From 26901f2bcf1a32af48ed47b72079b033ac3d02a8 Mon Sep 17 00:00:00 2001 From: Russ Nelson Date: Sun, 8 May 2016 19:14:19 -0400 Subject: [PATCH] improve comments, fix indent --- src/Cache.cpp | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-) diff --git a/src/Cache.cpp b/src/Cache.cpp index f076158f..4af08ac5 100644 --- a/src/Cache.cpp +++ b/src/Cache.cpp @@ -59,7 +59,7 @@ void Cache::Add(long int frame_number, tr1::shared_ptr frame) // Create a scoped lock, to protect the cache from multiple threads const GenericScopedLock lock(*cacheCriticalSection); - // Remove frame if it already exists + // Freshen frame if it already exists if (frames.count(frame_number)) // Move frame to front of queue MoveToFront(frame_number); @@ -115,19 +115,19 @@ tr1::shared_ptr Cache::GetSmallestFrame() const GenericScopedLock lock(*cacheCriticalSection); tr1::shared_ptr f; - // Loop through frame numbers - deque::iterator itr; - long int smallest_frame = -1; - for(itr = frame_numbers.begin(); itr != frame_numbers.end(); ++itr) - { - if (*itr < smallest_frame || smallest_frame == -1) - smallest_frame = *itr; - } + // Loop through frame numbers + deque::iterator itr; + long int smallest_frame = -1; + for(itr = frame_numbers.begin(); itr != frame_numbers.end(); ++itr) + { + if (*itr < smallest_frame || smallest_frame == -1) + smallest_frame = *itr; + } - // Return frame - f = GetFrame(smallest_frame); + // Return frame + f = GetFrame(smallest_frame); - return f; + return f; } // Gets the maximum bytes value @@ -168,7 +168,7 @@ void Cache::Remove(long int frame_number) } } - // Remove frame from map + // Remove frame from map. If frame_number doesn't exist, frames.erase returns zero. frames.erase(frame_number); } @@ -179,6 +179,9 @@ void Cache::MoveToFront(long int frame_number) const GenericScopedLock lock(*cacheCriticalSection); // Does frame exists in cache? + /* FIXME if the frame number isn't present, the loop will do nothing, so why protect it? + * Is it to save time by avoiding a loop? + * Do we really need to optmize the case where we've been given a nonexisting frame_number? */ if (frames.count(frame_number)) { // Loop through frame numbers @@ -229,7 +232,7 @@ void Cache::CleanUp() { while (GetBytes() > max_bytes && frame_numbers.size() > 20) { - // Remove the oldest frame + // Get the oldest frame number. long int frame_to_remove = frame_numbers.back(); // Remove frame_number and frame