make it easier to patch in alternative rpc clients

lib/steem/api.rb

@@ -39,8 +39,8 @@ module Steem
     attr_accessor :chain, :methods
     
     # Use this for debugging naive thread handler.
-    # DEFAULT_RPC_CLIENT = RPC::BaseClient
-    DEFAULT_RPC_CLIENT = RPC::ThreadSafeHttpClient
+    # DEFAULT_RPC_CLIENT_CLASS = RPC::BaseClient
+    DEFAULT_RPC_CLIENT_CLASS = RPC::ThreadSafeHttpClient
     
     def self.api_name=(api_name)
       @api_name = api_name.to_s.
@@ -65,11 +65,22 @@ module Steem
       @jsonrpc
     end
     
+    # Override this if you want to use your own client.
+    def self.default_rpc_client_class
+      DEFAULT_RPC_CLIENT_CLASS
+    end
+    
     def initialize(options = {})
       @chain = options[:chain] || :steem
       @error_pipe = options[:error_pipe] || STDERR
       @api_name = self.class.api_name ||= :condenser_api
-      @rpc_client = options[:rpc_client] || DEFAULT_RPC_CLIENT.new(options.merge(api_name: @api_name))
+      
+      @rpc_client = if !!options[:rpc_client]
+        options[:rpc_client]
+      else
+        rpc_client_class = self.class.default_rpc_client_class
+        rpc_client_class.new(options.merge(api_name: @api_name))
+      end
       
       if @api_name == :jsonrpc
         Api::jsonrpc = self

lib/steem/rpc/base_client.rb

@@ -3,7 +3,7 @@ module Steem
     class BaseClient
       include ChainConfig
       
-      attr_accessor :chain, :error_pipe
+      attr_accessor :url, :chain, :error_pipe
       
       # @private
       MAX_TIMEOUT_RETRY_COUNT = 100
@@ -27,7 +27,7 @@ module Steem
       end
       
       def uri
-        @uri ||= URI.parse(@url)
+        @uri ||= URI.parse(url)
       end
       
       # Adds a request object to the stack.  Usually, this method is called

lib/steem/rpc/http_client.rb

@@ -16,7 +16,8 @@ module Steem
       # http status code of 200 and HTML page.
       # 
       # @private
-      TIMEOUT_ERRORS = [Net::OpenTimeout, Net::ReadTimeout, JSON::ParserError]
+      TIMEOUT_ERRORS = [Net::OpenTimeout, JSON::ParserError, Net::ReadTimeout,
+        Errno::EBADF, Errno::ECONNREFUSED, IOError]
       
       # @private
       POST_HEADERS = {
@@ -66,7 +67,7 @@ module Steem
           end
           
           if request_object.size > JSON_RPC_BATCH_SIZE_MAXIMUM
-            raise JsonRpcBatchMaximumSizeExceededError, 'Maximum json-rpc-batch is 50 elements.'
+            raise JsonRpcBatchMaximumSizeExceededError, "Maximum json-rpc-batch is #{JSON_RPC_BATCH_SIZE_MAXIMUM} elements."
           end
           
           request.body = if request_object.class == Hash