From 4332930b26ca3314bf380cb026fd886a72dc6793 Mon Sep 17 00:00:00 2001
From: Neel Shah <neelshah.sa@gmail.com>
Date: Thu, 10 Aug 2023 14:47:01 +0200
Subject: [PATCH] Implement Sentry.continue_trace and deprecate
 Sentry.from_sentry_trace

---
 sentry-ruby/lib/sentry-ruby.rb                |  9 ++++++++
 sentry-ruby/lib/sentry/hub.rb                 | 18 +++++++++++++++
 sentry-ruby/lib/sentry/propagation_context.rb | 22 ++++++++++++++-----
 .../lib/sentry/rack/capture_exceptions.rb     |  5 +----
 sentry-ruby/lib/sentry/transaction.rb         |  2 ++
 5 files changed, 47 insertions(+), 9 deletions(-)

diff --git a/sentry-ruby/lib/sentry-ruby.rb b/sentry-ruby/lib/sentry-ruby.rb
index 03edc0a08..daed11803 100644
--- a/sentry-ruby/lib/sentry-ruby.rb
+++ b/sentry-ruby/lib/sentry-ruby.rb
@@ -516,6 +516,15 @@ def get_trace_propagation_headers
       get_current_hub.get_trace_propagation_headers
     end
 
+    # Continue an incoming trace from a rack env like hash.
+    #
+    # @param env [Hash]
+    # @return [Transaction, nil]
+    def continue_trace(env, **options)
+      return nil unless initialized?
+      get_current_hub.continue_trace(env, **options)
+    end
+
     ##### Helpers #####
 
     # @!visibility private
diff --git a/sentry-ruby/lib/sentry/hub.rb b/sentry-ruby/lib/sentry/hub.rb
index 48a131cd9..85c93ea4c 100644
--- a/sentry-ruby/lib/sentry/hub.rb
+++ b/sentry-ruby/lib/sentry/hub.rb
@@ -257,6 +257,24 @@ def get_trace_propagation_headers
       headers
     end
 
+    def continue_trace(env, **options)
+      configure_scope { |s| s.generate_propagation_context(env) }
+
+      return nil unless configuration.tracing_enabled?
+
+      propagation_context = current_scope.propagation_context
+      return nil unless propagation_context.incoming_trace
+
+      Transaction.new(
+        hub: self,
+        trace_id: propagation_context.trace_id,
+        parent_span_id: propagation_context.parent_span_id,
+        parent_sampled: propagation_context.parent_sampled,
+        baggage: propagation_context.baggage,
+        **options
+      )
+    end
+
     private
 
     def current_layer
diff --git a/sentry-ruby/lib/sentry/propagation_context.rb b/sentry-ruby/lib/sentry/propagation_context.rb
index 40585455f..d6d5a9e42 100644
--- a/sentry-ruby/lib/sentry/propagation_context.rb
+++ b/sentry-ruby/lib/sentry/propagation_context.rb
@@ -20,23 +20,35 @@ class PropagationContext
     # @return [String]
     attr_reader :span_id
     # Span parent's span_id.
-    # @return [String]
+    # @return [String, nil]
     attr_reader :parent_span_id
+    # The sampling decision of the parent transaction.
+    # @return [Boolean, nil]
+    attr_reader :parent_sampled
+    # Is there an incoming trace or not?
+    # @return [Boolean]
+    attr_reader :incoming_trace
+    # This is only for accessing the current baggage variable.
+    # Please use the #get_baggage method for interfacing outside this class.
+    # @return [Baggage, nil]
+    attr_reader :baggage
 
     def initialize(scope, env = nil)
       @scope = scope
       @parent_span_id = nil
+      @parent_sampled = nil
       @baggage = nil
+      @incoming_trace = false
 
       if env
         sentry_trace_header = env["HTTP_SENTRY_TRACE"]
         baggage_header = env["HTTP_BAGGAGE"]
 
         if sentry_trace_header
-          sentry_trace_data = extract_sentry_trace(sentry_trace_header)
+          sentry_trace_data = self.class.extract_sentry_trace(sentry_trace_header)
 
           if sentry_trace_data
-            @trace_id, @parent_span_id, _ = sentry_trace_data
+            @trace_id, @parent_span_id, @parent_sampled = sentry_trace_data
 
             @baggage = if baggage_header && !baggage_header.empty?
                         Baggage.from_incoming_header(baggage_header)
@@ -48,6 +60,7 @@ def initialize(scope, env = nil)
                       end
 
             @baggage.freeze!
+            @incoming_trace = true
           end
         end
       end
@@ -70,7 +83,6 @@ def self.extract_sentry_trace(sentry_trace)
       [trace_id, parent_span_id, parent_sampled]
     end
 
-
     # Returns the trace context that can be used to embed in an Event.
     # @return [Hash]
     def get_trace_context
@@ -87,7 +99,7 @@ def get_traceparent
       "#{trace_id}-#{span_id}"
     end
 
-    # Returns the Baggage from the propagation context.
+    # Returns the Baggage from the propagation context or populates as head SDK if empty.
     # @return [Baggage, nil]
     def get_baggage
       populate_head_baggage if @baggage.nil? || @baggage.mutable
diff --git a/sentry-ruby/lib/sentry/rack/capture_exceptions.rb b/sentry-ruby/lib/sentry/rack/capture_exceptions.rb
index 36c8b1848..2248799a3 100644
--- a/sentry-ruby/lib/sentry/rack/capture_exceptions.rb
+++ b/sentry-ruby/lib/sentry/rack/capture_exceptions.rb
@@ -62,11 +62,8 @@ def capture_exception(exception, env)
       end
 
       def start_transaction(env, scope)
-        sentry_trace = env["HTTP_SENTRY_TRACE"]
-        baggage = env["HTTP_BAGGAGE"]
-
         options = { name: scope.transaction_name, source: scope.transaction_source, op: transaction_op }
-        transaction = Sentry::Transaction.from_sentry_trace(sentry_trace, baggage: baggage, **options) if sentry_trace
+        transaction = Sentry.continue_trace(env, **options)
         Sentry.start_transaction(transaction: transaction, custom_sampling_context: { env: env }, **options)
       end
 
diff --git a/sentry-ruby/lib/sentry/transaction.rb b/sentry-ruby/lib/sentry/transaction.rb
index abdb73b53..c64f9863e 100644
--- a/sentry-ruby/lib/sentry/transaction.rb
+++ b/sentry-ruby/lib/sentry/transaction.rb
@@ -89,6 +89,8 @@ def initialize(
       init_span_recorder
     end
 
+    # @deprecated use Sentry.continue_trace instead.
+    #
     # Initalizes a Transaction instance with a Sentry trace string from another transaction (usually from an external request).
     #
     # The original transaction will become the parent of the new Transaction instance. And they will share the same `trace_id`.