[Liblas-commits] libpc: minor cleanups and docs

[liblas-commits at liblas.org]

details:   http://hg.liblas.orglibpc/rev/85b0c5de9e47
changeset: 184:85b0c5de9e47
user:      Michael P. Gerlek <mpg at flaxen.com>
date:      Mon Mar 07 16:03:52 2011 -0800
description:
minor cleanups and docs

diffstat:

 include/libpc/CacheFilter.hpp |   6 +++++-
 src/CacheFilter.cpp           |  16 +++++++++-------
 2 files changed, 14 insertions(+), 8 deletions(-)

diffs (59 lines):

diff -r dacbbd3a3288 -r 85b0c5de9e47 include/libpc/CacheFilter.hpp
--- a/include/libpc/CacheFilter.hpp	Mon Mar 07 14:44:33 2011 -0800
+++ b/include/libpc/CacheFilter.hpp	Mon Mar 07 16:03:52 2011 -0800
@@ -40,7 +40,11 @@
 namespace libpc
 {
 
-// this is just a very simple MRU filter -- future versions will be smarter
+// This is just a very simple MRU filter -- future versions will be smarter.
+// This cache has the following constraints:
+//   - only one block is cached
+//   - read chunk sizes are assumed to be just 1 point
+// If more than one point is read, the cache is skipped.
 class LIBPC_DLL CacheFilter : public Filter
 {
 public:
diff -r dacbbd3a3288 -r 85b0c5de9e47 src/CacheFilter.cpp
--- a/src/CacheFilter.cpp	Mon Mar 07 14:44:33 2011 -0800
+++ b/src/CacheFilter.cpp	Mon Mar 07 16:03:52 2011 -0800
@@ -90,30 +90,32 @@
 
 boost::uint32_t CacheFilter::readBuffer(PointData& data)
 {
+    if (data.getNumPoints() != 1)
+    {
+        m_currentPointIndex += data.getNumPoints();
+        return m_prevStage.read(data);
+    }
+
     m_numPointsRequested += data.getNumPoints();
 
     boost::uint64_t pointToRead = getCurrentPointIndex();
 
     // do we meet the cache-checking criteria?
-    if (data.getNumPoints() == 1 && m_storedPointData != NULL)
+    if (m_storedPointData != NULL)
     {
         // do we have the point we want in the cache?
         if (pointToRead >= m_storedPointIndex && 
             pointToRead < m_storedPointIndex + m_storedPointData->getNumPoints())
         {
-            // the cache has the data we want
-
+            // the cache has the data we want, copy out the point we want
             boost::uint32_t index = (boost::uint32_t)(pointToRead - m_storedPointIndex);
-
             data.copyPointFast(0, index, *m_storedPointData);
-
             m_currentPointIndex += 1;
-
             return 1;
         }
     }
 
-    // not cached, so read a full block and replace cache with it
+    // not cached, so read a full block and replace cache with that new block
 
     delete m_storedPointData;