Clean up the directory structure to improve the flow of the lesson more.

02-filter-a-log-file/chains_parser/parser_slow.js

@@ -0,0 +1,260 @@
+import fs from "fs";
+import assert from "assert";
+import UAParser from "ua-parser-js";
+import readline from "readline";
+import { program } from "commander";
+
+class Parser {
+  constructor() {
+    this.text = "";
+    this.next = "";
+  }
+
+  match(reg, consume=true) {
+    const n = this.next.match(reg);
+
+    if(n === null) {
+      return undefined;
+    } else {
+      const element = n.length > 1 ? n.slice(1) : n[0];
+
+      if(consume) {
+        this.next = this.next.slice(n[0].length);
+      }
+
+      return element;
+    }
+  }
+
+  start(line) {
+    this.text = line;
+    this.next = line;
+  }
+
+  ws(consume=true) {
+    return this.match(/ +/, consume);
+  }
+
+  parse_new_log(ip) {
+    const [port, conn_id, conn_count] = this.match(/^([0-9]+):([0-9]+):([0-9]+)/);
+
+    this.ws();
+
+    const [ time ] = this.match(/\[(.*)\]/);
+
+    this.ws();
+
+    const [ full_url ] = this.match(/"(.+?)"/);
+
+    const [url, params] = full_url.split("?");
+
+    this.ws();
+
+    const code = this.match(/\-|[0-9]+/);
+
+    this.ws();
+
+    const bytes = this.match(/\-|[0-9]+/);
+
+    this.ws();
+
+    const [refer] = this.match(/"(.+?)"/);
+
+    this.ws();
+
+    const [ua] = this.match(/"(.+?)"/);
+
+    return {
+      ip,
+      conn_id: parseInt(conn_id),
+      conn_count: parseInt(conn_count),
+      time: new Date(time),
+      url, params,
+      code: parseInt(code),
+      size: parseInt(bytes),
+      refer: refer === '-' ? undefined : refer,
+      ua: UAParser(ua)
+    };
+  }
+
+  parse_old_log(ip) {
+    this.match(/- -/);
+
+    this.ws();
+
+    // FORMAT: 29/Mar/2022:22:40:52 +0200
+    const [ day, month, year, hour, minute, seconds, tz_offset ] = this.match(/\[([0-9]+)\/([A-Za-z]+)\/([0-9]+):([0-9]+):([0-9]+):([0-9]+) (.+?)\]/);
+
+    this.ws();
+
+    const [ method, full_url, http_version ] = this.match(/"([A-Z]+) (.+) HTTP\/([0-9].[0-9])"/);
+
+    const [ url, params ] = full_url.split("?");
+
+    this.ws();
+
+    const code = this.match(/\-|[0-9]+/);
+
+    this.ws();
+
+    const bytes = this.match(/\-|[0-9]+/);
+
+    this.ws();
+
+    const [refer] = this.match(/"(.+?)"/);
+
+    this.ws();
+
+    const [ua] = this.match(/"(.+?)"/);
+
+    // this is another IP address sometimes in another log format that I'll ignore
+    const unknown = this.match(/".+?"$/);
+
+    return {
+      ip,
+      method,
+      http_version,
+      time: new Date(`${day} ${month} ${year} ${hour}:${minute}:${seconds} ${tz_offset}`),
+      url, params,
+      code: parseInt(code),
+      size: parseInt(bytes),
+      refer: refer === '-' ? undefined : refer,
+      ua: UAParser(ua)
+    };
+  }
+
+  parse() {
+    const ip = this.match(/^[0-9\.]+/);
+    const test = this.match(/(:| )/);
+
+    // BUG: uhh for some reason it needs == here? === says : doesn't equal :
+    if(test == ":") {
+      return this.parse_new_log(ip);
+    } else if(test == " ") {
+      return this.parse_old_log(ip);
+    } else {
+      // console.log(`PARSE ERROR, expected : or ' ' but got ${test}`);
+      return {};
+    }
+  }
+}
+
+const parse_logs = async (file_name, errors) => {
+  const read_stream = fs.createReadStream(file_name);
+
+  const rl = readline.createInterface({
+    input: read_stream,
+    crlfDelay: Infinity
+  });
+
+  const parser = new Parser();
+
+  const stats = {
+    lines: 0,
+    chains: 0,
+    excluded: 0,
+    errors: 0,
+    roots: 0,
+    firsts: 0
+  };
+
+  const skip = /(authcheck|.*\.svg|.*\.webmanifest|.*\.js|.*\.css|.*php|socket\.io|\.env|.*\.png|.*\.txt|.*\.woff|.*\.jpg|.*\.mp4|.*\.torrent|\-|.*\.ico|\/api\/.*\?.*|.*\.html|.*\.map|.*.php)/
+
+  const by_ip = {};
+
+  for await (let line of rl) {
+    try {
+      stats.lines += 1;
+      parser.start(line);
+
+      const data = parser.parse();
+
+      // skip lines that have content we don't care about
+      if(data.url.match(skip)) continue;
+
+      // store or update the chain in the by_ip chain
+      const ip_chain = by_ip[data.ip] || [];
+
+      ip_chain.push(data);
+
+      by_ip[data.ip] = ip_chain;
+    } catch(error) {
+      if(errors) console.error(error);
+
+      stats.errors += 1;
+    }
+  }
+
+  return [by_ip, stats];
+}
+
+const chain_to_set = (requests) => {
+  const path = new Set();
+
+  for(let r of requests) {
+    path.add(r.url);
+  }
+
+  return path.values();
+}
+
+const chain_to_list = (requests) => {
+  const path = [];
+  let seen;
+
+  for(let r of requests) {
+    if(r.url != seen) {
+      path.push(r.url);
+      seen = r.url;
+    }
+  }
+
+  return path.values();
+}
+
+const sort_request_chains = (by_ip, as_set) => {
+  let ip_chains = {};
+  let seen;
+
+  for(let [ip, requests] of Object.entries(by_ip)) {
+    const chain = as_set ? chain_to_set(requests) : chain_to_list(requests);
+
+    const ref = requests[0].refer ? `[${requests[0].refer}]` : "";
+    const url_set = [ref, ...chain].join(" ");
+
+    ip_chains[url_set] = url_set in ip_chains ? ip_chains[url_set] + 1 : 1;
+  }
+
+  const chains_sorted = Object.entries(ip_chains);
+  chains_sorted.sort((a, b) => b[1] - a[1]);
+
+  return chains_sorted;
+}
+
+const output_results = (min, chains_sorted) => {
+  for(let [url, count] of chains_sorted) {
+    if(count >= min) {
+      console.log(count, url);
+    }
+  }
+
+  console.log(stats);
+}
+
+program
+  .option("--no-set", "Use a Set instead of a list for chains.")
+  .option("--min <Number>", "The lowest count to print. Stop at this.", 1)
+  .option("--errors", "Show the erorrs so you can fix them.", false)
+  .requiredOption("--input <String>", "Input file.")
+  .description("Processes different web server logs to determine request chain frequency.")
+  .version(0.1);
+
+program.parse();
+const OPTS = program.opts();
+OPTS.min = parseInt(OPTS.min);
+
+assert(!isNaN(OPTS.min), `min must be a number, you have ${OPTS.min}`);
+
+const [by_ip, stats] = await parse_logs(OPTS.input, OPTS.errors);
+const chains_sorted = sort_request_chains(by_ip, OPTS.set);
+output_results(OPTS.min, chains_sorted);