logql

type Engine ¶ added in v0.4.0

type Engine struct {
	// contains filtered or unexported fields
}

Engine is the LogQL engine.

func NewEngine(opts EngineOpts) *Engine

func (ng *Engine) NewInstantQuery(
	q Querier,
	qs string,
	ts time.Time,
	direction logproto.Direction, limit uint32) Query

func (ng *Engine) NewRangeQuery(
	q Querier,
	qs string,
	start, end time.Time, step time.Duration,
	direction logproto.Direction, limit uint32) Query

type EngineOpts ¶ added in v0.4.0

type EngineOpts struct {
	// Timeout for queries execution
	Timeout time.Duration `yaml:"timeout"`
	// MaxLookBackPeriod is the maximun amount of time to look back for log lines.
	// only used for instant log queries.
	MaxLookBackPeriod time.Duration `yaml:"max_look_back_period"`
}

EngineOpts is the list of options to use with the LogQL query engine.

type Expr ¶

type Expr interface{}

Expr is the root expression which can be a SampleExpr or LogSelectorExpr

func ParseExpr(input string) (expr Expr, err error)

type Filter ¶ added in v0.2.0

type Filter func(line []byte) bool

Filter is a function to filter logs.

type LogSelectorExpr ¶ added in v0.4.0

type LogSelectorExpr interface {
	Tags() ([]*TagMatcher, []Filter)
	Filter() (Filter, error)
	Matchers() []*labels.Matcher
	fmt.Stringer
}

LogSelectorExpr is a LogQL expression filtering and returning logs.

func NewFilterExpr(left LogSelectorExpr, ty labels.MatchType, match string) LogSelectorExpr

func ParseLogSelector(input string) (LogSelectorExpr, error)

type ParseError ¶

type ParseError struct {
	// contains filtered or unexported fields
}

ParseError is what is returned when we failed to parse.

func (p ParseError) Error() string

type Querier ¶

type Querier interface {
	Select(context.Context, SelectParams) (iter.EntryIterator, error)
}

Querier allows a LogQL expression to fetch an EntryIterator for a set of matchers and filters

type QuerierFunc ¶

type QuerierFunc func(context.Context, SelectParams) (iter.EntryIterator, error)

QuerierFunc implements Querier.

func (q QuerierFunc) Select(ctx context.Context, p SelectParams) (iter.EntryIterator, error)

type Query ¶ added in v0.4.0

type Query interface {
	// Exec processes the query.
	Exec(ctx context.Context) (promql.Value, error)
}

Query is a LogQL query to be executed.

type RangeVectorAggregator ¶ added in v0.4.0

type RangeVectorAggregator func(int64, []promql.Point) float64

RangeVectorAggregator aggregates samples for a given range of samples. It receives the current milliseconds timestamp and the list of point within the range.

type RangeVectorIterator ¶ added in v0.4.0

type RangeVectorIterator interface {
	Next() bool
	At(aggregator RangeVectorAggregator) (int64, promql.Vector)
	Close() error
}

RangeVectorIterator iterates through a range of samples. To fetch the current vector use `At` with a `RangeVectorAggregator`.

type SampleExpr ¶ added in v0.4.0

type SampleExpr interface {
	// Selector is the LogQL selector to apply when retrieving logs.
	Selector() LogSelectorExpr
	// Evaluator returns a `StepEvaluator` that can evaluate the expression step by step
	Evaluator() StepEvaluator
	// Close all resources used.
	Close() error
}

SampleExpr is a LogQL expression filtering logs and returning metric samples.

type SelectParams ¶ added in v0.4.0

type SelectParams struct {
	*logproto.QueryRequest
}

SelectParams specifies parameters passed to data selections.

func (s SelectParams) LogSelector() (LogSelectorExpr, error)

type StepEvaluator ¶ added in v0.4.0

type StepEvaluator interface {
	Next() (bool, int64, promql.Vector)
}

StepEvaluator evaluate a single step of a query.

type StepEvaluatorFn ¶ added in v0.4.0

type StepEvaluatorFn func() (bool, int64, promql.Vector)

StepEvaluatorFn is a function to chain multiple `StepEvaluator`.

func (s StepEvaluatorFn) Next() (bool, int64, promql.Vector)

type Streams ¶ added in v0.4.0

type Streams []*logproto.Stream

Streams is promql.Value

func (Streams) String() string

func (Streams) Type() promql.ValueType

type TagMatcher ¶ added in v0.4.0

type TagMatcher struct {
	Name  string
	Value string
}

Tag represents a high-cardinality KV label. It does not participate the computation of the streamID, so it will not affect the granularity of the aggregation of chunks.

Tag will store a different index entry, it points to the chunk which contains the log line which has the tag.

When performing a query, tag will be used to determine which chunk to look at, and it will return a Filter func just like any other Filter. And you should use it to filter the lines within that chunk.

func (t *TagMatcher) String() string