Initial commit - Event Planner application
This commit is contained in:
mberlin
265
node_modules/pg-cursor/index.js
generated
vendored
Normal file
265
node_modules/pg-cursor/index.js
generated
vendored
Normal file
@@ -0,0 +1,265 @@
|
||||
'use strict'
|
||||
// note: can remove these deep requires when we bump min version of pg to 9.x
|
||||
const Result = require('pg/lib/result.js')
|
||||
const prepare = require('pg/lib/utils.js').prepareValue
|
||||
const EventEmitter = require('events').EventEmitter
|
||||
const util = require('util')
|
||||
|
||||
let nextUniqueID = 1 // concept borrowed from org.postgresql.core.v3.QueryExecutorImpl
|
||||
|
||||
class Cursor extends EventEmitter {
|
||||
constructor(text, values, config) {
|
||||
super()
|
||||
|
||||
this._conf = config || {}
|
||||
this.text = text
|
||||
this.values = values ? values.map(prepare) : null
|
||||
this.connection = null
|
||||
this._queue = []
|
||||
this.state = 'initialized'
|
||||
this._result = new Result(this._conf.rowMode, this._conf.types)
|
||||
this._Promise = this._conf.Promise || global.Promise
|
||||
this._cb = null
|
||||
this._rows = null
|
||||
this._portal = null
|
||||
this._ifNoData = this._ifNoData.bind(this)
|
||||
this._rowDescription = this._rowDescription.bind(this)
|
||||
}
|
||||
|
||||
_ifNoData() {
|
||||
this.state = 'idle'
|
||||
this._shiftQueue()
|
||||
if (this.connection) {
|
||||
this.connection.removeListener('rowDescription', this._rowDescription)
|
||||
}
|
||||
}
|
||||
|
||||
_rowDescription() {
|
||||
if (this.connection) {
|
||||
this.connection.removeListener('noData', this._ifNoData)
|
||||
}
|
||||
}
|
||||
|
||||
submit(connection) {
|
||||
this.state = 'submitted'
|
||||
this.connection = connection
|
||||
this._portal = 'C_' + nextUniqueID++
|
||||
|
||||
const con = connection
|
||||
|
||||
con.parse(
|
||||
{
|
||||
text: this.text,
|
||||
},
|
||||
true
|
||||
)
|
||||
|
||||
con.bind(
|
||||
{
|
||||
portal: this._portal,
|
||||
values: this.values,
|
||||
},
|
||||
true
|
||||
)
|
||||
|
||||
con.describe(
|
||||
{
|
||||
type: 'P',
|
||||
name: this._portal, // AWS Redshift requires a portal name
|
||||
},
|
||||
true
|
||||
)
|
||||
|
||||
con.flush()
|
||||
|
||||
if (this._conf.types) {
|
||||
this._result._getTypeParser = this._conf.types.getTypeParser
|
||||
}
|
||||
|
||||
con.once('noData', this._ifNoData)
|
||||
con.once('rowDescription', this._rowDescription)
|
||||
}
|
||||
|
||||
_shiftQueue() {
|
||||
if (this._queue.length) {
|
||||
this._getRows.apply(this, this._queue.shift())
|
||||
}
|
||||
}
|
||||
|
||||
_closePortal() {
|
||||
if (this.state === 'done') return
|
||||
|
||||
// because we opened a named portal to stream results
|
||||
// we need to close the same named portal. Leaving a named portal
|
||||
// open can lock tables for modification if inside a transaction.
|
||||
// see https://github.com/brianc/node-pg-cursor/issues/56
|
||||
this.connection.close({ type: 'P', name: this._portal })
|
||||
|
||||
// If we've received an error we already sent a sync message.
|
||||
// do not send another sync as it triggers another readyForQuery message.
|
||||
if (this.state !== 'error') {
|
||||
this.connection.sync()
|
||||
}
|
||||
|
||||
this.state = 'done'
|
||||
}
|
||||
|
||||
handleRowDescription(msg) {
|
||||
this._result.addFields(msg.fields)
|
||||
this.state = 'idle'
|
||||
this._shiftQueue()
|
||||
}
|
||||
|
||||
handleDataRow(msg) {
|
||||
const row = this._result.parseRow(msg.fields)
|
||||
this.emit('row', row, this._result)
|
||||
this._rows.push(row)
|
||||
}
|
||||
|
||||
_sendRows() {
|
||||
this.state = 'idle'
|
||||
setImmediate(() => {
|
||||
const cb = this._cb
|
||||
// remove callback before calling it
|
||||
// because likely a new one will be added
|
||||
// within the call to this callback
|
||||
this._cb = null
|
||||
if (cb) {
|
||||
this._result.rows = this._rows
|
||||
cb(null, this._rows, this._result)
|
||||
}
|
||||
this._rows = []
|
||||
})
|
||||
}
|
||||
|
||||
handleCommandComplete(msg) {
|
||||
this._result.addCommandComplete(msg)
|
||||
this._closePortal()
|
||||
}
|
||||
|
||||
handlePortalSuspended() {
|
||||
this._sendRows()
|
||||
}
|
||||
|
||||
handleReadyForQuery() {
|
||||
this._sendRows()
|
||||
this.state = 'done'
|
||||
this.emit('end', this._result)
|
||||
}
|
||||
|
||||
handleEmptyQuery() {
|
||||
this.connection.sync()
|
||||
}
|
||||
|
||||
handleError(msg) {
|
||||
// If this cursor has already closed, don't try to handle the error.
|
||||
if (this.state === 'done') return
|
||||
|
||||
// If we're in an initialized state we've never been submitted
|
||||
// and don't have a connection instance reference yet.
|
||||
// This can happen if you queue a stream and close the client before
|
||||
// the client has submitted the stream. In this scenario we don't have
|
||||
// a connection so there's nothing to unsubscribe from.
|
||||
if (this.state !== 'initialized') {
|
||||
this.connection.removeListener('noData', this._ifNoData)
|
||||
this.connection.removeListener('rowDescription', this._rowDescription)
|
||||
// call sync to trigger a readyForQuery
|
||||
this.connection.sync()
|
||||
}
|
||||
|
||||
this.state = 'error'
|
||||
this._error = msg
|
||||
// satisfy any waiting callback
|
||||
if (this._cb) {
|
||||
this._cb(msg)
|
||||
}
|
||||
// dispatch error to all waiting callbacks
|
||||
for (let i = 0; i < this._queue.length; i++) {
|
||||
const queuedCallback = this._queue[i][1]
|
||||
queuedCallback.call(this, msg)
|
||||
}
|
||||
this._queue.length = 0
|
||||
|
||||
if (this.listenerCount('error') > 0) {
|
||||
// only dispatch error events if we have a listener
|
||||
this.emit('error', msg)
|
||||
}
|
||||
}
|
||||
|
||||
_getRows(rows, cb) {
|
||||
this.state = 'busy'
|
||||
this._cb = cb
|
||||
this._rows = []
|
||||
const msg = {
|
||||
portal: this._portal,
|
||||
rows: rows,
|
||||
}
|
||||
this.connection.execute(msg, true)
|
||||
this.connection.flush()
|
||||
}
|
||||
|
||||
// users really shouldn't be calling 'end' here and terminating a connection to postgres
|
||||
// via the low level connection.end api
|
||||
end(cb) {
|
||||
if (this.state !== 'initialized') {
|
||||
this.connection.sync()
|
||||
}
|
||||
this.connection.once('end', cb)
|
||||
this.connection.end()
|
||||
}
|
||||
|
||||
close(cb) {
|
||||
let promise
|
||||
|
||||
if (!cb) {
|
||||
promise = new this._Promise((resolve, reject) => {
|
||||
cb = (err) => (err ? reject(err) : resolve())
|
||||
})
|
||||
}
|
||||
|
||||
if (!this.connection || this.state === 'done') {
|
||||
setImmediate(cb)
|
||||
return promise
|
||||
}
|
||||
|
||||
this._closePortal()
|
||||
this.connection.once('readyForQuery', function () {
|
||||
cb()
|
||||
})
|
||||
|
||||
// Return the promise (or undefined)
|
||||
return promise
|
||||
}
|
||||
|
||||
read(rows, cb) {
|
||||
let promise
|
||||
|
||||
if (!cb) {
|
||||
promise = new this._Promise((resolve, reject) => {
|
||||
cb = (err, rows) => (err ? reject(err) : resolve(rows))
|
||||
})
|
||||
}
|
||||
|
||||
if (this.state === 'idle' || this.state === 'submitted') {
|
||||
this._getRows(rows, cb)
|
||||
} else if (this.state === 'busy' || this.state === 'initialized') {
|
||||
this._queue.push([rows, cb])
|
||||
} else if (this.state === 'error') {
|
||||
setImmediate(() => cb(this._error))
|
||||
} else if (this.state === 'done') {
|
||||
setImmediate(() => cb(null, []))
|
||||
} else {
|
||||
throw new Error('Unknown state: ' + this.state)
|
||||
}
|
||||
|
||||
// Return the promise (or undefined)
|
||||
return promise
|
||||
}
|
||||
}
|
||||
|
||||
Cursor.prototype.end = util.deprecate(
|
||||
Cursor.prototype.end,
|
||||
'Cursor.end is deprecated. Call end on the client itself to end a connection to the database.'
|
||||
)
|
||||
|
||||
module.exports = Cursor
|
||||
Reference in New Issue
Block a user