github.com/m3db/m3@v1.5.0/src/m3ninx/search/executor/executor.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
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     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 executor
    22  
    23  import (
    24  	"errors"
    25  	"sync"
    26  
    27  	"github.com/m3db/m3/src/m3ninx/doc"
    28  	"github.com/m3db/m3/src/m3ninx/index"
    29  	"github.com/m3db/m3/src/m3ninx/search"
    30  	"github.com/m3db/m3/src/x/context"
    31  )
    32  
    33  var (
    34  	errExecutorClosed = errors.New("executor is closed")
    35  )
    36  
    37  type newIteratorFn func(
    38  	ctx context.Context,
    39  	q search.Query,
    40  	rs index.Readers,
    41  ) (doc.QueryDocIterator, error)
    42  
    43  type executor struct {
    44  	sync.RWMutex
    45  
    46  	newIteratorFn newIteratorFn
    47  	readers       index.Readers
    48  
    49  	closed bool
    50  }
    51  
    52  // NewExecutor returns a new Executor for executing queries.
    53  func NewExecutor(rs index.Readers) search.Executor {
    54  	return &executor{
    55  		newIteratorFn: newIterator,
    56  		readers:       rs,
    57  	}
    58  }
    59  
    60  func (e *executor) Execute(ctx context.Context, q search.Query) (doc.QueryDocIterator, error) {
    61  	e.RLock()
    62  	defer e.RUnlock()
    63  	if e.closed {
    64  		return nil, errExecutorClosed
    65  	}
    66  
    67  	iter, err := e.newIteratorFn(ctx, q, e.readers)
    68  	if err != nil {
    69  		return nil, err
    70  	}
    71  
    72  	return iter, nil
    73  }
    74  
    75  func (e *executor) Close() error {
    76  	e.Lock()
    77  	if e.closed {
    78  		e.Unlock()
    79  		return errExecutorClosed
    80  	}
    81  	e.closed = true
    82  	e.Unlock()
    83  	return e.readers.Close()
    84  }