fix murmurhash fallthrough; remove colllectionID optimizations assumi…

…ng non-hashing

include/podio/EventStore.h

@@ -58,11 +58,6 @@ class DEPR_EVTSTORE EventStore : public ICollectionProvider, public IMetaDataPro
   template <typename T>
   bool get(const std::string& name, const T*& collection);
 
-  /// fast access to cached collections
-  CollectionBase* getFast(int id) const {
-    return (m_cachedCollections.size() > (unsigned)id ? m_cachedCollections[id] : nullptr);
-  }
-
   /// access a collection by ID. returns true if successful
   bool get(int id, CollectionBase*& coll) const final;
 
@@ -120,7 +115,6 @@ class DEPR_EVTSTORE EventStore : public ICollectionProvider, public IMetaDataPro
   // members
   mutable std::set<int> m_retrievedIDs{};
   mutable CollContainer m_collections{};
-  mutable std::vector<CollectionBase*> m_cachedCollections{};
   IReader* m_reader{nullptr};
   std::shared_ptr<CollectionIDTable> m_table;
 

src/EventStore.cc

@@ -7,7 +7,6 @@
 namespace podio {
 
 EventStore::EventStore() : m_table(new CollectionIDTable()) {
-  m_cachedCollections.resize(128); // allow for a sufficiently large initial number of collections
 }
 
 EventStore::~EventStore() {
@@ -17,23 +16,12 @@ EventStore::~EventStore() {
 }
 
 bool EventStore::get(int id, CollectionBase*& collection) const {
-  // see if we have a cached collection
-  if ((collection = getFast(id)) != nullptr) {
-    return true;
-  }
-
   auto val = m_retrievedIDs.insert(id);
   bool success = false;
   if (val.second == true) {
     // collection not yet retrieved in recursive-call
     auto name = m_table->name(id);
     success = doGet(name, collection, true);
-    if (collection != nullptr) { // cache the collection for faster retreaval later
-      if (m_cachedCollections.size() < (unsigned)id + 1) {
-        m_cachedCollections.resize(id + 1);
-      }
-      m_cachedCollections[id] = collection;
-    }
   } else {
     // collection already requested in recursive call
     // do not set the references to break collection dependency-cycle
@@ -135,8 +123,6 @@ void EventStore::clear() {
 
 void EventStore::clearCaches() {
   m_collections.clear();
-  m_cachedCollections.clear();
-  m_cachedCollections.resize(128);
   m_retrievedIDs.clear();
 }
 

src/MurmurHash2.cpp

@@ -69,8 +69,8 @@ uint32_t MurmurHash2 ( const void * key, int len, uint32_t seed )
 
   switch(len)
   {
-  case 3: h ^= data[2] << 16; break;
-  case 2: h ^= data[1] << 8;  break;
+  case 3: h ^= data[2] << 16; [[fallthrough]];
+  case 2: h ^= data[1] << 8;  [[fallthrough]];
   case 1: h ^= data[0];
       h *= m;
   };
@@ -119,12 +119,12 @@ uint64_t MurmurHash64A ( const void * key, int len, uint64_t seed )
 
   switch(len & 7)
   {
-  case 7: h ^= uint64_t(data2[6]) << 48; break;
-  case 6: h ^= uint64_t(data2[5]) << 40; break;
-  case 5: h ^= uint64_t(data2[4]) << 32; break;
-  case 4: h ^= uint64_t(data2[3]) << 24; break;
-  case 3: h ^= uint64_t(data2[2]) << 16; break;
-  case 2: h ^= uint64_t(data2[1]) << 8;  break;
+  case 7: h ^= uint64_t(data2[6]) << 48; [[fallthrough]];
+  case 6: h ^= uint64_t(data2[5]) << 40; [[fallthrough]];
+  case 5: h ^= uint64_t(data2[4]) << 32; [[fallthrough]];
+  case 4: h ^= uint64_t(data2[3]) << 24; [[fallthrough]];
+  case 3: h ^= uint64_t(data2[2]) << 16; [[fallthrough]];
+  case 2: h ^= uint64_t(data2[1]) << 8;  [[fallthrough]];
   case 1: h ^= uint64_t(data2[0]);
           h *= m;
   };
@@ -172,9 +172,9 @@ uint64_t MurmurHash64B ( const void * key, int len, uint64_t seed )
 
   switch(len)
   {
-  case 3: h2 ^= ((unsigned char*)data)[2] << 16; break;
-  case 2: h2 ^= ((unsigned char*)data)[1] << 8;  break;
-  case 1: h2 ^= ((unsigned char*)data)[0];       break;
+  case 3: h2 ^= ((unsigned char*)data)[2] << 16; [[fallthrough]];
+  case 2: h2 ^= ((unsigned char*)data)[1] << 8;  [[fallthrough]];
+  case 1: h2 ^= ((unsigned char*)data)[0];       [[fallthrough]];
       h2 *= m;
   };
 
@@ -227,8 +227,8 @@ uint32_t MurmurHash2A ( const void * key, int len, uint32_t seed )
 
   switch(len)
   {
-  case 3: t ^= data[2] << 16; break;
-  case 2: t ^= data[1] << 8;  break;
+  case 3: t ^= data[2] << 16; [[fallthrough]];
+  case 2: t ^= data[1] << 8;  [[fallthrough]];
   case 1: t ^= data[0];
   };
 
@@ -448,8 +448,8 @@ uint32_t MurmurHashAligned2 ( const void * key, int len, uint32_t seed )
     {
       switch(align)
       {
-      case 3: d |= data[2] << 16; break;
-      case 2: d |= data[1] << 8;  break;
+      case 3: d |= data[2] << 16; [[fallthrough]];
+      case 2: d |= data[1] << 8;  [[fallthrough]];
       case 1: d |= data[0];
       }
 
@@ -464,8 +464,8 @@ uint32_t MurmurHashAligned2 ( const void * key, int len, uint32_t seed )
 
       switch(len)
       {
-      case 3: h ^= data[2] << 16; break;
-      case 2: h ^= data[1] << 8;  break;
+      case 3: h ^= data[2] << 16; [[fallthrough]];
+      case 2: h ^= data[1] << 8;  [[fallthrough]];
       case 1: h ^= data[0];
           h *= m;
       };
@@ -474,9 +474,9 @@ uint32_t MurmurHashAligned2 ( const void * key, int len, uint32_t seed )
     {
       switch(len)
       {
-      case 3: d |= data[2] << 16; break;
-      case 2: d |= data[1] << 8;  break;
-      case 1: d |= data[0];       break;
+      case 3: d |= data[2] << 16; [[fallthrough]];
+      case 2: d |= data[1] << 8;  [[fallthrough]];
+      case 1: d |= data[0];       [[fallthrough]];
       case 0: h ^= (t >> sr) | (d << sl);
           h *= m;
       }
@@ -505,8 +505,8 @@ uint32_t MurmurHashAligned2 ( const void * key, int len, uint32_t seed )
 
     switch(len)
     {
-    case 3: h ^= data[2] << 16; break;
-    case 2: h ^= data[1] << 8;  break;
+    case 3: h ^= data[2] << 16; [[fallthrough]];
+    case 2: h ^= data[1] << 8;  [[fallthrough]];
     case 1: h ^= data[0];
         h *= m;
     };