Correctly test that changing the cache size on live archive has effect.

include/zim/archive.h

@@ -534,12 +534,18 @@ namespace zim
        */
       std::shared_ptr<FileImpl> getImpl() const { return m_impl; }
 
-      /** Get the size of the cluster cache.
+      /** Get the maximum size of the cluster cache.
        *
        * @return The maximum number of clusters stored in  the cache.
        */
       size_t get_cluster_cache_max_size() const;
 
+      /** Get the current size of the cluster cache.
+       *
+       * @return The number of clusters currently stored in  the cache.
+       */
+      size_t get_cluster_cache_current_size() const;
+
       /** Set the size of the cluster cache.
        *
        * If the new size is lower than the number of currently stored clusters
@@ -555,6 +561,12 @@ namespace zim
        */
       size_t get_dirent_cache_max_size() const;
 
+      /** Get the current size of the dirent cache.
+       *
+       * @return The number of dirents currently stored in  the cache.
+       */
+      size_t get_dirent_cache_current_size() const;
+
       /** Set the size of the dirent cache.
        *
        * If the new size is lower than the number of currently stored dirents

src/archive.cpp

@@ -509,6 +509,11 @@ namespace zim
     return m_impl->get_cluster_cache_max_size();
   }
 
+  size_t Archive::get_cluster_cache_current_size() const
+  {
+    return m_impl->get_cluster_cache_current_size();
+  }
+
   void Archive::set_cluster_cache_max_size(size_t nb_clusters)
   {
     m_impl->set_cluster_cache_max_size(nb_clusters);
@@ -519,6 +524,11 @@ namespace zim
     return m_impl->get_dirent_cache_max_size();
   }
 
+  size_t Archive::get_dirent_cache_current_size() const
+  {
+    return m_impl->get_dirent_cache_current_size();
+  }
+
   void Archive::set_dirent_cache_max_size(size_t nb_dirents)
   {
     m_impl->set_dirent_cache_max_size(nb_dirents);

src/concurrent_cache.h

@@ -90,6 +90,11 @@ class ConcurrentCache
     return impl_.get_max_size();
   }
 
+  size_t get_current_size() const {
+    std::unique_lock<std::mutex> l(lock_);
+    return impl_.size();
+  }
+
   void set_max_size(size_t new_size) {
     std::unique_lock<std::mutex> l(lock_);
     return impl_.set_max_size(new_size);

src/dirent_accessor.h

@@ -56,6 +56,7 @@ class LIBZIM_PRIVATE_API DirectDirentAccessor
   entry_index_t getDirentCount() const  {  return m_direntCount; }
 
   size_t get_max_cache_size() const { return m_direntCache.get_max_size(); }
+  size_t get_current_cache_size() const { return m_direntCache.size(); }
   void set_max_cache_size(size_t nb_dirents) const { m_direntCache.set_max_size(nb_dirents); }
 
 private: // functions

src/fileimpl.cpp

@@ -795,13 +795,19 @@ bool checkTitleListing(const IndirectDirentAccessor& accessor, entry_index_type
   size_t FileImpl::get_cluster_cache_max_size() const {
     return clusterCache.get_max_size();
   }
+  size_t FileImpl::get_cluster_cache_current_size() const {
+    return clusterCache.get_current_size();
+  }
   void FileImpl::set_cluster_cache_max_size(size_t nb_clusters) {
     clusterCache.set_max_size(nb_clusters);
   }
 
   size_t FileImpl::get_dirent_cache_max_size() const {
     return mp_pathDirentAccessor->get_max_cache_size();
   }
+  size_t FileImpl::get_dirent_cache_current_size() const {
+    return mp_pathDirentAccessor->get_current_cache_size();
+  }
   void FileImpl::set_dirent_cache_max_size(size_t nb_dirents) {
     mp_pathDirentAccessor->set_max_cache_size(nb_dirents);
   }

src/fileimpl.h

@@ -154,8 +154,10 @@ namespace zim
       bool checkIntegrity(IntegrityCheck checkType);
 
       size_t get_cluster_cache_max_size() const;
+      size_t get_cluster_cache_current_size() const;
       void set_cluster_cache_max_size(size_t nb_clusters);
       size_t get_dirent_cache_max_size() const;
+      size_t get_dirent_cache_current_size() const;
       void set_dirent_cache_max_size(size_t nb_dirents);
       size_t get_dirent_lookup_cache_max_size() const;
       void set_dirent_lookup_cache_max_size(size_t nb_ranges) { m_direntLookupSize = nb_ranges; };

test/archive.cpp

@@ -335,6 +335,70 @@ TEST(ZimArchive, cacheDontImpactReading)
   }
 }
 
+
+TEST(ZimArchive, cacheChange)
+{
+
+  for (auto& testfile: getDataFilePath("wikibooks_be_all_nopic_2017-02.zim")) {
+    auto archive = zim::Archive(testfile.path);
+
+    archive.set_dirent_cache_max_size(30);
+    archive.set_cluster_cache_max_size(5);
+
+    auto range = archive.iterEfficient();
+    auto it = range.begin();
+    for (auto i = 0; i<50 && it != range.end(); i++, it++) {
+      // Be sure to search by path to populate the dirent cache
+      auto entry = archive.getEntryByPath(it->getPath());
+      auto item = entry.getItem(true);
+      auto data = item.getData();
+    }
+    EXPECT_EQ(archive.get_dirent_cache_current_size(), 30);
+    EXPECT_EQ(archive.get_cluster_cache_current_size(), 2); // Only 2 clusters in the file
+
+    // Reduce cache size
+    archive.set_dirent_cache_max_size(10);
+    archive.set_cluster_cache_max_size(1);
+
+    EXPECT_EQ(archive.get_dirent_cache_current_size(), 10);
+    EXPECT_EQ(archive.get_cluster_cache_current_size(), 1);
+
+    for (auto i = 0; i<50 && it != range.end(); i++, it++) {
+      // Be sure to search by path to populate the dirent cache
+      auto entry = archive.getEntryByPath(it->getPath());
+      auto item = entry.getItem(true);
+      auto data = item.getData();
+    }
+
+    EXPECT_EQ(archive.get_dirent_cache_current_size(), 10);
+    EXPECT_EQ(archive.get_cluster_cache_current_size(), 1);
+
+    // Clean cache
+    // (More than testing the value, this is needed as we want to be sure the cache is actually populated later)
+    archive.set_dirent_cache_max_size(0);
+    archive.set_cluster_cache_max_size(0);
+
+    EXPECT_EQ(archive.get_dirent_cache_current_size(), 0);
+    EXPECT_EQ(archive.get_cluster_cache_current_size(), 0);
+
+    // Increase the cache
+    archive.set_dirent_cache_max_size(20);
+    archive.set_cluster_cache_max_size(1);
+    EXPECT_EQ(archive.get_dirent_cache_current_size(), 0);
+    EXPECT_EQ(archive.get_cluster_cache_current_size(), 0);
+
+    for (auto it = range.begin(); it != range.end(); it++) {
+      // Be sure to search by path to populate the dirent cache
+      auto entry = archive.getEntryByPath(it->getPath());
+      auto item = entry.getItem(true);
+      auto data = item.getData();
+    }
+
+    EXPECT_EQ(archive.get_dirent_cache_current_size(), 20);
+    EXPECT_EQ(archive.get_cluster_cache_current_size(), 1);
+  }
+}
+
 TEST(ZimArchive, openDontFallbackOnNonSplitZimArchive)
 {
   const char* fname = "wikibooks_be_all_nopic_2017-02.zim";