github.com/m3db/m3@v1.5.0/src/query/parser/interface.go (about)

     1  // Copyright (c) 2018 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
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     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package parser
    22  
    23  import (
    24  	"fmt"
    25  
    26  	"github.com/m3db/m3/src/query/models"
    27  )
    28  
    29  // Parser consists of the language specific representation of AST and can
    30  // convert into a common DAG.
    31  type Parser interface {
    32  	DAG() (Nodes, Edges, error)
    33  	String() string
    34  }
    35  
    36  // NodeID uniquely identifies all transforms in DAG.
    37  type NodeID string
    38  
    39  // Params is a function definition. It is immutable and contains no state.
    40  type Params interface {
    41  	fmt.Stringer
    42  	OpType() string
    43  }
    44  
    45  // Nodes is a slice of Node objects.
    46  type Nodes []Node
    47  
    48  // Node represents an immutable node in the common DAG with a unique identifier.
    49  // TODO: make this serializable
    50  type Node struct {
    51  	ID NodeID
    52  	Op Params
    53  }
    54  
    55  func (t Node) String() string {
    56  	return fmt.Sprintf("ID: %s, Op: %s", t.ID, t.Op)
    57  }
    58  
    59  // Edge identifies parent-child relation between transforms.
    60  type Edge struct {
    61  	ParentID NodeID
    62  	ChildID  NodeID
    63  }
    64  
    65  func (e Edge) String() string {
    66  	return fmt.Sprintf("parent: %s, child: %s", e.ParentID, e.ChildID)
    67  }
    68  
    69  // Edges is a slice of Edge objects.
    70  type Edges []Edge
    71  
    72  // NewTransformFromOperation creates a new transform.
    73  func NewTransformFromOperation(Op Params, nextID int) Node {
    74  	return Node{
    75  		Op: Op,
    76  		ID: NodeID(fmt.Sprintf("%v", nextID)),
    77  	}
    78  }
    79  
    80  // Source represents data sources which are handled differently than other
    81  // transforms as they are always independent and can always be parallelized.
    82  type Source interface {
    83  	Execute(queryCtx *models.QueryContext) error
    84  }