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authorJari Vetoniemi <jari.vetoniemi@indooratlas.com>2020-03-16 18:49:26 +0900
committerJari Vetoniemi <jari.vetoniemi@indooratlas.com>2020-03-30 00:39:06 +0900
commitfcbf63e62c627deae76c1b8cb8c0876c536ed811 (patch)
tree64cb17de3f41a2b6fef2368028fbd00349946994 /jni/ruby/lib/rake/invocation_chain.rb
Fresh start
Diffstat (limited to 'jni/ruby/lib/rake/invocation_chain.rb')
-rw-r--r--jni/ruby/lib/rake/invocation_chain.rb56
1 files changed, 56 insertions, 0 deletions
diff --git a/jni/ruby/lib/rake/invocation_chain.rb b/jni/ruby/lib/rake/invocation_chain.rb
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+++ b/jni/ruby/lib/rake/invocation_chain.rb
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+module Rake
+
+ # InvocationChain tracks the chain of task invocations to detect
+ # circular dependencies.
+ class InvocationChain < LinkedList
+
+ # Is the invocation already in the chain?
+ def member?(invocation)
+ head == invocation || tail.member?(invocation)
+ end
+
+ # Append an invocation to the chain of invocations. It is an error
+ # if the invocation already listed.
+ def append(invocation)
+ if member?(invocation)
+ fail RuntimeError, "Circular dependency detected: #{to_s} => #{invocation}"
+ end
+ conj(invocation)
+ end
+
+ # Convert to string, ie: TOP => invocation => invocation
+ def to_s
+ "#{prefix}#{head}"
+ end
+
+ # Class level append.
+ def self.append(invocation, chain)
+ chain.append(invocation)
+ end
+
+ private
+
+ def prefix
+ "#{tail} => "
+ end
+
+ # Null object for an empty chain.
+ class EmptyInvocationChain < LinkedList::EmptyLinkedList
+ @parent = InvocationChain
+
+ def member?(obj)
+ false
+ end
+
+ def append(invocation)
+ conj(invocation)
+ end
+
+ def to_s
+ "TOP"
+ end
+ end
+
+ EMPTY = EmptyInvocationChain.new
+ end
+end