Use session ID in connection

lib/clickhouse/cluster.rb

@@ -1,12 +1,14 @@
 module Clickhouse
   class Cluster < BasicObject
 
-    attr_reader :pond
+    attr_reader :pond, :use_session, :session_connection
 
     def initialize(config)
       config = config.dup
+      @use_session = config[:use_session]
       urls = config.delete(:urls) || config.delete("urls")
       urls.collect!{|url| ::Clickhouse::Utils.normalize_url(url)}
+      urls.shuffle! if use_session
 
       @pond = ::Pond.new :maximum_size => urls.size, :timeout => 5.0
       block = ::Proc.new do
@@ -32,12 +34,34 @@ def initialize(config)
   private
 
     def method_missing(*args, &block)
-      pond.checkout do |connection|
-        connection.send(*args, &block)
+      use_session ? call_in_session(*args,&block) : call_with_retry(*args,&block)
+    end
+
+    def call_in_session *args, &block
+
+      if @session_connection
+        @session_connection.send(*args, &block)
+      else
+        pond.checkout do |connection|
+          checked = connection.send(*args, &block)
+          @session_connection = connection
+          checked
+        end
       end
-    rescue ::Clickhouse::ConnectionError
-      retry if pond.available.any?
+
     end
 
+    def call_with_retry *args, &block
+      begin
+        pond.checkout do |connection|
+          connection.send(*args, &block)
+        end
+      rescue ::Clickhouse::ConnectionError
+        retry if pond.available.any?
+      end
+    end
+
+
+
   end
 end

lib/clickhouse/connection.rb

@@ -17,6 +17,7 @@ class Connection
 
     def initialize(config = {})
       @config = normalize_config(config)
+      @session_id = generate_session_id if @config[:use_session]
     end
 
   private
@@ -38,5 +39,11 @@ def normalize_config(config)
       DEFAULT_CONFIG.merge(config.reject{|_k, v| v.nil?})
     end
 
+    SESSIONID_LETTERS = (48..57).collect{|c| c.chr} + (65..90).collect{|c| c.chr} + (97..122).collect{|c| c.chr}
+
+    def generate_session_id
+      Array.new(20) { SESSIONID_LETTERS[rand(SESSIONID_LETTERS.size)] }.join
+    end
+
   end
 end

lib/clickhouse/connection/client.rb

@@ -37,7 +37,14 @@ def url
     private
 
       def client
-        @client ||= Faraday.new(:url => url)
+        @client ||= connect_faraday
+      end
+
+      def connect_faraday
+        Faraday.new(url: url, request: @config.slice(:open_timeout, :write_timeout, :timeout)) do |conn|
+               conn.request(:retry, max: 0)
+               conn.adapter(:net_http)
+        end
       end
 
       def ensure_authentication
@@ -49,7 +56,9 @@ def path(query)
         params = @config.select{|k, _v| k == :database}
         params[:query] = query
         params[:output_format_write_statistics] = 1
-        query_string = params.collect{|k, v| "#{k}=#{CGI.escape(v.to_s)}"}.join("&")
+        params[:session_id] = @session_id
+        params[:session_timeout] = @config[:session_timeout]
+        query_string = params.compact.collect{|k, v| "#{k}=#{CGI.escape(v.to_s)}"}.join("&")
 
         "/?#{query_string}"
       end
@@ -62,12 +71,16 @@ def request(method, query, body = nil)
         response = client.send(method, path(query), body)
         status = response.status
         duration = Time.now - start
-        query, format = Utils.extract_format(query)
+        query, format = Utils.extract_format("#{query} #{body}")
         response = parse_body(format, response.body)
         stats = parse_stats(response)
 
         write_log duration, query, stats
-        raise QueryError, "Got status #{status} (expected 200): #{response}" unless status == 200
+
+        if status!=200
+          raise QueryError, "#{response}, status returned #{status} (expected 200)"
+        end
+
         response
 
       rescue Faraday::Error => e

lib/clickhouse/connection/query.rb

@@ -14,7 +14,13 @@ def execute(query, body = nil)
       def query(query)
         query = Utils.extract_format(query)[0]
         query += " FORMAT JSONCompact"
-        parse_data get(query)
+
+        if query.size>4000 && ( comps = query.split /\A\s*(\w+)(.*)/m ).size==3
+          parse_data post(comps[1], comps[2])
+        else
+          parse_data get(query)
+        end
+
       end
 
       def databases

lib/clickhouse/connection/query/result_set.rb

@@ -53,13 +53,15 @@ def parse_value(type, value)
               parse_int_value value
             when "Float32", "Float64"
               parse_float_value value
-            when "String", "Enum8", "Enum16"
+            when /^Decimal/
+              parse_decimal_value value
+            when "String", "Enum8", "Enum16", "LowCardinality(String)"
               parse_string_value value
             when /FixedString\(\d+\)/
               parse_fixed_string_value value
             when "Date"
               parse_date_value value
-            when "DateTime"
+            when /^DateTime/
               parse_date_time_value value
             when /Array\(/
               parse_array_value value
@@ -77,6 +79,10 @@ def parse_float_value(value)
           value.to_f
         end
 
+        def parse_decimal_value(value)
+          value.to_d
+        end
+
         def parse_string_value(value)
           value.force_encoding("UTF-8")
         end
@@ -86,11 +92,19 @@ def parse_fixed_string_value(value)
         end
 
         def parse_date_value(value)
-          Date.parse(value)
+          if '0000-00-00'==value
+            nil
+          else
+            Date.parse(value)
+          end
         end
 
         def parse_date_time_value(value)
-          Time.parse(value)
+          if '0000-00-00 00:00:00'==value
+            nil
+          else
+            Time.parse(value)
+          end
         end
 
         def parse_array_value(value)

lib/clickhouse/version.rb

@@ -1,7 +1,7 @@
 module Clickhouse
   MAJOR = 0
   MINOR = 1
-  TINY  = 10
+  TINY  = 11
 
-  VERSION = [MAJOR, MINOR, TINY].join(".")
+  VERSION = [MAJOR, MINOR, TINY].join(".") + '-sessionId-to-11'
 end