AU: ApplyMap utility function
ApplyMap takes a vector<ValueType> and a map of
ValueType->ValueType. For each object in the collection that is a key
in the map, replace that element with the corresponding value in the
map.
E.g. ApplyMap({1, 2, 3, 4, 5}, {3->6, 5->7, 8->10}) changes the
collection to be: {1, 2, 6, 4, 7}.
BUG=7294
TEST=attached unittest
Review URL: http://codereview.chromium.org/3530011
diff --git a/utils.h b/utils.h
index a46ffef..bfe7378 100644
--- a/utils.h
+++ b/utils.h
@@ -182,6 +182,19 @@
}
}
+template<typename ValueType>
+void ApplyMap(std::vector<ValueType>* collection,
+ const std::map<ValueType, ValueType>& the_map) {
+ for (typename std::vector<ValueType>::iterator it = collection->begin();
+ it != collection->end(); ++it) {
+ typename std::map<ValueType, ValueType>::const_iterator map_it =
+ the_map.find(*it);
+ if (map_it != the_map.end()) {
+ *it = map_it->second;
+ }
+ }
+}
+
// Returns the currently booted device. "/dev/sda3", for example.
// This will not interpret LABEL= or UUID=. You'll need to use findfs
// or something with equivalent funcionality to interpret those.
diff --git a/utils_unittest.cc b/utils_unittest.cc
index 3514f8a..a5550d3 100644
--- a/utils_unittest.cc
+++ b/utils_unittest.cc
@@ -6,12 +6,14 @@
#include <sys/types.h>
#include <errno.h>
+#include <map>
#include <string>
#include <vector>
#include "gtest/gtest.h"
#include "update_engine/utils.h"
+using std::map;
using std::string;
using std::vector;
@@ -183,4 +185,24 @@
}
}
+TEST(UtilsTest, ApplyMapTest) {
+ int initial_values[] = {1, 2, 3, 4, 6};
+ vector<int> collection(&initial_values[0],
+ initial_values + arraysize(initial_values));
+ EXPECT_EQ(arraysize(initial_values), collection.size());
+ int expected_values[] = {1, 2, 5, 4, 8};
+ map<int, int> value_map;
+ value_map[3] = 5;
+ value_map[6] = 8;
+ value_map[5] = 10;
+
+ utils::ApplyMap(&collection, value_map);
+
+ size_t index = 0;
+ for (vector<int>::iterator it = collection.begin(), e = collection.end();
+ it != e; ++it) {
+ EXPECT_EQ(expected_values[index++], *it);
+ }
+}
+
} // namespace chromeos_update_engine