Implement connect with timeout

Author: renkun-ken

.Rbuildignore

@@ -21,3 +21,4 @@
 ^docs$
 ^doc$
 ^Meta$
+^\.vscode$

.gitignore

@@ -17,3 +17,6 @@ autobrew
 docs/
 doc
 Meta
+.vscode/
+*.o
+*.so

R/config.R

@@ -23,6 +23,9 @@
 ##' \code{SELECT}.  Do not use in a redis clustering context.
 ##' (default: \code{NULL}; i.e., don't switch).}
 ##'
+##' \item{\code{timeout}}{The maximum number of milliseconds to wait for the
+##' connection to be established.  (default: \code{NULL}; i.e. wait forever).}
+##'
 ##' }
 ##'
 ##' The way that configuration options are resolved follows the design
@@ -70,7 +73,8 @@ redis_config <- function(..., config = list(...)) {
                 port = as.integer(Sys_getenv("REDIS_PORT", 6379L)),
                 path = NULL,
                 password = NULL,
-                db = NULL)
+                db = NULL,
+                timeout = NULL)
   dots <- list(...)
   if (length(dots) > 0L && !identical(dots, config)) {
     warning("Ignoring dots in favour of config")

R/redis.R

@@ -4,9 +4,9 @@
 ## from user code; see the functions in connection.R for what to use.
 redis_connect <- function(config) {
   if (config$scheme == "redis") {
-    ptr <- redis_connect_tcp(config$host, config$port)
+    ptr <- redis_connect_tcp(config$host, config$port, config$timeout)
   } else {
-    ptr <- redis_connect_unix(config$path)
+    ptr <- redis_connect_unix(config$path, config$timeout)
   }
   if (!is.null(config$password)) {
     redis_command(ptr, c("AUTH", config$password))
@@ -17,12 +17,12 @@ redis_connect <- function(config) {
   ptr
 }
 
-redis_connect_tcp <- function(host, port) {
-  .Call(Credux_redis_connect, host, as.integer(port))
+redis_connect_tcp <- function(host, port, timeout) {
+  .Call(Credux_redis_connect, host, as.integer(port), as.integer(timeout))
 }
 
-redis_connect_unix <- function(path) {
-  .Call(Credux_redis_connect_unix, path)
+redis_connect_unix <- function(path, timeout) {
+  .Call(Credux_redis_connect_unix, path, as.integer(timeout))
 }
 
 redis_command <- function(ptr, command) {

src/connection.c

@@ -5,10 +5,23 @@ static void redis_finalize(SEXP extPtr);
 char * string_duplicate(const char * x);
 
 // API functions first:
-SEXP redux_redis_connect(SEXP host, SEXP port) {
-  redisContext *context = redisConnect(CHAR(STRING_ELT(host, 0)),
-                                       INTEGER(port)[0]);
-  if (context == NULL) {
+SEXP redux_redis_connect(SEXP host, SEXP port, SEXP timeout) {
+  redisContext *context;
+  if (LENGTH(timeout) == 0)
+  {
+    context = redisConnect(CHAR(STRING_ELT(host, 0)),
+                 INTEGER(port)[0]);
+  }
+  else
+  {
+    int timeout_ms = INTEGER(timeout)[0];
+    struct timeval tvout = {timeout_ms / 1000,
+                            (timeout_ms % 1000) * 1000};
+    context = redisConnectWithTimeout(CHAR(STRING_ELT(host, 0)),
+                                      INTEGER(port)[0], tvout);
+  }
+  if (context == NULL)
+  {
     error("Creating context failed catastrophically [tcp]"); // # nocov
   }
   if (context->err != 0) {
@@ -22,9 +35,21 @@ SEXP redux_redis_connect(SEXP host, SEXP port) {
   return extPtr;
 }
 
-SEXP redux_redis_connect_unix(SEXP path) {
-  redisContext *context = redisConnectUnix(CHAR(STRING_ELT(path, 0)));
-  if (context == NULL) {
+SEXP redux_redis_connect_unix(SEXP path, SEXP timeout) {
+  redisContext *context;
+  if (LENGTH(timeout) == 0)
+  {
+    context = redisConnectUnix(CHAR(STRING_ELT(path, 0)));
+  }
+  else
+  {
+    int timeout_ms = INTEGER(timeout)[0];
+    struct timeval tvout = {timeout_ms / 1000,
+                            (timeout_ms % 1000) * 1000};
+    context = redisConnectUnixWithTimeout(CHAR(STRING_ELT(path, 0)), tvout);
+  }
+  if (context == NULL)
+  {
     error("Creating context failed catastrophically [unix]"); // # nocov
   }
   if (context->err != 0) {

src/connection.h

@@ -3,8 +3,8 @@
 #include <hiredis.h>
 #include <stdbool.h>
 
-SEXP redux_redis_connect(SEXP host, SEXP port);
-SEXP redux_redis_connect_unix(SEXP path);
+SEXP redux_redis_connect(SEXP host, SEXP port, SEXP timeout);
+SEXP redux_redis_connect_unix(SEXP path, SEXP timeout);
 
 SEXP redux_redis_command(SEXP extPtr, SEXP cmd);
 

src/registration.c

@@ -8,8 +8,8 @@
 #include <Rversion.h>
 
 static const R_CallMethodDef callMethods[] = {
-  {"Credux_redis_connect",       (DL_FUNC) &redux_redis_connect,        2},
-  {"Credux_redis_connect_unix",  (DL_FUNC) &redux_redis_connect_unix,   1},
+  {"Credux_redis_connect",       (DL_FUNC) &redux_redis_connect,        3},
+  {"Credux_redis_connect_unix",  (DL_FUNC) &redux_redis_connect_unix,   2},
 
   {"Credux_redis_command",       (DL_FUNC) &redux_redis_command,        2},