Initial

resources/app/node_modules/abstract-level/lib/abstract-sublevel-iterator.js

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+'use strict'
+
+const { AbstractIterator, AbstractKeyIterator, AbstractValueIterator } = require('../abstract-iterator')
+
+const kUnfix = Symbol('unfix')
+const kIterator = Symbol('iterator')
+const kHandleOne = Symbol('handleOne')
+const kHandleMany = Symbol('handleMany')
+const kCallback = Symbol('callback')
+
+// TODO: unfix natively if db supports it
+class AbstractSublevelIterator extends AbstractIterator {
+  constructor (db, options, iterator, unfix) {
+    super(db, options)
+
+    this[kIterator] = iterator
+    this[kUnfix] = unfix
+    this[kHandleOne] = this[kHandleOne].bind(this)
+    this[kHandleMany] = this[kHandleMany].bind(this)
+    this[kCallback] = null
+  }
+
+  [kHandleOne] (err, key, value) {
+    const callback = this[kCallback]
+    if (err) return callback(err)
+    if (key !== undefined) key = this[kUnfix](key)
+    callback(err, key, value)
+  }
+
+  [kHandleMany] (err, entries) {
+    const callback = this[kCallback]
+    if (err) return callback(err)
+
+    for (const entry of entries) {
+      const key = entry[0]
+      if (key !== undefined) entry[0] = this[kUnfix](key)
+    }
+
+    callback(err, entries)
+  }
+}
+
+class AbstractSublevelKeyIterator extends AbstractKeyIterator {
+  constructor (db, options, iterator, unfix) {
+    super(db, options)
+
+    this[kIterator] = iterator
+    this[kUnfix] = unfix
+    this[kHandleOne] = this[kHandleOne].bind(this)
+    this[kHandleMany] = this[kHandleMany].bind(this)
+    this[kCallback] = null
+  }
+
+  [kHandleOne] (err, key) {
+    const callback = this[kCallback]
+    if (err) return callback(err)
+    if (key !== undefined) key = this[kUnfix](key)
+    callback(err, key)
+  }
+
+  [kHandleMany] (err, keys) {
+    const callback = this[kCallback]
+    if (err) return callback(err)
+
+    for (let i = 0; i < keys.length; i++) {
+      const key = keys[i]
+      if (key !== undefined) keys[i] = this[kUnfix](key)
+    }
+
+    callback(err, keys)
+  }
+}
+
+class AbstractSublevelValueIterator extends AbstractValueIterator {
+  constructor (db, options, iterator) {
+    super(db, options)
+    this[kIterator] = iterator
+  }
+}
+
+for (const Iterator of [AbstractSublevelIterator, AbstractSublevelKeyIterator]) {
+  Iterator.prototype._next = function (callback) {
+    this[kCallback] = callback
+    this[kIterator].next(this[kHandleOne])
+  }
+
+  Iterator.prototype._nextv = function (size, options, callback) {
+    this[kCallback] = callback
+    this[kIterator].nextv(size, options, this[kHandleMany])
+  }
+
+  Iterator.prototype._all = function (options, callback) {
+    this[kCallback] = callback
+    this[kIterator].all(options, this[kHandleMany])
+  }
+}
+
+for (const Iterator of [AbstractSublevelValueIterator]) {
+  Iterator.prototype._next = function (callback) {
+    this[kIterator].next(callback)
+  }
+
+  Iterator.prototype._nextv = function (size, options, callback) {
+    this[kIterator].nextv(size, options, callback)
+  }
+
+  Iterator.prototype._all = function (options, callback) {
+    this[kIterator].all(options, callback)
+  }
+}
+
+for (const Iterator of [AbstractSublevelIterator, AbstractSublevelKeyIterator, AbstractSublevelValueIterator]) {
+  Iterator.prototype._seek = function (target, options) {
+    this[kIterator].seek(target, options)
+  }
+
+  Iterator.prototype._close = function (callback) {
+    this[kIterator].close(callback)
+  }
+}
+
+exports.AbstractSublevelIterator = AbstractSublevelIterator
+exports.AbstractSublevelKeyIterator = AbstractSublevelKeyIterator
+exports.AbstractSublevelValueIterator = AbstractSublevelValueIterator