feat: reintroduce clone and rewind for cursors #2647
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This reintroduces support for rewinding a cursor to its uninitialized state. NODE-2811
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emadum
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src/cursor/find_cursor.ts
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| @@ -49,6 +49,16 @@ export class FindCursor extends AbstractCursor { | |||
| } | |||
| } | |||
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| /** | |||
| * Returns a new unitialized copy of this cursor, with options matching those that have been set on the current instance | |||
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| * Returns a new unitialized copy of this cursor, with options matching those that have been set on the current instance | |
| * Returns a new uninitialized copy of this cursor, with options matching those that have been set on the current instance |
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fixed here and in aggregation_cursor too!
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nbbeeken
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Description
These two commits add back support for cloning and rewinding cursors.
What changed?
The changes should be fairly straightforward, but I wanted to call out a few design decisions:
- I had originally intendedcloneto be an abstract method onAbstractCursor, forcing us to implement it for all possible cursor subclasses. This would have unfortunately required us to makeAbstractCursorgeneric over the subclass types, since the following signature results in type ambiguity at the point of implementation in the subclass:abstract clone(): thisTherefore,
cloneis implemented by hand inAbstractCursorsubclasses. I only implemented it forFindCursorandAggregateCursorbecause it's likely that's where legacy users have actually used this feature.There is a correction in the
rewindimplementation regarding sessions. When a session is started as part of cursor initialization I had originally marked this as anexplicit: truestart, however, this is clearly an implicit session the driver is creating in the absence of an explicitly provided one.Are there any files to ignore?
none