#172 Removed caching in ChangePronenessRanker

Removed caching in ChangePronenessRanker - there was no discernible difference.  Removing it will reduce memory use.

Author: jimbethancourt

change-proneness-ranker/src/main/java/org/hjug/git/ChangePronenessRanker.java

@@ -8,40 +8,25 @@
 @Slf4j
 public class ChangePronenessRanker {
 
-    private final Map<Integer, Integer> changeCountsByTimeStamps = new HashMap<>();
+    private final TreeMap<Integer, Integer> changeCountsByTimeStamps = new TreeMap<>();
     private final Map<String, ScmLogInfo> cachedScmLogInfos = new HashMap<>();
 
     public ChangePronenessRanker(GitLogReader repositoryLogReader) {
         try {
             log.info("Capturing change count based on commit timestamps");
-            changeCountsByTimeStamps.putAll(
-                    computeChangeCountsByTimeStamps(repositoryLogReader.captureChangeCountByCommitTimestamp()));
+            changeCountsByTimeStamps.putAll(repositoryLogReader.captureChangeCountByCommitTimestamp());
         } catch (IOException | GitAPIException e) {
             log.error("Error reading from repository: {}", e.getMessage());
         }
     }
 
-    private Map<Integer, Integer> computeChangeCountsByTimeStamps(TreeMap<Integer, Integer> commitsWithChangeCounts) {
-        HashMap<Integer, Integer> changeCountsByTimeStamps = new HashMap<>();
-        int runningTotal = 0;
-        for (Map.Entry<Integer, Integer> commitChangeCountEntry :
-                commitsWithChangeCounts.descendingMap().entrySet()) {
-            runningTotal += commitChangeCountEntry.getValue();
-            changeCountsByTimeStamps.put(commitChangeCountEntry.getKey(), runningTotal);
-        }
-
-        return changeCountsByTimeStamps;
-    }
-
     public void rankChangeProneness(List<ScmLogInfo> scmLogInfos) {
         for (ScmLogInfo scmLogInfo : scmLogInfos) {
             if (!cachedScmLogInfos.containsKey(scmLogInfo.getPath())) {
-                if (scmLogInfo.getEarliestCommit() == 0) {
-                    log.warn("No commits found for {}", scmLogInfo.getPath());
-                    continue;
-                }
-
-                int commitsInRepositorySinceCreation = changeCountsByTimeStamps.get(scmLogInfo.getEarliestCommit());
+                int commitsInRepositorySinceCreation =
+                        changeCountsByTimeStamps.tailMap(scmLogInfo.getEarliestCommit()).values().stream()
+                                .mapToInt(i -> i)
+                                .sum();
 
                 scmLogInfo.setChangeProneness((float) scmLogInfo.getCommitCount() / commitsInRepositorySinceCreation);
                 cachedScmLogInfos.put(scmLogInfo.getPath(), scmLogInfo);