Merge pull request #585 from matrix-org/dbkr/count_sessions_before_mi…

…grate Check for sessions in indexeddb before migrating
matrix-org · Dec 8, 2017 · da90a3c · da90a3c
2 parents d397c5a + 3d71bee
commit da90a3c
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Showing 5 changed files with 52 additions and 12 deletions.
diff --git a/src/crypto/OlmDevice.js b/src/crypto/OlmDevice.js
@@ -177,9 +177,9 @@ OlmDevice.prototype._migrateFromSessionStore = async function() {
                         this._cryptoStore.storeAccount(txn, pickledAccount);
                     }
                 }
-            },
-        );
-    });
+            });
+        },
+    );
 
     // remove the old account now the transaction has completed. Either we've
     // migrated it or decided not to, either way we want to blow away the old data.
@@ -190,16 +190,27 @@ OlmDevice.prototype._migrateFromSessionStore = async function() {
     if (Object.keys(sessions).length > 0) {
         await this._cryptoStore.doTxn(
             'readwrite', [IndexedDBCryptoStore.STORE_SESSIONS], (txn) => {
-                let numSessions = 0;
-                for (const deviceKey of Object.keys(sessions)) {
-                    for (const sessionId of Object.keys(sessions[deviceKey])) {
-                        numSessions++;
-                        this._cryptoStore.storeEndToEndSession(
-                            deviceKey, sessionId, sessions[deviceKey][sessionId], txn,
-                        );
+                // Don't migrate sessions from localstorage if we already have sessions
+                // in indexeddb, since this means we've already migrated and an old version
+                // has run against the same localstorage and created some spurious sessions.
+                this._cryptoStore.countEndToEndSessions(txn, (count) => {
+                    if (count) {
+                        console.log("Crypto store already has sessions: not migrating");
+                        return;
                     }
-                }
-                console.log("Migrating " + numSessions + " sessions from session store");
+                    let numSessions = 0;
+                    for (const deviceKey of Object.keys(sessions)) {
+                        for (const sessionId of Object.keys(sessions[deviceKey])) {
+                            numSessions++;
+                            this._cryptoStore.storeEndToEndSession(
+                                deviceKey, sessionId, sessions[deviceKey][sessionId], txn,
+                            );
+                        }
+                    }
+                    console.log(
+                        "Migrating " + numSessions + " sessions from session store",
+                    );
+                });
             },
         );
 

diff --git a/src/crypto/store/indexeddb-crypto-store-backend.js b/src/crypto/store/indexeddb-crypto-store-backend.js
@@ -275,6 +275,14 @@ export class Backend {
         objectStore.put(newData, "-");
     }
 
+    countEndToEndSessions(txn, func) {
+        const objectStore = txn.objectStore("sessions");
+        const countReq = objectStore.count();
+        countReq.onsuccess = function() {
+            func(countReq.result);
+        };
+    }
+
     getEndToEndSessions(deviceKey, txn, func) {
         const objectStore = txn.objectStore("sessions");
         const idx = objectStore.index("deviceKey");

diff --git a/src/crypto/store/indexeddb-crypto-store.js b/src/crypto/store/indexeddb-crypto-store.js
@@ -249,6 +249,15 @@ export default class IndexedDBCryptoStore {
         this._backendPromise.value().storeAccount(txn, newData);
     }
 
+    /**
+     * Returns the number of end-to-end sessions in the store
+     * @param {*} txn An active transaction. See doTxn().
+     * @param {function(int)} func Called with the count of sessions
+     */
+    countEndToEndSessions(txn, func) {
+        this._backendPromise.value().countEndToEndSessions(txn, func);
+    }
+
     /**
      * Retrieve a specific end-to-end session between the logged-in user
      * and another device.

diff --git a/src/crypto/store/localStorage-crypto-store.js b/src/crypto/store/localStorage-crypto-store.js
@@ -43,6 +43,14 @@ export default class LocalStorageCryptoStore extends MemoryCryptoStore {
         this.store = global.localStorage;
     }
 
+    countEndToEndSessions(txn, func) {
+        let count = 0;
+        for (let i = 0; i < this.store.length; ++i) {
+            if (this.store.key(i).startsWith(keyEndToEndSessions(''))) ++count;
+        }
+        func(count);
+    }
+
     _getEndToEndSessions(deviceKey, txn, func) {
         return getJsonItem(this.store, keyEndToEndSessions(deviceKey));
     }

diff --git a/src/crypto/store/memory-crypto-store.js b/src/crypto/store/memory-crypto-store.js
@@ -209,6 +209,10 @@ export default class MemoryCryptoStore {
         this._account = newData;
     }
 
+    countEndToEndSessions(txn, func) {
+        return Object.keys(this._sessions).length;
+    }
+
     getEndToEndSession(deviceKey, sessionId, txn, func) {
         const deviceSessions = this._sessions[deviceKey] || {};
         func(deviceSessions[sessionId] || null);