Class: Rack::Session::Memcache
- Inherits:
-
Abstract::ID
- Object
- Abstract::ID
- Rack::Session::Memcache
- Defined in:
- rack/rack/session/memcache.rb
Overview
Rack::Session::Memcache provides simple cookie based session management. Session data is stored in memcached. The corresponding session key is maintained in the cookie. You may treat Session::Memcache as you would Session::Pool with the following caveats.
-
Setting :expire_after to 0 would note to the Memcache server to hang onto the session data until it would drop it according to it's own specifications. However, the cookie sent to the client would expire immediately.
Note that memcache does drop data before it may be listed to expire. For a full description of behaviour, please see memcache's documentation.
Constant Summary
- DEFAULT_OPTIONS =
Abstract::ID::DEFAULT_OPTIONS.merge ::namespace => 'rack:session', :memcache_server => 'localhost:11211'
Instance Attribute Summary (collapse)
-
- (void) default_options
inherited
from Abstract::ID
readonly
Returns the value of attribute default_options.
-
- (void) key
inherited
from Abstract::ID
readonly
Returns the value of attribute key.
-
- (void) mutex
readonly
Returns the value of attribute mutex.
-
- (void) pool
readonly
Returns the value of attribute pool.
Instance Method Summary (collapse)
- - (void) destroy_session(env, session_id, options)
- - (void) generate_sid
- - (void) get_session(env, sid)
-
- (Memcache) initialize(app, options = {})
constructor
A new instance of Memcache.
- - (void) set_session(env, session_id, new_session, options)
- - (void) with_lock(env, default = nil)
Constructor Details
- (Memcache) initialize(app, options = {})
Returns a new instance of Memcache
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# File 'rack/rack/session/memcache.rb', line 29 def initialize(app, ={}) super @mutex = Mutex.new mserv = @default_options[:memcache_server] mopts = @default_options.reject{|k,v| !MemCache::DEFAULT_OPTIONS.include? k } @pool = [:cache] || MemCache.new(mserv, mopts) unless @pool.active? and @pool.servers.any?{|c| c.alive? } raise 'No memcache servers' end end |
Instance Attribute Details
- (void) default_options (readonly) Originally defined in class Abstract::ID
Returns the value of attribute default_options
- (void) key (readonly) Originally defined in class Abstract::ID
Returns the value of attribute key
- (void) mutex (readonly)
Returns the value of attribute mutex
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# File 'rack/rack/session/memcache.rb', line 23 def mutex @mutex end |
- (void) pool (readonly)
Returns the value of attribute pool
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# File 'rack/rack/session/memcache.rb', line 23 def pool @pool end |
Instance Method Details
- (void) destroy_session(env, session_id, options)
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# File 'rack/rack/session/memcache.rb', line 71 def destroy_session(env, session_id, ) with_lock(env) do @pool.delete(session_id) generate_sid unless [:drop] end end |
- (void) generate_sid
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# File 'rack/rack/session/memcache.rb', line 42 def generate_sid loop do sid = super break sid unless @pool.get(sid, true) end end |
- (void) get_session(env, sid)
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# File 'rack/rack/session/memcache.rb', line 49 def get_session(env, sid) with_lock(env, [nil, {}]) do unless sid and session = @pool.get(sid) sid, session = generate_sid, {} unless /^STORED/ =~ @pool.add(sid, session) raise "Session collision on '#{sid.inspect}'" end end [sid, session] end end |
- (void) set_session(env, session_id, new_session, options)
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# File 'rack/rack/session/memcache.rb', line 61 def set_session(env, session_id, new_session, ) expiry = [:expire_after] expiry = expiry.nil? ? 0 : expiry + 1 with_lock(env, false) do @pool.set session_id, new_session, expiry session_id end end |
- (void) with_lock(env, default = nil)
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# File 'rack/rack/session/memcache.rb', line 78 def with_lock(env, default=nil) @mutex.lock if env['rack.multithread'] yield rescue MemCache::MemCacheError, Errno::ECONNREFUSED if $VERBOSE warn "#{self} is unable to find memcached server." warn $!.inspect end default ensure @mutex.unlock if @mutex.locked? end |