Class: NewRelic::Rack::BrowserMonitoring
- Inherits:
-
Object
- Object
- NewRelic::Rack::BrowserMonitoring
- Defined in:
- lib/new_relic/rack/browser_monitoring.rb
Constant Summary collapse
- ALREADY_INSTRUMENTED_KEY =
"newrelic.browser_monitoring_already_instrumented"
- X_UA_COMPATIBLE_RE =
/<\s*meta[^>]+http-equiv=['"]x-ua-compatible['"][^>]*>/im.freeze
Instance Method Summary collapse
- #autoinstrument_source(response, headers) ⇒ Object
-
#calculate_content_length(source) ⇒ Object
String does not respond to ‘bytesize’ in 1.8.6.
-
#call(env) ⇒ Object
method required by Rack interface.
-
#initialize(app, options = {}) ⇒ BrowserMonitoring
constructor
A new instance of BrowserMonitoring.
- #should_instrument?(env, status, headers) ⇒ Boolean
Constructor Details
#initialize(app, options = {}) ⇒ BrowserMonitoring
Returns a new instance of BrowserMonitoring.
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# File 'lib/new_relic/rack/browser_monitoring.rb', line 10 def initialize(app, = {}) @app = app end |
Instance Method Details
#autoinstrument_source(response, headers) ⇒ Object
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# File 'lib/new_relic/rack/browser_monitoring.rb', line 44 def autoinstrument_source(response, headers) source = nil response.each {|fragment| source ? (source << fragment.to_s) : (source = fragment.to_s)} return nil unless source # Only scan the first 50k (roughly) then give up. beginning_of_source = source[0..50_000] # Don't scan for body close unless we find body start if (body_start = beginning_of_source.index("<body")) && (body_close = source.rindex("</body>")) = NewRelic::Agent. header = NewRelic::Agent.browser_timing_header match = X_UA_COMPATIBLE_RE.match(beginning_of_source) x_ua_compatible_position = match.end(0) if match head_pos = if x_ua_compatible_position # put after X-UA-Compatible meta tag if found ::NewRelic::Agent.logger.debug "Detected X-UA-Compatible meta tag. Attempting to insert RUM header after meta tag." x_ua_compatible_position elsif head_open = beginning_of_source.index("<head") ::NewRelic::Agent.logger.debug "Attempting to insert RUM header at beginning of head." # put at the beginning of the header beginning_of_source.index(">", head_open) + 1 else ::NewRelic::Agent.logger.debug "Failed to detect head tag. Attempting to insert RUM header at above body tag." # otherwise put the header right above body start body_start end # check that head_pos is less than body close. If it's not something # is really weird and we should punt. if head_pos && (head_pos < body_close) # rebuild the source source = source[0..(head_pos-1)] << header << source[head_pos..(body_close-1)] << << source[body_close..-1] else if head_pos ::NewRelic::Agent.logger.debug "Skipping RUM instrumentation. Failed to detect head tags." else ::NewRelic::Agent.logger.debug "Skipping RUM instrumentation. Detected head is after detected body close." end end end if headers['Content-Length'] headers['Content-Length'] = calculate_content_length(source).to_s end source end |
#calculate_content_length(source) ⇒ Object
String does not respond to ‘bytesize’ in 1.8.6. Fortunately String#length returns bytes rather than characters in 1.8.6 so we can use that instead.
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# File 'lib/new_relic/rack/browser_monitoring.rb', line 102 def calculate_content_length(source) if source.respond_to?(:bytesize) source.bytesize else source.length end end |
#call(env) ⇒ Object
method required by Rack interface
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# File 'lib/new_relic/rack/browser_monitoring.rb', line 15 def call(env) result = @app.call(env) # [status, headers, response] if (NewRelic::Agent.browser_timing_header != "") && should_instrument?(env, result[0], result[1]) response_string = autoinstrument_source(result[2], result[1]) env[ALREADY_INSTRUMENTED_KEY] = true if response_string response = Rack::Response.new(response_string, result[0], result[1]) response.finish else result end else result end end |
#should_instrument?(env, status, headers) ⇒ Boolean
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# File 'lib/new_relic/rack/browser_monitoring.rb', line 35 def should_instrument?(env, status, headers) status == 200 && !env[ALREADY_INSTRUMENTED_KEY] && headers["Content-Type"] && headers["Content-Type"].include?("text/html") && !headers['Content-Disposition'].to_s.include?('attachment') end |