wasmboy/lib/memory/idb.js

Gameboy / Gameboy Color Emulator written for Web Assembly using AssemblyScript. Shell/Debugger in Preact

// Get our idb instance, and initialize to asn idb-keyval
// This is so we don't get the default keyval DB name. And will allow
// Parent projects to use the slimmer idb keyval
// https://www.npmjs.com/package/idb

// Need to wrap in rollup replace to stop
// node commonjs from breaking
/*ROLLUP_REPLACE_BROWSER
import idb from 'idb';
ROLLUP_REPLACE_BROWSER*/

let keyval = false;

// Get our idb dPromise
if (typeof window !== 'undefined') {
  const dbPromise = idb.open('wasmboy', 1, upgradeDB => {
    upgradeDB.createObjectStore('keyval');
  });

  // Get our idb-keyval instance
  keyval = {
    get(key) {
      return dbPromise.then(db => {
        return db
          .transaction('keyval')
          .objectStore('keyval')
          .get(key);
      });
    },
    set(key, val) {
      return dbPromise.then(db => {
        const tx = db.transaction('keyval', 'readwrite');
        tx.objectStore('keyval').put(val, key);
        return tx.complete;
      });
    },
    delete(key) {
      return dbPromise.then(db => {
        const tx = db.transaction('keyval', 'readwrite');
        tx.objectStore('keyval').delete(key);
        return tx.complete;
      });
    },
    clear() {
      return dbPromise.then(db => {
        const tx = db.transaction('keyval', 'readwrite');
        tx.objectStore('keyval').clear();
        return tx.complete;
      });
    },
    keys() {
      return dbPromise.then(db => {
        const tx = db.transaction('keyval');
        const keys = [];
        const store = tx.objectStore('keyval');

        // This would be store.getAllKeys(), but it isn't supported by Edge or Safari.
        // openKeyCursor isn't supported by Safari, so we fall back
        (store.iterateKeyCursor || store.iterateCursor).call(store, cursor => {
          if (!cursor) return;
          keys.push(cursor.key);
          cursor.continue();
        });

        return tx.complete.then(() => keys);
      });
    }
  };
} else {
  // Create a mock keyval for node
  keyval = {
    get: () => {},
    set: () => {},
    delete: () => {},
    clear: () => {},
    keys: () => {}
  };
}

export const idbKeyval = keyval;