promql

Documentation

Index

• func Build(promql string, opts ...Option) (*query.Spec, error)
• func NewRangeOp(rng, offset time.Duration) (*query.Operation, error)
• func NewWhereOperation(metricName string, labels []*LabelMatcher) (*query.Operation, error)
• func Parse(filename string, b []byte, opts ...Option) (interface{}, error)
• func ParseFile(filename string, opts ...Option) (i interface{}, err error)
• func ParsePromQL(promql string, opts ...Option) (interface{}, error)
• func ParseReader(filename string, r io.Reader, opts ...Option) (interface{}, error)
• type Aggregate
  • func (a *Aggregate) QuerySpec() (*query.Operation, error)
• type AggregateExpr
  • func NewAggregateExpr(op *Operator, selector *Selector, group interface{}) (*AggregateExpr, error)
  • func (a *AggregateExpr) QuerySpec() (*query.Spec, error)
• type Arg
• type ArgKind
• type Comment
  • func (c *Comment) QuerySpec() (*query.Spec, error)
• type Duration
  • func (d *Duration) Type() ArgKind
  • func (d *Duration) Value() interface{}
• type Identifier
  • func NewIdentifierList(first *Identifier, rest interface{}) ([]*Identifier, error)
  • func (id *Identifier) Type() ArgKind
  • func (id *Identifier) Value() interface{}
• type LabelMatcher
  • func NewLabelMatcher(ident *Identifier, kind MatchKind, value Arg) (*LabelMatcher, error)
  • func NewLabelMatches(first *LabelMatcher, rest interface{}) ([]*LabelMatcher, error)
• type MatchKind
• type Number
  • func NewNumber(val string) (*Number, error)
  • func (n *Number) Type() ArgKind
  • func (n *Number) Value() interface{}
• type Operator
  • func (o *Operator) QuerySpec() (*query.Operation, error)
• type OperatorKind
  • func ToOperatorKind(op string) OperatorKind
• type Option
  • func Debug(b bool) Option
  • func GlobalStore(key string, value interface{}) Option
  • func MaxExpressions(maxExprCnt uint64) Option
  • func Memoize(b bool) Option
  • func Recover(b bool) Option
  • func Statistics(stats *Stats, choiceNoMatch string) Option
• type QueryBuilder
• type Selector
  • func NewSelector(metric *Identifier, block, rng, offset interface{}) (*Selector, error)
  • func (s *Selector) QuerySpec() (*query.Spec, error)
  • func (s *Selector) Type() ArgKind
  • func (s *Selector) Value() interface{}
• type Stats
• type StringLiteral
  • func (s *StringLiteral) Type() ArgKind
  • func (s *StringLiteral) Value() interface{}

Functions

func Build

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

func NewRangeOp

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

func NewWhereOperation

func NewWhereOperation(metricName string, labels []*LabelMatcher) (*query.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"`
	KeepCommon bool          `json:"keep_common,omitempty"`
	Labels     []*Identifier `json:"labels,omitempty"`
}

func (*Aggregate) QuerySpec

func (a *Aggregate) QuerySpec() (*query.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() (*query.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 Comment

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

func (*Comment) QuerySpec

func (c *Comment) QuerySpec() (*query.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() (*query.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 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 GlobalStore

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

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

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() (*query.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() (*query.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{}