门户网站开发报价单外贸营销员国家职业技能标准

经历了2次优化，

1. 优化为带缓冲输出
   将原始输出

for line in lines {println(unsafe { line.vstring() })}

改写为

// 带缓冲的输出函数
fn buffered_write_lines(lines []&char, buffer_size int) ! {// 获取标准输出写入器stdout := os.stdout()// 创建缓冲写入器配置config := io.BufferedWriterConfig{writer: stdoutcap:    buffer_size}// 创建缓冲写入器mut bw := io.new_buffered_writer(config)!defer {bw.flush() or { panic(err) } // 确保退出时刷新}// 写入所有行for line in lines {bw.write(unsafe { line.vstring().bytes()})!bw.write('\n'.bytes())! // 手动添加换行}// 显式刷新确保所有数据写出bw.flush()!
}

2. 在1的基础上优化比较函数，用指针取值比较代替字符串比较函数

//优化前
fn compare_offsets_old(a &&char, b &&char) int {a1:=unsafe { a.vstring() }b1:=unsafe { b.vstring() }return compare_strings(a1, b1)
}
//优化后
@[unsafe]
fn compare_offsets(a &&char, b &&char) int {mut pa := *amut pb := *bfor {if *pa == 0 || *pb == 0 || *pa != *pb {return int(*pa) - int(*pb)}pa++pb++}return 0
}

编译运行结果

#无缓冲
v/v  -prod sortlines.v
time ./sortlines varchar.txt >vvc.txtreal    0m4.034s
user    0m0.777s
sys     0m0.237s
#优化1
v/v  -prod sortlinesbuf.v
time ./sortlinesbuf varchar.txt >vvc.txtreal    0m1.904s
user    0m0.828s
sys     0m0.162s
#优化2
time ./sortlinesbuf varchar.txt >vvc.txtreal    0m1.497s
user    0m0.555s
sys     0m0.075s

没想到对V这种小众语言，DeepSeek的知识也这么渊博。
完整程序摘录如下

import os
import io
const max_lines = 1_000_000 // 最多100万行@[unsafe]
fn compare_offsets(a &&char, b &&char) int {mut pa := *amut pb := *bfor {if *pa == 0 || *pb == 0 || *pa != *pb {return int(*pa) - int(*pb)}pa++pb++}return 0
}
// 带缓冲的输出函数
fn buffered_write_lines(lines []&char, buffer_size int) ! {// 获取标准输出写入器stdout := os.stdout()// 创建缓冲写入器配置config := io.BufferedWriterConfig{writer: stdoutcap:    buffer_size}// 创建缓冲写入器mut bw := io.new_buffered_writer(config)!defer {bw.flush() or { panic(err) } // 确保退出时刷新}// 写入所有行for line in lines {bw.write(unsafe { line.vstring().bytes()})!bw.write('\n'.bytes())! // 手动添加换行}// 显式刷新确保所有数据写出bw.flush()!
}
fn main() {if os.args.len != 2 {eprintln('Usage: ${os.args[0]} <filename>')exit(1)}filename := os.args[1]// 读取文件内容buf := os.read_file(filename) or {eprintln('Failed to read file: $err')exit(1)}mut lines := []&char{cap: max_lines}//mut line_start := unsafe { &char(buf.str) }// 记录每行起始地址并将\n替换为\0for i in 0 .. buf.len {if buf[i] == `\n` {unsafe {mut p := &char(buf.str) + i*p=u8(0)if i + 1 < buf.len {lines << p + 1}}}}// 添加第一行lines << unsafe { &char(buf.str) }// 对行指针数组进行排序lines.sort_with_compare(compare_offsets)// 使用64KB缓冲区buffered_write_lines(lines, 64 * 1024) or {eprintln('写入失败: $err')exit(1)}}