Class: Blix::Rest::RequestMapper

Inherits:
Object
  • Object
show all
Defined in:
lib/blix/rest/request_mapper.rb

Overview

register routes with this class and then we can match paths to these routes and return an associated block and parameters.

Defined Under Namespace

Classes: TableNode

Constant Summary collapse

WILD_PLACEHOLDER = 
'/'
PATH_SEP = 
'/'
STAR_PLACEHOLDER = 
'*'
@@mutex = 
Mutex.new

Class Method Summary collapse

Class Method Details

.add_path(verb, path, opts = {}, &blk) ⇒ Object

declare a route



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# File 'lib/blix/rest/request_mapper.rb', line 165

def add_path(verb, path, opts = {}, &blk)
  path = path[1..-1] if path[0, 1] == PATH_SEP
  RequestMapper.locations[verb] << [verb, path, opts, blk]
  @table = nil # force recompile
  true
end

.compile ⇒ Object

compile routes into a tree structure for easy lookup



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# File 'lib/blix/rest/request_mapper.rb', line 131

def compile
  @table = Hash.new { |h, k| h[k] = TableNode.new('') }
  locations.each do |verb, routes|
    routes.each do |info|
      verb, path, opts, blk = info
      parts = path.split(PATH_SEP)
      current = @table[verb]
      parts.each_with_index do |section, idx|
        node = TableNode.new(section)
        # check that a wildstar is the last element.
        if (section[0] == STAR_PLACEHOLDER) && (idx < (parts.length - 1))
          raise RequestMapperError, "do not add a path after the * in #{path}"
        end

        # check that wild card match in name
        if current[node.value]
          if (node.value == WILD_PLACEHOLDER) && (node.parameter != current[node.value].parameter)
            raise RequestMapperError, "parameter mismatch in route=#{path}, expected #{current[node.value].parameter} but got #{node.parameter}"
          end

        else
          current[node.value] = node
        end
        current = current[node.value]
      end
      current.blk = blk
      current.opts = opts || {}
      current.extract_format = opts[:extension] if opts.key?(:extension)
    end
  end
  @table
end

.dump ⇒ Object 



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# File 'lib/blix/rest/request_mapper.rb', line 101

def dump
  table.each do |k, v|
    puts k
    dump_node(v, 1)
  end
end

.dump_node(item, indent = 0) ⇒ Object 



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# File 'lib/blix/rest/request_mapper.rb', line 108

def dump_node(item, indent = 0)
  puts "#{' ' * indent} value=#{item.value.inspect} opts=#{item.opts.inspect} params=#{item.parameter.inspect}"
  item.children.each_value { |c| dump_node(c, indent + 1) }
end

.ensure_full_path(path) ⇒ Object

ensure that absolute path is the full path



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# File 'lib/blix/rest/request_mapper.rb', line 85

def ensure_full_path(path)
  if path[0, 1] == '/' && (path_root_length>0) && path[0, path_root_length] != path_root[0, path_root_length]
    path = path_root + path[1..-1]
  end
  path
end

.full_path(path) ⇒ Object 



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# File 'lib/blix/rest/request_mapper.rb', line 79

def full_path(path)
  path = path[1..-1] if path[0, 1] == '/'
  path_root + path
end

.locations ⇒ Object 



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# File 'lib/blix/rest/request_mapper.rb', line 92

def locations
  @locations ||= Hash.new { |h, k| h[k] = [] }
end

.match(verb, path) ⇒ Object

match a given path to declared route.



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# File 'lib/blix/rest/request_mapper.rb', line 173

def match(verb, path)
  path = PATH_SEP + path if path[0, 1] != PATH_SEP # ensure a leading slash on path

  path = path[path_root_length..-1] if (path_root_length.to_i > 0) #&& (path[0,path_root_length] == path_root)
  if path
    path = path[1..-1] if path[0, 1] == PATH_SEP # remove the leading slash
  else
    return [nil, {}, nil]
  end

  parameters = StringHash.new

  parts = path.split(PATH_SEP)
  current = table[verb]
  limit   = parts.length - 1

  # handle the root node here
  if path == ''
    if current.blk
      return [current.blk, parameters, current.opts]
    elsif (havewild = current[STAR_PLACEHOLDER])
      parameters[havewild.parameter.to_s] = '/'
      return [havewild.blk, parameters, havewild.opts]
    else
      return [nil, {}, nil]
    end
  end

  parts.each_with_index do |section, idx|
    # first save the last node that we used
    # before updating the current node.

    last = current # table nodes

    # check to see if there is a path which includes a format part
    # only on the last section
    if idx == limit
      if last[section]
        current = last[section]
      else
        format  = File.extname(section)
        base    = File.basename(section, format)
        current = last[base]
        if current
          parameters['format'] = format[1..-1].to_sym # !format.empty?
          section = base
        end
      end
    else
      current = last[section]
    end

    # if current is set here that means that this section matches a fixed
    # part of the route.
    if current

      # if this is the last section then we have to decide here if we
      # have a valid result..
      # .. if we have a block then fine ..
      # .. if there is a wildpath foloowing then fine ..
      # .. otherwise an error !

      if idx == limit # the last section of path
        if current.blk
          return [current.blk, parameters, current.opts]
        elsif (havewild = current[STAR_PLACEHOLDER])
          parameters[havewild.parameter.to_s] = '/'
          return [havewild.blk, parameters, havewild.opts, true]
        else
          return [nil, {}, nil]
        end
      end
    else

      # this section is  not part of a static path so
      # check if we have a path variable first ..

      current = last[WILD_PLACEHOLDER]
      if current

        # yes this is a path variable section
        if idx == limit

          # the last section of request -
          if current.extract_format
            format  = File.extname(section)
            base    = File.basename(section, format)
            parameters[current.parameter.to_s] = base
            parameters['format'] = format[1..-1].to_sym unless format.empty?
          else
            parameters[current.parameter.to_s] = section
          end

          # check if we have a valid block otherwise see if
          # a wild path follows.

          if current.blk
            return [current.blk, parameters, current.opts]
          elsif (havewild = current[STAR_PLACEHOLDER])
            parameters[havewild.parameter.to_s] = '/'
            return [havewild.blk, parameters, havewild.opts, true]
          else
            return [nil, {}, nil]
          end

        else
          parameters[current.parameter.to_s] = section
        end
      else
        current = last[STAR_PLACEHOLDER]
        if current
          wildpath = '/' + parts[idx..-1].join('/')
          wildformat = File.extname(wildpath)
          unless wildformat.empty? || !current.extract_format
            wildpath = wildpath[0..-(wildformat.length + 1)]
            parameters['format'] = wildformat[1..-1].to_sym
          end
          parameters[current.parameter.to_s] = wildpath
          return [current.blk, parameters, current.opts, true]
        else
          return [nil, {}, nil]
        end
      end
    end
  end
  [nil, {}, nil]
end

.path_root ⇒ Object

if the path_root has not been set then return ‘/’



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# File 'lib/blix/rest/request_mapper.rb', line 70

def path_root
  @path_root || '/'
end

.path_root_length ⇒ Object

return 0 if the path_root has not been set



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# File 'lib/blix/rest/request_mapper.rb', line 75

def path_root_length
  @path_root_length || 0
end

.process(verb, path) ⇒ Object

match a path to a route and call any associated block with the extracted parameters.



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# File 'lib/blix/rest/request_mapper.rb', line 302

def process(verb, path)
  blk, params = match(verb, path)
  blk&.call(params)
end

.reset(vals = nil) ⇒ Object

used for testing only !!



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# File 'lib/blix/rest/request_mapper.rb', line 114

def reset(vals = nil)
  save = [@table&.dup, @locations&.dup, @path_root&.dup, @path_root_length]
  if vals
    @table     = vals[0]
    @locations = vals[1]
    @path_root = vals[2]
    @path_root_length = vals[3]
  else
    @table     = nil
    @locations = nil
    @path_root = nil
    @path_root_length = 0
  end
  save
end

.routes ⇒ Object 



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# File 'lib/blix/rest/request_mapper.rb', line 307

def routes
  hash = {}
  locations.values.each do |group|
    group.each do |route|
      verb = route[0]
      options = route[2]
      options_string = String.new
      options_string = ' ' + options.inspect.to_s unless options.empty?
      path = '/' + route[1]
      hash[path] ||= {}
      hash[path][verb] = options_string
    end
  end
  list = hash.to_a
  list.sort! { |a, b| a[0] <=> b[0] }
  str = String.new
  list.each do |route|
    pairs = route[1].to_a.sort{|a,b| a[0]<=>b[0]}
    pairs.each do |pair|
      str << pair[0] << "\t" << route[0] << "\t" << pair[1] << "\n"
    end
    str << "\n"
  end
  str
end

.set_path_root(root) ⇒ Object

the root always starts with ‘/’ and finishes with ‘/’



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# File 'lib/blix/rest/request_mapper.rb', line 61

def set_path_root(root)
  root = root.to_s
  root = '/' + root unless root.start_with?('/')
  root += '/' unless root.end_with?('/')
  @path_root = root
  @path_root_length = @path_root.length - 1
end

.table ⇒ Object 



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# File 'lib/blix/rest/request_mapper.rb', line 96

def table
  # compile the table in one thread only.
  @table || @@mutex.synchronize{@table ||= compile}
end