Class: SimplerDB::RESTServlet

Inherits:
WEBrick::HTTPServlet::AbstractServlet
  • Object
show all
Defined in:
lib/simplerdb/servlet.rb

Overview

A WEBrick servlet to handle API requests over REST

Instance Method Summary collapse

Instance Method Details

#build_result(action) ⇒ Object

Build a result for the given action. The given block will add action-specific return fields.



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# File 'lib/simplerdb/servlet.rb', line 151

def build_result(action)
  xml = ''
  doc = Builder::XmlMarkup.new(:target => xml)
    doc.tag!("#{action}Response", :xmlns => "http://sdb.amazonaws.com/doc/2007-11-07") do
      if block_given?
        yield doc
      end
      
      doc.ResponseMetadata do
        doc.RequestId "1234"
        doc.BoxUsage "0"
      end
    end
    
  xml
end

#do_createdomain(req) ⇒ Object

Handle CreateDomain requests



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# File 'lib/simplerdb/servlet.rb', line 49

def do_createdomain(req)
  name = req.query["DomainName"]
  DB.instance.create_domain(name)
  build_result("CreateDomain")
end

#do_deleteattributes(req) ⇒ Object

DeleteAttributes requests



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# File 'lib/simplerdb/servlet.rb', line 96

def do_deleteattributes(req)
  domain_name = req.query["DomainName"]
  item_name = req.query["ItemName"]
  attrs = parse_attribute_args(req)
  DB.instance.delete_attributes(domain_name, item_name, attrs)
  build_result("DeleteAttributes")
end

#do_deletedomain(req) ⇒ Object

DeleteDomains requests



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# File 'lib/simplerdb/servlet.rb', line 80

def do_deletedomain(req)
  name = req.query["DomainName"]
  DB.instance.delete_domain(name)
  build_result("DeleteDomain")  
end

#do_GET(req, res) ⇒ Object Also known as: do_POST, do_DELETE 



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# File 'lib/simplerdb/servlet.rb', line 24

def do_GET(req, res)
  action = req.query["Action"]
  
  begin
    if action.nil?
      # Raise an error
      raise ClientException.new(:MissingAction, "No action was supplied with this request")
    else
      # Process the action appropriately
      xml = eval("do_#{action.downcase}(req)")
      res.body = xml
      res.status = 200
    end
  rescue ClientException => e
    res.body = error_xml(e.code, e.msg)
    res.status = 400 # What is the right status?
  end
  
  res['content-type'] = 'text/xml'
end

#do_getattributes(req) ⇒ Object

GetAttributes request



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# File 'lib/simplerdb/servlet.rb', line 105

def do_getattributes(req)
  domain_name = req.query["DomainName"]
  item_name = req.query["ItemName"]
  attr_name = req.query["AttributeName"]
  attrs = DB.instance.get_attributes(domain_name, item_name)
  
  build_result("GetAttributes") do |doc|
    doc.GetAttributesResult do
      if attrs
        attrs.each do |attr|
          doc.Attribute do
            doc.Name attr.name
            doc.Value attr.value
          end
        end
      end
    end
  end
end

#do_listdomains(req) ⇒ Object

Handle ListDomains requests



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# File 'lib/simplerdb/servlet.rb', line 56

def do_listdomains(req)
  max = req.query["MaxNumberOfDomains"]
  next_token = req.query["NextToken"]
  
  max = max.to_i if max
  domains,token = DB.instance.list_domains(max, next_token)
  
  build_result("ListDomains") do |doc|
    doc.ListDomainsResult do
      if domains
        domains.each do |domain|
          doc.DomainName domain
        end
      end
      
      if token
        doc.NextToken token
      end
    end
  end
end

#do_putattributes(req) ⇒ Object

PutAttributes requests



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# File 'lib/simplerdb/servlet.rb', line 87

def do_putattributes(req)
  domain_name = req.query["DomainName"]
  item_name = req.query["ItemName"]
  attrs = parse_attribute_args(req)
  DB.instance.put_attributes(domain_name, item_name, attrs)
  build_result("PutAttributes")
end

#do_query(req) ⇒ Object

Query request



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# File 'lib/simplerdb/servlet.rb', line 126

def do_query(req)
  domain_name = req.query["DomainName"]
  max_items = req.query["MaxItems"].to_i
  max_items = 100 if (max_items < 1 || max_items > 250)
  next_token = req.query["NextToken"]
  query = req.query["QueryExpression"]
  
  results,token = DB.instance.query(domain_name, query, max_items, next_token)
  build_result("Query") do |doc|
    doc.QueryResult do
      if results
        results.each do |res|
          doc.ItemName res.name
        end
      end
    
      if token
        doc.NextToken token
      end
    end
  end
end

#error_xml(code, msg) ⇒ Object

Return the error response for the given error code and message



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# File 'lib/simplerdb/servlet.rb', line 169

def error_xml(code, msg)
  xml = ''
  doc = Builder::XmlMarkup.new(:target => xml)
  
  doc.Response do
    doc.Errors do
      doc.Error do
        doc.Code code.to_s
        doc.Message msg
        doc.BoxUsage "0"
      end
    end
    
    doc.RequestID  "1234"
  end
  
  xml
end

#parse_attribute_args(req) ⇒ Object 



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# File 'lib/simplerdb/servlet.rb', line 188

def parse_attribute_args(req)
  args = []
  for i in (0...100)
    name = req.query["Attribute.#{i}.Name"]
    value = req.query["Attribute.#{i}.Value"]
    replace = (req.query["Attribute.#{i}.Replace"] == "true")
    if name && value
      args << AttributeParam.new(name, value, replace)
    end
  end
  
  args
end