WIP

src/domain/ViewModel.js

@@ -30,8 +30,8 @@ export class ViewModel extends EventEmitter {
     }
 
     childOptions(explicitOptions) {
-        const {navigation, urlCreator, platform} = this._options;
-        return Object.assign({navigation, urlCreator, platform}, explicitOptions);
+        const {navigation, urlCreator, platform, logger} = this._options;
+        return Object.assign({navigation, urlCreator, platform, logger}, explicitOptions);
     }
 
     // makes it easier to pass through dependencies of a sub-view model
@@ -78,14 +78,9 @@ export class ViewModel extends EventEmitter {
     // we probably are, if we're using routing with a url, we could just refresh.
     i18n(parts, ...expr) {
         // just concat for now
-        let result = "";
-        for (let i = 0; i < parts.length; ++i) {
-            result = result + parts[i];
-            if (i < expr.length) {
-                result = result + expr[i];
-            }
-        }
-        return result;
+        return parts.reduce((all, p, i) => {
+            return all + p + expr[i];
+        });
     }
 
     updateOptions(options) {
@@ -108,6 +103,10 @@ export class ViewModel extends EventEmitter {
         return this._options.platform.clock;
     }
 
+    get logger() {
+        return this._options.logger;
+    }
+
     /**
      * The url router, only meant to be used to create urls with from view models.
      * @return {URLRouter}

src/logging/IDBLogger.js

@@ -0,0 +1,188 @@
+/*
+Copyright 2020 Bruno Windels <bruno@windels.cloud>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import {openDatabase, txnAsPromise, reqAsPromise, iterateCursor, fetchResults} from "../matrix/storage/idb/utils.js";
+import {LogItem} from "./LogItem.js";
+
+class Logger {
+    constructor(clock) {
+        this._openItems = new Set();
+        this._clock = clock;
+    }
+
+    decend(label, callback, logLevel) {
+        const item = new LogItem(label, this, logLevel, this._clock);
+
+        const failItem = (err) => {
+            item.catch(err);
+            finishItem();
+            throw err;
+        };
+
+        const finishItem = () => {
+            item.finish();
+            this._persistItem(item);
+            this._openItems.remove(item);
+        };
+
+        let result;
+        try {
+            result = callback(item);
+            if (result instanceof Promise) {
+                result = result.then(promiseResult => {
+                    finishItem();
+                    return promiseResult;
+                }, failItem);
+            }
+        } catch (err) {
+            failItem(err);
+        }
+    }
+
+    _persistItem(item) {
+        throw new Error("not implemented");
+    }
+
+    async extractItems() {
+        throw new Error("not implemented");
+    }
+}
+
+export function encodeUint64(n) {
+    const hex = n.toString(16);
+    return "0".repeat(16 - hex.length) + hex;
+}
+
+export default class IDBLogger extends Logger {
+    constructor({name, clock, utf8, flushInterval = 2 * 60 * 1000, limit = 1000}) {
+        super(clock);
+        this._utf8 = utf8;
+        this._name = name;
+        this._limit = limit;
+        // does not get loaded from idb on startup as we only use it to
+        // differentiate between two items with the same start time
+        this._itemCounter = 0;
+        this._queuedItems = this._loadQueuedItems();
+        window.addEventListener("pagehide", this, false);
+        this._flushInterval = this._clock.createInterval(() => this._tryFlush(), flushInterval);
+    }
+
+    dispose() {
+        window.removeEventListener("pagehide", this, false);
+        this._flushInterval.dispose();
+    }
+
+    handleEvent(evt) {
+        if (evt.type === "pagehide") {
+            this._finishAllAndFlush();
+        }
+    }
+
+    async _tryFlush() {
+        const db = await this._openDB();
+        try {
+            const txn = this.db.transaction(["logs"], "readwrite");
+            const logs = txn.objectStore("logs");
+            const amount = this._queuedItems.length;
+            for(const i of this._queuedItems) {
+                logs.add(i);
+            }
+            // trim logs if needed
+            const itemCount = await reqAsPromise(logs.count());
+            if (itemCount > this._limit) {
+                let currentCount = itemCount;
+                await iterateCursor(logs.openCursor(), (_, __, cursor) => {
+                    cursor.delete();
+                    currentCount -= 1;
+                    return {done: currentCount <= this._limit};
+                });
+            }
+            await txnAsPromise(txn);
+            this._queuedItems.splice(0, amount);
+        } finally {
+            try {
+                db.close();
+            } catch (e) {}
+        }
+    }
+
+    _finishAllAndFlush() {
+        for (const openItem of this._openItems) {
+            openItem.finish();
+            this._persistItem(openItem);
+        }
+        this._openItems.clear();
+        this._persistQueuedItems(this._queuedItems);
+    }
+
+    _loadQueuedItems() {
+        const key = `${this._name}_queuedItems`;
+        const json = window.localStorage.getItem(key);
+        if (json) {
+            window.localStorage.removeItem(key);
+            return JSON.parse(json);
+        }
+        return [];
+    }
+
+    _openDB() {
+        return openDatabase(this._name, db => db.createObjectStore("logs", {keyPath: "id"}), 1);
+    }
+    
+    _persistItem(item) {
+        this._itemCounter += 1;
+        this._queuedItems.push({
+            id: `${encodeUint64(item.start)}:${this._itemCounter}`,
+            // store as buffer so parsing overhead is lower
+            content: this._utf8.encode(JSON.stringify(item.serialize()))
+        });
+    }
+
+    _persistQueuedItems(items) {
+        window.localStorage.setItem(`${this._name}_queuedItems`, JSON.stringify(items));
+    }
+
+    // should we actually delete items and just not rely on trimming for it not to grow too large?
+    // just worried that people will create a file, not do anything with it, hit export logs again and then
+    // send a mostly empty file. we could just not delete but in _tryFlush (and perhaps make trimming delete a few more than needed to be below limit)
+    // how does eleweb handle this?
+    // 
+    // both deletes and reads items from store
+    async extractItems() {
+        const db = this._openDB();
+        try {
+            const queuedItems = this._queuedItems.slice();
+            const txn = this.db.transaction(["logs"], "readwrite");
+            const logs = txn.objectStore("logs");
+            const items = await fetchResults(logs.openCursor(), () => false);
+            // we know we have read all the items as we're doing this in a txn
+            logs.clear();
+            await txnAsPromise(txn);
+            // once the transaction is complete, remove the queued items
+            this._queuedItems.splice(0, queuedItems.length);
+            const sortedItems = items.concat(queuedItems).sort((a, b) => {
+                return a.id > b.id;
+            }).map(i => {
+
+            });
+            return sortedItems;
+        } finally {
+            try {
+                db.close();
+            } catch (e) {}
+        }
+    }
+}

src/logging/LogItem.js

@@ -0,0 +1,94 @@
+/*
+Copyright 2020 Bruno Windels <bruno@windels.cloud>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+export class LogItem {
+    constructor(label, parent, logLevel, clock) {
+        this._clock = clock;
+        this._start = clock.now();
+        this._end = null;
+        this._values = {label};
+        this._parent = parent;
+        this._error = null;
+        this._children = [];
+        this._logLevel = logLevel;
+    }
+
+    // should this handle errors in the same way as logger.descend/start?
+    descend(label, logLevel = this._logLevel) {
+        if (this._end !== null) {
+            throw new Error("can't descend on finished item");
+        }
+        const item = new LogItem(label, logLevel);
+        this._children.push(item);
+        return item;
+    }
+
+    set(key, value) {
+        if(typeof key === "object") {
+            const values = key;
+            Object.assign(this._values, values);
+        } else {
+            this._values[key] = value;
+        }
+    }
+
+    // XXX: where will this be called? from wrapAsync?
+    finish() {
+        if (this._end === null) {
+            for(const c of this._children) {
+                c.finish();
+            }
+            this._end = this._clock.now();
+            if (this._parent) {
+                this._parent._closeChild(this);
+            }
+        }
+    }
+
+    catch(err) {
+        this._error = err;
+        console.error(`log item ${this.values.label} failed: ${err.message}:\n${err.stack}`);
+    }
+
+    serialize() {
+        let error;
+        if (this._error) {
+            error = {
+                message: this._error.message,
+                stack: this._error.stack,
+            };
+        }
+        return {
+            start: this._start,
+            end: this._end,
+            values: this._values,
+            error,
+            children: this._children.map(c => c.serialize()),
+            logLevel: this._logLevel
+        };
+    }
+
+    async wrapAsync(fn) {
+        try {
+            const ret = await fn(this);
+            this.finish();
+            return ret;
+        } catch (err) {
+            this.fail(err);
+            throw err;
+        }
+    }
+}

src/logging/Logger.js

@@ -0,0 +1,51 @@
+/*
+Copyright 2020 Bruno Windels <bruno@windels.cloud>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import {LogItem} from "./LogItem.js";
+
+export class Logger {
+    constructor(persister) {
+        this._openItems = [];
+        this._persister = persister;
+        this._closing = false;
+    }
+
+    restore() {
+        const items = this._persister.loadTempItems();
+        return this._persister.persistItems(items);
+    }
+
+    start(label, logLevel) {
+        const item = new LogItem(label, logLevel, this);
+        this._openItems.push(item);
+        return item;
+    }
+
+    _closeChild(item) {
+        if (!this._closing) {
+            this._persister.persistItems([item.serialize()]);
+        }
+    }
+
+    close() {
+        this._closing = true;
+        for(const i of this._openItems) {
+            i.finish();
+        }
+        this._closing = false;
+        this._persister.persistTempItems(this._openItems.map(i => i.serialize()));
+    }
+}

src/matrix/storage/idb/utils.js

@@ -110,7 +110,7 @@ export function iterateCursor(cursorRequest, processValue) {
                 needsSyncPromise && Promise._flush && Promise._flush();
                 return; // end of results
             }
-            const result = processValue(cursor.value, cursor.key);
+            const result = processValue(cursor.value, cursor.key, cursor);
             // TODO: don't use object for result and assume it's jumpTo when not === true/false or undefined
             const done = result?.done;
             const jumpTo = result?.jumpTo;