use FileFd to parse all apt configuration files

Using different ways of opening files means we have different behaviour
and error messages for them, so by the same for all we can have more
uniformity for users and apt developers alike.

1 files changed, 29 insertions, 3 deletions

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index 630a98ce4..7633b07ef 100644
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -2493,9 +2493,6 @@ bool FileFd::Read(int const Fd, void *To, unsigned long long Size, unsigned long
 }
 									/*}}}*/
 // FileFd::ReadLine - Read a complete line from the file		/*{{{*/
-// ---------------------------------------------------------------------
-/* Beware: This method can be quite slow for big buffers on UNcompressed
-   files because of the naive implementation! */
 char* FileFd::ReadLine(char *To, unsigned long long const Size)
 {
    *To = '\0';
@@ -2503,6 +2500,29 @@ char* FileFd::ReadLine(char *To, unsigned long long const Size)
       return nullptr;
    return d->InternalReadLine(To, Size);
 }
+bool FileFd::ReadLine(std::string &To)
+{
+   To.clear();
+   if (d == nullptr || Failed())
+      return false;
+   constexpr size_t buflen = 4096;
+   char buffer[buflen];
+   size_t len;
+   do
+   {
+      if (d->InternalReadLine(buffer, buflen) == nullptr)
+	 return false;
+      len = strlen(buffer);
+      To.append(buffer, len);
+   } while (len == buflen - 1 && buffer[len - 2] != '\n');
+   // remove the newline at the end
+   auto const i = To.find_last_not_of("\r\n");
+   if (i == std::string::npos)
+      To.clear();
+   else
+      To.erase(i + 1);
+   return true;
+}
 									/*}}}*/
 // FileFd::Flush - Flush the file  					/*{{{*/
 bool FileFd::Flush()
@@ -3104,3 +3124,9 @@ bool DropPrivileges()							/*{{{*/
    return true;
 }
 									/*}}}*/
+bool OpenConfigurationFileFd(std::string const &File, FileFd &Fd) /*{{{*/
+{
+   APT::Configuration::Compressor none(".", "", "", nullptr, nullptr, 0);
+   return Fd.Open(File, FileFd::ReadOnly, none);
+}
+									/*}}}*/