Add support for TTL

cli/src/main/scala-2.11/coursier/cli/Helper.scala

@@ -10,6 +10,8 @@ import coursier.ivy.IvyRepository
 import coursier.util.{Print, Parse}
 
 import scala.annotation.tailrec
+import scala.concurrent.duration.{ Duration, FiniteDuration }
+
 import scalaz.{Failure, Success, \/-, -\/}
 import scalaz.concurrent.{ Task, Strategy }
 
@@ -80,15 +82,35 @@ class Helper(
 
   import Util._
 
-  val cachePoliciesValidation = CacheParse.cachePolicies(common.mode)
+  val ttl0 =
+    if (ttl.isEmpty)
+      Cache.defaultTtl
+    else {
+      val d = try {
+        Duration(ttl)
+      } catch {
+        case e: Exception =>
+          prematureExit(s"Unrecognized TTL duration: $ttl")
+      }
 
-  val cachePolicies = cachePoliciesValidation match {
-    case Success(cp) => cp
-    case Failure(errors) =>
-      prematureExit(
-        s"Error parsing modes:\n${errors.list.map("  "+_).mkString("\n")}"
-      )
-  }
+      d match {
+        case f: FiniteDuration => Some(f)
+        case _ =>
+          prematureExit(s"Non finite TTL duration: $ttl")
+      }
+    }
+
+  val cachePolicies =
+    if (common.mode.isEmpty)
+      CachePolicy.default
+    else
+      CacheParse.cachePolicies(common.mode) match {
+        case Success(cp) => cp
+        case Failure(errors) =>
+          prematureExit(
+            s"Error parsing modes:\n${errors.list.map("  "+_).mkString("\n")}"
+          )
+      }
 
   val cache = new File(cacheOptions.cache)
 
@@ -279,7 +301,7 @@ class Helper(
       None
 
   val fetchs = cachePolicies.map(p =>
-    Cache.fetch(cache, p, checksums = checksums, logger = logger, pool = pool)
+    Cache.fetch(cache, p, checksums = checksums, logger = logger, pool = pool, ttl = ttl0)
   )
   val fetchQuiet = coursier.Fetch.from(
     repositories,
@@ -524,11 +546,21 @@ class Helper(
     if (verbosityLevel >= 1 && artifacts0.nonEmpty)
       println(s"  Found ${artifacts0.length} artifacts")
 
-    val tasks = artifacts0.map(artifact =>
-      (Cache.file(artifact, cache, cachePolicies.head, checksums = checksums, logger = logger, pool = pool) /: cachePolicies.tail)(
-        _ orElse Cache.file(artifact, cache, _, checksums = checksums, logger = logger, pool = pool)
-      ).run.map(artifact.->)
-    )
+    val tasks = artifacts0.map { artifact =>
+      def file(policy: CachePolicy) = Cache.file(
+        artifact,
+        cache,
+        policy,
+        checksums = checksums,
+        logger = logger,
+        pool = pool,
+        ttl = ttl0
+      )
+
+      (file(cachePolicies.head) /: cachePolicies.tail)(_ orElse file(_))
+        .run
+        .map(artifact.->)
+    }
 
     logger.foreach(_.init())
 

cli/src/main/scala-2.11/coursier/cli/Options.scala

@@ -11,7 +11,11 @@ case class CommonOptions(
   @Help("Download mode (default: missing, that is fetch things missing from cache)")
   @Value("offline|update-changing|update|missing|force")
   @Short("m")
-    mode: String = "default",
+    mode: String = "",
+  @Help("TTL duration (e.g. \"24 hours\")")
+  @Value("duration")
+  @Short("l")
+    ttl: String,
   @Help("Quiet output")
   @Short("q")
     quiet: Boolean,