3 files changed, 73 insertions, 0 deletions
diff --git a/LibMatrix/Homeservers/Extensions/NamedCaches/NamedCache.cs b/LibMatrix/Homeservers/Extensions/NamedCaches/NamedCache.cs
new file mode 100644
index 0000000..622eef6
--- /dev/null
+++ b/LibMatrix/Homeservers/Extensions/NamedCaches/NamedCache.cs
@@ -0,0 +1,37 @@
+namespace LibMatrix.Homeservers.Extensions.NamedCaches;
+
+public class NamedCache<T>(AuthenticatedHomeserverGeneric hs, string name) where T : class {
+    private Dictionary<string, T>? _cache = new();
+    private DateTime _expiry = DateTime.MinValue;
+    
+    public async Task<Dictionary<string, T>> ReadCacheMapAsync() {
+        _cache = await hs.GetAccountDataOrNullAsync<Dictionary<string, T>>(name);
+
+        return _cache ?? new();
+    }
+    
+    public async Task<Dictionary<string,T>> ReadCacheMapCachedAsync() {
+        if (_expiry < DateTime.Now || _cache == null) {
+            _cache = await ReadCacheMapAsync();
+            _expiry = DateTime.Now.AddMinutes(5);
+        }
+
+        return _cache;
+    }
+    
+    public virtual async Task<T?> GetValueAsync(string key) {
+        return (await ReadCacheMapCachedAsync()).GetValueOrDefault(key);
+    }
+    
+    public virtual async Task<T> SetValueAsync(string key, T value) {
+        var cache = await ReadCacheMapCachedAsync();
+        cache[key] = value;
+        await hs.SetAccountDataAsync(name, cache);
+
+        return value;
+    }
+    
+    public virtual async Task<T> GetOrSetValueAsync(string key, Func<Task<T>> value) {
+        return (await ReadCacheMapCachedAsync()).GetValueOrDefault(key) ?? await SetValueAsync(key, await value());
+    }
+}
\ No newline at end of file
diff --git a/LibMatrix/Homeservers/Extensions/NamedCaches/NamedFileCache.cs b/LibMatrix/Homeservers/Extensions/NamedCaches/NamedFileCache.cs
new file mode 100644
index 0000000..87b7636
--- /dev/null
+++ b/LibMatrix/Homeservers/Extensions/NamedCaches/NamedFileCache.cs
@@ -0,0 +1,3 @@
+namespace LibMatrix.Homeservers.Extensions.NamedCaches;
+
+public class NamedFileCache(AuthenticatedHomeserverGeneric hs) : NamedCache<string>(hs, "gay.rory.libmatrix.named_cache.media") { }
\ No newline at end of file
diff --git a/LibMatrix/Homeservers/Extensions/NamedCaches/NamedFilterCache.cs b/LibMatrix/Homeservers/Extensions/NamedCaches/NamedFilterCache.cs
new file mode 100644
index 0000000..76533a4
--- /dev/null
+++ b/LibMatrix/Homeservers/Extensions/NamedCaches/NamedFilterCache.cs
@@ -0,0 +1,33 @@
+using LibMatrix.Filters;
+using LibMatrix.Utilities;
+
+namespace LibMatrix.Homeservers.Extensions.NamedCaches;
+
+public class NamedFilterCache(AuthenticatedHomeserverGeneric hs) : NamedCache<string>(hs, "gay.rory.libmatrix.named_cache.filter") {
+    /// <summary>
+    ///   <inheritdoc cref="NamedCache{T}.GetOrSetValueAsync"/>
+    ///   Allows passing a filter directly, or using a common filter.
+    ///   Substitutes @me for the user's ID.
+    /// </summary>
+    /// <param name="key">Filter name</param>
+    /// <param name="filter">Filter to upload if not cached, otherwise defaults to common filters if that exists.</param>
+    /// <returns></returns>
+    /// <exception cref="ArgumentNullException"></exception>
+    public async Task<string> GetOrSetValueAsync(string key, SyncFilter? filter = null) {
+        var existingValue = await GetValueAsync(key);
+        if (existingValue != null) {
+            return existingValue;
+        }
+
+        if (filter is null) {
+            if(CommonSyncFilters.FilterMap.TryGetValue(key, out var commonFilter)) {
+                filter = commonFilter;
+            } else {
+                throw new ArgumentNullException(nameof(filter));
+            }
+        }
+
+        var filterUpload = await hs.UploadFilterAsync(filter);
+        return await SetValueAsync(key, filterUpload.FilterId);
+    }
+}
\ No newline at end of file