Golang FinalizedQuery.IneqFilterHigh方法代码示例

func numComponents(fq *ds.FinalizedQuery) int {
	numComponents := len(fq.Orders())
	if p, _, _ := fq.IneqFilterLow(); p != "" {
		numComponents++
	}
	if p, _, _ := fq.IneqFilterHigh(); p != "" {
		numComponents++
	}
	for _, v := range fq.EqFilters() {
		numComponents += v.Len()
	}
	return numComponents
}

// GetBinaryBounds gets the binary encoding of the upper and lower bounds of
// the inequality filter on fq, if any is defined. If a bound does not exist,
// it is nil.
//
// NOTE: if fq specifies a descending sort order for the inequality, the bounds
// will be inverted, incremented, and flipped.
func GetBinaryBounds(fq *ds.FinalizedQuery) (lower, upper []byte) {
	// Pick up the start/end range from the inequalities, if any.
	//
	// start and end in the reducedQuery are normalized so that `start >=
	// X < end`. Because of that, we need to tweak the inequality filters
	// contained in the query if they use the > or <= operators.
	if ineqProp := fq.IneqFilterProp(); ineqProp != "" {
		_, startOp, startV := fq.IneqFilterLow()
		if startOp != "" {
			lower = serialize.ToBytes(startV)
			if startOp == ">" {
				lower = increment(lower)
			}
		}

		_, endOp, endV := fq.IneqFilterHigh()
		if endOp != "" {
			upper = serialize.ToBytes(endV)
			if endOp == "<=" {
				upper = increment(upper)
			}
		}

		// The inequality is specified in natural (ascending) order in the query's
		// Filter syntax, but the order information may indicate to use a descending
		// index column for it. If that's the case, then we must invert, swap and
		// increment the inequality endpoints.
		//
		// Invert so that the desired numbers are represented correctly in the index.
		// Swap so that our iterators still go from >= start to < end.
		// Increment so that >= and < get correctly bounded (since the iterator is
		// still using natrual bytes ordering)
		if fq.Orders()[0].Descending {
			hi, lo := []byte(nil), []byte(nil)
			if len(lower) > 0 {
				lo = increment(serialize.Invert(lower))
			}
			if len(upper) > 0 {
				hi = increment(serialize.Invert(upper))
			}
			upper, lower = lo, hi
		}
	}
	return
}

func (d rdsImpl) fixQuery(fq *ds.FinalizedQuery) (*datastore.Query, error) {
	ret := datastore.NewQuery(fq.Kind())

	start, end := fq.Bounds()
	if start != nil {
		ret = ret.Start(start.(datastore.Cursor))
	}
	if end != nil {
		ret = ret.End(end.(datastore.Cursor))
	}

	for prop, vals := range fq.EqFilters() {
		if prop == "__ancestor__" {
			p, err := dsF2RProp(d.aeCtx, vals[0])
			if err != nil {
				return nil, err
			}
			ret = ret.Ancestor(p.Value.(*datastore.Key))
		} else {
			filt := prop + "="
			for _, v := range vals {
				p, err := dsF2RProp(d.aeCtx, v)
				if err != nil {
					return nil, err
				}

				ret = ret.Filter(filt, p.Value)
			}
		}
	}

	if lnam, lop, lprop := fq.IneqFilterLow(); lnam != "" {
		p, err := dsF2RProp(d.aeCtx, lprop)
		if err != nil {
			return nil, err
		}
		ret = ret.Filter(lnam+" "+lop, p.Value)
	}

	if hnam, hop, hprop := fq.IneqFilterHigh(); hnam != "" {
		p, err := dsF2RProp(d.aeCtx, hprop)
		if err != nil {
			return nil, err
		}
		ret = ret.Filter(hnam+" "+hop, p.Value)
	}

	if fq.EventuallyConsistent() {
		ret = ret.EventualConsistency()
	}

	if fq.KeysOnly() {
		ret = ret.KeysOnly()
	}

	if lim, ok := fq.Limit(); ok {
		ret = ret.Limit(int(lim))
	}

	if off, ok := fq.Offset(); ok {
		ret = ret.Offset(int(off))
	}

	for _, o := range fq.Orders() {
		ret = ret.Order(o.String())
	}

	ret = ret.Project(fq.Project()...)
	if fq.Distinct() {
		ret = ret.Distinct()
	}

	return ret, nil
}