Commit | Line | Data |
---|---|---|
8eabb4ff MW |
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}; | |
c8292b34 | 31 | import scala.util.control.{Breaks, ControlThrowable}; |
8eabb4ff | 32 | |
c8292b34 | 33 | import java.io.{BufferedReader, Closeable, File, InputStream, Reader}; |
04a5abae | 34 | import java.net.{HttpURLConnection, URL, URLConnection}; |
8eabb4ff | 35 | import java.nio.{ByteBuffer, CharBuffer}; |
04a5abae MW |
36 | import java.nio.channels.{SelectionKey, Selector}; |
37 | import java.nio.channels.spi.{AbstractSelector, AbstractSelectableChannel}; | |
8eabb4ff | 38 | import java.nio.charset.Charset; |
a5ec891a | 39 | import java.text.SimpleDateFormat; |
04a5abae | 40 | import java.util.{Set => JSet}; |
8eabb4ff MW |
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); | |
c8292b34 MW |
48 | def unreachable(): Nothing = unreachable("unreachable"); |
49 | final val ok = (); | |
50 | final class Brand; | |
8eabb4ff MW |
51 | |
52 | /*----- Various pieces of implicit magic ----------------------------------*/ | |
53 | ||
54 | class InvalidCStringException(msg: String) extends Exception(msg); | |
8eabb4ff | 55 | |
25c35469 | 56 | object Implicits { |
8eabb4ff MW |
57 | |
58 | /* --- Syntactic sugar for locks --- */ | |
59 | ||
60 | implicit class LockOps(lk: Lock) { | |
61 | /* LK withLock { BODY } | |
62 | * LK.withLock(INTERRUPT) { BODY } | |
25c35469 MW |
63 | * LK.withLock(DUR, [INTERRUPT]) { BODY } orElse { ALT } |
64 | * LK.withLock(DL, [INTERRUPT]) { BODY } orElse { ALT } | |
8eabb4ff MW |
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 | ||
25c35469 | 90 | class PendingLock[T] private[Implicits] |
8eabb4ff MW |
91 | (val lk: Lock, val dur: Duration, |
92 | val interrupt: Boolean, body: => T) { | |
25c35469 | 93 | /* An auxiliary class for LockOps; provides the `orElse' qualifier. */ |
8eabb4ff | 94 | |
25c35469 | 95 | def orElse(alt: => T): T = { |
8eabb4ff MW |
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 | } | |
8eabb4ff MW |
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 | ||
c8292b34 MW |
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 | ||
04a5abae MW |
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 | ||
8eabb4ff MW |
256 | /*----- A gadget for fetching URLs ----------------------------------------*/ |
257 | ||
258 | class URLFetchException(msg: String) extends Exception(msg); | |
259 | ||
260 | trait URLFetchCallbacks { | |
261 | def preflight(conn: URLConnection) { } | |
c8292b34 | 262 | def write(buf: Array[Byte], n: Int, len: Long): Unit; |
8eabb4ff MW |
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 => | |
04a5abae | 270 | var win: Boolean = false; clean { cb.done(win); } |
8eabb4ff | 271 | |
04a5abae MW |
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 | */ | |
8eabb4ff | 275 | val c = url.openConnection(); |
8eabb4ff | 276 | |
04a5abae MW |
277 | /* Java's default URL handlers don't respond to interrupts, so we have to |
278 | * take over this duty. | |
8eabb4ff | 279 | */ |
04a5abae MW |
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 | } | |
c8292b34 | 300 | } |
8eabb4ff | 301 | |
04a5abae MW |
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 | } | |
8eabb4ff | 310 | |
04a5abae MW |
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 | } | |
8eabb4ff MW |
331 | } |
332 | } | |
333 | ||
8eabb4ff MW |
334 | /*----- Threading things --------------------------------------------------*/ |
335 | ||
04a5abae MW |
336 | def thread(name: String, run: Boolean = true, daemon: Boolean = true) |
337 | (f: => Unit): Thread = { | |
8eabb4ff MW |
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 | ||
04a5abae MW |
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 | ||
8eabb4ff MW |
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 | ||
c8292b34 MW |
462 | loopUnit { exit => nextToken(s, i) match { |
463 | case Some((w, j)) => b += w; i = j; | |
464 | case None => exit; | |
465 | } } | |
8eabb4ff MW |
466 | b.result |
467 | } | |
468 | ||
c8292b34 MW |
469 | /*----- Other random things -----------------------------------------------*/ |
470 | ||
8eabb4ff | 471 | trait LookaheadIterator[T] extends BufferedIterator[T] { |
c8292b34 MW |
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. */ | |
8eabb4ff | 482 | protected def fetch(): Option[T]; |
c8292b34 MW |
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; | |
8eabb4ff | 488 | private[this] def peek() { |
c8292b34 | 489 | /* Arrange to have a current item. */ |
8eabb4ff MW |
490 | if (st == None) fetch() match { |
491 | case None => st = null; | |
492 | case x@Some(_) => st = x; | |
493 | } | |
494 | } | |
c8292b34 MW |
495 | |
496 | /* The `BufferedIterator' protocol. */ | |
8eabb4ff | 497 | override def hasNext: Boolean = { peek(); st != null } |
c8292b34 | 498 | override def head: T = |
8eabb4ff | 499 | { peek(); if (st == null) throw new NoSuchElementException; st.get } |
c8292b34 | 500 | override def next(): T = { val it = head; st = None; it } |
8eabb4ff MW |
501 | } |
502 | ||
c8292b34 MW |
503 | def bufferedReader(r: Reader): BufferedReader = r match { |
504 | case br: BufferedReader => br | |
505 | case _ => new BufferedReader(r) | |
506 | } | |
8eabb4ff | 507 | |
c8292b34 MW |
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): | |
04a5abae | 527 | BufferedIterator[(Array[Byte], Int)] = blocks(in, 65536); |
c8292b34 MW |
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 | } | |
8eabb4ff | 539 | } |
c8292b34 | 540 | def blocks(in: BufferedReader): |
04a5abae | 541 | BufferedIterator[(Array[Char], Int)] = blocks(in, 65536); |
c8292b34 MW |
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 $b" | |
551 | case Seq(a, tail@_*) => | |
552 | val sb = new StringBuilder; | |
553 | sb ++= a; sb ++= ", "; | |
554 | def iter(rest: Seq[String]) { | |
555 | rest match { | |
556 | case Seq() => unreachable; | |
557 | case Seq(a) => sb ++= conj; sb += ' '; sb ++= a; | |
558 | case Seq(a, tail@_*) => sb ++= a; sb ++= ", "; iter(tail); | |
559 | } | |
560 | } | |
561 | iter(tail); | |
562 | sb.result | |
8eabb4ff MW |
563 | } |
564 | ||
a5ec891a MW |
565 | val datefmt = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss Z"); |
566 | ||
567 | def formatDuration(t: Int): String = | |
04a5abae MW |
568 | if (t < -1) "???" |
569 | else { | |
570 | val (s, t1) = (t%60, t/60); | |
571 | val (m, h) = (t1%60, t1/60); | |
572 | if (h > 0) f"$h%d:$m%02d:$s%02d" | |
573 | else f"$m%02d:$s%02d" | |
574 | } | |
575 | ||
8eabb4ff MW |
576 | /*----- That's all, folks -------------------------------------------------*/ |
577 | ||
578 | } |