Refactor exponential sleeping into seperate class

This is shared by Hive and Impala, likely we will need to do the same thing for
other big SQL engines.

Author: xyu

src/ThriftSQL/Hive.php

@@ -80,19 +80,21 @@ public function connect() {
 
   public function queryAndFetchAll( $queryStr ) {
     try {
+      $sleeper = new \ThriftSQL\Utils\Sleeper();
+
       $TExecuteStatementResp = $this->_client->ExecuteStatement( new \ThriftSQL\TExecuteStatementReq( array(
         'sessionHandle' => $this->_sessionHandle,
         'statement' => $queryStr,
         'runAsync' => true,
       ) ) );
 
       // Wait for results
-      $iteration = 0;
+      $sleeper->reset();
       do {
 
-        usleep( $this->_getSleepUsec( $iteration ) );
+        $slept = $sleeper->sleep()->getSleptSecs();
 
-        if ( $iteration > 250 ) {
+        if ( $slept > 18000 ) { // 5 Hours
           // TODO: Actually kill the query then throw exception.
           throw new \ThriftSQL\Exception( 'Hive Query Killed!' );
         }
@@ -202,15 +204,6 @@ public function disconnect() {
 
   }
 
-  private function _getSleepUsec( $iteration ) {
-    // Max out at 30 second sleep per check
-    if ( 14 < $iteration ) {
-      return 30000000;
-    }
-
-    return pow( 2, $iteration ) * 1000;
-  }
-
   private function _isOperationFinished( $state ) {
     return ( \ThriftSQL\TOperationState::FINISHED_STATE == $state );
   }

src/ThriftSQL/Impala.php

@@ -52,17 +52,19 @@ public function connect() {
 
   public function queryAndFetchAll( $queryStr ) {
     try {
+      $sleeper = new \ThriftSQL\Utils\Sleeper();
+
       $QueryHandle = $this->_client->query( new \ThriftSQL\Query( array(
         'query' => $queryStr,
       ) ) );
 
       // Wait for results
-      $iteration = 0;
+      $sleeper->reset();
       do {
 
-        usleep( $this->_getSleepUsec( $iteration ) );
+        $slept = $sleeper->sleep()->getSleptSecs();
 
-        if ( $iteration > 250 ) {
+        if ( $slept > 18000 ) { // 5 Hours
           // TODO: Actually kill the query then throw exception.
           throw new \ThriftSQL\Exception( 'Impala Query Killed!' );
         }
@@ -157,15 +159,6 @@ public function disconnect() {
 
   }
 
-  private function _getSleepUsec( $iteration ) {
-    // Max out at 30 second sleep per check
-    if ( 14 < $iteration ) {
-      return 30000000;
-    }
-
-    return pow( 2, $iteration ) * 1000;
-  }
-
   private function _isOperationFinished( $state ) {
     return ( \ThriftSQL\QueryState::FINISHED == $state );
   }

src/ThriftSQL/Utils/Sleeper.php

@@ -0,0 +1,43 @@
+<?php
+namespace ThriftSQL\Utils;
+
+/**
+ * Util to do exponential sleeping.
+ */
+
+class Sleeper {
+
+  private $_iterations = 0;
+  private $_slept = 0;
+
+  public function reset() {
+    $this->_iterations = 0;
+    $this->_slept = 0;
+
+    return $this;
+  }
+
+  public function sleep() {
+    $mSecs = $this->_getSleepMS();
+
+    usleep( $mSecs * 1000 );
+
+    $this->_iterations++;
+    $this->_slept += $mSecs;
+
+    return $this;
+  }
+
+  public function getSleptSecs() {
+    return $this->_slept / 1000;
+  }
+
+  private function _getSleepMS() {
+    if ( 14 < $this->_iterations ) {
+      return 30000; // Max out at 30 second sleep per check
+    }
+
+    return pow( 2, $this->_iterations );
+  }
+
+}

src/autoload_classmap.php

@@ -192,6 +192,7 @@
     'ThriftSQL\TTypeQualifiers'                                   => __DIR__ . '/Packages/TCLIService/Types.php',
     'ThriftSQL\TUnionTypeEntry'                                   => __DIR__ . '/Packages/TCLIService/Types.php',
     'ThriftSQL\TUserDefinedTypeEntry'                             => __DIR__ . '/Packages/TCLIService/Types.php',
+    'ThriftSQL\Utils\Sleeper'                                     => __DIR__ . '/ThriftSQL/Utils/Sleeper.php',
     'Thrift\Base\TBase'                                           => __DIR__ . '/Thrift/Base/TBase.php',
     'Thrift\ClassLoader\ThriftClassLoader'                        => __DIR__ . '/Thrift/ClassLoader/ThriftClassLoader.php',
     'Thrift\Exception\TApplicationException'                      => __DIR__ . '/Thrift/Exception/TApplicationException.php',