session-desktop/ts/receiver/cache.ts

import { EnvelopePlus } from './types';
import { StringUtils } from '../session/utils';
import _ from 'lodash';

export async function removeFromCache(envelope: EnvelopePlus) {
  const { id } = envelope;

  return window.textsecure.storage.unprocessed.remove(id);
}

export async function addToCache(
  envelope: EnvelopePlus,
  plaintext: ArrayBuffer
) {
  const { id } = envelope;

  const encodedEnvelope = StringUtils.decode(plaintext, 'base64');
  const data: any = {
    id,
    version: 2,
    envelope: encodedEnvelope,
    timestamp: Date.now(),
    attempts: 1,
  };

  if (envelope.senderIdentity) {
    data.senderIdentity = envelope.senderIdentity;
  }

  return window.textsecure.storage.unprocessed.add(data);
}

export async function getAllFromCache() {
  window.log.info('getAllFromCache');

  const { textsecure } = window;

  const count = await textsecure.storage.unprocessed.getCount();

  if (count > 1500) {
    await textsecure.storage.unprocessed.removeAll();
    window.log.warn(
      `There were ${count} messages in cache. Deleted all instead of reprocessing`
    );
    return [];
  }

  const items = await textsecure.storage.unprocessed.getAll();
  window.log.info('getAllFromCache loaded', items.length, 'saved envelopes');

  return Promise.all(
    _.map(items, async (item: any) => {
      const attempts = _.toNumber(item.attempts || 0) + 1;

      try {
        if (attempts >= 3) {
          window.log.warn(
            'getAllFromCache final attempt for envelope',
            item.id
          );
          await textsecure.storage.unprocessed.remove(item.id);
        } else {
          await textsecure.storage.unprocessed.updateAttempts(
            item.id,
            attempts
          );
        }
      } catch (error) {
        window.log.error(
          'getAllFromCache error updating item after load:',
          error && error.stack ? error.stack : error
        );
      }

      return item;
    })
  );
}

export async function updateCache(
  envelope: EnvelopePlus,
  plaintext: ArrayBuffer
): Promise<void> {
  const { id } = envelope;
  const item = await window.textsecure.storage.unprocessed.get(id);
  if (!item) {
    window.log.error(`updateCache: Didn't find item ${id} in cache to update`);
    return;
  }

  item.source = envelope.source;
  item.sourceDevice = envelope.sourceDevice;
  item.serverTimestamp = envelope.serverTimestamp;

  // For medium-size closed groups
  if (envelope.senderIdentity) {
    item.senderIdentity = envelope.senderIdentity;
  }

  item.decrypted = StringUtils.decode(plaintext, 'base64');

  return window.textsecure.storage.unprocessed.addDecryptedData(item.id, item);
}