Show absolute time while waiting for lock instead of %, rework message

Showing a percentage for a timeout is pretty non-standard. Rework the
progress class so it can show an absolute progress (currently hardcoded
to use seconds as a unit). If there is a timeout (aka if it's not the
maximum long long unsigned -1llu), then show the timeout, otherwise
just count up seconds, e.g.

Waiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 33842 (apt)... 1/120s

or

Waiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 33842 (apt)... 1s

Also improve the error message to use "Waiting for cache lock: %s" instead of "... (%s)", as having
multiple sentences inside parenthesis is super weird, as is having two closing parens.

We pass the information via _config, as that's reasonably easy and avoids
ABI hackage. It also provides an interesting debugging tool for other
kinds of progress.

1 files changed, 6 insertions, 1 deletions

diff --git a/apt-pkg/deb/debsystem.cc b/apt-pkg/deb/debsystem.cc
index da7ae2e42..6904879b6 100644
--- a/apt-pkg/deb/debsystem.cc
+++ b/apt-pkg/deb/debsystem.cc
@@ -79,6 +79,11 @@ debSystem::~debSystem()
    checking of the updates directory. */
 static int GetLockMaybeWait(std::string const &file, OpProgress *Progress, int &timeoutSec)
 {
+   struct ScopedAbsoluteProgress
+   {
+      ScopedAbsoluteProgress() { _config->Set("APT::Internal::OpProgress::Absolute", true); }
+      ~ScopedAbsoluteProgress() { _config->Set("APT::Internal::OpProgress::Absolute", false); }
+   } _scopedAbsoluteProgress;
    int fd = -1;
    if (timeoutSec == 0 || Progress == nullptr)
       return GetLock(file);
@@ -102,7 +107,7 @@ static int GetLockMaybeWait(std::string const &file, OpProgress *Progress, int &
       _error->PopMessage(poppedError);
       _error->RevertToStack();
 
-      strprintf(completeError, _("Waiting for cache lock (%s)"), poppedError.c_str());
+      strprintf(completeError, _("Waiting for cache lock: %s"), poppedError.c_str());
       sleep(1);
       Progress->OverallProgress(i, timeoutSec, 0, completeError);
    }