add presto phpclient

presto_phpclient/PrestoClient.php

@@ -0,0 +1,220 @@
+<?php
+/*
+PrestoClient provides a way to communicate with Presto server REST interface. Presto is a fast query
+engine developed by Facebook that runs distributed queries against Hadoop HDFS servers.
+
+Copyright 2013 Xtendsys | xtendsys.net
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at:
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.*/
+
+class PrestoClient {
+	/**
+	 * The following parameters may be modified depending on your configuration
+	 */
+	private $source = 'PrestoPhpClient';
+	private $version = '0.3';
+	private $maximumRetries = 5;
+	private $prestoUser = "presto";
+	private $prestoSchema = "default";
+	private $prestoCatalog = "hive";
+	private $userAgent = "";
+
+	//Do not modify below this line
+	private $nextUri =" ";
+	private $infoUri = "";
+	private $partialCancelUri = "";
+	private $state = "NONE";
+
+	private $url;
+	private $headers;
+	private $result;
+	private $request;
+
+
+	public $HTTP_error;
+	public $data = array();
+
+
+	/**
+	 * Constructs the presto connection instance
+	 *
+	 * @param $connectUrl
+	 * @param $catalog
+	 */
+	public function __construct($connectUrl,$catalog){
+		$this->url = $connectUrl;
+		$this->prestoCatalog = $catalog;
+	}
+	/**
+	 * Return Data as an array. Check that the current status is FINISHED
+	 *
+	 * @return array|false
+	 */
+	public function GetData(){
+		if ($this->state!="FINISHED"){
+			return false;
+		}
+		return $this->data;
+	}
+
+	/**
+	 * prepares the query
+	 *
+	 * @param $query
+	 * @return bool
+	 * @throws Exception
+	 */
+	public function Query($query) {
+
+		$this->data=array();
+		$this->userAgent = $this->source."/".$this->version;
+
+		$this->request = $query;
+		//check that no other queries are already running for this object
+		if ($this->state === "RUNNING") {
+			return false;
+		}
+
+		/**
+		 * check that query is completed, and that we don't start
+		 * a new query before the previous is finished
+		 */
+		if ($query="") {
+			return false;
+		}
+
+		$this->headers = array(
+			"X-Presto-User: ".$this->prestoUser,
+			"X-Presto-Catalog: ".$this->prestoCatalog,
+			"X-Presto-Schema: ".$this->prestoSchema,
+			"User-Agent: ".$this->userAgent);
+
+		$connect = \curl_init();
+		\curl_setopt($connect,CURLOPT_URL, $this->url);
+		\curl_setopt($connect,CURLOPT_HTTPHEADER, $this->headers);
+		\curl_setopt($connect,CURLOPT_RETURNTRANSFER, 1);
+		\curl_setopt($connect,CURLOPT_POST, 1);
+		\curl_setopt($connect,CURLOPT_POSTFIELDS, $this->request);
+
+		$this->result = \curl_exec($connect);
+
+		$httpCode = \curl_getinfo($connect, CURLINFO_HTTP_CODE);
+
+		if($httpCode!="200"){
+			$this->HTTP_error = $httpCode;
+            echo "HTTP ERRROR: ".$this->HTTP_error;
+            return false;
+			// throw new PrestoException("HTTP ERRROR: $this->HTTP_error");
+		}
+
+		//set status to RUNNING
+		curl_close($connect);
+		$this->state = "RUNNING";
+		return true;
+	}
+
+
+	/**
+	 * waits until query was executed
+	 *
+	 * @return bool
+	 * @throws PrestoException
+	 */
+	function WaitQueryExec() {
+
+		$this->GetVarFromResult();
+
+		while ($this->nextUri){
+
+			usleep(500000);
+			$this->result = file_get_contents($this->nextUri);
+			$this->GetVarFromResult();
+		}
+
+		if ($this->state!="FINISHED"){
+            // throw new PrestoException("Incoherent State at end of query");
+            echo "Incoherent State at end of query";
+            return false;
+        }
+
+		return true;
+
+	}
+
+	/**
+	 * Provide Information on the query execution
+	 * The server keeps the information for 15minutes
+	 * Return the raw JSON message for now
+	 *
+	 * @return string
+	 */
+	function GetInfo() {
+
+		$connect = \curl_init();
+        \curl_setopt($connect,CURLOPT_URL, $this->infoUri);
+        \curl_setopt($connect,CURLOPT_HTTPHEADER, $this->headers);
+		$infoRequest = \curl_exec($connect);
+		\curl_close($connect);
+
+		return $infoRequest;
+	}
+
+    public function GetResult() {
+        return json_decode($this->result);
+    }
+
+	private function GetVarFromResult() {
+		/* Retrieve the variables from the JSON answer */
+
+	  	$decodedJson = json_decode($this->result);
+
+	  	if (isset($decodedJson->{'nextUri'})){
+	  	$this->nextUri = $decodedJson->{'nextUri'};} else {$this->nextUri = false;}
+
+	  	if (isset($decodedJson->{'data'})){
+	  	$this->data = array_merge($this->data,$decodedJson->{'data'});}
+
+	  	if (isset($decodedJson->{'infoUri'})){
+	  	$this->infoUri = $decodedJson->{'infoUri'};}
+
+	  	if (isset($decodedJson->{'partialCancelUri'})){
+	  	$this->partialCancelUri = $decodedJson->{'partialCancelUri'};}
+
+	  	if (isset($decodedJson->{'stats'})){
+	  		$status = $decodedJson->{'stats'};
+	  		$this->state = $status->{'state'};}
+		}
+
+	/**
+	 * Provide a function to cancel current request if not yet finished
+	 */
+	private function Cancel(){
+		if (!isset($this->partialCancelUri)){
+			return false;
+
+		$connect = \curl_init();
+		\curl_setopt($connect,CURLOPT_URL, $this->partialCancelUri);
+		\curl_setopt($connect,CURLOPT_HTTPHEADER, $this->headers);
+		$infoRequest = \curl_exec($connect);
+		\curl_close($connect);
+
+		$httpCode = \curl_getinfo($connect, CURLINFO_HTTP_CODE);
+
+		if($httpCode!="204"){
+			return false;}else{
+		return true;}
+		}
+	}
+}
+
+?>

presto_phpclient/README.md

@@ -0,0 +1,63 @@
+PrestoPhpClient
+===============
+
+Simple Php Class to connect to a PrestoDB Server that runs distributed queries against
+a Hadoop HDFS cluster.
+Presto uses a subset of SQL as its query language. Presto is an alternative for
+Hadoop-Hive or Impala.
+
+Change from: https://github.com/360d-io-labs/PhpPrestoClient
+
+
+Usage
+-----------------
+See index.php for a short demo on how to use it
+
+Requirement
+-----------------
+Php-Curl
+
+Compatibility
+-----------------
+Tested successfully with all version of Presto up to 0.58
+
+Presto client protocol
+----------------------
+The following description was made by Ivo Herweijer for its Python interface
+
+The communication protocol used between Presto clients and servers is not documented yet. It seems to
+be as follows:
+
+Client sends http POST request to the Presto server, page: "/v1/statement". Header information should
+include: X-Presto-Catalog, X-Presto-Source, X-Presto-Schema, User-Agent, X-Presto-User. The body of the
+request should contain the sql statement. The server responds by returning JSON data (http status-code 200).
+This reply may contain up to 3 uri's. One giving the link to get more information about the query execution
+('infoUri'), another giving the link to fetch the next packet of data ('nextUri') and one with the uri to
+cancel the query ('partialCancelUri').
+
+The client should send GET requests to the server (Header: X-Presto-Source, User-Agent, X-Presto-User.
+Body: empty) following the 'nextUri' link from the previous response until the servers response does not
+contain an 'nextUri' link anymore. When there is no 'nextUri' the query is finished. If the last response
+from the server included an error section ('error') the query failed, otherwise the query succeeded. If
+the http status of the server response is anything other than 200 with Content-Type application/json, the
+query should also be considered failed. A 503 http response means that the server is (too) busy. Retry the
+request after waiting at least 50ms.
+The server response may contain a 'state' variable. This is for informational purposes only (may be subject
+to change in future implementations).
+Each response by the server to a 'nextUri' may contain information about the columns returned by the query
+and all- or part of the querydata. If the response contains a data section the columns section will always
+be available.
+
+The server reponse may contain a variable with the uri to cancel the query ('partialCancelUri'). The client
+may issue a DELETE request to the server using this link. Response http status-code is 204.
+
+The Presto server will retain information about finished queries for 15 minutes. When a client does not
+respond to the server (by following the 'nextUri' links) the server will cancel these 'dead' queries after
+5 minutes. These timeouts are hardcoded in the Presto server source code.
+
+
+Thanks
+------
+
+Thanks to Ivo Herweijer from easywarehousing.com that is doing a Python interface and from which I copied the
+protocol description and took some inspiration for the Php interface.

presto_phpclient/index.php

@@ -0,0 +1,68 @@
+<?php
+/*
+Copyright 2013 Xtendsys | xtendsys.net
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at:
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.*/
+
+
+require_once(__DIR__ . '/PrestoClient.php');
+
+//Create a new connection object. Provide URL and catalog as parameters
+$presto = new PrestoClient("http://localhost:8080/v1/statement","mysql");
+
+$str_sql = "select * from mysql.helight.MyClass a, mysql2.helight.myclass b where a.id =b.id";
+//Prepare your sql request
+try {
+    // $presto->Query("select count(*) from hive.default.my_table");
+    $presto->Query($str_sql);
+} catch (PrestoException $e) {
+    var_dump($e);
+}
+
+//Execute the request and build the result
+if ($presto->WaitQueryExec()) {
+    $res = $presto->GetResult()->columns; //[0]->name;
+    foreach($res as $key=>$value)  {
+        $a[$key]["name"]=$value->name;
+        $a[$key]["type"]=$value->type;
+    }
+
+    foreach($a as $key=>$value)  {
+        //print_r($key."\n".$value["type"]."\n".$value["name"]."\n");
+        $colum[$key]=array("DataType"=>"System.".$value["type"],"Index"=>$key,"Name"=>$value["name"],"DisplayName"=>null);
+        $colmap[$key]=array("ColumnName"=>$value["name"],"Description"=>"","DisplayName"=>"");
+    }
+
+    //print_r($res);
+    //Get the result
+    $data=array();
+    $rows=array();
+    $answer = $presto->GetData();
+    foreach($answer as $row=>$value1) { //get rows
+        foreach($value1 as $col=>$value2)    {
+            $data[$col]=array("ColumnName"=>$a[$col]["name"],"Value"=>$value2);
+            $item=array("ItemArray"=>$data);
+        }
+        $rows[$row]=$item;
+        //$rows=array("Rows"=&gt;$tmp);
+    }
+    $table[0]=array("Name"=>"sql","Sql"=>$str_sql,"Status"=>"0","ColumnMapping"=>$colmap,"Columns"=>$colum,"Rows"=>$rows);
+    $output=array("HasError"=>"false","Message"=>"","Tables"=>$table);
+    print_r(json_encode($output));
+} else {
+    #$output=array("HasError"=&gt;"true","Message"=&gt;"table is not found!","Tables"=&gt;array());
+    $output=array("HasError"=>"true","Message"=>$err,"Tables"=>array());
+    print_r(json_encode($output));
+}
+
+?>