github.com/lirm/aeron-go@v0.0.0-20230415210743-920325491dc4/aeron/position.go (about)

     1  /*
     2  Copyright 2016 Stanislav Liberman
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8  http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package aeron
    18  
    19  import (
    20  	"github.com/lirm/aeron-go/aeron/atomic"
    21  	"github.com/lirm/aeron-go/aeron/util"
    22  )
    23  
    24  // Position is a wrapper for a buffer location of a position counter
    25  type Position struct {
    26  	buffer *atomic.Buffer
    27  	id     int32
    28  	offset int32
    29  }
    30  
    31  // NewPosition is a factory method to create new Position wrappers
    32  func NewPosition(buffer *atomic.Buffer, id int32) Position {
    33  	var pos Position
    34  
    35  	pos.buffer = buffer
    36  	pos.id = id
    37  	pos.offset = id * 2 * util.CacheLineLength
    38  
    39  	logger.Debugf("<+ Counter[%d]: %d", id, pos.buffer.GetInt64(pos.offset))
    40  
    41  	return pos
    42  }
    43  
    44  //go:norace
    45  func (pos *Position) get() int64 {
    46  	p := pos.buffer.GetInt64(pos.offset)
    47  	return p
    48  }
    49  
    50  //go:norace
    51  func (pos *Position) set(value int64) {
    52  	pos.buffer.PutInt64(pos.offset, value)
    53  }