Fix variable name and change tests to use MemorySource (#420)

Author: elshize

Diff for: include/pisa/block_freq_index.hpp

@@ -21,7 +21,7 @@ class block_freq_index {
     block_freq_index() = default;
     explicit block_freq_index(MemorySource source) : m_source(std::move(source))
     {
-        mapper::map(*this, source.data(), mapper::map_flags::warmup);
+        mapper::map(*this, m_source.data(), mapper::map_flags::warmup);
     }
 
     class builder {

Diff for: include/pisa/freq_index.hpp

@@ -22,7 +22,7 @@ class freq_index {
 
     explicit freq_index(MemorySource source) : m_source(std::move(source))
     {
-        mapper::map(*this, source.data(), mapper::map_flags::warmup);
+        mapper::map(*this, m_source.data(), mapper::map_flags::warmup);
     }
 
     class builder {

Diff for: include/pisa/wand_data.hpp

@@ -32,7 +32,7 @@ class wand_data {
     wand_data() = default;
     explicit wand_data(MemorySource source) : m_source(std::move(source))
     {
-        mapper::map(*this, source.data(), mapper::map_flags::warmup);
+        mapper::map(*this, m_source.data(), mapper::map_flags::warmup);
     }
 
     template <typename LengthsIterator>

Diff for: test/test_block_freq_index.cpp

@@ -42,18 +42,15 @@ void test_block_freq_index()
     }
 
     Temporary_Directory tmpdir;
-    auto filename = tmpdir.path().string() + "temp.bin";
+    auto filename = (tmpdir.path() / "temp.bin").string();
     {
         collection_type coll;
         b.build(coll);
         pisa::mapper::freeze(coll, filename.c_str());
     }
 
     {
-        collection_type coll;
-        mio::mmap_source m(filename.c_str());
-        pisa::mapper::map(coll, m);
-
+        collection_type coll(pisa::MemorySource::mapped_file(filename));
         for (size_t i = 0; i < posting_lists.size(); ++i) {
             auto const& plist = posting_lists[i];
             auto doc_enum = coll[i];

Diff for: test/test_freq_index.cpp

@@ -10,15 +10,20 @@
 
 #include "freq_index.hpp"
 #include "mappable/mapper.hpp"
+#include "memory_source.hpp"
 #include "mio/mmap.hpp"
 #include "sequence/indexed_sequence.hpp"
 #include "sequence/partitioned_sequence.hpp"
 #include "sequence/positive_sequence.hpp"
 #include "sequence/uniform_partitioned_sequence.hpp"
+#include "temporary_directory.hpp"
 
 template <typename DocsSequence, typename FreqsSequence>
 void test_freq_index()
 {
+    Temporary_Directory tmpdir;
+    auto idx_path = (tmpdir.path() / "coll.bin").string();
+
     pisa::global_parameters params;
     uint64_t universe = 20000;
     using collection_type = pisa::freq_index<DocsSequence, FreqsSequence>;
@@ -40,14 +45,11 @@ void test_freq_index()
     {
         collection_type coll;
         b.build(coll);
-        pisa::mapper::freeze(coll, "temp.bin");
+        pisa::mapper::freeze(coll, idx_path.c_str());
     }
 
     {
-        collection_type coll;
-        mio::mmap_source m("temp.bin");
-        pisa::mapper::map(coll, m);
-
+        collection_type coll(pisa::MemorySource::mapped_file(idx_path));
         for (size_t i = 0; i < posting_lists.size(); ++i) {
             auto const& plist = posting_lists[i];
             auto doc_enum = coll[i];