| 1 | /* -*-scala-*- |
| 2 | * |
| 3 | * Miscellaneous utilities |
| 4 | * |
| 5 | * (c) 2018 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 9 | * |
| 10 | * This file is part of the Trivial IP Encryption (TrIPE) Android app. |
| 11 | * |
| 12 | * TrIPE is free software: you can redistribute it and/or modify it under |
| 13 | * the terms of the GNU General Public License as published by the Free |
| 14 | * Software Foundation; either version 3 of the License, or (at your |
| 15 | * option) any later version. |
| 16 | * |
| 17 | * TrIPE is distributed in the hope that it will be useful, but WITHOUT |
| 18 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 19 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 20 | * for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License |
| 23 | * along with TrIPE. If not, see <https://www.gnu.org/licenses/>. |
| 24 | */ |
| 25 | |
| 26 | package uk.org.distorted; package object tripe { |
| 27 | |
| 28 | /*----- Imports -----------------------------------------------------------*/ |
| 29 | |
| 30 | import scala.concurrent.duration.{Deadline, Duration}; |
| 31 | import scala.util.control.{Breaks, ControlThrowable}; |
| 32 | |
| 33 | import java.io.{BufferedReader, Closeable, File, InputStream, Reader}; |
| 34 | import java.net.{HttpURLConnection, URL, URLConnection}; |
| 35 | import java.nio.{ByteBuffer, CharBuffer}; |
| 36 | import java.nio.channels.{SelectionKey, Selector}; |
| 37 | import java.nio.channels.spi.{AbstractSelector, AbstractSelectableChannel}; |
| 38 | import java.nio.charset.Charset; |
| 39 | import java.text.SimpleDateFormat; |
| 40 | import java.util.{Set => JSet}; |
| 41 | import java.util.concurrent.locks.{Lock, ReentrantLock}; |
| 42 | |
| 43 | /*----- Miscellaneous useful things ---------------------------------------*/ |
| 44 | |
| 45 | val rng = new java.security.SecureRandom; |
| 46 | |
| 47 | def unreachable(msg: String): Nothing = throw new AssertionError(msg); |
| 48 | def unreachable(): Nothing = unreachable("unreachable"); |
| 49 | final val ok = (); |
| 50 | final class Brand; |
| 51 | |
| 52 | /*----- Various pieces of implicit magic ----------------------------------*/ |
| 53 | |
| 54 | class InvalidCStringException(msg: String) extends Exception(msg); |
| 55 | |
| 56 | object Implicits { |
| 57 | |
| 58 | /* --- Syntactic sugar for locks --- */ |
| 59 | |
| 60 | implicit class LockOps(lk: Lock) { |
| 61 | /* LK withLock { BODY } |
| 62 | * LK.withLock(INTERRUPT) { BODY } |
| 63 | * LK.withLock(DUR, [INTERRUPT]) { BODY } orElse { ALT } |
| 64 | * LK.withLock(DL, [INTERRUPT]) { BODY } orElse { ALT } |
| 65 | * |
| 66 | * Acquire a lock while executing a BODY. If a duration or deadline is |
| 67 | * given then wait so long for the lock, and then give up and run ALT |
| 68 | * instead. |
| 69 | */ |
| 70 | |
| 71 | def withLock[T](dur: Duration, interrupt: Boolean) |
| 72 | (body: => T): PendingLock[T] = |
| 73 | new PendingLock(lk, if (dur > Duration.Zero) dur else Duration.Zero, |
| 74 | interrupt, body); |
| 75 | def withLock[T](dur: Duration)(body: => T): PendingLock[T] = |
| 76 | withLock(dur, true)(body); |
| 77 | def withLock[T](dl: Deadline, interrupt: Boolean) |
| 78 | (body: => T): PendingLock[T] = |
| 79 | new PendingLock(lk, dl.timeLeft, interrupt, body); |
| 80 | def withLock[T](dl: Deadline)(body: => T): PendingLock[T] = |
| 81 | withLock(dl, true)(body); |
| 82 | def withLock[T](interrupt: Boolean)(body: => T): T = { |
| 83 | if (interrupt) lk.lockInterruptibly(); |
| 84 | else lk.lock(); |
| 85 | try { body; } finally lk.unlock(); |
| 86 | } |
| 87 | def withLock[T](body: => T): T = withLock(true)(body); |
| 88 | } |
| 89 | |
| 90 | class PendingLock[T] private[Implicits] |
| 91 | (val lk: Lock, val dur: Duration, |
| 92 | val interrupt: Boolean, body: => T) { |
| 93 | /* An auxiliary class for LockOps; provides the `orElse' qualifier. */ |
| 94 | |
| 95 | def orElse(alt: => T): T = { |
| 96 | val locked = (dur, interrupt) match { |
| 97 | case (Duration.Inf, true) => lk.lockInterruptibly(); true |
| 98 | case (Duration.Inf, false) => lk.lock(); true |
| 99 | case (Duration.Zero, false) => lk.tryLock() |
| 100 | case (_, true) => lk.tryLock(dur.length, dur.unit) |
| 101 | case _ => unreachable("timed wait is always interruptible"); |
| 102 | } |
| 103 | if (!locked) alt; |
| 104 | else try { body; } finally lk.unlock(); |
| 105 | } |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | /*----- Cleanup assistant -------------------------------------------------*/ |
| 110 | |
| 111 | class Cleaner { |
| 112 | /* A helper class for avoiding deep nests of `try'/`finally'. |
| 113 | * |
| 114 | * Make a `Cleaner' instance CL at the start of your operation. Apply it |
| 115 | * to blocks of code -- as CL { ACTION } -- as you proceed, to accumulate |
| 116 | * cleanup actions. Finally, call CL.cleanup() to invoke the accumulated |
| 117 | * actions, in reverse order. |
| 118 | */ |
| 119 | |
| 120 | var cleanups: List[() => Unit] = Nil; |
| 121 | def apply(cleanup: => Unit) { cleanups +:= { () => cleanup; } } |
| 122 | def cleanup() { cleanups foreach { _() } } |
| 123 | } |
| 124 | |
| 125 | def withCleaner[T](body: Cleaner => T): T = { |
| 126 | /* An easier way to use the `Cleaner' class. Just |
| 127 | * |
| 128 | * withCleaner { CL => BODY } |
| 129 | * |
| 130 | * The BODY can attach cleanup actions to the cleaner CL by saying |
| 131 | * CL { ACTION } as usual. When the BODY exits, normally or otherwise, the |
| 132 | * cleanup actions are invoked in reverse order. |
| 133 | */ |
| 134 | |
| 135 | val cleaner = new Cleaner; |
| 136 | try { body(cleaner) } |
| 137 | finally { cleaner.cleanup(); } |
| 138 | } |
| 139 | |
| 140 | def closing[T, U <: Closeable](thing: U)(body: U => T): T = |
| 141 | try { body(thing) } |
| 142 | finally { thing.close(); } |
| 143 | |
| 144 | /*----- Control structures ------------------------------------------------*/ |
| 145 | |
| 146 | private case class ExitBlock[T](brand: Brand, result: T) |
| 147 | extends ControlThrowable; |
| 148 | |
| 149 | def block[T](body: (T => Nothing) => T): T = { |
| 150 | /* block { exit[T] => ...; exit(x); ... } |
| 151 | * |
| 152 | * Execute the body until it calls the `exit' function or finishes. |
| 153 | * Annoyingly, Scala isn't clever enough to infer the return type, so |
| 154 | * you'll have to write it explicitly. |
| 155 | */ |
| 156 | |
| 157 | val mybrand = new Brand; |
| 158 | try { body { result => throw new ExitBlock(mybrand, result) } } |
| 159 | catch { |
| 160 | case ExitBlock(brand, result) if brand eq mybrand => |
| 161 | result.asInstanceOf[T] |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | def blockUnit(body: (=> Nothing) => Unit) { |
| 166 | /* blockUnit { exit => ...; exit; ... } |
| 167 | * |
| 168 | * Like `block'; it just saves you having to write `exit[Unit] => ...; |
| 169 | * exit(ok); ...'. |
| 170 | */ |
| 171 | |
| 172 | val mybrand = new Brand; |
| 173 | try { body { throw new ExitBlock(mybrand, null) }; } |
| 174 | catch { case ExitBlock(brand, result) if brand eq mybrand => ok; } |
| 175 | } |
| 176 | |
| 177 | def loop[T](body: (T => Nothing) => Unit): T = { |
| 178 | /* loop { exit[T] => ...; exit(x); ... } |
| 179 | * |
| 180 | * Repeatedly execute the body until it calls the `exit' function. |
| 181 | * Annoyingly, Scala isn't clever enough to infer the return type, so |
| 182 | * you'll have to write it explicitly. |
| 183 | */ |
| 184 | |
| 185 | block { exit => while (true) body(exit); unreachable } |
| 186 | } |
| 187 | |
| 188 | def loopUnit(body: (=> Nothing) => Unit): Unit = { |
| 189 | /* loopUnit { exit => ...; exit; ... } |
| 190 | * |
| 191 | * Like `loop'; it just saves you having to write `exit[Unit] => ...; |
| 192 | * exit(()); ...'. |
| 193 | */ |
| 194 | |
| 195 | blockUnit { exit => while (true) body(exit); } |
| 196 | } |
| 197 | |
| 198 | val BREAKS = new Breaks; |
| 199 | import BREAKS.{breakable, break}; |
| 200 | |
| 201 | /*----- Interruptably doing things ----------------------------------------*/ |
| 202 | |
| 203 | private class InterruptCatcher[T](body: => T, onWakeup: => Unit) |
| 204 | extends AbstractSelector(null) { |
| 205 | /* Hook onto the VM's thread interruption machinery. |
| 206 | * |
| 207 | * The `run' method is the only really interesting one. It will run the |
| 208 | * BODY, returning its result; if the thread is interrupted during this |
| 209 | * time, ONWAKEUP is invoked for effect. The expectation is that ONWAKEUP |
| 210 | * will somehow cause BODY to stop early. |
| 211 | * |
| 212 | * Credit for this hack goes to Nicholas Wilson: see |
| 213 | * <https://github.com/NWilson/javaInterruptHook>. |
| 214 | */ |
| 215 | |
| 216 | private def nope: Nothing = |
| 217 | { throw new UnsupportedOperationException("can't do that"); } |
| 218 | protected def implCloseSelector() { } |
| 219 | protected def register(chan: AbstractSelectableChannel, |
| 220 | ops: Int, att: Any): SelectionKey = nope; |
| 221 | def keys(): JSet[SelectionKey] = nope; |
| 222 | def selectedKeys(): JSet[SelectionKey] = nope; |
| 223 | def select(): Int = nope; |
| 224 | def select(millis: Long): Int = nope; |
| 225 | def selectNow(): Int = nope; |
| 226 | |
| 227 | def run(): T = try { |
| 228 | begin(); |
| 229 | val ret = body; |
| 230 | if (Thread.interrupted()) throw new InterruptedException; |
| 231 | ret |
| 232 | } finally { |
| 233 | end(); |
| 234 | } |
| 235 | def wakeup(): Selector = { onWakeup; this } |
| 236 | } |
| 237 | |
| 238 | class PendingInterruptable[T] private[tripe](body: => T) { |
| 239 | /* This class exists to provide the `onInterrupt THUNK' syntax. */ |
| 240 | |
| 241 | def onInterrupt(thunk: => Unit): T = |
| 242 | new InterruptCatcher(body, thunk).run(); |
| 243 | } |
| 244 | def interruptably[T](body: => T) = { |
| 245 | /* interruptably { BODY } onInterrupt { THUNK } |
| 246 | * |
| 247 | * Execute BODY and return its result. If the thread receives an |
| 248 | * interrupt -- or is already in an interrupted state -- execute THUNK for |
| 249 | * effect; it is expected to cause BODY to return expeditiously, and when |
| 250 | * the BODY completes, an `InterruptedException' is thrown. |
| 251 | */ |
| 252 | |
| 253 | new PendingInterruptable(body); |
| 254 | } |
| 255 | |
| 256 | /*----- A gadget for fetching URLs ----------------------------------------*/ |
| 257 | |
| 258 | class URLFetchException(msg: String) extends Exception(msg); |
| 259 | |
| 260 | trait URLFetchCallbacks { |
| 261 | def preflight(conn: URLConnection) { } |
| 262 | def write(buf: Array[Byte], n: Int, len: Long): Unit; |
| 263 | def done(win: Boolean) { } |
| 264 | } |
| 265 | |
| 266 | def fetchURL(url: URL, cb: URLFetchCallbacks) { |
| 267 | /* Fetch the URL, feeding the data through the callbacks CB. */ |
| 268 | |
| 269 | withCleaner { clean => |
| 270 | var win: Boolean = false; clean { cb.done(win); } |
| 271 | |
| 272 | /* Set up the connection. This isn't going to block, I think, and we |
| 273 | * need to use it in the interrupt handler. |
| 274 | */ |
| 275 | val c = url.openConnection(); |
| 276 | |
| 277 | /* Java's default URL handlers don't respond to interrupts, so we have to |
| 278 | * take over this duty. |
| 279 | */ |
| 280 | interruptably { |
| 281 | /* Run the caller's preflight check. This must be done here, since it |
| 282 | * might well block while it discovers things like the content length. |
| 283 | */ |
| 284 | cb.preflight(c); |
| 285 | |
| 286 | /* Start fetching data. */ |
| 287 | val in = c.getInputStream; clean { in.close(); } |
| 288 | val explen = c.getContentLength; |
| 289 | |
| 290 | /* Read a buffer at a time, and give it to the callback. Maintain a |
| 291 | * running total. |
| 292 | */ |
| 293 | var len: Long = 0; |
| 294 | blockUnit { exit => |
| 295 | for ((buf, n) <- blocks(in)) { |
| 296 | cb.write(buf, n, len); |
| 297 | len += n; |
| 298 | if (explen != -1 && len > explen) exit; |
| 299 | } |
| 300 | } |
| 301 | |
| 302 | /* I can't find it documented anywhere that the existing machinery |
| 303 | * checks the received stream against the advertised content length. |
| 304 | * It doesn't hurt to check again, anyway. |
| 305 | */ |
| 306 | if (explen != -1 && explen != len) { |
| 307 | throw new URLFetchException( |
| 308 | s"received $len /= $explen bytes from `$url'"); |
| 309 | } |
| 310 | |
| 311 | /* Glorious success is ours. */ |
| 312 | win = true; |
| 313 | } onInterrupt { |
| 314 | /* Oh. How do we do this? */ |
| 315 | |
| 316 | c match { |
| 317 | case c: HttpURLConnection => |
| 318 | /* It's an HTTP connection (what happened to the case here?). |
| 319 | * HTTPS connections match too because they're a subclass. Getting |
| 320 | * the input stream will block, but there's an easier way. |
| 321 | */ |
| 322 | c.disconnect(); |
| 323 | |
| 324 | case _ => |
| 325 | /* It's something else. Let's hope that getting the input stream |
| 326 | * doesn't block. |
| 327 | */ |
| 328 | c.getInputStream.close(); |
| 329 | } |
| 330 | } |
| 331 | } |
| 332 | } |
| 333 | |
| 334 | /*----- Threading things --------------------------------------------------*/ |
| 335 | |
| 336 | def thread(name: String, run: Boolean = true, daemon: Boolean = true) |
| 337 | (f: => Unit): Thread = { |
| 338 | /* Make a thread with a given name, and maybe start running it. */ |
| 339 | |
| 340 | val t = new Thread(new Runnable { def run() { f; } }, name); |
| 341 | if (daemon) t.setDaemon(true); |
| 342 | if (run) t.start(); |
| 343 | t |
| 344 | } |
| 345 | |
| 346 | class ValueThread[T](name: String, group: ThreadGroup = null, |
| 347 | stacksz: Long = 0)(body: => T) |
| 348 | extends Thread(group, null, name, stacksz) { |
| 349 | private[this] var exc: Throwable = _; |
| 350 | private[this] var ret: T = _; |
| 351 | |
| 352 | override def run() { |
| 353 | try { ret = body; } |
| 354 | catch { case e: Throwable => exc = e; } |
| 355 | } |
| 356 | def get: T = |
| 357 | if (isAlive) throw new IllegalArgumentException("still running"); |
| 358 | else if (exc != null) throw exc; |
| 359 | else ret; |
| 360 | } |
| 361 | def valueThread[T](name: String, run: Boolean = true) |
| 362 | (body: => T): ValueThread[T] = { |
| 363 | val t = new ValueThread(name)(body); |
| 364 | if (run) t.start(); |
| 365 | t |
| 366 | } |
| 367 | |
| 368 | /*----- Quoting and parsing tokens ----------------------------------------*/ |
| 369 | |
| 370 | def quoteTokens(v: Seq[String]): String = { |
| 371 | /* Return a string representing the token sequence V. |
| 372 | * |
| 373 | * The tokens are quoted as necessary. |
| 374 | */ |
| 375 | |
| 376 | val b = new StringBuilder; |
| 377 | var sep = false; |
| 378 | for (s <- v) { |
| 379 | |
| 380 | /* If this isn't the first word, then write a separating space. */ |
| 381 | if (!sep) sep = true; |
| 382 | else b += ' '; |
| 383 | |
| 384 | /* Decide how to handle this token. */ |
| 385 | if (s.length > 0 && |
| 386 | (s forall { ch => (ch != ''' && ch != '"' && ch != '\\' && |
| 387 | !ch.isWhitespace) })) { |
| 388 | /* If this word is nonempty and contains no problematic characters, |
| 389 | * we can write it literally. |
| 390 | */ |
| 391 | |
| 392 | b ++= s; |
| 393 | } else { |
| 394 | /* Otherwise, we shall have to do this the hard way. We could be |
| 395 | * cleverer about this, but it's not worth the effort. |
| 396 | */ |
| 397 | |
| 398 | b += '"'; |
| 399 | s foreach { ch => |
| 400 | if (ch == '"' || ch == '\\') b += '\\'; |
| 401 | b += ch; |
| 402 | } |
| 403 | b += '"'; |
| 404 | } |
| 405 | } |
| 406 | b.result |
| 407 | } |
| 408 | |
| 409 | class InvalidQuotingException(msg: String) extends Exception(msg); |
| 410 | |
| 411 | def nextToken(s: String, pos: Int = 0): Option[(String, Int)] = { |
| 412 | /* Parse the next token from a string S. |
| 413 | * |
| 414 | * If there is a token in S starting at or after index POS, then return |
| 415 | * it, and the index for the following token; otherwise return `None'. |
| 416 | */ |
| 417 | |
| 418 | val b = new StringBuilder; |
| 419 | val n = s.length; |
| 420 | var i = pos; |
| 421 | var q = 0; |
| 422 | |
| 423 | /* Skip whitespace while we find the next token. */ |
| 424 | while (i < n && s(i).isWhitespace) i += 1; |
| 425 | |
| 426 | /* Maybe there just isn't anything to find. */ |
| 427 | if (i >= n) return None; |
| 428 | |
| 429 | /* There is something there. Unpick the quoting and escaping. */ |
| 430 | while (i < n && (q != 0 || !s(i).isWhitespace)) { |
| 431 | s(i) match { |
| 432 | case '\\' => |
| 433 | if (i + 1 >= n) throw new InvalidQuotingException("trailing `\\'"); |
| 434 | b += s(i + 1); i += 2; |
| 435 | case ch@('"' | ''') => |
| 436 | if (q == 0) q = ch; |
| 437 | else if (q == ch) q = 0; |
| 438 | else b += ch; |
| 439 | i += 1; |
| 440 | case ch => |
| 441 | b += ch; |
| 442 | i += 1; |
| 443 | } |
| 444 | } |
| 445 | |
| 446 | /* Check that the quoting was valid. */ |
| 447 | if (q != 0) throw new InvalidQuotingException(s"unmatched `$q'"); |
| 448 | |
| 449 | /* Skip whitespace before the next token. */ |
| 450 | while (i < n && s(i).isWhitespace) i += 1; |
| 451 | |
| 452 | /* We're done. */ |
| 453 | Some((b.result, i)) |
| 454 | } |
| 455 | |
| 456 | def splitTokens(s: String, pos: Int = 0): Seq[String] = { |
| 457 | /* Return all of the tokens in string S into tokens, starting at POS. */ |
| 458 | |
| 459 | val b = List.newBuilder[String]; |
| 460 | var i = pos; |
| 461 | |
| 462 | loopUnit { exit => nextToken(s, i) match { |
| 463 | case Some((w, j)) => b += w; i = j; |
| 464 | case None => exit; |
| 465 | } } |
| 466 | b.result |
| 467 | } |
| 468 | |
| 469 | /*----- Other random things -----------------------------------------------*/ |
| 470 | |
| 471 | trait LookaheadIterator[T] extends BufferedIterator[T] { |
| 472 | /* An iterator in terms of a single `maybe there's another item' function. |
| 473 | * |
| 474 | * It seems like every time I write an iterator in Scala, the only way to |
| 475 | * find out whether there's a next item, for `hasNext', is to actually try |
| 476 | * to fetch it. So here's an iterator in terms of a function which goes |
| 477 | * off and maybe returns a next thing. It turns out to be easy to satisfy |
| 478 | * the additional requirements for `BufferedIterator', so why not? |
| 479 | */ |
| 480 | |
| 481 | /* Subclass responsibility. */ |
| 482 | protected def fetch(): Option[T]; |
| 483 | |
| 484 | /* The machinery. `st' is `None' if there's no current item, null if we've |
| 485 | * actually hit the end, or `Some(x)' if the current item is x. |
| 486 | */ |
| 487 | private[this] var st: Option[T] = None; |
| 488 | private[this] def peek() { |
| 489 | /* Arrange to have a current item. */ |
| 490 | if (st == None) fetch() match { |
| 491 | case None => st = null; |
| 492 | case x@Some(_) => st = x; |
| 493 | } |
| 494 | } |
| 495 | |
| 496 | /* The `BufferedIterator' protocol. */ |
| 497 | override def hasNext: Boolean = { peek(); st != null } |
| 498 | override def head: T = |
| 499 | { peek(); if (st == null) throw new NoSuchElementException; st.get } |
| 500 | override def next(): T = { val it = head; st = None; it } |
| 501 | } |
| 502 | |
| 503 | def bufferedReader(r: Reader): BufferedReader = r match { |
| 504 | case br: BufferedReader => br |
| 505 | case _ => new BufferedReader(r) |
| 506 | } |
| 507 | |
| 508 | def lines(r: BufferedReader): BufferedIterator[String] = |
| 509 | new LookaheadIterator[String] { |
| 510 | /* Iterates over the lines of text in a `Reader' object. */ |
| 511 | override protected def fetch() = Option(r.readLine()); |
| 512 | } |
| 513 | def lines(r: Reader): BufferedIterator[String] = lines(bufferedReader(r)); |
| 514 | |
| 515 | def blocks(in: InputStream, blksz: Int): |
| 516 | BufferedIterator[(Array[Byte], Int)] = |
| 517 | /* Iterates over (possibly irregularly sized) blocks in a stream. */ |
| 518 | new LookaheadIterator[(Array[Byte], Int)] { |
| 519 | val buf = new Array[Byte](blksz) |
| 520 | override protected def fetch() = { |
| 521 | val n = in.read(buf); |
| 522 | if (n < 0) None |
| 523 | else Some((buf, n)) |
| 524 | } |
| 525 | } |
| 526 | def blocks(in: InputStream): |
| 527 | BufferedIterator[(Array[Byte], Int)] = blocks(in, 65536); |
| 528 | |
| 529 | def blocks(in: BufferedReader, blksz: Int): |
| 530 | BufferedIterator[(Array[Char], Int)] = |
| 531 | /* Iterates over (possibly irregularly sized) blocks in a reader. */ |
| 532 | new LookaheadIterator[(Array[Char], Int)] { |
| 533 | val buf = new Array[Char](blksz) |
| 534 | override protected def fetch() = { |
| 535 | val n = in.read(buf); |
| 536 | if (n < 0) None |
| 537 | else Some((buf, n)) |
| 538 | } |
| 539 | } |
| 540 | def blocks(in: BufferedReader): |
| 541 | BufferedIterator[(Array[Char], Int)] = blocks(in, 65536); |
| 542 | def blocks(r: Reader, blksz: Int): BufferedIterator[(Array[Char], Int)] = |
| 543 | blocks(bufferedReader(r), blksz); |
| 544 | def blocks(r: Reader): BufferedIterator[(Array[Char], Int)] = |
| 545 | blocks(bufferedReader(r)); |
| 546 | |
| 547 | def oxford(conj: String, things: Seq[String]): String = things match { |
| 548 | case Seq() => "<nothing>" |
| 549 | case Seq(a) => a |
| 550 | case Seq(a, b) => s"$a $conj $b" |
| 551 | case Seq(a, tail@_*) => |
| 552 | val sb = new StringBuilder; |
| 553 | sb ++= a; sb ++= ", "; |
| 554 | def iter(rest: Seq[String]) { |
| 555 | rest match { |
| 556 | case Seq() => unreachable; |
| 557 | case Seq(a) => sb ++= conj; sb += ' '; sb ++= a; |
| 558 | case Seq(a, tail@_*) => sb ++= a; sb ++= ", "; iter(tail); |
| 559 | } |
| 560 | } |
| 561 | iter(tail); |
| 562 | sb.result |
| 563 | } |
| 564 | |
| 565 | val datefmt = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss Z"); |
| 566 | |
| 567 | def formatDuration(t: Int): String = |
| 568 | if (t < -1) "???" |
| 569 | else { |
| 570 | val (s, t1) = (t%60, t/60); |
| 571 | val (m, h) = (t1%60, t1/60); |
| 572 | if (h > 0) f"$h%d:$m%02d:$s%02d" |
| 573 | else f"$m%02d:$s%02d" |
| 574 | } |
| 575 | |
| 576 | /*----- That's all, folks -------------------------------------------------*/ |
| 577 | |
| 578 | } |