chucknorris: fix loading

[user/henk/code/ruby/rbot.git] / lib / rbot / journal / postgres.rb

diff --git a/lib/rbot/journal/postgres.rb b/lib/rbot/journal/postgres.rb
index 52f5fb368f0b8c848c01085eddcdef3aaa4f267c..7b333158642d55bbc339ab9ff5ebeb337fe273a8 100644 (file)
--- a/lib/rbot/journal/postgres.rb
+++ b/lib/rbot/journal/postgres.rb
@@ -7,6 +7,82 @@
 require 'pg'
 require 'json'
 
+# wraps the postgres driver in a single thread
+class PGWrapper
+  def initialize(uri)
+    @uri = uri
+    @queue = Queue.new
+    run_thread
+  end
+
+  def run_thread
+    Thread.new do
+      @conn = PG.connect(@uri)
+      while message = @queue.pop
+        return_queue = message.shift
+        begin
+          result = @conn.send(*message)
+          return_queue << [:result, result]
+        rescue Exception => e
+          return_queue << [:exception, e]
+        end
+      end
+      @conn.finish
+    end
+  end
+
+  def run_in_thread(*args)
+    rq = Queue.new
+    @queue << [rq, *args]
+    type, result = rq.pop
+    if type == :exception
+      raise result
+    else
+      result
+    end
+  end
+
+  public
+
+  def destroy
+    @queue << nil
+  end
+
+  def exec(query)
+    run_in_thread(:exec, query)
+  end
+
+  def exec_params(query, params)
+    run_in_thread(:exec_params, query, params)
+  end
+
+  def escape_string(string)
+    @conn.escape_string(string)
+  end
+end
+
+# as a replacement for CREATE INDEX IF NOT EXIST that is not in postgres.
+# define function to be able to create an index in case it doesnt exist:
+# source: http://stackoverflow.com/a/26012880
+CREATE_INDEX = <<-EOT
+CREATE OR REPLACE FUNCTION create_index(table_name text, index_name text, column_name text) RETURNS void AS $$ 
+declare 
+   l_count integer;
+begin
+  select count(*)
+     into l_count
+  from pg_indexes
+  where schemaname = 'public'
+    and tablename = lower(table_name)
+    and indexname = lower(index_name);
+
+  if l_count = 0 then 
+     execute 'create index ' || index_name || ' on ' || table_name || '(' || column_name || ')';
+  end if;
+end;
+$$ LANGUAGE plpgsql;
+EOT
+
 module Irc
 class Bot
 module Journal
@@ -17,9 +93,10 @@ module Journal
       attr_reader :conn
 
       def initialize(opts={})
-        @uri = opts[:uri] || 'postgresql://localhost/rbot_journal'
-        @conn = PG.connect(@uri)
+        @uri = opts[:uri] || 'postgresql://localhost/rbot'
+        @conn = PGWrapper.new(@uri)
         @conn.exec('set client_min_messages = warning')
+        @conn.exec(CREATE_INDEX)
         @version = @conn.exec('SHOW server_version;')[0]['server_version']
 
         @version.gsub!(/^(\d+\.\d+)$/, '\1.0')
@@ -32,9 +109,12 @@ module Journal
         end
         @jsonb = (version >= 940)
         log 'journal storage: no jsonb support, consider upgrading postgres' unless @jsonb
+        log 'journal storage: postgres backend is using JSONB :)' if @jsonb
 
         drop if opts[:drop]
         create_table
+        create_index('topic_index', 'topic')
+        create_index('timestamp_index', 'timestamp')
       end
 
       def create_table
@@ -46,12 +126,35 @@ module Journal
              payload %s NOT NULL)' % [@jsonb ? 'JSONB' : 'JSON'])
       end
 
+      def create_index(index_name, column_name)
+        debug 'journal postges backend: create index %s for %s' % [
+          index_name, column_name]
+        @conn.exec_params('SELECT create_index($1, $2, $3)', [
+          'journal', index_name, column_name])
+      end
+
+      def create_payload_index(key)
+        index_name = 'idx_payload_' + key.gsub('.', '_')
+        column = sql_payload_selector(key)
+        create_index(index_name, column)
+      end
+
+      def ensure_index(key)
+        create_payload_index(key)
+      end
+
       def insert(m)
         @conn.exec_params('INSERT INTO journal VALUES ($1, $2, $3, $4);',
           [m.id, m.topic, m.timestamp, JSON.generate(m.payload)])
       end
 
-      def find(query=nil, limit=100, offset=0)
+      def find(query=nil, limit=100, offset=0, &block)
+        def to_message(row)
+          timestamp = DateTime.strptime(row['timestamp'], '%Y-%m-%d %H:%M:%S%z')
+          JournalMessage.new(id: row['id'], timestamp: timestamp,
+            topic: row['topic'], payload: JSON.parse(row['payload']))
+        end
+
         if query
           sql, params = query_to_sql(query)
           sql = 'SELECT * FROM journal WHERE ' + sql + ' LIMIT %d OFFSET %d' % [limit.to_i, offset.to_i]
@@ -60,10 +163,10 @@ module Journal
           params = []
         end
         res = @conn.exec_params(sql, params)
-        res.map do |row|
-          timestamp = DateTime.strptime(row['timestamp'], '%Y-%m-%d %H:%M:%S%z')
-          JournalMessage.new(id: row['id'], timestamp: timestamp,
-            topic: row['topic'], payload: JSON.parse(row['payload']))
+        if block_given?
+          res.each { |row| block.call(to_message(row)) }
+        else
+          res.map { |row| to_message(row) }
         end
       end
 
@@ -95,6 +198,19 @@ module Journal
         @conn.exec('DROP TABLE journal;') rescue nil
       end
 
+      def sql_payload_selector(key)
+        selector = 'payload'
+        k = key.to_s.split('.')
+        k.each_index { |i|
+          if i >= k.length-1
+            selector += '->>\'%s\'' % [@conn.escape_string(k[i])]
+          else
+            selector += '->\'%s\'' % [@conn.escape_string(k[i])]
+          end
+        }
+        selector
+      end
+
       def query_to_sql(query)
         params = []
         placeholder = Proc.new do |value|
@@ -142,15 +258,7 @@ module Journal
         unless query.payload.empty?
           list = []
           query.payload.each_pair do |key, value|
-            selector = 'payload'
-            k = key.to_s.split('.')
-            k.each_index { |i|
-              if i >= k.length-1
-                selector += '->>\'%s\'' % [@conn.escape_string(k[i])]
-              else
-                selector += '->\'%s\'' % [@conn.escape_string(k[i])]
-              end
-            }
+            selector = sql_payload_selector(key)
             list << selector + ' = ' + placeholder.call(value)
           end
           sql[:list] << {