Class: Neo4j::Driver::Internal::DefaultBookmarkManager

Inherits:
Object
  • Object
show all
Defined in:
lib/neo4j/driver/internal/default_bookmark_manager.rb

Overview

Thread-safe in-memory implementation behind BookmarkManagers.default_manager. Internal because callers code against the duck type (bookmarks + update_bookmarks) and shouldn't depend on this class name.

bookmarks_supplier runs on every bookmarks call so external state (e.g. bookmarks persisted by another node in a cluster of app servers) is folded into what we send on BEGIN. bookmarks_consumer runs on every successful update_bookmarks so external listeners can react.

Instance Method Summary collapse

Constructor Details

#initialize(initial_bookmarks: nil, bookmarks_supplier: nil, bookmarks_consumer: nil) ⇒ DefaultBookmarkManager

Returns a new instance of DefaultBookmarkManager.



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# File 'lib/neo4j/driver/internal/default_bookmark_manager.rb', line 17

def initialize(initial_bookmarks: nil, bookmarks_supplier: nil, bookmarks_consumer: nil)
  @bookmarks = normalize(initial_bookmarks)
  @supplier = bookmarks_supplier
  @consumer = bookmarks_consumer
  @lock = Mutex.new
end

Instance Method Details

#bookmarks ⇒ Object 



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# File 'lib/neo4j/driver/internal/default_bookmark_manager.rb', line 24

def bookmarks
  @lock.synchronize { @bookmarks.dup } | normalize(@supplier&.call)
end

#update_bookmarks(previous, new) ⇒ Object

Java's BookmarkManagerImpl semantics: drop everything in previous (set-difference is a no-op for entries we don't have, so callers can pass the full "what I sent on BEGIN" snapshot — including the session's own bookmarks — without special-casing), then add the new ones from the commit response. Consumer sees the post-update set.



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# File 'lib/neo4j/driver/internal/default_bookmark_manager.rb', line 34

def update_bookmarks(previous, new)
  prev_set = normalize(previous)
  new_set = normalize(new)
  updated_snapshot = nil
  @lock.synchronize do
    @bookmarks -= prev_set
    @bookmarks |= new_set
    updated_snapshot = @bookmarks.dup
  end
  @consumer&.call(updated_snapshot)
end