HBASE-28905: Skip excessive evaluations of LINK_NAME_PATTERN and REF_…

…NAME_PATTERN regular expressions (#6348)

Signed-off-by: Wellington Chevreuil <wchevreuil@apache.org>

hbase-server/src/main/java/org/apache/hadoop/hbase/io/HFileLink.java

@@ -188,6 +188,13 @@ public static boolean isHFileLink(final Path path) {
  * @return True if the path is a HFileLink.
  */
  public static boolean isHFileLink(String fileName) {
+ // The LINK_NAME_PATTERN regex is not computationally trivial, so see if we can fast-fail
+ // on a simple heuristic first. The regex contains a literal "=", so if that character
+ // isn't in the fileName, then the regex cannot match.
+ if (!fileName.contains("=")) {
+ return false;
+ }
+
  Matcher m = LINK_NAME_PATTERN.matcher(fileName);
  if (!m.matches()) {
  return false;

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreFileInfo.java

@@ -54,7 +54,7 @@ public class StoreFileInfo implements Configurable {
 
  /**
  * A non-capture group, for hfiles, so that this can be embedded. HFiles are uuid ([0-9a-z]+).
- * Bulk loaded hfiles has (_SeqId_[0-9]+_) has suffix. The mob del file has (_del) as suffix.
+ * Bulk loaded hfiles have (_SeqId_[0-9]+_) as a suffix. The mob del file has (_del) as a suffix.
  */
  public static final String HFILE_NAME_REGEX = "[0-9a-f]+(?:(?:_SeqId_[0-9]+_)|(?:_del))?";
 
@@ -66,7 +66,7 @@ public class StoreFileInfo implements Configurable {
  * hfilelink reference names ({@code
  *
  <table>
- * =<region>-<hfile>.<parentEncRegion>}) If reference, then the regex has more than just one
+ * =<region>-<hfile>.<parentEncRegion>}). If reference, then the regex has more than just one
  * group. Group 1, hfile/hfilelink pattern, is this file's id. Group 2 '(.+)' is the reference's
  * parent region name.
  */
@@ -533,6 +533,13 @@ public static boolean isReference(final Path path) {
  * @return True if the path has format of a HStoreFile reference.
  */
  public static boolean isReference(final String name) {
+ // The REF_NAME_PATTERN regex is not computationally trivial, so see if we can fast-fail
+ // on a simple heuristic first. The regex contains a literal ".", so if that character
+ // isn't in the name, then the regex cannot match.
+ if (!name.contains(".")) {
+ return false;
+ }
+
  Matcher m = REF_NAME_PATTERN.matcher(name);
  return m.matches() && m.groupCount() > 1;
  }