Documentation
¶
Index ¶
- Constants
- Variables
- func Inspect(node Node, f inspector)
- func ParseMetric(input string) (m labels.Labels, err error)
- func ParseMetricSelector(input string) (m []*labels.Matcher, err error)
- func Tree(node Node) string
- func Walk(v Visitor, node Node, path []Node) error
- type AggregateExpr
- type AlertStmt
- type BinaryExpr
- type Call
- type Engine
- type ErrQueryCanceled
- type ErrQueryTimeout
- type ErrStorage
- type EvalNodeHelper
- type EvalStmt
- type Expr
- type Expressions
- type Function
- type ItemType
- type Matrix
- type MatrixSelector
- type Node
- type NumberLiteral
- type ParenExpr
- type ParseErr
- type Point
- type Pos
- type Query
- type RecordStmt
- type Result
- type Sample
- type Scalar
- type Series
- type Statement
- type Statements
- type String
- type StringLiteral
- type Test
- type UnaryExpr
- type Value
- type ValueType
- type Vector
- type VectorMatchCardinality
- type VectorMatching
- type VectorSelector
- type Visitor
Constants ¶
const ( ValueTypeNone = "none" ValueTypeVector = "vector" ValueTypeScalar = "scalar" ValueTypeMatrix = "matrix" ValueTypeString = "string" )
The valid value types.
const LowestPrec = 0 // Non-operators.
LowestPrec is a constant for operator precedence in expressions.
Variables ¶
var LookbackDelta = 5 * time.Minute
LookbackDelta determines the time since the last sample after which a time series is considered stale.
Functions ¶
func Inspect ¶
func Inspect(node Node, f inspector)
Inspect traverses an AST in depth-first order: It starts by calling f(node, path); node must not be nil. If f returns a nil error, Inspect invokes f for all the non-nil children of node, recursively.
func ParseMetric ¶
ParseMetric parses the input into a metric
func ParseMetricSelector ¶
ParseMetricSelector parses the provided textual metric selector into a list of label matchers.
func Walk ¶
Walk traverses an AST in depth-first order: It starts by calling v.Visit(node, path); node must not be nil. If the visitor w returned by v.Visit(node, path) is not nil and the visitor returns no error, Walk is invoked recursively with visitor w for each of the non-nil children of node, followed by a call of w.Visit(nil), returning an error As the tree is descended the path of previous nodes is provided.
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 []string // The labels by which to group the Vector.
Without bool // Whether to drop the given labels rather than keep them.
}
AggregateExpr represents an aggregation operation on a Vector.
func (*AggregateExpr) String ¶
func (node *AggregateExpr) String() string
func (*AggregateExpr) Type ¶
func (e *AggregateExpr) Type() ValueType
type AlertStmt ¶
type AlertStmt struct {
Name string
Expr Expr
Duration time.Duration
Labels labels.Labels
Annotations labels.Labels
}
AlertStmt represents an added alert rule.
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() 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(logger log.Logger, reg prometheus.Registerer, maxConcurrent int, timeout time.Duration) *Engine
NewEngine returns a new engine.
func (*Engine) NewInstantQuery ¶
NewInstantQuery returns an evaluation query for the given expression at the given time.
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 ErrStorage ¶ added in v1.6.0
type ErrStorage error
ErrStorage is returned if an error was encountered in the storage layer during query handling.
type EvalNodeHelper ¶
type EvalNodeHelper struct {
// contains filtered or unexported fields
}
EvalNodeHelper stores extra information and caches for evaluating a single node across steps.
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 time.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() 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 []ValueType
Variadic int
ReturnType ValueType
// vals is a list of the evaluated arguments for the function call.
// For range vectors it will be a Matrix with one series, instant vectors a
// Vector, scalars a Vector with one series whose value is the scalar
// value,and nil for strings.
// args are the original arguments to the function, where you can access
// matrixSelectors, vectorSelectors, and StringLiterals.
// enh.out is a pre-allocated empty vector that you may use to accumulate
// output before returning it. The vectors in vals should not be returned.a
// Range vector functions need only return a vector with the right value,
// the metric and timestamp are not neded.
// Instant vector functions need only return a vector with the right values and
// metrics, the timestamp are not needed.
// Scalar results should be returned as the value of a sample in a Vector.
Call func(vals []Value, args Expressions, enh *EvalNodeHelper) Vector
}
Function represents a function of the expression language and is used by function nodes.
type Matrix ¶
type Matrix []Series
Matrix is a slice of Seriess that implements sort.Interface and has a String method.
type MatrixSelector ¶
type MatrixSelector struct {
Name string
Range time.Duration
Offset time.Duration
LabelMatchers []*labels.Matcher
// 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() 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 float64
}
NumberLiteral represents a number.
func (*NumberLiteral) String ¶
func (node *NumberLiteral) String() string
func (*NumberLiteral) Type ¶
func (e *NumberLiteral) Type() 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 Point ¶
Point represents a single data point for a given timestamp.
func (Point) MarshalJSON ¶
MarshalJSON implements json.Marshaler.
type Query ¶
type Query interface {
// Exec processes the query. Can only be called once.
Exec(ctx context.Context) *Result
// Close recovers memory used by the query result.
Close()
// Statement returns the parsed statement of the query.
Statement() Statement
// Stats returns statistics about the lifetime of the query.
Stats() *stats.QueryTimers
// 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 Scalar ¶
Scalar is a data point that's explicitly not associated with a metric.
func (Scalar) MarshalJSON ¶
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() 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.
type UnaryExpr ¶
UnaryExpr represents a unary operation on another expression. Currently unary operations are only supported for Scalars.
type Vector ¶
type Vector []Sample
Vector is basically only an alias for model.Samples, but the contract is that in a Vector, all Samples have the same timestamp.
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 []string
// 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 []string
}
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 []*labels.Matcher
// 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() ValueType
type Visitor ¶
Visitor allows visiting a Node and its child nodes. The Visit method is invoked for each node with the path leading to the node provided additionally. If the result visitor w is not nil and no error, Walk visits each of the children of node with the visitor w, followed by a call of w.Visit(nil, nil).
Source Files