github.com/matrixorigin/matrixone@v1.2.0/pkg/common/morpc/cache.go (about)

     1  // Copyright 2023 Matrix Origin
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package morpc
    16  
    17  import (
    18  	"sync"
    19  
    20  	"github.com/matrixorigin/matrixone/pkg/common/moerr"
    21  )
    22  
    23  type cache struct {
    24  	sync.RWMutex
    25  	closed bool
    26  	queue  []Message
    27  }
    28  
    29  func newCache() MessageCache {
    30  	return &cache{}
    31  }
    32  
    33  func (c *cache) Add(value Message) error {
    34  	c.Lock()
    35  	defer c.Unlock()
    36  	if c.closed {
    37  		return moerr.NewInvalidStateNoCtx("cache is closed")
    38  	}
    39  	c.queue = append(c.queue, value)
    40  	return nil
    41  }
    42  
    43  func (c *cache) Len() (int, error) {
    44  	c.RLock()
    45  	defer c.RUnlock()
    46  	if c.closed {
    47  		return 0, moerr.NewInvalidStateNoCtx("cache is closed")
    48  	}
    49  	return len(c.queue), nil
    50  }
    51  
    52  func (c *cache) Pop() (Message, bool, error) {
    53  	c.Lock()
    54  	defer c.Unlock()
    55  	if c.closed {
    56  		return nil, false, moerr.NewInvalidStateNoCtx("cache is closed")
    57  	}
    58  
    59  	if len(c.queue) == 0 {
    60  		return nil, false, nil
    61  	}
    62  	v := c.queue[0]
    63  	c.queue[0] = nil
    64  	c.queue = c.queue[1:]
    65  	return v, true, nil
    66  }
    67  
    68  func (c *cache) Close() {
    69  	c.Lock()
    70  	defer c.Unlock()
    71  	for idx := range c.queue {
    72  		c.queue[idx] = nil
    73  	}
    74  	c.closed = true
    75  }