lib/picky/backends/redis.rb in picky-3.6.2 vs lib/picky/backends/redis.rb in picky-3.6.3

@@ -86,30 +86,48 @@
       # routines, can do so analogue to this in their own
       # backend implementations.
       #
       # Note: We use the amount and offset hints to speed Redis up.
       #
-#       def ids combinations, amount, offset
-#         if redis_with_scripting?
-#           @@script = <<-SCRIPT
-# redis.call('zinterstore', KEYS[1], ARGV[1]);
-# local result = redis.call('zrange', KEYS[1], ARGV[2], ARGV[3])
-# redis.call('del', KEYS[1])
-# return result
-# SCRIPT
-#           # Scripting version of #ids.
-#           #
-#           def ids combinations, amount, offset
-#             identifiers = combinations.inject([]) do |identifiers, combination|
-#               identifiers << "#{combination.identifier}"
-#             end
-#
-#             # Assume it's using EVALSHA.
-#             #
-#             client.eval @@script, generate_intermediate_result_id, identifiers, offset, (offset + amount)
-#           end
-#         else
+      def ids combinations, amount, offset
+        # Just checked once on the first call.
+        #
+        if redis_with_scripting?
+          @@script = "local intersected = redis.call('zinterstore', ARGV[1], #(KEYS), unpack(KEYS)); if intersected == 0 then redis.call('del', ARGV[1]); return {}; end local results = redis.call('zrange', ARGV[1], tonumber(ARGV[2]), tonumber(ARGV[3])); redis.call('del', ARGV[1]); return results;"
+
+          require 'digest/sha1'
+          @@sent_once = nil
+
+          # Scripting version of #ids.
+          #
+          def ids combinations, amount, offset
+            identifiers = combinations.inject([]) do |identifiers, combination|
+              identifiers << "#{combination.identifier}"
+            end
+
+            # Assume it's using EVALSHA.
+            #
+            begin
+              client.evalsha @@sent_once,
+                             identifiers.size,
+                             *identifiers,
+                             generate_intermediate_result_id,
+                             offset,
+                             (offset + amount)
+            rescue RuntimeError => e
+              # Make the server have a SHA-1 for the script.
+              #
+              @@sent_once = Digest::SHA1.hexdigest @@script
+              client.eval @@script,
+                          identifiers.size,
+                          *identifiers,
+                          generate_intermediate_result_id,
+                          offset,
+                          (offset + amount)
+            end
+          end
+        else
           # Non-Scripting version of #ids.
           #
           def ids combinations, amount, offset
             identifiers = combinations.inject([]) do |identifiers, combination|
               identifiers << "#{combination.identifier}"
@@ -117,25 +135,37 @@
 
             result_id = generate_intermediate_result_id
 
             # Intersect and store.
             #
-            client.zinterstore result_id, identifiers
+            intersected = client.zinterstore result_id, identifiers
 
+            # Return clean and early if there has been no intersection.
+            #
+            if intersected.zero?
+              client.del result_id
+              return []
+            end
+
             # Get the stored result.
             #
             results = client.zrange result_id, offset, (offset + amount)
 
             # Delete the stored result as it was only for temporary purposes.
             #
-            # Note: I could also not delete it, but that would not be clean at all.
+            # Note: I could also not delete it, but that
+            #       would not be clean at all.
             #
             client.del result_id
 
             results
           end
-        # end
-      # end
+        end
+
+        # Call the newly installed version.
+        #
+        ids combinations, amount, offset
+      end
 
       # Generate a multiple host/process safe result id.
       #
       # Note: Generated when this class loads.
       #
\ No newline at end of file