Only load tracks if cache is invalid

src/core/FileScanner.cpp

@@ -57,6 +57,7 @@ struct DirectoryChild
     uint64 LastModified;
 };
 
+static uint32 GetPathChecksum(const utf8 * path);
 static bool MatchWildcard(const utf8 * fileName, const utf8 * pattern);
 
 class FileScannerBase : public IFileScanner
@@ -363,6 +364,40 @@ IFileScanner * Path::ScanDirectory(const utf8 * pattern, bool recurse)
 #endif
 }
 
+void Path::QueryDirectory(QueryDirectoryResult * result, const utf8 * pattern)
+{
+    IFileScanner * scanner = Path::ScanDirectory(pattern, true);
+    while (scanner->Next())
+    {
+        const FileInfo * fileInfo = scanner->GetFileInfo();
+        const utf8 * path = scanner->GetPath();
+
+        result->TotalFiles++;
+        result->TotalFileSize += fileInfo->Size;
+        result->FileDateModifiedChecksum ^=
+            (uint32)(fileInfo->LastModified >> 32) ^
+            (uint32)(fileInfo->LastModified & 0xFFFFFFFF);
+        result->FileDateModifiedChecksum = ror32(result->FileDateModifiedChecksum, 5);
+        result->PathChecksum += GetPathChecksum(path);
+    }
+    delete scanner;
+}
+
+static uint32 GetPathChecksum(const utf8 * path)
+{
+    uint32 hash = 0xD8430DED;
+    for (const utf8 * ch = path; *ch != '\0'; ch++)
+    {
+        hash += (*ch);
+        hash += (hash << 10);
+        hash ^= (hash >> 6);
+    }
+    hash += (hash << 3);
+    hash ^= (hash >> 11);
+    hash += (hash << 15);
+    return hash;
+}
+
 /**
  * Due to FindFirstFile / FindNextFile searching for DOS names as well, *.doc also matches *.docx which isn't what the pattern
  * specified. This will verify if a filename does indeed match the pattern we asked for.

src/core/FileScanner.h

@@ -41,7 +41,30 @@ interface IFileScanner
     virtual bool Next() abstract;
 };
 
+struct QueryDirectoryResult
+{
+    uint32 TotalFiles;
+    uint64 TotalFileSize;
+    uint32 FileDateModifiedChecksum;
+    uint32 PathChecksum;
+};
+
 namespace Path
 {
+    /**
+     * Scans a directory and optionally sub directories for files that matches the
+     * given pattern and returns an enumerator.
+     * @param pattern The path followed by a semi-colon delimited list of wildcard patterns.
+     * @param recurse Whether to scan sub directories or not.
+     * @returns A new FileScanner, this must be deleted when no longer needed.
+     */
     IFileScanner * ScanDirectory(const utf8 * pattern, bool recurse);
+
+    /**
+     * Scans a directory and all sub directories 
+     * @param result The query result to modify.
+     * @param pattern The path followed by a semi-colon delimited list of wildcard patterns.
+     * @returns An aggregated result of all scanned files.
+     */
+    void QueryDirectory(QueryDirectoryResult * result, const utf8 * pattern);
 }

src/object/ObjectRepository.cpp

@@ -46,7 +46,7 @@ extern "C"
     #include "../object_list.h"
     #include "../platform/platform.h"
     #include "../util/sawyercoding.h"
-	#include "../util/util.h"
+    #include "../util/util.h"
 }
 
 constexpr uint16 OBJECT_REPOSITORY_VERSION = 10;
@@ -65,14 +65,6 @@ struct ObjectRepositoryHeader
 assert_struct_size(ObjectRepositoryHeader, 28);
 #pragma pack(pop)
 
-struct QueryDirectoryResult
-{
-    uint32  TotalFiles;
-    uint64  TotalFileSize;
-    uint32  FileDateModifiedChecksum;
-    uint32  PathChecksum;
-};
-
 struct ObjectEntryHash
 {
     size_t operator()(const rct_object_entry &entry) const
@@ -239,22 +231,7 @@ private:
         utf8 pattern[MAX_PATH];
         String::Set(pattern, sizeof(pattern), directory);
         Path::Append(pattern, sizeof(pattern), "*.dat");
-
+        Path::QueryDirectory(result, pattern);
-        IFileScanner * scanner = Path::ScanDirectory(pattern, true);
-        while (scanner->Next())
-        {
-            const FileInfo * fileInfo = scanner->GetFileInfo();
-            const utf8 * path = scanner->GetPath();
-
-            result->TotalFiles++;
-            result->TotalFileSize += fileInfo->Size;
-            result->FileDateModifiedChecksum ^=
-                (uint32)(fileInfo->LastModified >> 32) ^
-                (uint32)(fileInfo->LastModified & 0xFFFFFFFF);
-            result->FileDateModifiedChecksum = ror32(result->FileDateModifiedChecksum, 5);
-            result->PathChecksum += GetPathChecksum(path);
-        }
-        delete scanner;
     }
 
     void Construct()
@@ -650,21 +627,6 @@ private:
     {
         platform_get_user_directory(buffer, "object", bufferSize);
     }
-
-    static uint32 GetPathChecksum(const utf8 * path)
-    {
-        uint32 hash = 0xD8430DED;
-        for (const utf8 * ch = path; *ch != '\0'; ch++)
-        {
-            hash += (*ch);
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-        }
-        hash += (hash << 3);
-        hash ^= (hash >> 11);
-        hash += (hash << 15);
-        return hash;
-    }
 };
 
 static std::unique_ptr<ObjectRepository> _objectRepository;

src/ride/TrackDesignRepository.cpp

@@ -35,6 +35,10 @@ struct TrackRepositoryHeader
 {
     uint32  MagicNumber;
     uint16  Version;
+    uint32  TotalFiles;
+    uint64  TotalFileSize;
+    uint32  FileDateModifiedChecksum;
+    uint32  PathChecksum;
     uint32  NumItems;
 };
 #pragma pack(pop)
@@ -60,6 +64,7 @@ class TrackDesignRepository : public ITrackDesignRepository
 {
 private:
     std::vector<TrackRepositoryItem> _items;
+    QueryDirectoryResult _directoryQueryResult;
 
 public:
     virtual ~TrackDesignRepository()
@@ -111,16 +116,24 @@ public:
 
     void Scan() override
     {
-        utf8 directory[MAX_PATH];
+        utf8 rct2Directory[MAX_PATH];
+        utf8 userDirectory[MAX_PATH];
 
-        GetRCT2Directory(directory, sizeof(directory));
+        GetRCT2Directory(rct2Directory, sizeof(rct2Directory));
-        Scan(directory, TRIF_READ_ONLY);
+        GetUserDirectory(userDirectory, sizeof(userDirectory));
 
-        GetUserDirectory(directory, sizeof(directory));
+        _items.clear();
-        Scan(directory);
+        _directoryQueryResult = { 0 };
+        Query(rct2Directory);
+        Query(userDirectory);
 
-        SortItems();
+        if (!Load())
-        Save();
+        {
+            Scan(rct2Directory, TRIF_READ_ONLY);
+            Scan(userDirectory);
+            SortItems();
+            Save();
+        }
     }
 
     bool Delete(const utf8 * path) override
@@ -193,6 +206,14 @@ public:
     }
 
 private:
+    void Query(const utf8 * directory)
+    {
+        utf8 pattern[MAX_PATH];
+        String::Set(pattern, sizeof(pattern), directory);
+        Path::Append(pattern, sizeof(pattern), "*.td4;*.td6");
+        Path::QueryDirectory(&_directoryQueryResult, pattern);
+    }
+
     void Scan(const utf8 * directory, uint32 flags = 0)
     {
         utf8 pattern[MAX_PATH];
@@ -240,6 +261,46 @@ private:
             });
     }
 
+    bool Load()
+    {
+        utf8 path[MAX_PATH];
+        GetRepositoryPath(path, sizeof(path));
+
+        bool result = false;
+        try
+        {
+            auto fs = FileStream(path, FILE_MODE_OPEN);
+
+            // Read header, check if we need to re-scan
+            auto header = fs.ReadValue<TrackRepositoryHeader>();
+            if (header.MagicNumber == TRACK_REPOSITORY_MAGIC_NUMBER &&
+                header.Version == TRACK_REPOSITORY_VERSION &&
+                header.TotalFiles == _directoryQueryResult.TotalFiles &&
+                header.TotalFileSize == _directoryQueryResult.TotalFileSize &&
+                header.FileDateModifiedChecksum == _directoryQueryResult.FileDateModifiedChecksum &&
+                header.PathChecksum == _directoryQueryResult.PathChecksum)
+            {
+                // Directory is the same, just read the saved items
+                for (uint32 i = 0; i < header.NumItems; i++)
+                {
+                    TrackRepositoryItem item;
+                    item.Name = fs.ReadString();
+                    item.Path = fs.ReadString();
+                    item.RideType = fs.ReadValue<uint8>();
+                    item.ObjectEntry = fs.ReadString();
+                    item.Flags = fs.ReadValue<uint32>();
+                    _items.push_back(item);
+                }
+                result = true;
+            }
+        }
+        catch (Exception ex)
+        {
+            Console::Error::WriteLine("Unable to write object repository index.");
+        }
+        return result;
+    }
+
     void Save() const
     {
         utf8 path[MAX_PATH];
@@ -253,6 +314,10 @@ private:
             TrackRepositoryHeader header = { 0 };
             header.MagicNumber = TRACK_REPOSITORY_MAGIC_NUMBER;
             header.Version = TRACK_REPOSITORY_VERSION;
+            header.TotalFiles = _directoryQueryResult.TotalFiles;
+            header.TotalFileSize = _directoryQueryResult.TotalFileSize;
+            header.FileDateModifiedChecksum = _directoryQueryResult.FileDateModifiedChecksum;
+            header.PathChecksum = _directoryQueryResult.PathChecksum;
             header.NumItems = (uint32)_items.size();
             fs.WriteValue(header);