THRIFT-1510:There should be an implementation of the JsonProtocol for ruby

Client: ruby
Patch: Wim Crols

JSON impl for ruby



git-svn-id: https://svn.apache.org/repos/asf/thrift/trunk@1238144 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 757 insertions, 0 deletions

diff --git a/lib/rb/lib/thrift.rb b/lib/rb/lib/thrift.rb
index 02d67b8ba..72050b1d1 100644
--- a/lib/rb/lib/thrift.rb
+++ b/lib/rb/lib/thrift.rb
@@ -40,6 +40,7 @@ require 'thrift/protocol/base_protocol'
 require 'thrift/protocol/binary_protocol'
 require 'thrift/protocol/binary_protocol_accelerated'
 require 'thrift/protocol/compact_protocol'
+require 'thrift/protocol/json_protocol'
 
 # transport
 require 'thrift/transport/base_transport'
diff --git a/lib/rb/lib/thrift/protocol/json_protocol.rb b/lib/rb/lib/thrift/protocol/json_protocol.rb
new file mode 100644
index 000000000..ddbf193f3
--- /dev/null
+++ b/lib/rb/lib/thrift/protocol/json_protocol.rb
@@ -0,0 +1,756 @@
+# 
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+# 
+#   http://www.apache.org/licenses/LICENSE-2.0
+# 
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# 
+
+@@kJSONObjectStart = '{'
+@@kJSONObjectEnd = '}'
+@@kJSONArrayStart = '['
+@@kJSONArrayEnd = ']'
+@@kJSONNewline = '\n'
+@@kJSONElemSeparator = ','
+@@kJSONPairSeparator = ':'
+@@kJSONBackslash = '\\'
+@@kJSONStringDelimiter = '"'
+
+@@kThriftVersion1 = 1
+
+@@kThriftNan = "NaN"
+@@kThriftInfinity = "Infinity"
+@@kThriftNegativeInfinity = "-Infinity"
+
+module Thrift
+  class LookaheadReader
+    def initialize(trans)
+      @trans = trans
+      @hasData = false
+      @data = nil
+    end
+
+    def read
+      if @hasData
+        @hasData = false
+      else
+        @data = @trans.read(1)
+      end
+
+      return @data
+    end
+
+    def peek
+      if !@hasData
+        @data = @trans.read(1)
+      end
+      @hasData = true
+      return @data
+    end
+  end
+
+  #
+  # Class to serve as base JSON context and as base class for other context
+  # implementations
+  #
+  class JSONContext
+    #
+    # Write context data to the trans. Default is to do nothing.
+    #
+    def write(trans)
+    end
+
+    #
+    # Read context data from the trans. Default is to do nothing.
+    #
+    def read(reader)
+    end
+
+    #
+    # Return true if numbers need to be escaped as strings in this context.
+    # Default behavior is to return false.
+    #
+    def escapeNum
+      return false
+    end
+  end
+
+  # Context class for object member key-value pairs
+  class JSONPairContext < JSONContext
+    def initialize
+      @first = true
+      @colon = true
+    end
+
+    def write(trans)
+      if (@first)
+        @first = false
+        @colon = true
+      else
+        trans.write(@colon ? @@kJSONPairSeparator : @@kJSONElemSeparator)
+        @colon = !@colon
+      end
+    end
+
+    def read(reader)
+      if (@first)
+        @first = false
+        @colon = true
+      else
+        ch = (@colon ? @@kJSONPairSeparator : @@kJSONElemSeparator)
+        @colon = !@colon
+        JsonProtocol::read_syntax_char(reader, ch)
+      end
+    end
+
+    # Numbers must be turned into strings if they are the key part of a pair
+    def escapeNum
+      return @colon
+    end
+  end
+
+  # Context class for lists
+  class JSONListContext < JSONContext
+
+    def initialize
+      @first = true
+    end
+
+    def write(trans)
+      if (@first)
+        @first = false
+      else
+        trans.write(@@kJSONElemSeparator)
+      end
+    end
+
+    def read(reader)
+      if (@first)
+        @first = false
+      else
+        JsonProtocol::read_syntax_char(reader, @@kJSONElemSeparator)
+      end
+    end
+  end
+
+  class JsonProtocol < BaseProtocol
+    def initialize(trans)
+      super(trans)
+      @context = JSONContext.new
+      @contexts = Array.new
+      @reader = LookaheadReader.new(trans)
+    end
+
+    def get_type_name_for_type_id(id)
+      case id
+      when Types::BOOL
+        "tf"
+      when Types::BYTE
+        "i8"
+      when Types::I16
+        "i16"
+      when Types::I32
+        "i32"
+      when Types::I64
+        "i64"
+      when Types::DOUBLE
+        "dbl"
+      when Types::STRING
+        "str"
+      when Types::STRUCT
+        "rec"
+      when Types::MAP
+        "map"
+      when Types::SET
+        "set"
+      when Types::LIST
+        "lst"
+      else
+        raise NotImplementedError
+      end
+    end
+
+    def get_type_id_for_type_name(name)
+      if (name == "tf")
+        result = Types::BOOL
+      elsif (name == "i8")
+        result = Types::BYTE
+      elsif (name == "i16")
+        result = Types::I16
+      elsif (name == "i32")
+        result = Types::I32
+      elsif (name == "i64")
+        result = Types::I64
+      elsif (name == "dbl")
+        result = Types::DOUBLE
+      elsif (name == "str")
+        result = Types::STRING
+      elsif (name == "rec")
+        result = Types::STRUCT
+      elsif (name == "map")
+        result = Types::MAP
+      elsif (name == "set")
+        result = Types::SET
+      elsif (name == "lst")
+        result = Types::LIST
+      else
+        result = Types::STOP
+      end
+      if (result == Types::STOP)
+        raise NotImplementedError
+      end
+      return result
+    end
+
+    # Static helper functions
+
+    # Read 1 character from the trans and verify that it is the expected character ch.
+    # Throw a protocol exception if it is not.
+    def self.read_syntax_char(reader, ch)
+      ch2 = reader.read
+      if (ch2 != ch)
+        raise ProtocolException.new(ProtocolException::INVALID_DATA, "Expected \'#{ch}\' got \'#{ch2}\'.")
+      end
+    end
+
+   # Return true if the character ch is in [-+0-9.Ee]; false otherwise
+    def is_json_numeric(ch)
+      case ch
+      when '+', '-', '.', '0' .. '9', 'E', "e"
+        return true
+      else
+        return false
+      end
+    end
+
+    def push_context(context)
+      @contexts.push(@context)
+      @context = context
+    end
+
+    def pop_context
+      @context = @contexts.pop
+    end
+
+    # Write the character ch as a JSON escape sequence ("\u00xx")
+    def write_json_escape_char(ch)
+      trans.write('\\u')
+      ch_value = ch[0]
+      if (ch_value.kind_of? String)
+        ch_value = ch.bytes.first
+      end
+      trans.write(ch_value.to_s(16).rjust(4,'0'))
+    end
+
+    # Write the character ch as part of a JSON string, escaping as appropriate.
+    def write_json_char(ch)
+      # This table describes the handling for the first 0x30 characters
+      # 0 : escape using "\u00xx" notation
+      # 1 : just output index
+      # <other> : escape using "\<other>" notation
+      kJSONCharTable = [
+          # 0 1 2 3 4 5 6 7 8 9 A B C D E F
+          0, 0, 0, 0, 0, 0, 0, 0,'b','t','n', 0,'f','r', 0, 0, # 0
+          0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, # 1
+          1, 1,'"', 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, # 2
+      ]
+
+      ch_value = ch[0]
+      if (ch_value.kind_of? String)
+        ch_value = ch.bytes.first
+      end
+      if (ch_value >= 0x30)
+        if (ch == @@kJSONBackslash) # Only special character >= 0x30 is '\'
+          trans.write(@@kJSONBackslash)
+          trans.write(@@kJSONBackslash)
+        else
+          trans.write(ch)
+        end
+      else
+        outCh = kJSONCharTable[ch_value];
+        # Check if regular character, backslash escaped, or JSON escaped
+        if outCh.kind_of? String
+          trans.write(@@kJSONBackslash)
+          trans.write(outCh)
+        elsif outCh == 1
+          trans.write(ch)
+        else
+          write_json_escape_char(ch)
+        end
+      end
+    end
+
+    # Write out the contents of the string str as a JSON string, escaping characters as appropriate.
+    def write_json_string(str)
+      @context.write(trans)
+      trans.write(@@kJSONStringDelimiter)
+      str.split('').each do |ch|
+        write_json_char(ch)
+      end
+      trans.write(@@kJSONStringDelimiter)
+    end
+
+    # Write out the contents of the string as JSON string, base64-encoding
+    # the string's contents, and escaping as appropriate
+    def write_json_base64(str)
+      @context.write(trans)
+      trans.write(@@kJSONStringDelimiter)
+      write_json_string([str].pack("m"))
+      trans.write(@@kJSONStringDelimiter)
+    end
+
+    # Convert the given integer type to a JSON number, or a string
+    # if the context requires it (eg: key in a map pair).
+    def write_json_integer(num)
+      @context.write(trans)
+      escapeNum = @context.escapeNum
+      if (escapeNum)
+        trans.write(@@kJSONStringDelimiter)
+      end
+      trans.write(num.to_s);
+      if (escapeNum)
+        trans.write(@@kJSONStringDelimiter)
+      end
+    end
+
+    # Convert the given double to a JSON string, which is either the number,
+    # "NaN" or "Infinity" or "-Infinity".
+    def write_json_double(num)
+      @context.write(trans)
+      # Normalize output of boost::lexical_cast for NaNs and Infinities
+      special = false;
+      if (num.nan?)
+        special = true;
+        val = @@kThriftNan;
+      elsif (num.infinite?)
+        special = true;
+        val = @@kThriftInfinity;
+        if (num < 0.0)
+          val = @@kThriftNegativeInfinity;
+        end
+      else
+        val = num.to_s
+      end
+
+      escapeNum = special || @context.escapeNum
+      if (escapeNum)
+        trans.write(@@kJSONStringDelimiter)
+      end
+      trans.write(val)
+      if (escapeNum)
+        trans.write(@@kJSONStringDelimiter)
+      end
+    end
+
+    def write_json_object_start
+      @context.write(trans)
+      trans.write(@@kJSONObjectStart)
+      push_context(JSONPairContext.new);
+    end
+
+    def write_json_object_end
+      pop_context
+      trans.write(@@kJSONObjectEnd)
+    end
+
+    def write_json_array_start
+      @context.write(trans)
+      trans.write(@@kJSONArrayStart)
+      push_context(JSONListContext.new);
+    end
+
+    def write_json_array_end
+      pop_context
+      trans.write(@@kJSONArrayEnd)
+    end
+
+    def write_message_begin(name, type, seqid)
+      write_json_array_start
+      write_json_integer(@@kThriftVersion1)
+      write_json_string(name)
+      write_json_integer(type)
+      write_json_integer(seqid)
+    end
+
+    def write_message_end
+      write_json_array_end
+    end
+
+    def write_struct_begin(name)
+      write_json_object_start
+    end
+
+    def write_struct_end
+      write_json_object_end
+    end
+
+    def write_field_begin(name, type, id)
+      write_json_integer(id)
+      write_json_object_start
+      write_json_string(get_type_name_for_type_id(type))
+    end
+
+    def write_field_end
+      write_json_object_end
+    end
+
+    def write_field_stop; nil; end
+
+    def write_map_begin(ktype, vtype, size)
+      write_json_array_start
+      write_json_string(get_type_name_for_type_id(ktype))
+      write_json_string(get_type_name_for_type_id(vtype))
+      write_json_integer(size)
+      write_json_object_start
+    end
+
+    def write_map_end
+      write_json_object_end
+      write_json_array_end
+    end
+
+    def write_list_begin(etype, size)
+      write_json_array_start
+      write_json_string(get_type_name_for_type_id(etype))
+      write_json_integer(size)
+    end
+
+    def write_list_end
+      write_json_array_end
+    end
+
+    def write_set_begin(etype, size)
+      write_json_array_start
+      write_json_string(get_type_name_for_type_id(etype))
+      write_json_integer(size)
+    end
+
+    def write_set_end
+      write_json_array_end
+    end
+
+    def write_bool(bool)
+      write_json_integer(bool ? 1 : 0)
+    end
+
+    def write_byte(byte)
+      write_json_integer(byte)
+    end
+
+    def write_i16(i16)
+      write_json_integer(i16)
+    end
+
+    def write_i32(i32)
+      write_json_integer(i32)
+    end
+
+    def write_i64(i64)
+      write_json_integer(i64)
+    end
+
+    def write_double(dub)
+      write_json_double(dub)
+    end
+
+    def write_string(str)
+      write_json_string(str)
+    end
+
+    def write_binary(str)
+      write_json_base64(str)
+    end
+
+    ##
+    # Reading functions
+    ##
+
+    # Reads 1 byte and verifies that it matches ch.
+    def read_json_syntax_char(ch)
+      JsonProtocol::read_syntax_char(@reader, ch)
+    end
+
+    # Decodes the four hex parts of a JSON escaped string character and returns
+    # the character via out. The first two characters must be "00".
+    def read_json_escape_char
+      read_json_syntax_char('0')
+      read_json_syntax_char('0')
+      str = @reader.read
+      str += @reader.read
+      str.hex.chr
+    end
+
+    # Decodes a JSON string, including unescaping, and returns the string via str
+    def read_json_string(skipContext = false)
+      # This string's characters must match up with the elements in escape_char_vals.
+      # I don't have '/' on this list even though it appears on www.json.org --
+      # it is not in the RFC
+      escape_chars = "\"\\bfnrt"
+
+      # The elements of this array must match up with the sequence of characters in
+      # escape_chars
+      escape_char_vals = [
+        '"', '\\', '\b', '\f', '\n', '\r', '\t',
+      ]
+
+      if !skipContext
+        @context.read(@reader)
+      end
+      read_json_syntax_char(@@kJSONStringDelimiter)
+      ch = ""
+      str = ""
+      while (true)
+        ch = @reader.read
+        if (ch == @@kJSONStringDelimiter)
+          break
+        end
+        if (ch == @@kJSONBackslash)
+          ch = @reader.read
+          if (ch == 'u')
+            ch = read_json_escape_char
+          else
+            pos = escape_chars.index(ch);
+            if (pos.nil?) # not found
+              raise ProtocolException.new(ProtocolException::INVALID_DATA, "Expected control char, got \'#{ch}\'.")
+            end
+            ch = escape_char_vals[pos]
+          end
+        end
+        str += ch
+      end
+      return str
+    end
+
+    # Reads a block of base64 characters, decoding it, and returns via str
+    def read_json_base64
+      read_json_string.unpack("m")[0]
+    end
+
+    # Reads a sequence of characters, stopping at the first one that is not
+    # a valid JSON numeric character.
+    def read_json_numeric_chars
+      str = ""
+      while (true)
+        ch = @reader.peek
+        if (!is_json_numeric(ch))
+          break;
+        end
+        ch = @reader.read
+        str += ch
+      end
+      return str
+    end
+
+    # Reads a sequence of characters and assembles them into a number,
+    # returning them via num
+    def read_json_integer
+      @context.read(@reader)
+      if (@context.escapeNum)
+        read_json_syntax_char(@@kJSONStringDelimiter)
+      end
+      str = read_json_numeric_chars
+
+      begin
+        num = Integer(str);
+      rescue
+        raise ProtocolException.new(ProtocolException::INVALID_DATA, "Expected numeric value; got \"#{str}\"")
+      end
+
+      if (@context.escapeNum)
+        read_json_syntax_char(@@kJSONStringDelimiter)
+      end
+
+      return num
+    end
+
+    # Reads a JSON number or string and interprets it as a double.
+    def read_json_double
+      @context.read(@reader)
+      num = 0
+      if (@reader.peek == @@kJSONStringDelimiter)
+        str = read_json_string(true)
+        # Check for NaN, Infinity and -Infinity
+        if (str == @@kThriftNan)
+          num = (+1.0/0.0)/(+1.0/0.0)
+        elsif (str == @@kThriftInfinity)
+          num = +1.0/0.0
+        elsif (str == @@kThriftNegativeInfinity)
+          num = -1.0/0.0
+        else
+          if (!@context.escapeNum)
+            # Raise exception -- we should not be in a string in this case
+            raise ProtocolException.new(ProtocolException::INVALID_DATA, "Numeric data unexpectedly quoted")
+          end
+          begin
+            num = Float(str)
+          rescue
+            raise ProtocolException.new(ProtocolException::INVALID_DATA, "Expected numeric value; got \"#{str}\"")
+          end
+        end
+      else
+        if (@context.escapeNum)
+          # This will throw - we should have had a quote if escapeNum == true
+          read_json_syntax_char(@@kJSONStringDelimiter)
+        end
+        str = read_json_numeric_chars
+        begin
+          num = Float(str)
+        rescue
+          raise ProtocolException.new(ProtocolException::INVALID_DATA, "Expected numeric value; got \"#{str}\"")
+        end
+      end
+      return num
+    end
+
+    def read_json_object_start
+      @context.read(@reader)
+      read_json_syntax_char(@@kJSONObjectStart)
+      push_context(JSONPairContext.new)
+      nil
+    end
+
+    def read_json_object_end
+      read_json_syntax_char(@@kJSONObjectEnd)
+      pop_context
+      nil
+    end
+
+    def read_json_array_start
+      @context.read(@reader)
+      read_json_syntax_char(@@kJSONArrayStart)
+      push_context(JSONListContext.new)
+      nil
+    end
+
+    def read_json_array_end
+      read_json_syntax_char(@@kJSONArrayEnd)
+      pop_context
+      nil
+    end
+
+    def read_message_begin
+      read_json_array_start
+      version = read_json_integer
+      if (version != @@kThriftVersion1)
+        raise ProtocolException.new(ProtocolException::BAD_VERSION, 'Message contained bad version.')
+      end
+      name = read_json_string
+      message_type = read_json_integer
+      seqid = read_json_integer
+      [name, message_type, seqid]
+    end
+
+    def read_message_end
+      read_json_array_end
+      nil
+    end
+
+    def read_struct_begin
+      read_json_object_start
+      nil
+    end
+
+    def read_struct_end
+      read_json_object_end
+      nil
+    end
+
+    def read_field_begin
+      # Check if we hit the end of the list
+      ch = @reader.peek
+      if (ch == @@kJSONObjectEnd)
+        field_type = Types::STOP
+      else
+        field_id = read_json_integer
+        read_json_object_start
+        field_type = get_type_id_for_type_name(read_json_string)
+      end
+      [nil, field_type, field_id]
+    end
+
+    def read_field_end
+      read_json_object_end
+    end
+
+    def read_map_begin
+      read_json_array_start
+      key_type = get_type_id_for_type_name(read_json_string)
+      val_type = get_type_id_for_type_name(read_json_string)
+      size = read_json_integer
+      read_json_object_start
+      [key_type, val_type, size]
+    end
+
+    def read_map_end
+      read_json_object_end
+      read_json_array_end
+    end
+
+    def read_list_begin
+      read_json_array_start
+      [get_type_id_for_type_name(read_json_string), read_json_integer]
+    end
+
+    def read_list_end
+      read_json_array_end
+    end
+
+    def read_set_begin
+      read_json_array_start
+    end
+
+    def read_set_end
+      read_json_array_end
+    end
+
+    def read_bool
+      byte = read_byte
+      byte != 0
+    end
+
+    def read_byte
+      read_json_integer
+    end
+
+    def read_i16
+      read_json_integer
+    end
+
+    def read_i32
+      read_json_integer
+    end
+
+    def read_i64
+      read_json_integer
+    end
+
+    def read_double
+      read_json_double
+    end
+
+    def read_string
+      read_json_string
+    end
+
+    def read_binary
+      read_json_base64
+    end
+  end
+
+  class JsonProtocolFactory < BaseProtocolFactory
+    def get_protocol(trans)
+      return Thrift::JsonProtocol.new(trans)
+    end
+  end
+end