.DBool:
		var x int64
		if t {
			x = 1
		} else {
			x = 0
		}
		if dir == encoding.Ascending {
			return encoding.EncodeVarintAscending(b, x), nil
		}
		return encoding.EncodeVarintDescending(b, x), nil
	case parser.DInt:
		if dir == encoding.Ascending {
			return encoding.EncodeVarintAscending(b, int64(t)), nil
		}
		return encoding.EncodeVarintDescending(b, int64(t)), nil
	case parser.DFloat:
		if dir == encoding.Ascending {
			return encoding.EncodeFloatAscending(b, float64(t)), nil
		}
		return encoding.EncodeFloatDescending(b, float64(t)), nil
	case parser.DDecimal:
		if dir == encoding.Ascending {
			return encoding.EncodeDecimalAscending(b, t.Decimal), nil
		}
		return encoding.EncodeDecimalDescending(b, t.Decimal), nil
	case parser.DString:
		if dir == encoding.Ascending {
			return encoding.EncodeStringAscending(b, string(t)), nil
		}
		return encoding.EncodeStringDescending(b, string(t)), nil
	case parser.DBytes:
		if dir == encoding.Ascending {
			return encoding.EncodeStringAscending(b, string(t)), nil
		}
		return encoding.EncodeStringDescending(b, string(t)), nil
	case parser.DDate:
		if dir == encoding.Ascending {
			return encoding.EncodeVarintAscending(b, int64(t)), nil
		}
		return encoding.EncodeVarintDescending(b, int64(t)), nil
	case parser.DTimestamp:
		if dir == encoding.Ascending {
			return encoding.EncodeTimeAscending(b, t.Time), nil
		}
		return encoding.EncodeTimeDescending(b, t.Time), nil
	case parser.DInterval:
		if dir == encoding.Ascending {
			return encoding.EncodeVarintAscending(b, int64(t.Duration)), nil
		}
		return encoding.EncodeVarintDescending(b, int64(t.Duration)), nil
	}
	return nil, roachpb.NewUErrorf("unable to encode table key: %T", val)
}

开发者ID:ekkotron，项目名称:cockroach，代码行数:68，代码来源:table.go

注：本文中的github.com/cockroachdb/cockroach/util/encoding.EncodeNullDescending函数示例整理自Github/MSDocs等源码及文档管理平台，相关代码片段筛选自各路编程大神贡献的开源项目，源码版权归原作者所有，传播和使用请参考对应项目的License；未经允许，请勿转载。