[v3,0/6] tools/ocaml/xenstored: simplify code

Message

Edwin Török Aug. 17, 2020, 6:45 p.m. UTC

Fix warnings, and delete some obsolete code.
oxenstored contained a hand-rolled GC to perform hash-consing:
this can be done with a lot fewer lines of code by using the built-in Weak module.

The choice of data structures for trees/tries is not very efficient: they are just
lists. Using a map improves lookup and deletion complexity, and replaces hand-rolled
recursion with higher-level library calls.

There is a lot more that could be done to optimize socket polling:
an epoll backend with a poll fallback,but API structured around event-based polling
would be better. But first lets drop the legacy select based code: I think every
modern *nix should have a working poll(3) by now.

This is a draft series, in need of more testing.
Changes since v1:
    * fix bug where a 'set_node' call was missed
    * simplify 'compare' code
    * fix commit title for 'drop select based'
    * passed some testing

Please ignore V2, something went wrong and V2 was nearly identical to V1,
not matching what I had in my git tree.

Edwin Török (6):
  tools/ocaml/libs/xc: Fix ambiguous documentation comment
  tools/ocaml/xenstored: fix deprecation warning
  tools/ocaml/xenstored: replace hand rolled GC with weak GC references
  tools/ocaml/xenstored: drop select based socket watching
  tools/ocaml/xenstored: use more efficient node trees
  tools/ocaml/xenstored: use more efficient tries

 tools/ocaml/libs/xc/xenctrl.mli               |  2 +
 tools/ocaml/xenstored/Makefile                | 12 ++--
 tools/ocaml/xenstored/connection.ml           |  3 -
 tools/ocaml/xenstored/connections.ml          |  2 +-
 tools/ocaml/xenstored/disk.ml                 |  2 +-
 tools/ocaml/xenstored/history.ml              | 14 ----
 tools/ocaml/xenstored/parse_arg.ml            |  7 +-
 tools/ocaml/xenstored/{select.ml => poll.ml}  | 14 +---
 .../ocaml/xenstored/{select.mli => poll.mli}  | 12 +---
 tools/ocaml/xenstored/store.ml                | 49 ++++++-------
 tools/ocaml/xenstored/symbol.ml               | 70 +++++--------------
 tools/ocaml/xenstored/symbol.mli              | 22 ++----
 tools/ocaml/xenstored/trie.ml                 | 59 +++++++---------
 tools/ocaml/xenstored/trie.mli                | 26 +++----
 tools/ocaml/xenstored/xenstored.ml            | 20 +-----
 15 files changed, 103 insertions(+), 211 deletions(-)
 rename tools/ocaml/xenstored/{select.ml => poll.ml} (85%)
 rename tools/ocaml/xenstored/{select.mli => poll.mli} (58%)