Integrated: 8269957: facilitate alternate impls of NameTable and Name

Archie Cobbs acobbs at
Mon Aug 28 14:52:27 UTC 2023

On Sun, 2 Apr 2023 15:06:53 GMT, Archie Cobbs <acobbs at> wrote:

> The `Name.Table` class is used by the compiler to hold unique instances of strings as `Name` objects.
> In theory the `Name` superclass supports alternate implementations beyond the two existing implementations (`SharedNameTable` and `UnsharedNameTable`), but its current design presumes that strings are stored as UTF-8 byte arrays, which discourages other approaches.
> The goal of this PR is to refactor things to allow for more flexibility in alternate `Name` implementations.
> As a simple test case of this idea, it should be relatively simple to implement a `Name.Table` that stores `String`s in a hash table. This patch includes such an example in the new class `StringNameTable`, which can be enabled via the `-XDuseStringTable=true` command line flag.  A simple performance test with this class enabled ([]( shows a 17% speedup.
> Changes:
> * Remove all byte-oriented methods from the `Name` and `Name.Table` API's, except for those that import/export Modified UTF-8.
> * Change the semantics of `Name.subName()` so the offset is a character offset, not a byte offset.
> * Consolidate the common UTF-8 machinery of `SharedNameTable` and `UnsharedNameTable` into a new common superclass `Utf8NameTable`.
> * Rename `Name.lastIndexOf()` -> `Name.lastIndexOfAscii()` to more accurately reflect its expected behavior.
> * Add new `StringNameTable` implementation.

This pull request has now been integrated.

Changeset: 11da15d1
Author:    Archie Cobbs <acobbs at>
Committer: Vicente Romero <vromero at>
Stats:     834 lines in 11 files changed: 571 ins; 162 del; 101 mod

8269957: facilitate alternate impls of NameTable and Name

Reviewed-by: jjg, vromero



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