Project design
Design the skeleton of the expert final mini app.
Project design
In this project you will build a parallel log processor: zero-copy level parsing with Span<T>, a producer-consumer flow with Channel, a source generator simulation for DTOs, and multi-threaded counting with Parallel.ForEach.
All pieces live in one static class LogProcessor. Each lesson adds one piece; the initial code includes the previous lesson's solution. The final lesson ties everything together.
LogProcessor skeleton
The skeleton holds two methods: ParseLevel and CountByLevel. ParseLevel maps a level name (INFO, WARN, ERROR) to an integer code. CountByLevel counts how many logs in an array have a given level.
This base will be extended with Span, Channel, and a source generator in later lessons. Each piece builds on the previous one.
Exercise Write the LogProcessor skeleton
Add two methods to the LogProcessor static class. public static int ParseLevel(string level): use a switch with "INFO" => 0, "WARN" => 1, "ERROR" => 2, _ => -1. public static int CountByLevel(string[] logs, int targetLevel): with foreach, find each log's level with ParseLevel(log.Split(':')[0]) and count. In Main, define logs as { "INFO: a", "WARN: b", "INFO: c", "ERROR: d" } and print CountByLevel(logs, 0).
Show example solution
var logs = new[] { "INFO: a", "WARN: b", "INFO: c", "ERROR: d" }; Console.WriteLine(LogProcessor.CountByLevel(logs, 0));
Example solution:
using System;
static class LogProcessor
{
public static int ParseLevel(string level)
{
return level switch
{
"INFO" => 0,
"WARN" => 1,
"ERROR" => 2,
_ => -1
};
}
public static int CountByLevel(string[] logs, int targetLevel)
{
int count = 0;
foreach (var log in logs)
{
if (ParseLevel(log.Split(':')[0]) == targetLevel)
{
count++;
}
}
return count;
}
}
class Program
{
static void Main()
{
Console.WriteLine("LogProcessor skeleton ready");
var logs = new[] { "INFO: a", "WARN: b", "INFO: c", "ERROR: d" };
Console.WriteLine(LogProcessor.CountByLevel(logs, 0));
}
}Test yourself
-
Which component is used to process logs in parallel in this project?
- Channel (producer-consumer)
- ArrayList
- DataTable
- StringBuilder
Show answer
Channel (producer-consumer) — Correct. Channel is used for the producer-consumer flow.
-
Complete the ParseLevel declaration
public static int ____(string level)Show answer
public static int ParseLevel(string level) -
Match each project component
- Span<T>
- Low-copy memory view
- Channel<T>
- Producer-consumer channel
- unsafe
- Pointer-based low-level access