From b40d3f7ca3f92373eca8dd0683d37183559c78e6 Mon Sep 17 00:00:00 2001 From: tv Date: Sun, 8 Nov 2026 19:48:45 +0000 Subject: document: tell whether a document holds a change without building it MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit With the policy's reads kept, judging a change still costs about one read (some 3.5 µs), and so does judging without a policy: what is left is At::new, which asks get_change_by_hash for each head. Automerge builds the change again from the document's operations to answer, at a cost growing with its history. Screening asks it again for every candidate and every dependency, and sync for heads. Ask by the missing dependencies instead (changes::holds), which look the hash up: one the document holds is not among them. A change queued in the document, waiting for its dependencies, isn't either; but then some are missing, and only then is it asked the slow way. Every check of whether a document holds a change goes through it. --- src/access/screen.rs | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'src/access/screen.rs') diff --git a/src/access/screen.rs b/src/access/screen.rs index 1c6c8c7..793e8bb 100644 --- a/src/access/screen.rs +++ b/src/access/screen.rs @@ -40,7 +40,7 @@ use crate::document::inspect::{Action, Inspector, Op, Path}; use crate::document::meta; use crate::document::replica::{Epoch, user_of}; use crate::document::signatures::Signatures; -use crate::document::{Change, ChangeHash, Document, ReadDoc}; +use crate::document::{Change, ChangeHash, Document}; /// Changes waiting for their dependencies, kept at most: the oldest go. const MAX_WAITING: usize = 10_000; @@ -289,7 +289,7 @@ pub(crate) fn apply( .into_iter() .chain(received) .filter(|change| seen.insert(change.hash())) - .filter(|change| doc.get_change_by_hash(&change.hash()).is_none()) + .filter(|change| !crate::document::changes::holds(doc, &change.hash())) .filter(|change| match refusals.root(&change.hash()) { Some(root) => { screened.refused_again += 1; @@ -780,7 +780,7 @@ fn in_order(doc: &Document, candidates: Vec) -> (Vec, Vec