Take three for as.POSIXct() on R (< 4.3.0)

Author: HenrikBengtsson

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: future.p2p
 Title: A Peer-to-Peer Compute Cluster via Futureverse
-Version: 0.3.0-9031
+Version: 0.3.0-9032
 Description: Implementation of the 'Future' API <doi:10.32614/RJ-2021-048> that resolves futures on a peer-to-peer ('P2P') compute environment. By using this future backend, you and your friends can share your spare compute resources with each other.
 Imports:
     future (>= 1.67.0),

R/host_cluster.R

@@ -56,7 +56,7 @@ host_cluster <- function(cluster = p2p_cluster_name(users, host = host, ssh_args
   now <- pico_p2p_time()
 
   expires <- pico_p2p_time(delta = duration)
-  duration <- difftime(duration, 0)
+  duration <- difftime2(duration, 0)
 
   info("Launch p2p cluster %s for %d users (%s) until %s (%s)", sQuote(cluster), length(users), commaq(users), format(Sys.time() + duration), format(duration))
   topic <- sprintf("%s/future.p2p", cluster_name)

R/utils-basic.R

@@ -91,6 +91,19 @@ hexpr <- function(expr, trim = TRUE, collapse = "; ", maxHead = 6L, maxTail = 3L
 } # hexpr()
 
 
+## Backporting for R (< 4.3.0)
 as_POSIXct <- function(x, tz = "", origin = as.POSIXct("1970-01-01", tz = "GMT"), ...) {
   as.POSIXct(x, tz = tz, origin = origin, ...)
 }
+
+difftime2 <- function(time1, time2, tz, ..., origin = as.POSIXct("1970-01-01", tz = "GMT")) {
+  if (missing(tz)) {
+    time1 <- as.POSIXct(time1, origin = origin)
+    time2 <- as.POSIXct(time2, origin = origin)
+  } else {
+    time1 <- as.POSIXct(time1, tz = tz, origin = origin)
+    time2 <- as.POSIXct(time2, tz = tz, origin = origin)
+  }
+
+  difftime(time1, time2, ...)
+}

R/waitForWorker.R

@@ -52,7 +52,7 @@ waitForWorker <- function(type,
     await()
 
     iter <- iter + 1L
-    dt <- difftime(Sys.time(), t0)
+    dt <- difftime2(Sys.time(), t0)
   }
 
   if (!finished) {

R/worker.R

@@ -370,7 +370,7 @@ run_worker <- function(cluster, worker_id, host, ssh_args, duration, channels) {
   now <- pico_p2p_time()
 
   expires <- pico_p2p_time(delta = duration)
-  duration <- difftime(duration, 0)
+  duration <- difftime2(duration, 0)
 
   info("get 'wormhole'")
   bin <- find_wormhole()
@@ -432,7 +432,7 @@ run_worker <- function(cluster, worker_id, host, ssh_args, duration, channels) {
       dt <- system.time({
         res <- pico_p2p_receive_future(p, via = via)
       })
-      dt <- difftime(dt[3], 0)
+      dt <- difftime2(dt[3], 0)
       info("Future %s received in %s", sQuote(future), format(dt))
 
       f <- res[["future"]]
@@ -443,7 +443,7 @@ run_worker <- function(cluster, worker_id, host, ssh_args, duration, channels) {
       dt <- system.time({
         r <- tryCatch({ result(f) }, error = identity)  ## Note, result() handles 'interrupt':s
       })
-      dt <- difftime(dt[3], 0)
+      dt <- difftime2(dt[3], 0)
       info("Future %s resolved after %s", sQuote(future), format(dt))
       tx_parent("resolved")
 
@@ -453,7 +453,7 @@ run_worker <- function(cluster, worker_id, host, ssh_args, duration, channels) {
       dt <- system.time({
         pico_p2p_send_result(p, future = f, to = client, via = via)
       })
-      dt <- difftime(dt[3], 0)
+      dt <- difftime2(dt[3], 0)
       info("future result %s sent in %s", sQuote(future), format(dt))
       tx_parent("ready")
       state <- "ready"