有什么办法可以让此C＃代码更快？

本文介绍了有什么办法可以让此C＃代码更快？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我读一个大文件X12和解析内的信息。我有两个瓶颈的功能，我似乎无法变通。 read_line（）和get_element（）有什么办法，我可以让这两个函数更快？在get_element功能的主要瓶颈似乎是子串的方法。

公共字符串get_element（INT将Element_number）{诠释计数= 0; INT START_INDEX = 0; INT END_INDEX = 0; INT CURRENT_INDEX = 0; ，而（COUNT<将Element_number&放大器;&安培;！CURRENT_INDEX = -1）{ = CURRENT_INDEX line_text.IndexOf（x12_reader.element_delimiter，START_INDEX）; START_INDEX = CURRENT_INDEX + 1; 计数++; } 如果（CURRENT_INDEX！= -1）{ END_INDEX = line_text.IndexOf（x12_reader.element_delimiter，START_INDEX）; 如果（END_INDEX == -1）= END_INDEX line_text.Length; 返回line_text.Substring（START_INDEX，END_INDEX - START_INDEX）; }其他{返回; } } 私人字符串read_line（）{ string_builder.Clear（）; INT N; ，而（（N = stream_reader.Read（））！= -1）{如果（N == line_terminator）返回string_builder.ToString（）; string_builder.Append（（char）的N）; } 返回string_builder.ToString（）; }

我读X12的数据。这里是什么样子的例子。 examples.x12/005010X221/dollars-and-数据发送在一起/

解决方案

由于您的分析器告诉你 get_element 是一个瓶颈，方法本身是非常有效的编码，你需要减少的时候调用此方法的次数。

调用 get_element 反复循环的力量是重复执行相同的分析工作：

为（ INT I = 0; i = N;！我++）{$​​ b $ b VAR元= get_element（I） ... //做的元素} 的东西

您应该可以通过重写来解决这个问题 get_element 为的getElements 返回所有元素的集合，然后采取从各个元素同一集合在一个循环：

VAR allElements =的getElements（）; 的for（int i = 0; i = N;！我++）{$​​ B $ B VAR元= allElements [I] ... //做的元素}

$ B的东西$ b

在大多数情况下，我只需要一个或两个元素

在这种情况下，你可以使检索所有必需的方法同时指标 - 例如，通过传递的 BitArray 所需的索引。

I am reading in a large file X12 and parsing the information within. I have two bottleneck functions that I can't seem to work around. read_line() and get_element() Is there any way I could make these two functions faster? The main bottleneck in the get_element function seems to be the Substring method.

public String get_element(int element_number) { int count = 0; int start_index = 0; int end_index = 0; int current_index = 0; while (count < element_number && current_index != -1) { current_index = line_text.IndexOf(x12_reader.element_delimiter, start_index); start_index = current_index + 1; count++; } if (current_index != -1) { end_index = line_text.IndexOf(x12_reader.element_delimiter, start_index); if (end_index == -1) end_index = line_text.Length; return line_text.Substring(start_index, end_index - start_index); } else { return ""; } } private String read_line() { string_builder.Clear(); int n; while ((n = stream_reader.Read()) != -1) { if (n == line_terminator) return string_builder.ToString(); string_builder.Append((char)n); } return string_builder.ToString(); }

I am reading x12 data. Here is an example of what it looks like. examples.x12/005010X221/dollars-and-data-sent-together/

解决方案

Since your profiler tells you get_element is a bottleneck, and the method itself is coded very efficiently, you need to minimize the number of times this method is called.

Calling get_element repeatedly in a loop forces it to performs the same parsing job repeatedly:

for (int i = 0 ; i != n ; i++) { var element = get_element(i); ... // Do something with the element }

You should be able to fix this problem by rewriting get_element as GetElements returning all elements as a collection, and then taking individual elements from the same collection in a loop:

var allElements = GetElements(); for (int i = 0 ; i != n ; i++) { var element = allElements[i]; ... // Do something with the element }

in most cases I only need one or two elements

In this case you could make a method that retrieves all required indexes at once - for example, by passing BitArray of required indexes.