64e8ce0c07
It frees us from using C++ to track JS objects, thus improves the performance of collecting memory.
65 lines
1.9 KiB
CoffeeScript
65 lines
1.9 KiB
CoffeeScript
EventEmitter = require('events').EventEmitter
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v8Util = process.atomBinding 'v8_util'
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class ObjectsRegistry extends EventEmitter
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constructor: ->
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@setMaxListeners Number.MAX_VALUE
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@nextId = 0
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# Stores all objects by ref-counting.
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# (id) => {object, count}
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@storage = {}
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# Stores the IDs of objects referenced by WebContents.
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# (webContentsId) => {(id) => (count)}
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@owners = {}
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# Register a new object, the object would be kept referenced until you release
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# it explicitly.
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add: (webContentsId, obj) ->
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id = @saveToStorage obj
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# Remember the owner.
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@owners[webContentsId] ?= {}
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@owners[webContentsId][id] ?= 0
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@owners[webContentsId][id]++
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# Returns object's id
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id
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# Get an object according to its ID.
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get: (id) ->
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@storage[id]?.object
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# Dereference an object according to its ID.
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remove: (webContentsId, id) ->
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@dereference id, 1
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# Also reduce the count in owner.
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pointer = @owners[webContentsId]
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--pointer[id]
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delete pointer[id] if pointer[id] is 0
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# Clear all references to objects refrenced by the WebContents.
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clear: (webContentsId) ->
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@emit "clear-#{webContentsId}"
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return unless @owners[webContentsId]?
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@dereference id, count for id, count of @owners[webContentsId]
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delete @owners[webContentsId]
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# Private: Saves the object into storage and assigns an ID for it.
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saveToStorage: (object) ->
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id = v8Util.getHiddenValue object, 'atomId'
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unless id
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id = ++@nextId
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@storage[id] = {count: 0, object}
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v8Util.setHiddenValue object, 'atomId', id
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++@storage[id].count
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id
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# Private: Dereference the object from store.
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dereference: (id, count) ->
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pointer = @storage[id]
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pointer.count -= count
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if pointer.count is 0
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v8Util.deleteHiddenValue pointer.object, 'atomId'
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delete @storage[id]
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module.exports = new ObjectsRegistry
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