97 lines
1.6 KiB
Ruby
97 lines
1.6 KiB
Ruby
# -*- coding => binary -*-
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require 'json'
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require 'fileutils'
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#
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# This class provides a thread-friendly hash file store in JSON format
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#
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module Rex
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class JSONHashFile
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attr_accessor :path
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def initialize(path)
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self.path = path
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@lock = Mutex.new
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@hash = {}
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@last = 0
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::FileUtils.mkdir_p(::File.dirname(path))
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synced_update
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end
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def [](k)
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synced_update
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@hash[k]
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end
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def []=(k,v)
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synced_update do
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@hash[k] = v
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end
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end
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def keys
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synced_update
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@hash.keys
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end
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def delete(k)
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synced_update do
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@hash.delete(k)
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end
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end
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def clear
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synced_update do
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@hash.clear
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end
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end
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private
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# Save the file, but prevent thread & process contention
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def synced_update(&block)
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@lock.synchronize do
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::File.open(path, ::File::RDWR|::File::CREAT) do |fd|
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fd.flock(::File::LOCK_EX)
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# Reload and merge if the file has changed recently
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if fd.stat.mtime.to_f > @last
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parse_data(fd.read).merge(@hash).each_pair do |k,v|
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@hash[k] = v
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end
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end
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res = nil
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# Update the file on disk if new data is written
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if block_given?
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res = block.call
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fd.rewind
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fd.write(JSON.pretty_generate(@hash))
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fd.sync
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fd.truncate(fd.pos)
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end
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@last = fd.stat.mtime.to_f
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res
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end
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end
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end
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def parse_data(data)
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return {} if data.to_s.strip.length == 0
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begin
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JSON.parse(data)
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rescue JSON::ParserError => e
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# elog("JSONHashFile @ #{path} was corrupt: #{e.class} #{e}"
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{}
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end
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end
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end
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end
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