adjust SortKey to have fragmentKey instead of gapKey

with FragmentIndex to compare fragment keys
This commit is contained in:
Bruno Windels 2019-05-01 14:47:39 +02:00
parent 8670ab6331
commit d90411a6dd
7 changed files with 231 additions and 213 deletions

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@ -1,5 +1,10 @@
- DONE: write FragmentIndex
- adapt SortKey
- adapt SortKey ... naming! :
- FragmentIndex (index as in db index)
- compare(fragmentKeyA, fragmentKeyB)
- SortKey
- FragmentKey
- EventKey (we don't use id here because we already have event_id in the event)
- write fragmentStore
- adapt timelineStore
- adapt persister

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@ -1,4 +1,4 @@
import SortKey from "../storage/sortkey.js";
import SortKey from "./timeline/SortKey.js";
import FragmentIndex from "./timeline/FragmentIndex.js";
function gapEntriesAreEqual(a, b) {
@ -31,6 +31,7 @@ export default class RoomPersister {
constructor({roomId, storage}) {
this._roomId = roomId;
this._storage = storage;
// TODO: load fragmentIndex?
this._lastSortKey = new SortKey();
}
@ -38,6 +39,7 @@ export default class RoomPersister {
//fetch key here instead?
const [lastEvent] = await txn.roomTimeline.lastEvents(this._roomId, 1);
if (lastEvent) {
// TODO: load fragmentIndex?
this._lastSortKey = new SortKey(lastEvent.sortKey);
console.log("room persister load", this._roomId, this._lastSortKey.toString());
} else {

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@ -1,10 +1,3 @@
class Fragment {
constructor(previousId, nextId) {
this.previousId = previousId;
this.nextId = nextId;
}
}
/*
lookups will be far more frequent than changing fragment order,
so data structure should be optimized for fast lookup
@ -93,7 +86,7 @@ class Island {
});
}
compareIds(idA, idB) {
compare(idA, idB) {
const sortIndexA = this._idToSortIndex.get(idA);
if (sortIndexA === undefined) {
throw new Error(`first id ${idA} isn't part of this island`);
@ -126,7 +119,7 @@ export default class FragmentIndex {
return island;
}
compareIds(idA, idB) {
compare(idA, idB) {
if (idA === idB) {
return 0;
}
@ -135,7 +128,7 @@ export default class FragmentIndex {
if (islandA !== islandB) {
throw new Error(`${idA} and ${idB} are on different islands, can't tell order`);
}
return islandA.compareIds(idA, idB);
return islandA.compare(idA, idB);
}
rebuild(fragments) {
@ -166,6 +159,7 @@ export default class FragmentIndex {
// }
}
//#ifdef TESTS
export function tests() {
return {
test_1_island_3_fragments(assert) {
@ -174,24 +168,24 @@ export function tests() {
{id: 1, nextId: 2},
{id: 2, nextId: 3, previousId: 1},
]);
assert(index.compareIds(1, 2) < 0);
assert(index.compareIds(2, 1) > 0);
assert(index.compare(1, 2) < 0);
assert(index.compare(2, 1) > 0);
assert(index.compareIds(1, 3) < 0);
assert(index.compareIds(3, 1) > 0);
assert(index.compare(1, 3) < 0);
assert(index.compare(3, 1) > 0);
assert(index.compareIds(2, 3) < 0);
assert(index.compareIds(3, 2) > 0);
assert(index.compare(2, 3) < 0);
assert(index.compare(3, 2) > 0);
assert.equal(index.compareIds(1, 1), 0);
assert.equal(index.compare(1, 1), 0);
},
test_2_island_dont_compare(assert) {
const index = new FragmentIndex([
{id: 1},
{id: 2},
]);
assert.throws(() => index.compareIds(1, 2));
assert.throws(() => index.compareIds(2, 1));
assert.throws(() => index.compare(1, 2));
assert.throws(() => index.compare(2, 1));
},
test_2_island_compare_internally(assert) {
const index = new FragmentIndex([
@ -202,16 +196,16 @@ export function tests() {
]);
assert(index.compareIds(1, 2) < 0);
assert(index.compareIds(11, 12) < 0);
assert(index.compare(1, 2) < 0);
assert(index.compare(11, 12) < 0);
assert.throws(() => index.compareIds(1, 11));
assert.throws(() => index.compareIds(12, 2));
assert.throws(() => index.compare(1, 11));
assert.throws(() => index.compare(12, 2));
},
test_unknown_id(assert) {
const index = new FragmentIndex([{id: 1}]);
assert.throws(() => index.compareIds(1, 2));
assert.throws(() => index.compareIds(2, 1));
assert.throws(() => index.compare(1, 2));
assert.throws(() => index.compare(2, 1));
},
test_rebuild_flushes_old_state(assert) {
const index = new FragmentIndex([
@ -223,8 +217,9 @@ export function tests() {
{id: 12, previousId: 11},
]);
assert.throws(() => index.compareIds(1, 2));
assert(index.compareIds(11, 12) < 0);
assert.throws(() => index.compare(1, 2));
assert(index.compare(11, 12) < 0);
},
}
}
//#endif

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@ -0,0 +1,197 @@
const MIN_INT32 = -2147483648;
const MID_INT32 = 0;
const MAX_INT32 = 2147483647;
const MIN_UINT32 = 0;
const MID_UINT32 = 2147483647;
const MAX_UINT32 = 4294967295;
const MIN = MIN_UINT32;
const MID = MID_UINT32;
const MAX = MAX_UINT32;
export default class SortKey {
constructor(fragmentIndex, buffer) {
if (buffer) {
this._keys = new DataView(buffer);
} else {
this._keys = new DataView(new ArrayBuffer(8));
// start default key right at the middle fragment key, min event key
// so we have the same amount of key address space either way
this.fragmentKey = MID;
this.eventKey = MIN;
}
this._fragmentIndex = fragmentIndex;
}
get fragmentKey() {
return this._keys.getUint32(0, false);
}
set fragmentKey(value) {
return this._keys.setUint32(0, value, false);
}
get eventKey() {
return this._keys.getUint32(4, false);
}
set eventKey(value) {
return this._keys.setUint32(4, value, false);
}
get buffer() {
return this._keys.buffer;
}
nextFragmentKey() {
const k = new SortKey(this._fragmentIndex);
k.fragmentKey = this.fragmentKey + 1;
k.eventKey = MIN;
return k;
}
nextKey() {
const k = new SortKey(this._fragmentIndex);
k.fragmentKey = this.fragmentKey;
k.eventKey = this.eventKey + 1;
return k;
}
previousKey() {
const k = new SortKey(this._fragmentIndex);
k.fragmentKey = this.fragmentKey;
k.eventKey = this.eventKey - 1;
return k;
}
clone() {
const k = new SortKey();
k.fragmentKey = this.fragmentKey;
k.eventKey = this.eventKey;
return k;
}
static get maxKey() {
const maxKey = new SortKey(null);
maxKey.fragmentKey = MAX;
maxKey.eventKey = MAX;
return maxKey;
}
static get minKey() {
const minKey = new SortKey(null);
minKey.fragmentKey = MIN;
minKey.eventKey = MIN;
return minKey;
}
compare(otherKey) {
const fragmentDiff = this.fragmentKey - otherKey.fragmentKey;
if (fragmentDiff === 0) {
return this.eventKey - otherKey.eventKey;
} else {
// minKey and maxKey might not have fragmentIndex, so short-circuit this first ...
if (this.fragmentKey === MIN || otherKey.fragmentKey === MAX) {
return -1;
}
if (this.fragmentKey === MAX || otherKey.fragmentKey === MIN) {
return 1;
}
// ... then delegate to fragmentIndex.
// This might throw if the relation of two fragments is unknown.
return this._fragmentIndex.compare(this.fragmentKey, otherKey.fragmentKey);
}
}
toString() {
return `[${this.fragmentKey}/${this.eventKey}]`;
}
}
//#ifdef TESTS
export function tests() {
const fragmentIndex = {compare: (a, b) => a - b};
return {
test_default_key(assert) {
const k = new SortKey(fragmentIndex);
assert.equal(k.fragmentKey, MID);
assert.equal(k.eventKey, MIN);
},
test_inc(assert) {
const a = new SortKey(fragmentIndex);
const b = a.nextKey();
assert.equal(a.fragmentKey, b.fragmentKey);
assert.equal(a.eventKey + 1, b.eventKey);
const c = b.previousKey();
assert.equal(b.fragmentKey, c.fragmentKey);
assert.equal(c.eventKey + 1, b.eventKey);
assert.equal(a.eventKey, c.eventKey);
},
test_min_key(assert) {
const minKey = SortKey.minKey;
const k = new SortKey(fragmentIndex);
assert(minKey.fragmentKey <= k.fragmentKey);
assert(minKey.eventKey <= k.eventKey);
assert(k.compare(minKey) > 0);
assert(minKey.compare(k) < 0);
},
test_max_key(assert) {
const maxKey = SortKey.maxKey;
const k = new SortKey(fragmentIndex);
assert(maxKey.fragmentKey >= k.fragmentKey);
assert(maxKey.eventKey >= k.eventKey);
assert(k.compare(maxKey) < 0);
assert(maxKey.compare(k) > 0);
},
test_immutable(assert) {
const a = new SortKey(fragmentIndex);
const fragmentKey = a.fragmentKey;
const eventKey = a.eventKey;
a.nextFragmentKey();
assert.equal(a.fragmentKey, fragmentKey);
assert.equal(a.eventKey, eventKey);
},
test_cmp_fragmentkey_first(assert) {
const a = new SortKey(fragmentIndex);
const b = new SortKey(fragmentIndex);
a.fragmentKey = 2;
a.eventKey = 1;
b.fragmentKey = 1;
b.eventKey = 100000;
assert(a.compare(b) > 0);
},
test_cmp_eventkey_second(assert) {
const a = new SortKey(fragmentIndex);
const b = new SortKey(fragmentIndex);
a.fragmentKey = 1;
a.eventKey = 100000;
b.fragmentKey = 1;
b.eventKey = 2;
assert(a.compare(b) > 0);
},
test_cmp_max_larger_than_min(assert) {
assert(SortKey.minKey.compare(SortKey.maxKey) < 0);
},
test_cmp_fragmentkey_first_large(assert) {
const a = new SortKey(fragmentIndex);
const b = new SortKey(fragmentIndex);
a.fragmentKey = MAX;
a.eventKey = MIN;
b.fragmentKey = MIN;
b.eventKey = MAX;
assert(b < a);
assert(a > b);
}
};
}
//#endif

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@ -1,4 +1,4 @@
import SortKey from "../../sortkey.js";
import SortKey from "../../../room/timeline/SortKey.js";
class Range {
constructor(only, lower, upper, lowerOpen, upperOpen) {

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@ -1,6 +1,6 @@
import SortKey from "../sortkey.js";
import SortKey from "../../room/timeline/SortKey.js";
import sortedIndex from "../../../utils/sortedIndex.js";
import Store from "./Store";
import Store from "./Store.js";
function compareKeys(key, entry) {
if (key.roomId === entry.roomId) {

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@ -1,181 +0,0 @@
const MIN_INT32 = -2147483648;
const MID_INT32 = 0;
const MAX_INT32 = 2147483647;
const MIN_UINT32 = 0;
const MID_UINT32 = 2147483647;
const MAX_UINT32 = 4294967295;
const MIN = MIN_UINT32;
const MID = MID_UINT32;
const MAX = MAX_UINT32;
export default class SortKey {
constructor(buffer) {
if (buffer) {
this._keys = new DataView(buffer);
} else {
this._keys = new DataView(new ArrayBuffer(8));
// start default key right at the middle gap key, min event key
// so we have the same amount of key address space either way
this.gapKey = MID;
this.eventKey = MIN;
}
}
get gapKey() {
return this._keys.getUint32(0, false);
}
set gapKey(value) {
return this._keys.setUint32(0, value, false);
}
get eventKey() {
return this._keys.getUint32(4, false);
}
set eventKey(value) {
return this._keys.setUint32(4, value, false);
}
get buffer() {
return this._keys.buffer;
}
nextKeyWithGap() {
const k = new SortKey();
k.gapKey = this.gapKey + 1;
k.eventKey = MIN;
return k;
}
nextKey() {
const k = new SortKey();
k.gapKey = this.gapKey;
k.eventKey = this.eventKey + 1;
return k;
}
previousKey() {
const k = new SortKey();
k.gapKey = this.gapKey;
k.eventKey = this.eventKey - 1;
return k;
}
clone() {
const k = new SortKey();
k.gapKey = this.gapKey;
k.eventKey = this.eventKey;
return k;
}
static get maxKey() {
const maxKey = new SortKey();
maxKey.gapKey = MAX;
maxKey.eventKey = MAX;
return maxKey;
}
static get minKey() {
const minKey = new SortKey();
minKey.gapKey = MIN;
minKey.eventKey = MIN;
return minKey;
}
compare(otherKey) {
const gapDiff = this.gapKey - otherKey.gapKey;
if (gapDiff === 0) {
return this.eventKey - otherKey.eventKey;
} else {
return gapDiff;
}
}
toString() {
return `[${this.gapKey}/${this.eventKey}]`;
}
}
//#ifdef TESTS
export function tests() {
return {
test_default_key(assert) {
const k = new SortKey();
assert.equal(k.gapKey, MID);
assert.equal(k.eventKey, MIN);
},
test_inc(assert) {
const a = new SortKey();
const b = a.nextKey();
assert.equal(a.gapKey, b.gapKey);
assert.equal(a.eventKey + 1, b.eventKey);
const c = b.previousKey();
assert.equal(b.gapKey, c.gapKey);
assert.equal(c.eventKey + 1, b.eventKey);
assert.equal(a.eventKey, c.eventKey);
},
test_min_key(assert) {
const minKey = SortKey.minKey;
const k = new SortKey();
assert(minKey.gapKey <= k.gapKey);
assert(minKey.eventKey <= k.eventKey);
},
test_max_key(assert) {
const maxKey = SortKey.maxKey;
const k = new SortKey();
assert(maxKey.gapKey >= k.gapKey);
assert(maxKey.eventKey >= k.eventKey);
},
test_immutable(assert) {
const a = new SortKey();
const gapKey = a.gapKey;
const eventKey = a.eventKey;
a.nextKeyWithGap();
assert.equal(a.gapKey, gapKey);
assert.equal(a.eventKey, eventKey);
},
test_cmp_gapkey_first(assert) {
const a = new SortKey();
const b = new SortKey();
a.gapKey = 2;
a.eventKey = 1;
b.gapKey = 1;
b.eventKey = 100000;
assert(a.compare(b) > 0);
},
test_cmp_eventkey_second(assert) {
const a = new SortKey();
const b = new SortKey();
a.gapKey = 1;
a.eventKey = 100000;
b.gapKey = 1;
b.eventKey = 2;
assert(a.compare(b) > 0);
},
test_cmp_max_larger_than_min(assert) {
assert(SortKey.minKey.compare(SortKey.maxKey) < 0);
},
test_cmp_gapkey_first_large(assert) {
const a = new SortKey();
const b = new SortKey();
a.gapKey = MAX;
a.eventKey = MIN;
b.gapKey = MIN;
b.eventKey = MAX;
assert(b < a);
assert(a > b);
}
};
}
//#endif