Hopefully finally squashed the race condition that would randomly reload files

common/spaces/evented_space_primitives.ts

@@ -12,7 +12,9 @@ import type { SpacePrimitives } from "./space_primitives.ts";
  * - page:deleted (string)
  */
 export class EventedSpacePrimitives implements SpacePrimitives {
+  // Avoid file listing while performing another fetch (read, write, meta) operation
   alreadyFetching = false;
+
   initialFileListLoad = true;
 
   spaceSnapshot: Record<string, number> = {};
@@ -28,55 +30,73 @@ export class EventedSpacePrimitives implements SpacePrimitives {
   async fetchFileList(): Promise<FileMeta[]> {
     const newFileList = await this.wrapped.fetchFileList();
     if (this.alreadyFetching) {
-      // Avoid race conditions
+      // Avoid race conditions, let's just skip this in terms of event triggering: that's ok
       return newFileList;
     }
-    this.alreadyFetching = true;
-    const deletedFiles = new Set<string>(Object.keys(this.spaceSnapshot));
-    for (const meta of newFileList) {
-      const oldHash = this.spaceSnapshot[meta.name];
-      const newHash = meta.lastModified;
-      if (
-        (
-          // New file scenario
-          !oldHash && !this.initialFileListLoad
-        ) || (
-          // Changed file scenario
-          oldHash &&
-          oldHash !== newHash
-        )
-      ) {
-        await this.dispatchEvent("file:changed", meta.name);
+    try {
+      this.alreadyFetching = true;
+      const deletedFiles = new Set<string>(Object.keys(this.spaceSnapshot));
+      for (const meta of newFileList) {
+        const oldHash = this.spaceSnapshot[meta.name];
+        const newHash = meta.lastModified;
+        // Update in snapshot
+        this.spaceSnapshot[meta.name] = newHash;
+
+        // Check what happened to the file
+        if (
+          (
+            // New file scenario
+            !oldHash && !this.initialFileListLoad
+          ) || (
+            // Changed file scenario
+            oldHash &&
+            oldHash !== newHash
+          )
+        ) {
+          await this.dispatchEvent(
+            "file:changed",
+            meta.name,
+            false,
+            oldHash,
+            newHash,
+          );
+        }
+        // Page found, not deleted
+        deletedFiles.delete(meta.name);
       }
-      // Page found, not deleted
-      deletedFiles.delete(meta.name);
 
-      // Update in snapshot
-      this.spaceSnapshot[meta.name] = newHash;
-    }
+      for (const deletedFile of deletedFiles) {
+        delete this.spaceSnapshot[deletedFile];
+        await this.dispatchEvent("file:deleted", deletedFile);
 
-    for (const deletedFile of deletedFiles) {
-      delete this.spaceSnapshot[deletedFile];
-      await this.dispatchEvent("file:deleted", deletedFile);
-
-      if (deletedFile.endsWith(".md")) {
-        const pageName = deletedFile.substring(0, deletedFile.length - 3);
-        await this.dispatchEvent("page:deleted", pageName);
+        if (deletedFile.endsWith(".md")) {
+          const pageName = deletedFile.substring(0, deletedFile.length - 3);
+          await this.dispatchEvent("page:deleted", pageName);
+        }
       }
-    }
 
-    await this.dispatchEvent("file:listed", newFileList);
-    this.alreadyFetching = false;
-    this.initialFileListLoad = false;
-    return newFileList;
+      await this.dispatchEvent("file:listed", newFileList);
+      this.initialFileListLoad = false;
+      return newFileList;
+    } finally {
+      this.alreadyFetching = false;
+    }
   }
 
   async readFile(
     name: string,
   ): Promise<{ data: Uint8Array; meta: FileMeta }> {
-    const data = await this.wrapped.readFile(name);
-    this.triggerEventsAndCache(name, data.meta.lastModified);
-    return data;
+    try {
+      // Fetching mutex
+      this.alreadyFetching = true;
+
+      // Fetch file
+      const data = await this.wrapped.readFile(name);
+      this.triggerEventsAndCache(name, data.meta.lastModified);
+      return data;
+    } finally {
+      this.alreadyFetching = false;
+    }
   }
 
   async writeFile(
@@ -85,31 +105,36 @@ export class EventedSpacePrimitives implements SpacePrimitives {
     selfUpdate?: boolean,
     meta?: FileMeta,
   ): Promise<FileMeta> {
-    const newMeta = await this.wrapped.writeFile(
-      name,
-      data,
-      selfUpdate,
-      meta,
-    );
-    if (!selfUpdate) {
-      await this.dispatchEvent("file:changed", name, true);
-    }
-    this.spaceSnapshot[name] = newMeta.lastModified;
+    try {
+      this.alreadyFetching = true;
+      const newMeta = await this.wrapped.writeFile(
+        name,
+        data,
+        selfUpdate,
+        meta,
+      );
+      if (!selfUpdate) {
+        await this.dispatchEvent("file:changed", name, true);
+      }
+      this.spaceSnapshot[name] = newMeta.lastModified;
 
-    if (name.endsWith(".md")) {
-      // Let's trigger some page-specific events
-      const pageName = name.substring(0, name.length - 3);
-      let text = "";
-      const decoder = new TextDecoder("utf-8");
-      text = decoder.decode(data);
+      if (name.endsWith(".md")) {
+        // Let's trigger some page-specific events
+        const pageName = name.substring(0, name.length - 3);
+        let text = "";
+        const decoder = new TextDecoder("utf-8");
+        text = decoder.decode(data);
 
-      await this.dispatchEvent("page:saved", pageName, newMeta);
-      await this.dispatchEvent("page:index_text", {
-        name: pageName,
-        text,
-      });
+        await this.dispatchEvent("page:saved", pageName, newMeta);
+        await this.dispatchEvent("page:index_text", {
+          name: pageName,
+          text,
+        });
+      }
+      return newMeta;
+    } finally {
+      this.alreadyFetching = false;
     }
-    return newMeta;
   }
 
   triggerEventsAndCache(name: string, newHash: number) {
@@ -124,6 +149,7 @@ export class EventedSpacePrimitives implements SpacePrimitives {
 
   async getFileMeta(name: string): Promise<FileMeta> {
     try {
+      this.alreadyFetching = true;
       const newMeta = await this.wrapped.getFileMeta(name);
       this.triggerEventsAndCache(name, newMeta.lastModified);
       return newMeta;
@@ -137,17 +163,24 @@ export class EventedSpacePrimitives implements SpacePrimitives {
         }
       }
       throw e;
+    } finally {
+      this.alreadyFetching = false;
     }
   }
 
   async deleteFile(name: string): Promise<void> {
-    if (name.endsWith(".md")) {
-      const pageName = name.substring(0, name.length - 3);
-      await this.dispatchEvent("page:deleted", pageName);
+    try {
+      this.alreadyFetching = true;
+      if (name.endsWith(".md")) {
+        const pageName = name.substring(0, name.length - 3);
+        await this.dispatchEvent("page:deleted", pageName);
+      }
+      // await this.getPageMeta(name); // Check if page exists, if not throws Error
+      await this.wrapped.deleteFile(name);
+      delete this.spaceSnapshot[name];
+      await this.dispatchEvent("file:deleted", name);
+    } finally {
+      this.alreadyFetching = false;
     }
-    // await this.getPageMeta(name); // Check if page exists, if not throws Error
-    await this.wrapped.deleteFile(name);
-    delete this.spaceSnapshot[name];
-    await this.dispatchEvent("file:deleted", name);
   }
 }

common/spaces/plug_space_primitives.ts

@@ -53,8 +53,11 @@ export class PlugSpacePrimitives implements SpacePrimitives {
           for (const pm of await plug.invoke(name, [])) {
             allFiles.push(pm);
           }
-        } catch (e) {
-          console.error("Error listing files", e);
+        } catch (e: any) {
+          if (!e.message.includes("not available")) {
+            // Don't report "not available in" environments errors
+            console.error("Error listing files", e);
+          }
         }
       }
     }