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利用DeepSeek辅助编写带输出缓冲的Zig程序

news 2025/8/5 7:22:00

前面通过改写Rust程序输出缓冲功能为C实现了输出速度提升以后，想将同样的思路用在Zig程序上。
又来请DeepSeek改写，第一次改写，它杜撰了一个函数bufferedWriterSize函数，查阅文档发现，只有bufferedWriter函数，但此函数只有一个参数，size固定为4096。

pub fn bufferedWriter(underlying_stream: anytype) BufferedWriter(4096, @TypeOf(underlying_stream))

将bufferedWriterSize函数替换为正确的bufferedWriter，编译通过，但执行效率没有提升。
然后试图调用底层的BufferedWriter，并传入第一个参数，编译总是出错，于是再次求助DeepSeek，它给出了解释，并提供了正确的写法：

问题分析

类型错误：`BufferedWriter` 是一个类型，不能直接当值使用

使用结构体初始化语法，必须提供 unbuffered_writer 字段

初始化问题：需要先创建该类型的实例

BufferedWriter(…) 是类型构造器，需要创建该类型的实例才能使用

方法调用：正确的 `writer()` 调用方式

不需要手动释放资源flush() 确保数据写出

    // 创建带缓冲的写入器var buffered = std.io.BufferedWriter(BUFFER_SIZE, @TypeOf(stdout)){.unbuffered_writer = stdout,};const writer = buffered.writer();...// 刷新缓冲区try buffered.flush();

完整改写后的代码如下：

const std = @import("std");
const ArrayList = std.ArrayList;pub fn main() !void {var gpa = std.heap.GeneralPurposeAllocator(.{}){};defer _ = gpa.deinit();const allocator = gpa.allocator();const output = std.io.getStdOut().writer();var stream = std.io.bufferedWriter(output);const stdout = stream.writer();// 1. Get filename from command line argumentsvar args = std.process.args();_ = args.next(); // Skip program nameconst filename = args.next() orelse {std.debug.print("Usage: program <filename>\n", .{});return;};// 2. Open and read the fileconst file = std.fs.cwd().openFile(filename, .{}) catch |err| {std.debug.print("Open file '{s}' failed: {}\n", .{ filename, err });return;};defer file.close();// 3. Read file linesconst content = try file.readToEndAlloc(allocator, std.math.maxInt(usize));defer allocator.free(content);var lines = ArrayList([]const u8).init(allocator);defer lines.deinit();var iterator = std.mem.splitScalar(u8, content, '\n');while (iterator.next()) |line| {try lines.append(line);}// 4. Sortstd.mem.sort([]const u8, lines.items, {}, compare);const BUFFER_SIZE = 64 * 1024; // 64KB 缓冲区// 创建缓冲写入器 (64KB 缓冲)//var buffered_writer = std.io.bufferedWriterWithSize(BUFFER_SIZE, stdout);var buffered_writer = std.io.BufferedWriter(BUFFER_SIZE,  @TypeOf(stdout)){.unbuffered_writer = stdout,};const writer = buffered_writer.writer();// 写入所有行for (lines.items) |line| {try writer.print("{s}\n", .{line});}// 确保所有缓冲数据被刷新try buffered_writer.flush();}fn compare(context: void, a: []const u8, b: []const u8) bool {_ = context;return std.mem.order(u8, a, b) == .lt;
}

编译执行

zig014/zig build-exe main.zig -O ReleaseFast
# 无缓冲的输出
time ./main varchar.txt >vvc.txtreal    0m3.044s
user    0m0.544s
sys     0m0.201szig014/zig build-exe mainbuf.zig -O ReleaseFast
#调用默认4096缓冲区大小的bufferedWriter
time ./mainbuf varchar.txt >vvc.txtreal    0m2.929s
user    0m0.483s
sys     0m0.196s
#调用64KB缓冲区大小的BufferedWriter
time ./mainbuf varchar.txt >vvc.txtreal    0m1.168s
user    0m0.459s
sys     0m0.094stime ./mainbuf varchar.txt >/dev/nullreal    0m0.838s
user    0m0.456s
sys     0m0.093s