Acquire first entry of type constants in BuilderTemplate

Current code is relying on xtend Conversions to get first entry
from keySet/values separately. That code ends up copying the entire
collection into an array before picking the first element, which
is ... far from optimal.

Peel the first entrySet item using iterator().next() and then
reference key/value from there, which removes a dependency on
Conversions and is way more efficient.

Change-Id: I9cf16c416e65e538697aab26ebb5b9a81965e871
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
(cherry picked from commit a27fbe05be80601723f60371ff4130bca16ca568)

diff --git a/binding/mdsal-binding-java-api-generator/src/main/java/org/opendaylight/mdsal/binding/java/api/generator/BuilderTemplate.xtend b/binding/mdsal-binding-java-api-generator/src/main/java/org/opendaylight/mdsal/binding/java/api/generator/BuilderTemplate.xtend
index 17f20843f2a30de1fc31029a820d81d076356698..29978c2992e8711c7a063cda3d852a8581101b54 100644 (file)
--- a/binding/mdsal-binding-java-api-generator/src/main/java/org/opendaylight/mdsal/binding/java/api/generator/BuilderTemplate.xtend
+++ b/binding/mdsal-binding-java-api-generator/src/main/java/org/opendaylight/mdsal/binding/java/api/generator/BuilderTemplate.xtend
@@ -247,8 +247,9 @@ class BuilderTemplate extends AbstractBuilderTemplate {
                 «val cValue = c.value as Map<String, String>»
                 «val String fieldSuffix = c.getName.substring(TypeConstants.PATTERN_CONSTANT_NAME.length)»
                 «IF cValue.size == 1»
-                   private static final «Pattern.importedName» «Constants.MEMBER_PATTERN_LIST»«fieldSuffix» = «Pattern.importedName».compile("«cValue.keySet.get(0).escapeJava»");
-                   private static final String «Constants.MEMBER_REGEX_LIST»«fieldSuffix» = "«cValue.values.get(0).escapeJava»";
+                   «val firstEntry = cValue.entrySet.iterator.next»
+                   private static final «Pattern.importedName» «Constants.MEMBER_PATTERN_LIST»«fieldSuffix» = «Pattern.importedName».compile("«firstEntry.key.escapeJava»");
+                   private static final String «Constants.MEMBER_REGEX_LIST»«fieldSuffix» = "«firstEntry.value.escapeJava»";
                 «ELSE»
                    private static final «Pattern.importedName»[] «Constants.MEMBER_PATTERN_LIST»«fieldSuffix» = «CodeHelpers.importedName».compilePatterns(«ImmutableList.importedName».of(
                    «FOR v : cValue.keySet SEPARATOR ", "»"«v.escapeJava»"«ENDFOR»));