BotConfig.register BotConfigIntegerValue.new('http.max_redir',
:default => 5,
:desc => "Maximum number of redirections to be used when getting a document")
+ BotConfig.register BotConfigIntegerValue.new('http.expire_time',
+ :default => 60,
+ :desc => "After how many minutes since last use a cached document is considered to be expired")
+ BotConfig.register BotConfigIntegerValue.new('http.max_cache_time',
+ :default => 60*24,
+ :desc => "After how many minutes since first use a cached document is considered to be expired")
+ BotConfig.register BotConfigIntegerValue.new('http.no_expire_cache',
+ :default => false,
+ :desc => "Set this to true if you want the bot to never expire the cached pages")
def initialize(bot)
@bot = bot
+ @cache = Hash.new
@headers = {
'User-Agent' => "rbot http util #{$version} (http://linuxbrit.co.uk/rbot/)",
}
+ @last_response = nil
end
+ attr_reader :last_response
+ attr_reader :headers
# if http_proxy_include or http_proxy_exclude are set, then examine the
# uri to see if this is a proxied uri
# readtimeout:: timeout for reading the response
# opentimeout:: timeout for opening the connection
#
- # simple get request, returns response body if the status code is 200 and
- # the request doesn't timeout.
- def get(uri, readtimeout=10, opentimeout=5, redirs=0)
+ # simple get request, returns (if possible) response body following redirs
+ # and caching if requested
+ # if a block is given, it yields the urls it gets redirected to
+ # TODO we really need something to implement proper caching
+ def get(uri_or_str, readtimeout=10, opentimeout=5, max_redir=@bot.config["http.max_redir"], cache=false)
+ if uri_or_str.kind_of?(URI)
+ uri = uri_or_str
+ else
+ uri = URI.parse(uri_or_str.to_s)
+ end
+ debug "Getting #{uri}"
+
proxy = get_proxy(uri)
proxy.open_timeout = opentimeout
proxy.read_timeout = readtimeout
begin
proxy.start() {|http|
- resp = http.get(uri.request_uri(), @headers)
- case resp.code
- when "200"
+ yield uri.request_uri() if block_given?
+ req = Net::HTTP::Get.new(uri.request_uri(), @headers)
+ if uri.user and uri.password
+ req.basic_auth(uri.user, uri.password)
+ end
+ resp = http.request(req)
+ case resp
+ when Net::HTTPSuccess
+ if cache
+ debug "Caching #{uri.to_s}"
+ cache_response(uri.to_s, resp)
+ end
return resp.body
- when "302"
+ when Net::HTTPRedirection
debug "Redirecting #{uri} to #{resp['location']}"
- if redirs < @bot.config["http.max_redir"]
- return get( URI.parse(resp['location']), readtimeout, opentimeout, redirs+1 )
+ yield resp['location'] if block_given?
+ if max_redir > 0
+ # If cache is an Array, we assume get was called by get_cached
+ # because of a cache miss and that the first value of the Array
+ # was the noexpire value. Since the cache miss might have been
+ # caused by a redirection, we want to try get_cached again
+ # TODO FIXME look at Python's httplib2 for a most likely
+ # better way to handle all this mess
+ if cache.kind_of?(Array)
+ return get_cached( URI.join(uri.to_s, resp['location']), readtimeout, opentimeout, max_redir-1, cache[0])
+ else
+ return get( URI.join(uri.to_s, resp['location']), readtimeout, opentimeout, max_redir-1, cache)
+ end
else
warning "Max redirection reached, not going to #{resp['location']}"
- return nil
end
else
debug "HttpUtil.get return code #{resp.code} #{resp.body}"
end
+ @last_response = resp
return nil
}
rescue StandardError, Timeout::Error => e
error "HttpUtil.get exception: #{e.inspect}, while trying to get #{uri}"
+ debug e.backtrace.join("\n")
end
+ @last_response = nil
return nil
end
+
+ # just like the above, but only gets the head
+ def head(uri_or_str, readtimeout=10, opentimeout=5, max_redir=@bot.config["http.max_redir"])
+ if uri_or_str.kind_of?(URI)
+ uri = uri_or_str
+ else
+ uri = URI.parse(uri_or_str.to_s)
+ end
+
+ proxy = get_proxy(uri)
+ proxy.open_timeout = opentimeout
+ proxy.read_timeout = readtimeout
+
+ begin
+ proxy.start() {|http|
+ yield uri.request_uri() if block_given?
+ req = Net::HTTP::Head.new(uri.request_uri(), @headers)
+ if uri.user and uri.password
+ req.basic_auth(uri.user, uri.password)
+ end
+ resp = http.request(req)
+ case resp
+ when Net::HTTPSuccess
+ return resp
+ when Net::HTTPRedirection
+ debug "Redirecting #{uri} to #{resp['location']}"
+ yield resp['location'] if block_given?
+ if max_redir > 0
+ return head( URI.parse(resp['location']), readtimeout, opentimeout, max_redir-1)
+ else
+ warning "Max redirection reached, not going to #{resp['location']}"
+ end
+ else
+ debug "HttpUtil.head return code #{resp.code}"
+ end
+ @last_response = resp
+ return nil
+ }
+ rescue StandardError, Timeout::Error => e
+ error "HttpUtil.head exception: #{e.inspect}, while trying to get #{uri}"
+ debug e.backtrace.join("\n")
+ end
+ @last_response = nil
+ return nil
+ end
+
+ def cache_response(k, resp)
+ begin
+ if resp.key?('pragma') and resp['pragma'] == 'no-cache'
+ debug "Not caching #{k}, it has Pragma: no-cache"
+ return
+ end
+ # TODO should we skip caching if neither last-modified nor etag are present?
+ now = Time.new
+ u = Hash.new
+ u = Hash.new
+ u[:body] = resp.body
+ u[:last_modified] = nil
+ u[:last_modified] = Time.httpdate(resp['date']) if resp.key?('date')
+ u[:last_modified] = Time.httpdate(resp['last-modified']) if resp.key?('last-modified')
+ u[:expires] = Time.now
+ u[:expires] = Time.httpdate(resp['expires']) if resp.key?('expires')
+ u[:revalidate] = false
+ if resp.key?('cache-control')
+ # TODO max-age
+ case resp['cache-control']
+ when /no-cache|must-revalidate/
+ u[:revalidate] = true
+ end
+ end
+ u[:etag] = ""
+ u[:etag] = resp['etag'] if resp.key?('etag')
+ u[:count] = 1
+ u[:first_use] = now
+ u[:last_use] = now
+ rescue => e
+ error "Failed to cache #{k}/#{resp.to_hash.inspect}: #{e.inspect}"
+ return
+ end
+ # @cache[k] = u
+ # For debugging purposes
+ @cache[k] = u.dup
+ u.delete(:body)
+ debug "Cached #{k}/#{resp.to_hash.inspect}: #{u.inspect}"
+ debug "#{@cache.size} pages (#{@cache.keys.join(', ')}) cached up to now"
+ end
+
+ def expired?(uri, readtimeout, opentimeout)
+ k = uri.to_s
+ debug "Checking cache validity for #{k}"
+ begin
+ return true unless @cache.key?(k)
+ u = @cache[k]
+
+ # TODO we always revalidate for the time being
+
+ if u[:etag].empty? and u[:last_modified].nil?
+ # TODO max-age
+ return true
+ end
+
+ proxy = get_proxy(uri)
+ proxy.open_timeout = opentimeout
+ proxy.read_timeout = readtimeout
+
+ proxy.start() {|http|
+ yield uri.request_uri() if block_given?
+ headers = @headers
+ headers['If-None-Match'] = u[:etag] unless u[:etag].empty?
+ headers['If-Modified-Since'] = u[:last_modified].rfc2822 if u[:last_modified]
+ # FIXME TODO We might want to use a Get here
+ # because if a 200 OK is returned we would get the new body
+ # with one connection less ...
+ req = Net::HTTP::Head.new(uri.request_uri(), headers)
+ if uri.user and uri.password
+ req.basic_auth(uri.user, uri.password)
+ end
+ resp = http.request(req)
+ debug "Checking cache validity of #{u.inspect} against #{resp.to_hash.inspect}"
+ case resp
+ when Net::HTTPNotModified
+ return false
+ else
+ return true
+ end
+ }
+ rescue => e
+ error "Failed to check cache validity for #{uri}: #{e.inspect}"
+ return true
+ end
+ end
+
+ # gets a page from the cache if it's still (assumed to be) valid
+ # TODO remove stale cached pages, except when called with noexpire=true
+ def get_cached(uri_or_str, readtimeout=10, opentimeout=5,
+ max_redir=@bot.config['http.max_redir'],
+ noexpire=@bot.config['http.no_expire_cache'])
+ if uri_or_str.kind_of?(URI)
+ uri = uri_or_str
+ else
+ uri = URI.parse(uri_or_str.to_s)
+ end
+ debug "Getting cached #{uri}"
+
+ if expired?(uri, readtimeout, opentimeout)
+ debug "Cache expired"
+ bod = get(uri, readtimeout, opentimeout, max_redir, [noexpire])
+ else
+ debug "Using cache"
+ @cache[k][:count] += 1
+ @cache[k][:last_use] = now
+ bod = @cache[k][:body]
+ end
+ unless noexpire
+ remove_stale_cache
+ end
+ return bod
+ end
+
+ # We consider a page to be manually expired if it has no
+ # etag and no last-modified and if any of the expiration
+ # conditions are met (expire_time, max_cache_time, Expires)
+ def manually_expired?(hash, time)
+ auto = hash[:etag].empty? and hash[:last_modified].nil?
+ # TODO max-age
+ manual = (time - hash[:last_use] > @bot.config['http.expire_time']*60) or
+ (time - hash[:first_use] > @bot.config['http.max_cache_time']*60) or
+ (hash[:expires] < time)
+ return (auto and manual)
+ end
+
+ def remove_stale_cache
+ debug "Removing stale cache"
+ debug "#{@cache.size} pages before"
+ begin
+ now = Time.new
+ @cache.reject! { |k, val|
+ manually_expired?(val, now)
+ }
+ rescue => e
+ error "Failed to remove stale cache: #{e.inspect}"
+ end
+ debug "#{@cache.size} pages after"
+ end
end
end
end
projects / user / henk / code / ruby / rbot.git / blobdiff