PouchDB init

src/db/index.ts

@@ -0,0 +1,107 @@
+import _ from 'lodash';
+import uri from '../lib/ids';
+
+const dbDefinitionId = uri('dbdef', {});
+
+const currentDbDefinition = {
+  _id: dbDefinitionId,
+  type: dbDefinitionId,
+  def: { version: '0.000001' },
+};
+
+export const initDb = async (db: any, setDbReady?: any) => {
+  var previousDbDefinition = {
+    _id: dbDefinitionId,
+    type: dbDefinitionId,
+    def: { version: '0' },
+  };
+  try {
+    previousDbDefinition = await db.get(dbDefinitionId);
+  } catch (error: any) {
+    if (error.status !== 404) {
+      console.log(
+        `Unexpected error fetching db definition: ${JSON.stringify(error)}`
+      );
+      return;
+    }
+  }
+
+  if (previousDbDefinition.def.version < currentDbDefinition.def.version) {
+    previousDbDefinition.def = currentDbDefinition.def;
+    db.put(previousDbDefinition);
+    // TODO: support migrations
+  }
+  await await db.compact();
+  await db.viewCleanup();
+
+  // WARNING: defs must use the canonical form and be identical to what will be returned by db.getIndexes
+  const requiredIndexes: any = [
+    {
+      name: 'type-subtype',
+      def: {
+        fields: [{ type: 'asc' }, { subtype: 'asc' }],
+      },
+    },
+    {
+      name: 'type-trkpt-gpx-time',
+      def: {
+        fields: [{ type: 'asc' }, { gpx: 'asc' }, { 'trkpt.time': 'asc' }],
+      },
+    },
+  ];
+
+  const existingIndexes = (await db.getIndexes()).indexes;
+
+  const pruneIndex = ({ name, def }: any) => ({ name, def });
+
+  const isSameIndex = (idx1: any, idx2: any) => {
+    return _.isEqual(pruneIndex(idx1), pruneIndex(idx2));
+  };
+
+  const findIndex = (targetIndexes: any, index: any) =>
+    targetIndexes.find((targetIndex: any) => {
+      return isSameIndex(targetIndex, index);
+    });
+
+  for (var index of existingIndexes) {
+    if (index.type === 'json') {
+      // Non system indexes
+      //      console.log(`Checking existing index :${JSON.stringify(index)}`);
+      if (!findIndex(requiredIndexes, index)) {
+        //        console.log(`db.deleteIndex(${JSON.stringify(index)})`);
+        await db.deleteIndex(index);
+      }
+    }
+  }
+
+  for (index of requiredIndexes) {
+    if (!findIndex(existingIndexes, index)) {
+      //      console.log(`db.createIndex(${JSON.stringify(index)})`);
+      await db.createIndex({ name: index.name, ...index.def });
+    }
+  }
+
+  if (setDbReady !== undefined) setDbReady(true);
+
+  /*   const indexes = await db.getIndexes();
+  console.log(`indexes: ${JSON.stringify(indexes)}`);
+
+  const explain1 = await db.explain({
+    selector: {
+      type: 'trkpt',
+      gpx: 'xxxx',
+    },
+    //   sort: ['trkpt.time'],
+    // use_index: 'type-trkpt-gpx-time',
+  });
+  console.log(`explain1: ${JSON.stringify(explain1)}`);
+  const explain2 = await db.explain({
+    selector: {
+      type: 'gpx',
+    },
+    //   sort: ['trkpt.time'],
+    // use_index: 'type-trkpt-gpx-time',
+  });
+  console.log(`explain2: ${JSON.stringify(explain2)}`);
+ */
+};