Class: Protocol::HTTP::Headers

Inherits:
Object
  • Object
show all
Defined in:
lib/protocol/http/headers.rb

Overview

Headers are an array of key-value pairs. Some header keys represent multiple values.

Defined Under Namespace

Classes: Merged, Multiple, Split

Constant Summary collapse

MERGE_POLICY = 
{
  # Headers which may only be specified once.
  'content-type' => false,
  'content-disposition' => false,
  'content-length' => false,
  'user-agent' => false,
  'referer' => false,
  'host' => false,
  'authorization' => false,
  'proxy-authorization' => false,
  'if-modified-since' => false,
  'if-unmodified-since' => false,
  'from' => false,
  'location' => false,
  'max-forwards' => false,
  
  'connection' => Split,
  
  # Headers specifically for proxies:
  'via' => Split,
  'x-forwarded-for' => Split,
  
  # Headers which may be specified multiple times, but which can't be concatenated.
  'set-cookie' => Multiple,
  'www-authenticate' => Multiple,
  'proxy-authenticate' => Multiple
}.tap{|hash| hash.default = Split}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(fields = nil, indexed = nil) ⇒ Headers

Returns a new instance of Headers.



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# File 'lib/protocol/http/headers.rb', line 61

def initialize(fields = nil, indexed = nil)
  if fields
    @fields = fields.dup
  else
    @fields = []
  end
  
  if indexed
    @indexed = indexed.dup
  else
    @indexed = nil
  end
end

Instance Attribute Details

#fields ⇒ Object (readonly)

An array of ‘[key, value]` pairs.



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# File 'lib/protocol/http/headers.rb', line 85

def fields
  @fields
end

Class Method Details

.[](hash) ⇒ Object 



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# File 'lib/protocol/http/headers.rb', line 57

def self.[] hash
  self.new(hash.to_a)
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/protocol/http/headers.rb', line 238

def == other
  case other
  when Hash
    to_h == other
  when Headers
    @fields == other.fields
  else
    @fields == other
  end
end

#[](key) ⇒ Object 



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# File 'lib/protocol/http/headers.rb', line 221

def [] key
  to_h[key]
end

#[]=(key, value) ⇒ Object

Append the value to the given key. Some values can be appended multiple times, others can only be set once.

Parameters:

  • key (String) —

    The header key.

  • value —

    The header value.



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# File 'lib/protocol/http/headers.rb', line 147

def []= key, value
  if @indexed
    merge_into(@indexed, key.downcase, value)
  end
  
  @fields << [key, value]
end

#add(key, value) ⇒ Object 



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# File 'lib/protocol/http/headers.rb', line 128

def add(key, value)
  self[key] = value
end

#clear ⇒ Object 



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# File 'lib/protocol/http/headers.rb', line 79

def clear
  @fields = []
  @indexed = nil
end

#delete(key) ⇒ Object

Delete all headers with the given key, and return the merged value.



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# File 'lib/protocol/http/headers.rb', line 184

def delete(key)
  deleted, @fields = @fields.partition do |field|
    field.first.downcase == key
  end
  
  if deleted.empty?
    return nil
  end
  
  if @indexed
    return @indexed.delete(key)
  elsif policy = MERGE_POLICY[key]
    (key, value), *tail = deleted
    merged = policy.new(value)
    
    tail.each{|k,v| merged << v}
    
    return merged
  else
    key, value = deleted.last
    return value
  end
end

#dup ⇒ Object 



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# File 'lib/protocol/http/headers.rb', line 75

def dup
  self.class.new(@fields, @indexed)
end

#each(&block) ⇒ Object 



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# File 'lib/protocol/http/headers.rb', line 103

def each(&block)
  @fields.each(&block)
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/protocol/http/headers.rb', line 99

def empty?
  @fields.empty?
end

#extract(keys) ⇒ Object Also known as: slice! 



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# File 'lib/protocol/http/headers.rb', line 111

def extract(keys)
  deleted, @fields = @fields.partition do |field|
    keys.include?(field.first.downcase)
  end
  
  if @indexed
    keys.each do |key|
      @indexed.delete(key)
    end
  end
  
  return deleted
end

#freeze ⇒ Object 



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# File 'lib/protocol/http/headers.rb', line 87

def freeze
  return if frozen?
  
  # Ensure @indexed is generated:
  self.to_h
  
  @fields.freeze
  @indexed.freeze
  
  super
end

#include?(key) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/protocol/http/headers.rb', line 107

def include? key
  self[key] != nil
end

#inspect ⇒ Object 



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# File 'lib/protocol/http/headers.rb', line 234

def inspect
  "#<#{self.class} #{@fields.inspect}>"
end

#merge(headers) ⇒ Object 



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# File 'lib/protocol/http/headers.rb', line 140

def merge(headers)
  self.dup.merge!(headers)
end

#merge!(headers) ⇒ Object 



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# File 'lib/protocol/http/headers.rb', line 132

def merge!(headers)
  headers.each do |key, value|
    self[key] = value
  end
  
  return self
end

#to_h ⇒ Object

A hash table of ‘policy.map(values)`



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# File 'lib/protocol/http/headers.rb', line 226

def to_h
  @indexed ||= @fields.inject({}) do |hash, (key, value)|
    merge_into(hash, key.downcase, value)
    
    hash
  end
end