Optimize opening arrays. (#5651)

Fixed some performance bottlenecks identified during profiling, as part
of CORE-383.

---
TYPE: IMPROVEMENT
DESC: Improved performance when opening arrays

Author: teo-tsirpanis

tiledb/sm/array/array_directory.cc

@@ -1035,14 +1035,14 @@ ArrayDirectory::compute_uris_to_vacuum(
           if (timestamps_overlap(
                   fragment_timestamp_range,
                   !full_overlap_only &&
-                      consolidation_with_timestamps_supported(uri))) {
+                      consolidation_with_timestamps_supported(fragment_id))) {
             overlapping_vac_file_bitmap[i] = 1;
           }
         } else {
           if (!timestamps_overlap(
                   fragment_timestamp_range,
                   !full_overlap_only &&
-                      consolidation_with_timestamps_supported(uri))) {
+                      consolidation_with_timestamps_supported(fragment_id))) {
             non_vac_uri_bitmap[i] = 1;
           }
         }
@@ -1167,7 +1167,7 @@ ArrayDirectory::compute_filtered_uris(
         if (timestamps_overlap(
                 fragment_timestamp_ranges[i],
                 !full_overlap_only &&
-                    consolidation_with_timestamps_supported(uri))) {
+                    consolidation_with_timestamps_supported(fragment_id))) {
           overlaps_bitmap[i] = 1;
         }
         return Status::Ok();
@@ -1311,13 +1311,12 @@ Status ArrayDirectory::is_fragment(
 }
 
 bool ArrayDirectory::consolidation_with_timestamps_supported(
-    const URI& uri) const {
+    const FragmentID& id) const {
   // FragmentID::array_format_version() returns UINT32_MAX for versions <= 2
   // so we should explicitly exclude this case when checking if consolidation
   // with timestamps is supported on a fragment
-  FragmentID fragment_id{uri};
   return mode_ == ArrayDirectoryMode::READ &&
-         fragment_id.array_format_version() >=
+         id.array_format_version() >=
              constants::consolidation_with_timestamps_min_version;
 }
 

tiledb/sm/array/array_directory.h

@@ -827,10 +827,10 @@ class ArrayDirectory {
   /**
    * Checks if consolidation with timestamps is supported for a fragment
    *
-   * @param uri The fragment URI to be checked.
+   * @param id The fragment ID to be checked.
    * @return True if supported, false otherwise
    */
-  bool consolidation_with_timestamps_supported(const URI& uri) const;
+  bool consolidation_with_timestamps_supported(const FragmentID& id) const;
 };
 
 }  // namespace tiledb::sm

tiledb/sm/filesystem/uri.cc

@@ -420,7 +420,7 @@ std::string URI::to_path() const {
   return to_path(uri_);
 }
 
-std::string URI::to_string() const {
+const std::string& URI::to_string() const {
   return uri_;
 }
 

tiledb/sm/filesystem/uri.h

@@ -319,7 +319,7 @@ class URI {
   std::string to_path() const;
 
   /** Returns the URI string. */
-  std::string to_string() const;
+  const std::string& to_string() const;
 
   /** Returns the parent dir URI */
   URI parent_path() const;

tiledb/sm/fragment/fragment_identifier.cc

@@ -120,7 +120,7 @@ bool FragmentID::has_fragment_name(const URI& uri) {
   return name.find_last_of('_') != std::string::npos;
 }
 
-FragmentID::FragmentID(const std::string_view& path)
+FragmentID::FragmentID(std::string_view path)
     : FragmentID(URI(path)) {
 }
 

tiledb/sm/fragment/fragment_identifier.h

@@ -91,10 +91,10 @@ class FragmentID {
 
  public:
   /** Constructor. */
-  FragmentID(const URI& uri);
+  explicit FragmentID(const URI& uri);
 
   /** Constructor. */
-  FragmentID(const std::string_view& path);
+  explicit FragmentID(const std::string_view path);
 
   /** Destructor. */
   ~FragmentID() = default;