move stuff to mvcc.ts (#484)

apps/actors/systems/kvSync/client.ts

@@ -18,9 +18,10 @@ import {
 } from "./types";
 import * as effects from "../../effects";
 import { mapObj, randStep } from "../../../../util/util";
-import { addNewVersion, runMutation } from "./mutations/run";
+import { runMutation } from "./mutations/run";
 import { InterpreterState } from "./mutations/builtins";
 import { garbageCollectTransactions } from "./gc";
+import { addNewVersion } from "./mvcc";
 
 export type QueryStatus = "Loading" | "Online";
 

apps/actors/systems/kvSync/mutations/run.ts

@@ -2,7 +2,7 @@ import { pairsToObj } from "../../../../../util/util";
 import { Expr, Lambda, Outcome, Scope, Value } from "./types";
 import { KVData, Trace, VersionedValue, WriteOp } from "../types";
 import { BUILTINS, InterpreterState } from "./builtins";
-import { getVisibleValue } from "./common";
+import { addNewVersion, getVisibleValue } from "../mvcc";
 
 export function runMutation(
   kvData: KVData,
@@ -346,18 +346,3 @@ function doWrite(
     },
   ];
 }
-
-export function addNewVersion(
-  kvData: KVData,
-  key: string,
-  newVersion: VersionedValue
-) {
-  const versions = kvData[key] || [];
-  // Check if the transactionID is already in the list
-  // This can result from overlapping live queries
-  // TODO: this is O(n) and could be O(1)
-  if (versions.some((v) => v.transactionID === newVersion.transactionID)) {
-    return versions;
-  }
-  return [...versions, newVersion];
-}

apps/actors/systems/kvSync/mvcc.ts

@@ -0,0 +1,34 @@
+import { reversed } from "../../../../util/util";
+import { KVData, VersionedValue } from "./types";
+
+export function getVisibleValue(
+  isTxnCommitted: (txnID: string) => boolean,
+  kvData: KVData,
+  key: string
+): VersionedValue | null {
+  if (!kvData[key]) {
+    return null;
+  }
+
+  for (const vv of reversed(kvData[key])) {
+    if (isTxnCommitted(vv.transactionID)) {
+      return vv;
+    }
+  }
+  return null;
+}
+
+export function addNewVersion(
+  kvData: KVData,
+  key: string,
+  newVersion: VersionedValue
+) {
+  const versions = kvData[key] || [];
+  // Check if the transactionID is already in the list
+  // This can result from overlapping live queries
+  // TODO: this is O(n) and could be O(1)
+  if (versions.some((v) => v.transactionID === newVersion.transactionID)) {
+    return versions;
+  }
+  return [...versions, newVersion];
+}

apps/actors/systems/kvSync/query.ts

@@ -1,5 +1,5 @@
 import { QueryResults } from "./hooks";
-import { getVisibleValue } from "./mutations/common";
+import { getVisibleValue } from "./mvcc";
 import { KVData, Query } from "./types";
 
 export function keyInQuery(key: string, query: Query): boolean {

apps/actors/systems/kvSync/uiCommon/kvInspector.tsx

@@ -1,10 +1,10 @@
 import React from "react";
 import { Client } from "../hooks";
 import { VersionedValue } from "../types";
-import { getVisibleValue } from "../mutations/common";
 import { TransactionState, isTxnVisible } from "../client";
 import { reversed } from "../../../../../util/util";
 import { Table } from "../../../../../uiCommon/generic/table";
+import { getVisibleValue } from "../mvcc";
 
 export function KVInspector(props: {
   client: Client;