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.

4 files changed, 21 insertions, 5 deletions

diff --git a/apt-pkg/contrib/progress.cc b/apt-pkg/contrib/progress.cc
index 971198270..03f88d4ce 100644
--- a/apt-pkg/contrib/progress.cc
+++ b/apt-pkg/contrib/progress.cc
@@ -91,7 +91,10 @@ void OpProgress::SubProgress(unsigned long long SubTotal,const string &Op,
    an update the display would be swamped and the system much slower.
    This provides an upper bound on the update rate. */
 bool OpProgress::CheckChange(float Interval)
-{  
+{
+   // For absolute progress, we assume every call is relevant.
+   if (_config->FindB("APT::Internal::OpProgress::Absolute", false))
+      return true;
    // New major progress indication
    if (Op != LastOp)
    {
@@ -199,9 +202,14 @@ void OpTextProgress::Update()
       Write(S);
       cout << endl;
    }
-   
-   // Print the spinner
-   snprintf(S,sizeof(S),_("%c%s... %u%%"),'\r',Op.c_str(),(unsigned int)Percent);
+
+   // Print the spinner. Absolute progress shows us a time progress.
+   if (_config->FindB("APT::Internal::OpProgress::Absolute", false) && Total != -1llu)
+      snprintf(S, sizeof(S), _("%c%s... %llu/%llus"), '\r', Op.c_str(), Current, Total);
+   else if (_config->FindB("APT::Internal::OpProgress::Absolute", false))
+      snprintf(S, sizeof(S), _("%c%s... %llus"), '\r', Op.c_str(), Current);
+   else
+      snprintf(S, sizeof(S), _("%c%s... %u%%"), '\r', Op.c_str(), (unsigned int)Percent);
    Write(S);
 
    OldOp = Op;
diff --git a/apt-pkg/contrib/progress.h b/apt-pkg/contrib/progress.h
index 4d118ee99..d6a698af3 100644
--- a/apt-pkg/contrib/progress.h
+++ b/apt-pkg/contrib/progress.h
@@ -28,6 +28,7 @@
 class Configuration;
 class APT_PUBLIC OpProgress
 {
+   friend class OpTextProgress;
    unsigned long long Current;
    unsigned long long Total;
    unsigned long long Size;
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);
    }
diff --git a/doc/examples/configure-index b/doc/examples/configure-index
index 4e0bd57ae..bf9efc109 100644
--- a/doc/examples/configure-index
+++ b/doc/examples/configure-index
@@ -826,3 +826,5 @@ dir::filelistdir "<STRING>";
 dir::dpkg::tupletable "<FILE>";
 dir::dpkg::triplettable "<FILE>";
 dir::dpkg::cputable "<FILE>";
+
+APT::Internal::OpProgress::Absolute "<BOOL>";