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")

因为它存储在一个充满现在无用数据的文件中，如何以编程方式清除或删除“存储”？显然我可以删除store.pstore文件，但我正在寻找的是PStore相当于：

DELETE FROM store WHERE 1=1;

Answer 1

您正在寻找的是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

如果要截断store，可以迭代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

1 个答案: