promql

package
v2.0.0-beta.5 Latest Latest
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 Go to latest Published: Feb 13, 2020 License: MIT Imports: 19 Imported by: 0

Documentation

Overview

Package promql implements a promql parser to build flux query specifications from promql.

Package promql implements a promql parser to build flux query specifications from promql.

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func Build 

func Build(promql string, opts ...Option) (*flux.Spec, error)

func NewRangeOp 

func NewRangeOp(rng, offset time.Duration) (*flux.Operation, error)

func NewWhereOperation 

func NewWhereOperation(metricName string, labels []*LabelMatcher) (*flux.Operation, error)

func Parse 

func Parse(filename string, b []byte, opts ...Option) (interface{}, error)

Parse parses the data from b using filename as information in the error messages.

func ParseFile 

func ParseFile(filename string, opts ...Option) (i interface{}, err error)

ParseFile parses the file identified by filename.

func ParsePromQL 

func ParsePromQL(promql string, opts ...Option) (interface{}, error)

func ParseReader 

func ParseReader(filename string, r io.Reader, opts ...Option) (interface{}, error)

ParseReader parses the data from r using filename as information in the error messages.

Types

type Aggregate 

type Aggregate struct {
	Without bool          `json:"without,omitempty"`
	By      bool          `json:"by,omitempty"`
	Labels  []*Identifier `json:"labels,omitempty"`
}

func (*Aggregate) QuerySpec 

func (a *Aggregate) QuerySpec() (*flux.Operation, error)

type AggregateExpr 

type AggregateExpr struct {
	Op        *Operator  `json:"op,omitempty"`
	Selector  *Selector  `json:"selector,omitempty"`
	Aggregate *Aggregate `json:"aggregate,omitempty"`
}

func NewAggregateExpr 

func NewAggregateExpr(op *Operator, selector *Selector, group interface{}) (*AggregateExpr, error)

func (*AggregateExpr) QuerySpec 

func (a *AggregateExpr) QuerySpec() (*flux.Spec, error)

type Arg 

type Arg interface {
	Type() ArgKind
	Value() interface{}
}

type ArgKind 

type ArgKind int
const (
	IdentifierKind ArgKind = iota
	DurationKind
	ExprKind
	NumberKind
	StringKind
	SelectorKind
)

type Cloner 

type Cloner interface {
	Clone() interface{}
}

Cloner is implemented by any value that has a Clone method, which returns a copy of the value. This is mainly used for types which are not passed by value (e.g map, slice, chan) or structs that contain such types.

This is used in conjunction with the global state feature to create proper copies of the state to allow the parser to properly restore the state in the case of backtracking.

type Comment 

type Comment struct {
	Source string `json:"source,omitempty"`
}

func (*Comment) QuerySpec 

func (c *Comment) QuerySpec() (*flux.Spec, error)

type Duration 

type Duration struct {
	Dur time.Duration `json:"dur,omitempty"`
}

func (*Duration) Type 

func (d *Duration) Type() ArgKind

func (*Duration) Value 

func (d *Duration) Value() interface{}

type Identifier 

type Identifier struct {
	Name string `json:"name,omitempty"`
}

func NewIdentifierList 

func NewIdentifierList(first *Identifier, rest interface{}) ([]*Identifier, error)

func (*Identifier) Type 

func (id *Identifier) Type() ArgKind

func (*Identifier) Value 

func (id *Identifier) Value() interface{}

type LabelMatcher 

type LabelMatcher struct {
	Name  string    `json:"name,omitempty"`
	Kind  MatchKind `json:"kind,omitempty"`
	Value Arg       `json:"value,omitempty"`
}

func NewLabelMatcher 

func NewLabelMatcher(ident *Identifier, kind MatchKind, value Arg) (*LabelMatcher, error)

func NewLabelMatches 

func NewLabelMatches(first *LabelMatcher, rest interface{}) ([]*LabelMatcher, error)

type MatchKind 

type MatchKind int

MatchKind is an enum for label matching types. 

const (
	Equal MatchKind = iota
	NotEqual
	RegexMatch
	RegexNoMatch
)

Possible MatchKinds.

type Number 

type Number struct {
	Val float64 `json:"val,omitempty"`
}

func NewNumber 

func NewNumber(val string) (*Number, error)

func (*Number) Type 

func (n *Number) Type() ArgKind

func (*Number) Value 

func (n *Number) Value() interface{}

type Operator 

type Operator struct {
	Kind OperatorKind `json:"kind,omitempty"`
	Arg  Arg          `json:"arg,omitempty"`
}

func (*Operator) QuerySpec 

func (o *Operator) QuerySpec() (*flux.Operation, error)

type OperatorKind 

type OperatorKind int
const (
	UnknownOpKind OperatorKind = iota
	CountValuesKind
	TopKind
	BottomKind
	QuantileKind
	SumKind
	MinKind
	MaxKind
	AvgKind
	StdevKind
	StdVarKind
	CountKind
)

func ToOperatorKind 

func ToOperatorKind(op string) OperatorKind

type Option 

type Option func(*parser) Option

Option is a function that can set an option on the parser. It returns the previous setting as an Option.

func AllowInvalidUTF8 

func AllowInvalidUTF8(b bool) Option

AllowInvalidUTF8 creates an Option to allow invalid UTF-8 bytes. Every invalid UTF-8 byte is treated as a utf8.RuneError (U+FFFD) by character class matchers and is matched by the any matcher. The returned matched value, c.text and c.offset are NOT affected.

The default is false.

func Debug 

func Debug(b bool) Option

Debug creates an Option to set the debug flag to b. When set to true, debugging information is printed to stdout while parsing.

The default is false.

func Entrypoint 

func Entrypoint(ruleName string) Option

Entrypoint creates an Option to set the rule name to use as entrypoint. The rule name must have been specified in the -alternate-entrypoints if generating the parser with the -optimize-grammar flag, otherwise it may have been optimized out. Passing an empty string sets the entrypoint to the first rule in the grammar.

The default is to start parsing at the first rule in the grammar.

func GlobalStore 

func GlobalStore(key string, value interface{}) Option

GlobalStore creates an Option to set a key to a certain value in the globalStore.

func InitState 

func InitState(key string, value interface{}) Option

InitState creates an Option to set a key to a certain value in the global "state" store.

func MaxExpressions 

func MaxExpressions(maxExprCnt uint64) Option

MaxExpressions creates an Option to stop parsing after the provided number of expressions have been parsed, if the value is 0 then the parser will parse for as many steps as needed (possibly an infinite number).

The default for maxExprCnt is 0.

func Memoize 

func Memoize(b bool) Option

Memoize creates an Option to set the memoize flag to b. When set to true, the parser will cache all results so each expression is evaluated only once. This guarantees linear parsing time even for pathological cases, at the expense of more memory and slower times for typical cases.

The default is false.

func Recover 

func Recover(b bool) Option

Recover creates an Option to set the recover flag to b. When set to true, this causes the parser to recover from panics and convert it to an error. Setting it to false can be useful while debugging to access the full stack trace.

The default is true.

func Statistics 

func Statistics(stats *Stats, choiceNoMatch string) Option

Statistics adds a user provided Stats struct to the parser to allow the user to process the results after the parsing has finished. Also the key for the "no match" counter is set.

Example usage: 

input := "input"
stats := Stats{}
_, err := Parse("input-file", []byte(input), Statistics(&stats, "no match"))
if err != nil {
    log.Panicln(err)
}
b, err := json.MarshalIndent(stats.ChoiceAltCnt, "", "  ")
if err != nil {
    log.Panicln(err)
}
fmt.Println(string(b))

type QueryBuilder 

type QueryBuilder interface {
	QuerySpec() (*flux.Spec, error)
}

type Selector 

type Selector struct {
	Name          string          `json:"name,omitempty"`
	Range         time.Duration   `json:"range,omitempty"`
	Offset        time.Duration   `json:"offset,omitempty"`
	LabelMatchers []*LabelMatcher `json:"label_matchers,omitempty"`
}

func NewSelector 

func NewSelector(metric *Identifier, block, rng, offset interface{}) (*Selector, error)

func (*Selector) QuerySpec 

func (s *Selector) QuerySpec() (*flux.Spec, error)

func (*Selector) Type 

func (s *Selector) Type() ArgKind

func (*Selector) Value 

func (s *Selector) Value() interface{}

type Stats 

type Stats struct {
	// ExprCnt counts the number of expressions processed during parsing
	// This value is compared to the maximum number of expressions allowed
	// (set by the MaxExpressions option).
	ExprCnt uint64

	// ChoiceAltCnt is used to count for each ordered choice expression,
	// which alternative is used how may times.
	// These numbers allow to optimize the order of the ordered choice expression
	// to increase the performance of the parser
	//
	// The outer key of ChoiceAltCnt is composed of the name of the rule as well
	// as the line and the column of the ordered choice.
	// The inner key of ChoiceAltCnt is the number (one-based) of the matching alternative.
	// For each alternative the number of matches are counted. If an ordered choice does not
	// match, a special counter is incremented. The name of this counter is set with
	// the parser option Statistics.
	// For an alternative to be included in ChoiceAltCnt, it has to match at least once.
	ChoiceAltCnt map[string]map[string]int
}

Stats stores some statistics, gathered during parsing

type StringLiteral 

type StringLiteral struct {
	String string `json:"string,omitempty"`
}

func (*StringLiteral) Type 

func (s *StringLiteral) Type() ArgKind

func (*StringLiteral) Value 

func (s *StringLiteral) Value() interface{}

Source Files

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