清除或删除 Ruby PStore

Question

我一直在尝试使用 PStore 来保存相对大量的哈希值：

 require "pstore"
 store = PStore.new("data.pstore")

由于它存储在一个充满现在无用数据的文件中，我该如何以编程方式清除或删除 "store"？显然我可以只删除 store.pstore 文件，但我正在寻找的是 PStore 等价于：

DELETE FROM store WHERE 1=1;

Answer 1

您要找的是delete:

store.transaction { store.delete(key) }


store = PStore.new("data.pstore")
#=> #<PStore:0x007fd67f35a040 @abort=false, @filename="data.pstore", @lock=#<Thread::Mutex:0x007fd67f359f28>, @thread_safe=false, @ultra_safe=false>
store.transaction { store[:foo] = :bar }
# => #<PStore:0x007fd67f35a040 @abort=false, @filename="data.pstore", @lock=#<Thread::Mutex:0x007fd67f359f28>, @rdonly=false, @table={:foo=>:bar}, @thread_safe=false, @ultra_safe=false>
store.transaction { store.delete(:foo) }
#=> :bar
store
#=> #<PStore:0x007fd67f35a040 @abort=false, @filename="data.pstore", @lock=#<Thread::Mutex:0x007fd67f359f28>, @thread_safe=false, @ultra_safe=false

如果您想截断 store，您可以遍历 roots 并在事务中删除它们：

store.transaction do
  store.roots.each do |root|
    store.delete(root)
  end
end

清除或删除 Ruby PStore

Clearing or Deleting a Ruby PStore

ruby

flat-file