如何检测文件夹是否太重，如果是，请删除其中的一部分

How to detect if a folder is too heavy, and if so delete part of it

本文关键字：如果 删除 一部分 何检测 检测 是否 文件夹      更新时间：2023-10-16

我需要控制由路径定义的文件夹是否充满了文件夹，如果这些文件夹太多，我需要从旧的文件夹中删除，例如其中的一半，最新的。实际上，我需要为将来的文件夹腾出空间。

void fCID(long pThreadId)
{
ULARGE_INTEGER rFreeBytesAvailable, rTotalNumberOfBytes, rTotalNumberOfFreeBytes;
if(sc.LB.TMCI && sc.LB.ISM == 1)
{
for(10000000000;10000000000 > sd;sd--) //wrong, i'm looking for it
{
if (::GetDiskFreeSpaceEx (NULL, &rFreeBytesAvailable, &rTotalNumberOfBytes, 
&rTotalNumberOfFreeBytes))
{
if (rFreeBytesAvailable.QuadPart > 10000000000)     //10gb
{
fAFOZA("C:\S\H1\CA");   //function zip   
}
else
{
sd=sd - 50% of (LA); //sd = space disposable
}
}
}
}
else  
{
fDFOP(where.Trace_C_P);  //not interesting
fDFOP(where.Trace_C_CL_P); //not interesting
}
}

这段代码只是一个想法

ULARGE_INTEGER rFreeBytesAvailable, rTotalNumberOfBytes, 
rTotalNumberOfFreeBytes;
if(sc.LB.TMCI && sc.LB.ISM == 1)
{
if (::GetDiskFreeSpaceEx ("C:\S\H1\CA\LA", &rFreeBytesAvailable, &rTotalNumberOfBytes, &rTotalNumberOfFreeBytes))
{
do
{
fDFOP("C:\S\H1\CA\LA"); //this function deletes what's inside the path
}while(rFreeBytesAvailable.QuadPart == 10000000000)
if (rFreeBytesAvailable.QuadPart > 10000000000)     //10gb
{
fAFOZA("C:\S\H1\CA");//this one makes a zip 
}
}
}

这可能是另一种可能的实现

如果要删除目录结构中最旧的文件以回收一定数量的空间，则可以使用 C++17std::filesystem库类recursive_directory_iterator和函数last_write_time和remove来自同一个库。

例：

#include <cstdint>
#include <filesystem>
#include <set>
#include <string>
#include <system_error>
#include <tuple>
namespace fs = std::filesystem;
// a class containing the interesting information about each file
struct file {
fs::path path;
std::uintmax_t file_size;
std::filesystem::file_time_type write_time;
// An operator< to be able to sort files in this order:
//  ascending write_time
//  decending file_size (to remove the biggest of two files with the same write_time)
//  ascending path
bool operator<(const file& rhs) const {
return
std::tie(write_time, rhs.file_size, path) <
std::tie(rhs.write_time, file_size, rhs.path);
}
};
// A function to traverse a directory structure, collect file names, age and sizes
// and to remove the oldest until "bytes_to_remove" bytes have been removed
std::uintmax_t rm_old_files(const std::wstring& dir, std::uintmax_t bytes_to_remove) {
std::uintmax_t bytes_removed = 0;
std::set<file> files; // the set will sort file entries with the oldest first
// collect all regular files in the directory structure starting at "dir"
for (const fs::directory_entry& de : fs::recursive_directory_iterator(dir)) {
if (de.is_regular_file()) {
files.emplace(file{de, de.file_size(), fs::last_write_time(de)});
}
}
// remove files until at least "bytes_to_remove" bytes have been removed
std::error_code ec; // unread but used to prevent exceptions in fs::remove
for (auto const& [path, file_size, write_time] : files) {
std::wcout << L"removing " << path << L'n';
/* uncomment this part when you've made sure that it'll
remove the correct files.
if (fs::remove(path, ec)) {
bytes_removed += file_size;
if (bytes_removed >= bytes_to_remove) break;
}
*/
}
return bytes_removed;
}

用法示例：

std::wstring dir = L"C:\S\H1\CA\LA";
ULARGE_INTEGER FreeBytesAvailableToCaller;
ULARGE_INTEGER TotalNumberOfBytes;
ULARGE_INTEGER TotalNumberOfFreeBytes;
if (GetDiskFreeSpaceExW(dir.c_str(), &FreeBytesAvailableToCaller,
&TotalNumberOfBytes, 
&TotalNumberOfFreeBytes)) {
// if less than half the total number of bytes are available,
// execute rm_old_files to try to make at least half available.
if (FreeBytesAvailableToCaller.QuadPart < TotalNumberOfBytes.QuadPart/2) {
auto bytes_removed = 
rm_old_files(dir, TotalNumberOfBytes.QuadPart/2 -
FreeBytesAvailableToCaller.QuadPart);
std::wcout << L"removed " << bytes_removed << L" bytesn";
}
}
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