From ae41b5c4ac725d3bab6d3ab88f6b8444225c2e19 Mon Sep 17 00:00:00 2001
From: Shivaram Venkataraman <shivaram@cs.berkeley.edu>
Date: Fri, 22 May 2015 18:24:54 -0700
Subject: [PATCH] Remove native libraries from SparkR Also include the built
 SparkR package in make-distribution.sh

---
 R/pkg/NAMESPACE                              |  5 ++-
 R/pkg/R/utils.R                              | 38 +++++++++++++++++++-
 R/pkg/{src => src-native}/Makefile           |  0
 R/pkg/{src => src-native}/Makefile.win       |  0
 R/pkg/{src => src-native}/string_hash_code.c |  0
 make-distribution.sh                         |  2 ++
 6 files changed, 43 insertions(+), 2 deletions(-)
 rename R/pkg/{src => src-native}/Makefile (100%)
 rename R/pkg/{src => src-native}/Makefile.win (100%)
 rename R/pkg/{src => src-native}/string_hash_code.c (100%)

diff --git a/R/pkg/NAMESPACE b/R/pkg/NAMESPACE
index 64ffdcffc9caf..411126a377950 100644
--- a/R/pkg/NAMESPACE
+++ b/R/pkg/NAMESPACE
@@ -1,6 +1,9 @@
 # Imports from base R
 importFrom(methods, setGeneric, setMethod, setOldClass)
-useDynLib(SparkR, stringHashCode)
+
+# Disable native libraries till we figure out how to package it
+# See SPARKR-7839
+#useDynLib(SparkR, stringHashCode)
 
 # S3 methods exported
 export("sparkR.init")
diff --git a/R/pkg/R/utils.R b/R/pkg/R/utils.R
index 0e7b7bd5a5b34..69b2700191c9a 100644
--- a/R/pkg/R/utils.R
+++ b/R/pkg/R/utils.R
@@ -122,13 +122,49 @@ hashCode <- function(key) {
     intBits <- packBits(rawToBits(rawVec), "integer")
     as.integer(bitwXor(intBits[2], intBits[1]))
   } else if (class(key) == "character") {
-    .Call("stringHashCode", key)
+    # TODO: SPARK-7839 means we might not have the native library available
+    if (is.loaded("stringHashCode")) {
+      .Call("stringHashCode", key)
+    } else {
+      n <- nchar(key)
+      if (n == 0) {
+        0L
+      } else {
+        asciiVals <- sapply(charToRaw(key), function(x) { strtoi(x, 16L) })
+        hashC <- 0
+        for (k in 1:length(asciiVals)) {
+          hashC <- mult31AndAdd(hashC, asciiVals[k])
+        }
+        as.integer(hashC)
+      }
+    }
   } else {
     warning(paste("Could not hash object, returning 0", sep = ""))
     as.integer(0)
   }
 }
 
+# Helper function used to wrap a 'numeric' value to integer bounds.
+# Useful for implementing C-like integer arithmetic
+wrapInt <- function(value) {
+  if (value > .Machine$integer.max) {
+    value <- value - 2 * .Machine$integer.max - 2
+  } else if (value < -1 * .Machine$integer.max) {
+    value <- 2 * .Machine$integer.max + value + 2
+  }
+  value
+}
+
+# Multiply `val` by 31 and add `addVal` to the result. Ensures that
+# integer-overflows are handled at every step.
+mult31AndAdd <- function(val, addVal) {
+  vec <- c(bitwShiftL(val, c(4,3,2,1,0)), addVal)
+  Reduce(function(a, b) {
+          wrapInt(as.numeric(a) + as.numeric(b))
+         },
+         vec)
+}
+
 # Create a new RDD with serializedMode == "byte".
 # Return itself if already in "byte" format.
 serializeToBytes <- function(rdd) {
diff --git a/R/pkg/src/Makefile b/R/pkg/src-native/Makefile
similarity index 100%
rename from R/pkg/src/Makefile
rename to R/pkg/src-native/Makefile
diff --git a/R/pkg/src/Makefile.win b/R/pkg/src-native/Makefile.win
similarity index 100%
rename from R/pkg/src/Makefile.win
rename to R/pkg/src-native/Makefile.win
diff --git a/R/pkg/src/string_hash_code.c b/R/pkg/src-native/string_hash_code.c
similarity index 100%
rename from R/pkg/src/string_hash_code.c
rename to R/pkg/src-native/string_hash_code.c
diff --git a/make-distribution.sh b/make-distribution.sh
index 8d6e91d67593f..78827341b956c 100755
--- a/make-distribution.sh
+++ b/make-distribution.sh
@@ -229,6 +229,8 @@ cp "$SPARK_HOME"/conf/*.template "$DISTDIR"/conf
 cp "$SPARK_HOME/README.md" "$DISTDIR"
 cp -r "$SPARK_HOME/bin" "$DISTDIR"
 cp -r "$SPARK_HOME/python" "$DISTDIR"
+mkdir -p "$DISTDIR"/R/lib
+cp -r "$SPARK_HOME/R/lib/SparkR" "$DISTDIR"/R/lib
 cp -r "$SPARK_HOME/sbin" "$DISTDIR"
 cp -r "$SPARK_HOME/ec2" "$DISTDIR"