[HBASE-5110] code enhancement - remove unnecessary if-checks in every loop in HLog class

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Not A Problem
• Affects Version/s: 0.90.1, 0.90.2, 0.90.4, 0.92.0
• Component/s: wal
• Assignee: Unassigned
• Reporter: Mikael Sitruk
• Created: 30/Dec/11 19:01
• Updated: 12/Jun/22 20:02
• Resolved: 21/Apr/15 00:50

Description

The HLog class (method findMemstoresWithEditsEqualOrOlderThan) has unnecessary if check in a loop.

static byte [][] findMemstoresWithEditsEqualOrOlderThan(final long oldestWALseqid,
final Map<byte [], Long> regionsToSeqids) {
// This method is static so it can be unit tested the easier.
List<byte []> regions = null;
for (Map.Entry<byte [], Long> e: regionsToSeqids.entrySet()) {
if (e.getValue().longValue() <= oldestWALseqid)

{ if (regions == null) regions = new ArrayList<byte []>(); regions.add(e.getKey()); }

}
return regions == null?
null: regions.toArray(new byte [][]

{HConstants.EMPTY_BYTE_ARRAY});
}

The following change is suggested

static byte [][] findMemstoresWithEditsEqualOrOlderThan(final long oldestWALseqid,
final Map<byte [], Long> regionsToSeqids) {
// This method is static so it can be unit tested the easier.
List<byte []> regions = new ArrayList<byte []>();
for (Map.Entry<byte [], Long> e: regionsToSeqids.entrySet()) {
if (e.getValue().longValue() <= oldestWALseqid) { regions.add(e.getKey()); }
}
return regions.size() == 0?
null: regions.toArray(new byte [][] {HConstants.EMPTY_BYTE_ARRAY}

);
}