move all automerge references to document

1 files changed, 21 insertions, 1 deletions

diff --git a/src/document/changes.rs b/src/document/changes.rs
index d369c79..655063b 100644
--- a/src/document/changes.rs
+++ b/src/document/changes.rs
@@ -8,6 +8,26 @@ use anyhow::{Context, Result, anyhow, bail};
 
 use super::{Change, ChangeHash, Document};
 
+/// Those of `heads` that `doc` doesn't have. (Looking a change up needs the document
+/// mutably.)
+pub(crate) fn missing(doc: &mut Document, heads: &[ChangeHash]) -> Vec<ChangeHash> {
+    heads
+        .iter()
+        .copied()
+        .filter(|head| doc.get_change_by_hash(head).is_none())
+        .collect()
+}
+
+/// When the changes after `since` were committed, in Unix milliseconds by their
+/// writers' clocks (`Replica::commit`); changes without a time (snapshots) left out.
+pub(crate) fn commit_times(doc: &mut Document, since: &[ChangeHash]) -> Vec<i64> {
+    doc.get_changes(since)
+        .iter()
+        .map(|change| change.timestamp())
+        .filter(|&time| time > 0)
+        .collect()
+}
+
 /// The change `hash` as the document encodes it; None if `doc` doesn't have it.
 pub(crate) fn change_bytes(doc: &mut Document, hash: &ChangeHash) -> Option<Vec<u8>> {
     doc.get_change_by_hash(hash)
@@ -33,7 +53,7 @@ pub(crate) fn delta_bytes(
     from: &[ChangeHash],
     to: &[ChangeHash],
 ) -> Option<Vec<u8>> {
-    if to.iter().any(|head| doc.get_change_by_hash(head).is_none()) {
+    if !missing(doc, to).is_empty() {
         return None;
     }
     // Heads of `from` we don't have can't hide anything we have.