update previous fragment in comparer when appending a new line fragment

This commit is contained in:
Bruno Windels 2020-03-21 10:45:09 +01:00
parent aa7e5d4e0a
commit c4a5de20c0
2 changed files with 50 additions and 2 deletions

View File

@ -78,6 +78,14 @@ function createIslands(fragments) {
return islands.map(a => new Island(a)); return islands.map(a => new Island(a));
} }
class Fragment {
constructor(id, previousId, nextId) {
this.id = id;
this.previousId = previousId;
this.nextId = nextId;
}
}
class Island { class Island {
constructor(sortedFragments) { constructor(sortedFragments) {
this._idToSortIndex = new Map(); this._idToSortIndex = new Map();
@ -149,8 +157,32 @@ export default class FragmentIdComparer {
} }
} }
/** use for fragments coming out of persistence, not newly created ones, or also fragments for a new island (like for a permalink) */
add(fragment) { add(fragment) {
this._fragmentsById.set(fragment.id, fragment); const copy = new Fragment(fragment.id, fragment.previousId, fragment.nextId);
this._fragmentsById.set(fragment.id, copy);
this.rebuild(this._fragmentsById.values());
}
/** use for appending newly created fragments */
append(id, previousId) {
const fragment = new Fragment(id, previousId, null);
const prevFragment = this._fragmentsById.get(previousId);
if (prevFragment) {
prevFragment.nextId = id;
}
this._fragmentsById.set(id, fragment);
this.rebuild(this._fragmentsById.values());
}
/** use for prepending newly created fragments */
prepend(id, nextId) {
const fragment = new Fragment(id, null, nextId);
const nextFragment = this._fragmentsById.get(nextId);
if (nextFragment) {
nextFragment.previousId = id;
}
this._fragmentsById.set(id, fragment);
this.rebuild(this._fragmentsById.values()); this.rebuild(this._fragmentsById.values());
} }
} }
@ -254,6 +286,22 @@ export function tests() {
assert.throws(() => index.compare(1, 2)); assert.throws(() => index.compare(1, 2));
assert(index.compare(11, 12) < 0); assert(index.compare(11, 12) < 0);
}, },
test_append(assert) {
const index = new FragmentIdComparer([]);
// add livefragment when opening timeline,
// note that there is no nextId as the sync
// hasn't come in yet
index.add({id: 1});
// now sync comes in and replaces the live fragment
index.append(2, 1);
assert(index.compare(1, 2) < 0);
},
test_prepend(assert) {
const index = new FragmentIdComparer([]);
index.add({id: 2});
index.prepend(1, 2);
assert(index.compare(1, 2) < 0);
}
} }
} }
//#endif //#endif

View File

@ -77,7 +77,7 @@ export default class SyncWriter {
nextToken: null nextToken: null
}; };
txn.timelineFragments.add(newFragment); txn.timelineFragments.add(newFragment);
this._fragmentIdComparer.add(newFragment); this._fragmentIdComparer.append(newFragmentId, oldFragmentId);
return {oldFragment, newFragment}; return {oldFragment, newFragment};
} }