Make ConfigurationReader able to handle leading whitespace

CHANGELOG.md

@@ -3,10 +3,11 @@
 ## Unreleased
 
 ### Bug fixes
-- ``deque-scan-back`` was returning the wrong cursor to signal end of
+- ``DEQUE-SCAN-BACK`` was returning the wrong cursor to signal end of
 iteration: ``next:0`` while it should have been ``0``.
-- A race condition was sometimes causing elections to fail spuriously, making
-the election of a stable leader to require slightly more rounds than it should have.
+- A race condition was sometimes causing elections to fail spuriously.
+Establishing a stable quorum would occasionally require slightly more election
+rounds than it should have.
 
 ### New features
 - Implementation of health indicators through ``QUARKDB-HEALTH`` command.
@@ -20,21 +21,20 @@ on locality hint.
 - Add ``RECOVERY-SCAN`` command for scanning through complete keyspace, including
 internal rocksdb keys.
 - Add tool ``quarkdb-sst-inspect`` to allow low-level inspection of SST files.
+- Add command ``RAFT-JOURNAL-SCAN`` to make searching through the contents of the
+raft journal easier.
 
 ### Improvements
 - Protection for a strange case of corruption which brought down a development
 test cluster. (last-applied jumped ahead of commit-index by 1024, causing all
 writes to stall). From now on, similar kind of corruption should only take out
 a single node, and not spread to the entire cluster.
-- Add command ``RAFT-JOURNAL-SCAN`` to make searching through the contents of the
-raft journal easier.
 - ``KEYS`` is now implemented in terms of ``SCAN``, making prefix matching of the
 keyspace just as efficient as with ``SCAN``. (Note: The use of ``KEYS`` is still
 generally discouraged due to potentially huge response size)
 - Removed unused tool ``quarkdb-scrub``.
 
 
-
 ## 0.3.8 (2019-05-27)
 - Prevent elections from hanging on the TCP timeout when one of the member hosts
 is dropping packets, which could bring down an otherwise healthy cluster.

src/config/ConfigurationReader.cc

@@ -57,6 +57,15 @@ std::string ConfigurationReader::getCurrentWord() const {
   return ss.str();
 }
 
+//------------------------------------------------------------------------------
+// Advance to next word, if we're currently sitting on whitespace
+//------------------------------------------------------------------------------
+void ConfigurationReader::advanceWordIfOnWhitespace() {
+  if(!mContents.empty() && isspace(mContents[mPosition])) {
+    advanceWord();
+  }
+}
+
 //------------------------------------------------------------------------------
 // Advance to next word
 //------------------------------------------------------------------------------
@@ -73,6 +82,7 @@ void ConfigurationReader::advanceLine() {
     mPosition++;
     if(mContents[mPosition] == '\n') {
       mPosition++;
+      advanceWordIfOnWhitespace();
       break;
     }
   }

src/config/ConfigurationReader.hh

@@ -69,7 +69,10 @@ private:
   //----------------------------------------------------------------------------
   size_t findNextNonWhitespace() const;
 
-
+  //----------------------------------------------------------------------------
+  // Advance to next word, if we're currently sitting on whitespace
+  //----------------------------------------------------------------------------
+  void advanceWordIfOnWhitespace();
 
   std::string mContents;
   size_t mPosition = 0;

test/configuration.cc

@@ -32,7 +32,7 @@ TEST(ConfigurationReader, BasicSanity) {
       "if         exec                              xrootd\n"
       "xrd.protocol redis:7776 libXrdQuarkDB.so\n"
       "redis.mode raft\n"
-      "redis.database /home/user/mydb\n"
+      "    redis.database /home/user/mydb\n"
       "redis.myself server1:7776\n"
       "redis.trace debug\n"
       "redis.write_ahead_log true\n"