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dont use dynamic functions to parse rows, closes #1417 #1603

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Merged
merged 1 commit into from
May 4, 2018
Merged

dont use dynamic functions to parse rows, closes #1417 #1603

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35 changes: 11 additions & 24 deletions lib/result.js
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Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,6 @@
*/

var types = require('pg-types')
var escape = require('js-string-escape')

// result object returned from query
// in the 'end' event and also
Expand Down Expand Up @@ -65,29 +64,24 @@ Result.prototype._parseRowAsArray = function (rowData) {
return row
}

// rowData is an array of text or binary values
// this turns the row into a JavaScript object
Result.prototype.parseRow = function (rowData) {
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This is a simple reduce but I kept the same style as the array parser for consistency.

return new this.RowCtor(this._parsers, rowData)
var row = {}
for (var i = 0, len = rowData.length; i < len; i++) {
var rawValue = rowData[i]
var field = this.fields[i].name
if (rawValue !== null) {
row[field] = this._parsers[i](rawValue)
} else {
row[field] = null
}
}
return row
}

Result.prototype.addRow = function (row) {
this.rows.push(row)
}

var inlineParser = function (fieldName, i) {
return "\nthis['" +
// fields containing single quotes will break
// the evaluated javascript unless they are escaped
// see https://github.com/brianc/node-postgres/issues/507
// Addendum: However, we need to make sure to replace all
// occurences of apostrophes, not just the first one.
// See https://github.com/brianc/node-postgres/issues/934
escape(fieldName) +
"'] = " +
'rowData[' + i + '] == null ? null : parsers[' + i + '](rowData[' + i + ']);'
}

Result.prototype.addFields = function (fieldDescriptions) {
// clears field definitions
// multiple query statements in 1 action can result in multiple sets
Expand All @@ -97,18 +91,11 @@ Result.prototype.addFields = function (fieldDescriptions) {
this.fields = []
this._parsers = []
}
var ctorBody = ''
for (var i = 0; i < fieldDescriptions.length; i++) {
var desc = fieldDescriptions[i]
this.fields.push(desc)
var parser = this._getTypeParser(desc.dataTypeID, desc.format || 'text')
this._parsers.push(parser)
// this is some craziness to compile the row result parsing
// results in ~60% speedup on large query result sets
ctorBody += inlineParser(desc.name, i)
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if you guys are dead set against this pull, then at least one improvement that could be definitely made to pg is to make ctorBody an array, have this line push the inline parser string into the array and then do an array.join at the end, currently here we are making 2 strings for each field of the results

}
if (!this.rowAsArray) {
this.RowCtor = Function('parsers', 'rowData', ctorBody)
}
}

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1 change: 0 additions & 1 deletion package.json
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Original file line number Diff line number Diff line change
Expand Up @@ -20,7 +20,6 @@
"main": "./lib",
"dependencies": {
"buffer-writer": "1.0.1",
"js-string-escape": "1.0.1",
"packet-reader": "0.3.1",
"pg-connection-string": "0.1.3",
"pg-pool": "~2.0.3",
Expand Down