36 lines
1.0 KiB
JavaScript
36 lines
1.0 KiB
JavaScript
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'use strict'
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module.exports = function clear (db, location, keyRange, options, callback) {
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if (options.limit === 0) return db.nextTick(callback)
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const transaction = db.db.transaction([location], 'readwrite')
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const store = transaction.objectStore(location)
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let count = 0
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transaction.oncomplete = function () {
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callback()
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}
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transaction.onabort = function () {
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callback(transaction.error || new Error('aborted by user'))
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}
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// A key cursor is faster (skips reading values) but not supported by IE
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// TODO: we no longer support IE. Test others
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const method = store.openKeyCursor ? 'openKeyCursor' : 'openCursor'
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const direction = options.reverse ? 'prev' : 'next'
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store[method](keyRange, direction).onsuccess = function (ev) {
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const cursor = ev.target.result
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if (cursor) {
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// Wait for a request to complete before continuing, saving CPU.
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store.delete(cursor.key).onsuccess = function () {
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if (options.limit <= 0 || ++count < options.limit) {
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cursor.continue()
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}
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}
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}
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}
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}
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