Cache optimized default searches

lib/jmespath.rb

@@ -10,6 +10,7 @@ module JMESPath
   require 'jmespath/nodes'
   require 'jmespath/parser'
   require 'jmespath/runtime'
+  require 'jmespath/caching_runtime'
   require 'jmespath/token'
   require 'jmespath/token_stream'
   require 'jmespath/util'
@@ -28,12 +29,15 @@ def search(expression, data, runtime_options = {})
              when IO, StringIO then JSON.parse(data.read)
              else data
         end
-      Runtime.new(runtime_options).search(expression, data)
+      runtime = runtime_options.empty? ? DEFAULT_RUNTIME : Runtime.new(runtime_options)
+      runtime.search(expression, data)
     end
 
     # @api private
     def load_json(path)
       JSON.parse(File.open(path, 'r', encoding: 'UTF-8', &:read))
     end
   end
+
+  DEFAULT_RUNTIME = CachingRuntime.new
 end

lib/jmespath/caching_runtime.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+require 'thread'
+
+module JMESPath
+  # @api private
+  class CachingRuntime < Runtime
+    def initialize(options = {})
+      super(options.merge(cache_expressions: false))
+      @mutex = Mutex.new
+      @cache = {}
+    end
+
+    def search(expression, data)
+      if cached = @cache[expression]
+        cached.visit(data)
+      else
+        cache_expression(expression).visit(data)
+      end
+    end
+
+    private
+
+    def cache_expression(expression)
+      @mutex.synchronize do
+        @cache.clear if @cache.size > 1000
+        @cache[expression] ||= @parser.parse(expression).optimize
+      end
+    end
+  end
+end