// *****************************************************************************
// Copyright 2013-2018 Aerospike, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License")
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// *****************************************************************************
'use strict'
/**
* Policy governing the use of the global command queue.
*
* **Which commands are affected by the command queue?**
*
* Not all client commands use the command queue. Only single-key commands
* (e.g. Put, Get, etc.), the BatchRead, BatchWrite commands, and {@link Query#foreach},
* {@link Scan#foreach} commands use the command queue (if enabled).
*
* Commands that are based on the Aerospike info protocol (Index
* Create/Remove, UDF Register/Remove, Truncate, Info), the legacy Batch
* Get/Select/Exists commands as well as all other Query and Scan commands do
* not use the command queue and will always be executed immediately.
*
* @see {@link module:aerospike.setupGlobalCommandQueue
* Aerospike.setupGlobalCommandQueue} - function used to initialize the global
* command queue.
*
* @example
*
* const Aerospike = require('aerospike')
*
* const policy = {
* maxCommandsInProcess: 50,
* maxCommandsInQueue: 150
* }
* Aerospike.setupGlobalCommandQueue(policy)
*
* Aerospike.connect()
* .then(client => {
* let commands = []
* for (var i = 0; i < 100; i++) {
* let cmd = client.put(new Aerospike.Key('test', 'test', i), {i: i})
* commands.push(cmd)
* }
*
* // First 50 commands will be executed immediately,
* // remaining commands will be queued and executed once the client frees up.
* Promise.all(commands)
* .then(() => console.info('All commands executed successfully'))
* .catch(error => console.error('Error:', error))
* .then(() => client.close())
* })
*/
class CommandQueuePolicy {
/**
* Initializes a new CommandQueuePolicy from the provided policy values.
*
* @param {Object} [props] - Policy values
* @param {number} [props.maxCommandsInProcess] - Maximum number of async
* commands that can be processed at any point in time.
* @param {number} [props.maxCommandsInQueue] - Maximum number of commands that can be queued for later execution.
* @param {number} [props.queueInitialCapacity] - Initial capacity of the command queue.
*/
constructor (props) {
props = props || {}
/**
* Maximum number of commands that can be processed at any point in time.
* Each executing command requires a socket connection. Consuming too many
* sockets can negatively affect application reliability and performance.
* If you do not limit command count in your application, this setting
* should be used to enforce a limit internally in the client.
*
* If this limit is reached, the next command will be placed on the
* client's command queue for later execution. If this limit is zero, all
* commands will be executed immediately and the command queue will not be
* used. (Note: {@link Config#maxConnsPerNode} may still limit number of
* connections per cluster node.)
*
* If defined, a reasonable value is 40. The optimal value will depend on
* the CPU speed and network bandwidth.
*
* @type Number
* @default 0 (execute all commands immediately)
*/
this.maxCommandsInProcess = props.maxCommandsInProcess
/**
* Maximum number of commands that can be stored in the global command
* queue for later execution. Queued commands consume memory, but they do
* not consume sockets. This limit should be defined when it's possible
* that the application executes so many commands that memory could be
* exhausted.
*
* If this limit is reached, the next command will be rejected with error
* code <code>ERR_ASYNC_QUEUE_FULL</code>. If this limit is zero, all
* commands will be accepted into the delay queue.
*
* The optimal value will depend on the application's magnitude of command
* bursts and the amount of memory available to store commands.
*
* @type Number
* @default 0 (no command queue limit)
*/
this.maxCommandsInQueue = props.maxCommandsInQueue
/**
* Initial capacity of the command queue. The command queue can resize
* beyond this initial capacity.
*
* @type Number
* @default 256 (if command queue is used)
*/
this.queueInitialCapacity = props.queueInitialCapacity
}
}
module.exports = CommandQueuePolicy