ftparchive/byhash.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 /* ######################################################################
   4
   5    ByHash
   6
   7    ByHash helper functions
   8
   9    ##################################################################### */
  10                                                                         /*}}}*/
  11 // Include Files                                                        /*{{{*/
  12 #include <config.h>
  13
  14 #include<algorithm>
  15 #include<string>
  16
  17 #include <unistd.h>
  18 #include <sys/stat.h>
  19
  20 #include <apt-pkg/fileutl.h>
  21 #include <apt-pkg/hashes.h>
  22 #include "byhash.h"
  23
  24 // Delete all files in a directory except the most recent N ones
  25 void DeleteAllButMostRecent(std::string dir, int KeepFiles)
  26 {
  27    struct Cmp {
  28       bool operator() (const std::string& lhs, const std::string& rhs) {
  29          struct stat buf_l, buf_r;
  30          stat(lhs.c_str(), &buf_l);
  31          stat(rhs.c_str(), &buf_r);
  32          if (buf_l.st_mtim.tv_sec == buf_r.st_mtim.tv_sec)
  33             return buf_l.st_mtim.tv_nsec < buf_r.st_mtim.tv_nsec;
  34          return buf_l.st_mtim.tv_sec < buf_r.st_mtim.tv_sec;
  35       }
  36    };
  37
  38    if (!DirectoryExists(dir))
  39       return;
  40
  41    auto files = GetListOfFilesInDir(dir, false);
  42    std::sort(files.begin(), files.end(), Cmp());
  43
  44    for (auto I=files.begin(); I<files.end()-KeepFiles; I++) {
  45       unlink((*I).c_str());
  46    }
  47 }
  48
  49 // Takes a input filename (e.g. binary-i386/Packages) and a hashstring
  50 // of the Input data and transforms it into a suitable by-hash filename
  51 std::string GenByHashFilename(std::string Input, HashString h)
  52 {
  53    std::string ByHashOutputFile = Input;
  54    std::string const ByHash = "/by-hash/" + h.HashType() + "/" + h.HashValue();
  55    size_t trailing_slash = ByHashOutputFile.find_last_of("/");
  56    if (trailing_slash == std::string::npos)
  57       trailing_slash = 0;
  58    ByHashOutputFile = ByHashOutputFile.replace(
  59       trailing_slash,
  60       ByHashOutputFile.substr(trailing_slash+1).size()+1,
  61       ByHash);
  62    return ByHashOutputFile;
  63 }