Add support for writing by-hash dirs in apt-ftparchive

This option is enabled via the APT::FTPArchive::DoByHash switch.
It will also honor the option APT::FTPArchive::By-Hash-Keep that
controls how many previous generation of by-hash files should be
kept (defaults to 3).

Merged from https://github.com/mvo5/apt/tree/feature/apt-ftparchive-by-hash

1 files changed, 63 insertions, 0 deletions

diff --git a/ftparchive/byhash.cc b/ftparchive/byhash.cc
new file mode 100644
index 000000000..04f8f1629
--- /dev/null
+++ b/ftparchive/byhash.cc
@@ -0,0 +1,63 @@
+// -*- mode: cpp; mode: fold -*-
+// Description								/*{{{*/
+/* ######################################################################
+
+   ByHash 
+   
+   ByHash helper functions
+   
+   ##################################################################### */
+									/*}}}*/
+// Include Files							/*{{{*/
+#include <config.h>
+
+#include<algorithm>
+#include<string>
+
+#include <unistd.h>
+#include <sys/stat.h>
+
+#include <apt-pkg/fileutl.h>
+#include <apt-pkg/hashes.h>
+#include "byhash.h"
+
+// Delete all files in a directory except the most recent N ones
+void DeleteAllButMostRecent(std::string dir, int KeepFiles)
+{
+   struct Cmp {
+      bool operator() (const std::string& lhs, const std::string& rhs) {
+         struct stat buf_l, buf_r;
+         stat(lhs.c_str(), &buf_l);
+         stat(rhs.c_str(), &buf_r);
+         if (buf_l.st_mtim.tv_sec == buf_r.st_mtim.tv_sec)
+            return buf_l.st_mtim.tv_nsec < buf_r.st_mtim.tv_nsec;
+         return buf_l.st_mtim.tv_sec < buf_r.st_mtim.tv_sec;
+      }
+   };
+
+   if (!DirectoryExists(dir))
+      return;
+
+   auto files = GetListOfFilesInDir(dir, false);
+   std::sort(files.begin(), files.end(), Cmp());
+
+   for (auto I=files.begin(); I<files.end()-KeepFiles; I++) {
+      unlink((*I).c_str());
+   }
+}
+
+// Takes a input filename (e.g. binary-i386/Packages) and a hashstring
+// of the Input data and transforms it into a suitable by-hash filename
+std::string GenByHashFilename(std::string Input, HashString h)
+{
+   std::string ByHashOutputFile = Input;
+   std::string const ByHash = "/by-hash/" + h.HashType() + "/" + h.HashValue();
+   size_t trailing_slash = ByHashOutputFile.find_last_of("/");
+   if (trailing_slash == std::string::npos)
+      trailing_slash = 0;
+   ByHashOutputFile = ByHashOutputFile.replace(
+      trailing_slash,
+      ByHashOutputFile.substr(trailing_slash+1).size()+1,
+      ByHash);
+   return ByHashOutputFile;
+}