Presentation: Enable an option for presentation backend to use memory…

… mapped i/o for worker SQLite connections (#690)
iTwin · Feb 1, 2021 · 83e76fd · 83e76fd
1 parent b3fc3c6
commit 83e76fd
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diff --git a/presentation/backend/src/presentation-backend/NativePlatform.ts b/presentation/backend/src/presentation-backend/NativePlatform.ts
@@ -68,6 +68,7 @@ export interface DefaultNativePlatformProps {
   isChangeTrackingEnabled: boolean;
   cacheConfig?: IModelJsNative.ECPresentationHierarchyCacheConfig;
   contentCacheSize?: number;
+  useMmap?: boolean | number;
 }
 
 /** @internal */

diff --git a/presentation/backend/src/presentation-backend/PresentationManager.ts b/presentation/backend/src/presentation-backend/PresentationManager.ts
@@ -246,6 +246,16 @@ export interface PresentationManagerProps {
   /** @alpha */
   contentCacheSize?: number;
 
+  /**
+   * Use [SQLite's Memory-Mapped I/O](https://sqlite.org/mmap.html) for worker connections. This mode improves performance of handling
+   * requests with high I/O intensity, e.g. filtering large tables on non-indexed columns. No downsides have been noticed.
+   *
+   * Set to a falsy value to turn off. `true` for memory-mapping the whole iModel. Number value for memory-mapping the specified amount of bytes.
+   *
+   * @alpha
+   */
+  useMmap?: boolean | number;
+
   /**
    * An identifier which helps separate multiple presentation managers. It's
    * mostly useful in tests where multiple presentation managers can co-exist
@@ -307,6 +317,7 @@ export class PresentationManager {
         isChangeTrackingEnabled,
         cacheConfig: createCacheConfig(this._props.cacheConfig),
         contentCacheSize: this._props.contentCacheSize,
+        useMmap: this._props.useMmap,
       });
       this._nativePlatform = new nativePlatformImpl();
     }

diff --git a/test-apps/presentation-test-app/src/backend/main.ts b/test-apps/presentation-test-app/src/backend/main.ts
@@ -38,6 +38,7 @@ import { PresentationBackendLoggerCategory, PresentationBackendNativeLoggerCateg
     taskAllocationsMap: {
       [RequestPriority.Max]: 1,
     },
+    useMmap: true,
   });
   // __PUBLISH_EXTRACT_END__