refactor: move solver execution into his own EDSP method

1 files changed, 42 insertions, 0 deletions

diff --git a/apt-pkg/edsp.cc b/apt-pkg/edsp.cc
index 170e2a4c6..c3e608d17 100644
--- a/apt-pkg/edsp.cc
+++ b/apt-pkg/edsp.cc
@@ -441,3 +441,45 @@ bool EDSP::WriteProgress(unsigned short const percent, const char* const message
 }
 									/*}}}*/
 bool EDSP::WriteError(std::string const &message, FILE* output) { return false; }
+
+// EDSP::ExecuteSolver - fork requested solver and setup ipc pipes	{{{*/
+bool EDSP::ExecuteSolver(const char* const solver, int *solver_in, int *solver_out) {
+      std::vector<std::string> const solverDirs = _config->FindVector("Dir::Bin::Solvers");
+      std::string file;
+      for (std::vector<std::string>::const_iterator dir = solverDirs.begin();
+	   dir != solverDirs.end(); ++dir) {
+	 file = flCombine(*dir, solver);
+	 if (RealFileExists(file.c_str()) == true)
+	    break;
+	 file.clear();
+      }
+
+      if (file.empty() == true)
+	 return _error->Error("Can't call external solver '%s' as it is not in a configured directory!", solver);
+      int external[4] = {-1, -1, -1, -1};
+      if (pipe(external) != 0 || pipe(external + 2) != 0)
+	 return _error->Errno("Resolve", "Can't create needed IPC pipes for EDSP");
+      for (int i = 0; i < 4; ++i)
+	 SetCloseExec(external[i], true);
+
+      pid_t Solver = ExecFork();
+      if (Solver == 0)
+      {
+	 dup2(external[0], STDIN_FILENO);
+	 dup2(external[3], STDOUT_FILENO);
+	 const char* calling[2] = { file.c_str(), 0 };
+	 execv(calling[0], (char**) calling);
+	 std::cerr << "Failed to execute solver '" << solver << "'!" << std::endl;
+	 _exit(100);
+      }
+      close(external[0]);
+      close(external[3]);
+
+      if (WaitFd(external[1], true, 5) == false)
+         return _error->Errno("Resolve", "Timed out while Waiting on availability of solver stdin");
+
+      *solver_in = external[1];
+      *solver_out = external[2];
+      return true;
+}
+									/*}}}*/