hydrogen-web/scripts/logviewer/main.js

/*
Copyright 2020 The Matrix.org Foundation C.I.C.

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 {tag as t} from "./html.js";
import {openFile, readFileAsText} from "./file.js";

const main = document.querySelector("main");

let selectedItemNode;
let rootItem;

const logLevels = [undefined, "All", "Debug", "Detail", "Info", "Warn", "Error", "Fatal", "Off"];

main.addEventListener("click", event => {
    if (selectedItemNode) {
        selectedItemNode.classList.remove("selected");
        selectedItemNode = null;
    }
    if (event.target.classList.contains("toggleExpanded")) {
        const li = event.target.parentElement.parentElement;
        li.classList.toggle("expanded");
    } else {
        const itemNode = event.target.closest(".item");
        if (itemNode) {
            selectedItemNode = itemNode;
            selectedItemNode.classList.add("selected");
            const path = selectedItemNode.dataset.path;
            let item = rootItem;
            let parent;
            if (path.length) {
                const indices = path.split("/").map(i => parseInt(i, 10));
                for(const i of indices) {
                    parent = item;
                    item = itemChildren(item)[i];
                }
            }
            showItemDetails(item, parent, itemNode);
        }
    }
});

function stringifyItemValue(value) {
    if (typeof value === "object" && value !== null) {
        return JSON.stringify(value, undefined, 2);
    } else {
        return value + "";
    }
}

function showItemDetails(item, parent, itemNode) {
    const parentOffset = itemStart(parent) ? `${itemStart(item) - itemStart(parent)}ms` : "none";
    const expandButton = t.button("Expand recursively");
    expandButton.addEventListener("click", () => expandResursively(itemNode.parentElement.parentElement));
    const aside = t.aside([
        t.h3(itemCaption(item)),
        t.p([t.strong("Log level: "), logLevels[itemLevel(item)]]),
        t.p([t.strong("Error: "), itemError(item) ? `${itemError(item).name} ${itemError(item).stack}` : "none"]),
        t.p([t.strong("Parent offset: "), parentOffset]),
        t.p([t.strong("Start: "), new Date(itemStart(item)).toString()]),
        t.p([t.strong("Duration: "), `${itemDuration(item)}ms`]),
        t.p([t.strong("Child count: "), itemChildren(item) ? `${itemChildren(item).length}` : "none"]),
        t.p(t.strong("Values:")),
        t.ul({class: "values"}, Object.entries(itemValues(item)).map(([key, value]) => {
            return t.li([
                t.span({className: "key"}, normalizeValueKey(key)),
                t.span({className: "value"}, stringifyItemValue(value))
            ]);
        })),
        t.p(expandButton)
    ]);
    document.querySelector("aside").replaceWith(aside);
}

function expandResursively(li) {
    li.classList.add("expanded");
    const ol = li.querySelector("ol");
    if (ol) {
        const len = ol.children.length;
        for (let i = 0; i < len; i += 1) {
            expandResursively(ol.children[i]);
        }
    }
}

document.getElementById("openFile").addEventListener("click", loadFile);

async function loadFile() {
    const file = await openFile();
    const json = await readFileAsText(file);
    const logs = JSON.parse(json);
    rootItem = {c: logs.items};
    const fragment = logs.items.reduce((fragment, item, i, items) => {
        const prevItem = i === 0 ? null : items[i - 1];
        fragment.appendChild(t.section([
            t.h2(prevItem ? `+ ${formatTime(itemStart(item) - itemEnd(prevItem))}` : new Date(itemStart(item)).toString()),
            t.div({className: "timeline"}, t.ol(itemToNode(item, [i])))
        ]));
        return fragment;
    }, document.createDocumentFragment());
    main.replaceChildren(fragment);
}

function formatTime(ms) {
    if (ms < 1000) {
        return `${ms}ms`;
    } else if (ms < 1000 * 60) {
        return `${(ms / 1000).toFixed(2)}s`;
    } else if (ms < 1000 * 60 * 60) {
        return `${(ms / (1000 * 60)).toFixed(2)}m`;
    } else if (ms < 1000 * 60 * 60 * 24) {
        return `${(ms / (1000 * 60 * 60)).toFixed(2)}h`;
    } else  {
        return `${(ms / (1000 * 60 * 60 * 24)).toFixed(2)}d`;
    }
}

function itemChildren(item) { return item.c; }
function itemStart(item) { return item.s; }
function itemEnd(item) { return item.s + item.d; }
function itemDuration(item) { return item.d; }
function itemValues(item) { return item.v; }
function itemLevel(item) { return item.l; }
function itemLabel(item) { return item.v?.l; }
function itemType(item) { return item.v?.t; }
function itemError(item) { return item.e; }
function itemShortErrorMessage(item) {
    if (itemError(item)) {
        const e = itemError(item);
        return e.name || e.stack.substr(0, e.stack.indexOf("\n")); 
    }
}

function itemCaption(item) {
    if (itemType(item) === "network") {
        return `${itemValues(item)?.method} ${itemValues(item)?.url}`;
    } else if (itemLabel(item) && itemValues(item)?.id) {
        return `${itemLabel(item)} ${itemValues(item).id}`;
    } else if (itemLabel(item) && itemValues(item)?.status) {
        return `${itemLabel(item)} (${itemValues(item).status})`;
    } else if (itemLabel(item) && itemError(item)) {
        return `${itemLabel(item)} (${itemShortErrorMessage(item)})`;
    } else {
        return itemLabel(item) || itemType(item);
    }
}
function normalizeValueKey(key) {
    switch (key) {
        case "t": return "type";
        case "l": return "label";
        default: return key;
    }
} 

// returns the node and the total range (recursively) occupied by the node
function itemToNode(item, path) {
    const hasChildren = !!itemChildren(item)?.length;
    const className = {
        item: true,
        "has-children": hasChildren,
        error: itemError(item),
        [`type-${itemType(item)}`]: !!itemType(item),
        [`level-${itemLevel(item)}`]: true,
    };

    const li = t.li([
        t.div([
            hasChildren ? t.button({className: "toggleExpanded"}) : "",
            t.div({className, "data-path": path.join("/")}, [
                t.span({class: "caption"}, itemCaption(item)),
                t.span({class: "duration"}, `(${itemDuration(item)}ms)`),
            ])
        ])
    ]);
    if (itemChildren(item) && itemChildren(item).length) {
        li.appendChild(t.ol(itemChildren(item).map((item, i) => {
            return itemToNode(item, path.concat(i));
        })));
    }
    return li;
}