Documentation
¶
Index ¶
- Constants
- Variables
- func Inspect(node Node, f func(Node) bool)
- func ParseMetric(input string) (m model.Metric, err error)
- func ParseMetricSelector(input string) (m metric.LabelMatchers, err error)
- func Tree(node Node) string
- func Walk(v Visitor, node Node)
- type AggregateExpr
- type AlertStmt
- type Benchmark
- type BinaryExpr
- type Call
- type Engine
- type EngineOptions
- type ErrQueryCanceled
- type ErrQueryTimeout
- type EvalStmt
- type Expr
- type Expressions
- type Function
- type MatrixSelector
- type Node
- type NumberLiteral
- type ParenExpr
- type ParseErr
- type Pos
- type Query
- type Queryable
- type RecordStmt
- type Result
- type Statement
- type Statements
- type StringLiteral
- type Test
- type UnaryExpr
- type VectorMatchCardinality
- type VectorMatching
- type VectorSelector
- type Visitor
Constants ¶
const LowestPrec = 0 // Non-operators.
LowestPrec is a constant for operator precedence in expressions.
Variables ¶
var DefaultEngineOptions = &EngineOptions{ MaxConcurrentQueries: 20, Timeout: 2 * time.Minute, }
DefaultEngineOptions are the default engine options.
var StalenessDelta = 5 * time.Minute
StalenessDelta determines the time since the last sample after which a time series is considered stale.
Functions ¶
func Inspect ¶
Inspect traverses an AST in depth-first order: It starts by calling f(node); node must not be nil. If f returns true, Inspect invokes f for all the non-nil children of node, recursively.
func ParseMetric ¶
ParseMetric parses the input into a metric
func ParseMetricSelector ¶
func ParseMetricSelector(input string) (m metric.LabelMatchers, err error)
ParseMetricSelector parses the provided textual metric selector into a list of label matchers.
Types ¶
type AggregateExpr ¶
type AggregateExpr struct {
Op itemType // The used aggregation operation.
Expr Expr // The vector expression over which is aggregated.
Param Expr // Parameter used by some aggregators.
Grouping model.LabelNames // The labels by which to group the vector.
Without bool // Whether to drop the given labels rather than keep them.
KeepCommonLabels bool // Whether to keep common labels among result elements.
}
AggregateExpr represents an aggregation operation on a vector.
func (*AggregateExpr) String ¶
func (node *AggregateExpr) String() string
func (*AggregateExpr) Type ¶
func (e *AggregateExpr) Type() model.ValueType
type AlertStmt ¶
type AlertStmt struct {
Name string
Expr Expr
Duration time.Duration
Labels model.LabelSet
Annotations model.LabelSet
}
AlertStmt represents an added alert rule.
type Benchmark ¶
type Benchmark struct {
// contains filtered or unexported fields
}
A Benchmark holds context for running a unit test as a benchmark.
func NewBenchmark ¶
NewBenchmark returns an initialized empty Benchmark.
type BinaryExpr ¶
type BinaryExpr struct {
Op itemType // The operation of the expression.
LHS, RHS Expr // The operands on the respective sides of the operator.
// The matching behavior for the operation if both operands are vectors.
// If they are not this field is nil.
VectorMatching *VectorMatching
// If a comparison operator, return 0/1 rather than filtering.
ReturnBool bool
}
BinaryExpr represents a binary expression between two child expressions.
func (*BinaryExpr) String ¶
func (node *BinaryExpr) String() string
func (*BinaryExpr) Type ¶
func (e *BinaryExpr) Type() model.ValueType
type Call ¶
type Call struct {
Func *Function // The function that was called.
Args Expressions // Arguments used in the call.
}
Call represents a function call.
type Engine ¶
type Engine struct {
// contains filtered or unexported fields
}
Engine handles the lifetime of queries from beginning to end. It is connected to a querier.
func NewEngine ¶
func NewEngine(queryable Queryable, o *EngineOptions) *Engine
NewEngine returns a new engine.
func (*Engine) NewInstantQuery ¶
NewInstantQuery returns an evaluation query for the given expression at the given time.
type EngineOptions ¶
EngineOptions contains configuration parameters for an Engine.
type ErrQueryCanceled ¶
type ErrQueryCanceled string
ErrQueryCanceled is returned if a query was canceled during processing.
func (ErrQueryCanceled) Error ¶
func (e ErrQueryCanceled) Error() string
type ErrQueryTimeout ¶
type ErrQueryTimeout string
ErrQueryTimeout is returned if a query timed out during processing.
func (ErrQueryTimeout) Error ¶
func (e ErrQueryTimeout) Error() string
type EvalStmt ¶
type EvalStmt struct {
Expr Expr // Expression to be evaluated.
// The time boundaries for the evaluation. If Start equals End an instant
// is evaluated.
Start, End model.Time
// Time between two evaluated instants for the range [Start:End].
Interval time.Duration
}
EvalStmt holds an expression and information on the range it should be evaluated on.
type Expr ¶
type Expr interface {
Node
// Type returns the type the expression evaluates to. It does not perform
// in-depth checks as this is done at parsing-time.
Type() model.ValueType
// contains filtered or unexported methods
}
Expr is a generic interface for all expression types.
type Expressions ¶
type Expressions []Expr
Expressions is a list of expression nodes that implements Node.
func (Expressions) String ¶
func (es Expressions) String() (s string)
type Function ¶
type Function struct {
Name string
ArgTypes []model.ValueType
OptionalArgs int
ReturnType model.ValueType
Call func(ev *evaluator, args Expressions) model.Value
}
Function represents a function of the expression language and is used by function nodes.
type MatrixSelector ¶
type MatrixSelector struct {
Name string
Range time.Duration
Offset time.Duration
LabelMatchers metric.LabelMatchers
// contains filtered or unexported fields
}
MatrixSelector represents a matrix selection.
func (*MatrixSelector) String ¶
func (node *MatrixSelector) String() string
func (*MatrixSelector) Type ¶
func (e *MatrixSelector) Type() model.ValueType
type Node ¶
type Node interface {
// String representation of the node that returns the given node when parsed
// as part of a valid query.
String() string
}
Node is a generic interface for all nodes in an AST.
Whenever numerous nodes are listed such as in a switch-case statement or a chain of function definitions (e.g. String(), expr(), etc.) convention is to list them as follows:
- Statements
- statement types (alphabetical)
- ...
- Expressions
- expression types (alphabetical)
- ...
type NumberLiteral ¶
type NumberLiteral struct {
Val model.SampleValue
}
NumberLiteral represents a number.
func (*NumberLiteral) String ¶
func (node *NumberLiteral) String() string
func (*NumberLiteral) Type ¶
func (e *NumberLiteral) Type() model.ValueType
type ParenExpr ¶
type ParenExpr struct {
Expr Expr
}
ParenExpr wraps an expression so it cannot be disassembled as a consequence of operator precedence.
type ParseErr ¶
ParseErr wraps a parsing error with line and position context. If the parsing input was a single line, line will be 0 and omitted from the error string.
type Query ¶
type Query interface {
// Exec processes the query and
Exec(ctx context.Context) *Result
// Statement returns the parsed statement of the query.
Statement() Statement
// Stats returns statistics about the lifetime of the query.
Stats() *stats.TimerGroup
// Cancel signals that a running query execution should be aborted.
Cancel()
}
A Query is derived from an a raw query string and can be run against an engine it is associated with.
type RecordStmt ¶
RecordStmt represents an added recording rule.
func (*RecordStmt) String ¶
func (node *RecordStmt) String() string
type Result ¶
Result holds the resulting value of an execution or an error if any occurred.
func (*Result) Matrix ¶
Matrix returns a matrix. An error is returned if the result was an error or the result value is not a matrix.
type Statement ¶
type Statement interface {
Node
// contains filtered or unexported methods
}
Statement is a generic interface for all statements.
type Statements ¶
type Statements []Statement
Statements is a list of statement nodes that implements Node.
func ParseStmts ¶
func ParseStmts(input string) (Statements, error)
ParseStmts parses the input and returns the resulting statements or any occurring error.
func (Statements) String ¶
func (stmts Statements) String() (s string)
type StringLiteral ¶
type StringLiteral struct {
Val string
}
StringLiteral represents a string.
func (*StringLiteral) String ¶
func (node *StringLiteral) String() string
func (*StringLiteral) Type ¶
func (e *StringLiteral) Type() model.ValueType
type Test ¶
Test is a sequence of read and write commands that are run against a test storage.
func (*Test) QueryEngine ¶
QueryEngine returns the test's query engine.
func (*Test) Run ¶
Run executes the command sequence of the test. Until the maximum error number is reached, evaluation errors do not terminate execution.
func (*Test) RunAsBenchmark ¶
RunAsBenchmark runs the test in benchmark mode. This will not count any loads or non eval functions.
type UnaryExpr ¶
type UnaryExpr struct {
Op itemType
Expr Expr
}
UnaryExpr represents a unary operation on another expression. Currently unary operations are only supported for scalars.
type VectorMatchCardinality ¶
type VectorMatchCardinality int
VectorMatchCardinality describes the cardinality relationship of two vectors in a binary operation.
const ( CardOneToOne VectorMatchCardinality = iota CardManyToOne CardOneToMany CardManyToMany )
func (VectorMatchCardinality) String ¶
func (vmc VectorMatchCardinality) String() string
type VectorMatching ¶
type VectorMatching struct {
// The cardinality of the two vectors.
Card VectorMatchCardinality
// MatchingLabels contains the labels which define equality of a pair of
// elements from the vectors.
MatchingLabels model.LabelNames
// On includes the given label names from matching,
// rather than excluding them.
On bool
// Include contains additional labels that should be included in
// the result from the side with the lower cardinality.
Include model.LabelNames
}
VectorMatching describes how elements from two vectors in a binary operation are supposed to be matched.
type VectorSelector ¶
type VectorSelector struct {
Name string
Offset time.Duration
LabelMatchers metric.LabelMatchers
// contains filtered or unexported fields
}
VectorSelector represents a vector selection.
func (*VectorSelector) String ¶
func (node *VectorSelector) String() string
func (*VectorSelector) Type ¶
func (e *VectorSelector) Type() model.ValueType
Source Files