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

Constant Summary collapse

Split =
Header::Split
Multiple =
Header::Multiple
TRAILER =
'trailer'
POLICY =
{
	# Headers which may only be specified once.
	'content-type' => false,
	'content-disposition' => false,
	'content-length' => false,
	'user-agent' => false,
	'referer' => false,
	'host' => false,
	'if-modified-since' => false,
	'if-unmodified-since' => false,
	'from' => false,
	'location' => false,
	'max-forwards' => false,
	
	# Custom headers:
	'connection' => Header::Connection,
	'cache-control' => Header::CacheControl,
	'vary' => Header::Vary,
	
	# Headers specifically for proxies:
	'via' => Split,
	'x-forwarded-for' => Split,
	
	# Authorization headers:
	'authorization' => Header::Authorization,
	'proxy-authorization' => Header::Authorization,
	
	# Cache validations:
	'etag' => Header::ETag,
	'if-match' => Header::ETags,
	'if-none-match' => Header::ETags,
	
	# Headers which may be specified multiple times, but which can't be concatenated:
	'www-authenticate' => Multiple,
	'proxy-authenticate' => Multiple,
	
	# Custom headers:
	'set-cookie' => Header::SetCookie,
	'cookie' => Header::Cookie,
}.tap{|hash| hash.default = Split}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

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

Returns a new instance of Headers.


66
67
68
69
70
71
72
# File 'lib/protocol/http/headers.rb', line 66

def initialize(fields = [], indexed = nil)
	@fields = fields
	@indexed = indexed
	
	# Marks where trailer start in the @fields array.
	@tail = nil
end

Instance Attribute Details

#fieldsObject (readonly)

An array of `[key, value]` pairs.


102
103
104
# File 'lib/protocol/http/headers.rb', line 102

def fields
  @fields
end

Class Method Details

.[](headers) ⇒ Headers

Construct an instance from a headers Array or Hash. No-op if already an instance of `Headers`. If the underlying array is frozen, it will be duped.

Returns:

  • (Headers)

    an instance of headers.


44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
# File 'lib/protocol/http/headers.rb', line 44

def self.[] headers
	if headers.nil?
		return self.new
	end
	
	if headers.is_a?(self)
		if headers.frozen?
			return headers.dup
		else
			return headers
		end
	end
	
	fields = headers.to_a
	
	if fields.frozen?
		fields = fields.dup
	end
	
	return self.new(fields)
end

Instance Method Details

#==(other) ⇒ Object


309
310
311
312
313
314
315
316
317
318
# File 'lib/protocol/http/headers.rb', line 309

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

#[](key) ⇒ Object


292
293
294
# File 'lib/protocol/http/headers.rb', line 292

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.


205
206
207
208
209
210
211
# File 'lib/protocol/http/headers.rb', line 205

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

#add(key, value) ⇒ Object

Add the specified header key value pair.

Parameters:

  • key (String)

    the header key.

  • value (String)

    the header value to assign.


177
178
179
# File 'lib/protocol/http/headers.rb', line 177

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

#clearObject


81
82
83
84
85
# File 'lib/protocol/http/headers.rb', line 81

def clear
	@fields.clear
	@indexed = nil
	@tail = nil
end

#delete(key) ⇒ Object

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


255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
# File 'lib/protocol/http/headers.rb', line 255

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 = 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

#each(&block) ⇒ Object


147
148
149
# File 'lib/protocol/http/headers.rb', line 147

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

#empty?Boolean

Returns:

  • (Boolean)

143
144
145
# File 'lib/protocol/http/headers.rb', line 143

def empty?
	@fields.empty?
end

#extract(keys) ⇒ Object


159
160
161
162
163
164
165
166
167
168
169
170
171
# File 'lib/protocol/http/headers.rb', line 159

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

#flattenObject


97
98
99
# File 'lib/protocol/http/headers.rb', line 97

def flatten
	self.dup.flatten!
end

#flatten!Object

Flatten trailer into the headers.


88
89
90
91
92
93
94
95
# File 'lib/protocol/http/headers.rb', line 88

def flatten!
	if @tail
		self.delete(TRAILER)
		@tail = nil
	end
	
	return self
end

#freezeObject


131
132
133
134
135
136
137
138
139
140
141
# File 'lib/protocol/http/headers.rb', line 131

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

#include?(key) ⇒ Boolean

Returns:

  • (Boolean)

151
152
153
# File 'lib/protocol/http/headers.rb', line 151

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

#initialize_dup(other) ⇒ Object


74
75
76
77
78
79
# File 'lib/protocol/http/headers.rb', line 74

def initialize_dup(other)
	super
	
	@fields = @fields.dup
	@indexed = @indexed.dup
end

#inspectObject


305
306
307
# File 'lib/protocol/http/headers.rb', line 305

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

#keysObject


155
156
157
# File 'lib/protocol/http/headers.rb', line 155

def keys
	self.to_h.keys
end

#merge(headers) ⇒ Object


198
199
200
# File 'lib/protocol/http/headers.rb', line 198

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

#merge!(headers) ⇒ Object


190
191
192
193
194
195
196
# File 'lib/protocol/http/headers.rb', line 190

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

#set(key, value) ⇒ Object

Set the specified header key to the specified value, replacing any existing header keys with the same name.

Parameters:

  • key (String)

    the header key to replace.

  • value (String)

    the header value to assign.


184
185
186
187
188
# File 'lib/protocol/http/headers.rb', line 184

def set(key, value)
	# TODO This could be a bit more efficient:
	self.delete(key)
	self.add(key, value)
end

#to_hObject

A hash table of `policy.map(values)`


297
298
299
300
301
302
303
# File 'lib/protocol/http/headers.rb', line 297

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

#trailer(&block) ⇒ Object

Enumerate all headers in the trailer, if there are any.


123
124
125
126
127
128
129
# File 'lib/protocol/http/headers.rb', line 123

def trailer(&block)
	return to_enum(:trailer) unless block_given?
	
	if @tail
		@fields.drop(@tail).each(&block)
	end
end

#trailer!(&block) ⇒ Object

Record the current headers, and prepare to receive trailer.


110
111
112
113
114
115
116
117
118
119
120
# File 'lib/protocol/http/headers.rb', line 110

def trailer!(&block)
	return nil unless self.include?(TRAILER)
	
	@tail ||= @fields.size
	
	return to_enum(:trailer!) unless block_given?
	
	if @tail
		@fields.drop(@tail).each(&block)
	end
end

#trailer?Boolean

Returns the trailer if there are any.

Returns:

  • (Boolean)

    the trailer if there are any.


105
106
107
# File 'lib/protocol/http/headers.rb', line 105

def trailer?
	@tail != nil
end