packages/node_modules/pouchdb-adapter-idb/src/allDocs.js

import { createError, IDB_ERROR } from 'pouchdb-errors';
import { collectConflicts } from 'pouchdb-merge';

import {
  ATTACH_STORE,
  BY_SEQ_STORE,
  DOC_STORE
} from './constants';

import {
  decodeDoc,
  decodeMetadata,
  fetchAttachmentsIfNecessary,
  postProcessAttachments,
  openTransactionSafely
} from './utils';

function createKeyRange(start, end, inclusiveEnd, key, descending) {
  try {
    if (start && end) {
      if (descending) {
        return IDBKeyRange.bound(end, start, !inclusiveEnd, false);
      } else {
        return IDBKeyRange.bound(start, end, false, !inclusiveEnd);
      }
    } else if (start) {
      if (descending) {
        return IDBKeyRange.upperBound(start);
      } else {
        return IDBKeyRange.lowerBound(start);
      }
    } else if (end) {
      if (descending) {
        return IDBKeyRange.lowerBound(end, !inclusiveEnd);
      } else {
        return IDBKeyRange.upperBound(end, !inclusiveEnd);
      }
    } else if (key) {
      return IDBKeyRange.only(key);
    }
  } catch (e) {
    return {error: e};
  }
  return null;
}

function handleKeyRangeError(api, opts, err, callback) {
  if (err.name === "DataError" && err.code === 0) {
    // data error, start is less than end
    return callback(null, {
      total_rows: api._meta.docCount,
      offset: opts.skip,
      rows: []
    });
  }
  callback(createError(IDB_ERROR, err.name, err.message));
}

function idbAllDocs(opts, api, idb, callback) {

  function allDocsQuery(opts, callback) {
    var start = 'startkey' in opts ? opts.startkey : false;
    var end = 'endkey' in opts ? opts.endkey : false;
    var key = 'key' in opts ? opts.key : false;
    var skip = opts.skip || 0;
    var limit = typeof opts.limit === 'number' ? opts.limit : -1;
    var inclusiveEnd = opts.inclusive_end !== false;
    var descending = 'descending' in opts && opts.descending ? 'prev' : null;

    var keyRange = createKeyRange(start, end, inclusiveEnd, key, descending);
    if (keyRange && keyRange.error) {
      return handleKeyRangeError(api, opts, keyRange.error, callback);
    }

    var stores = [DOC_STORE, BY_SEQ_STORE];

    if (opts.attachments) {
      stores.push(ATTACH_STORE);
    }
    var txnResult = openTransactionSafely(idb, stores, 'readonly');
    if (txnResult.error) {
      return callback(txnResult.error);
    }
    var txn = txnResult.txn;
    var docStore = txn.objectStore(DOC_STORE);
    var seqStore = txn.objectStore(BY_SEQ_STORE);
    var cursor = descending ?
      docStore.openCursor(keyRange, descending) :
      docStore.openCursor(keyRange);
    var docIdRevIndex = seqStore.index('_doc_id_rev');
    var results = [];
    var docCount = 0;

    // if the user specifies include_docs=true, then we don't
    // want to block the main cursor while we're fetching the doc
    function fetchDocAsynchronously(metadata, row, winningRev) {
      var key = metadata.id + "::" + winningRev;
      docIdRevIndex.get(key).onsuccess =  function onGetDoc(e) {
        row.doc = decodeDoc(e.target.result);
        if (opts.conflicts) {
          var conflicts = collectConflicts(metadata);
          if (conflicts.length) {
            row.doc._conflicts = conflicts;
          }
        }
        fetchAttachmentsIfNecessary(row.doc, opts, txn);
      };
    }

    function allDocsInner(cursor, winningRev, metadata) {
      var row = {
        id: metadata.id,
        key: metadata.id,
        value: {
          rev: winningRev
        }
      };
      var deleted = metadata.deleted;
      if (opts.deleted === 'ok') {
        results.push(row);
        // deleted docs are okay with "keys" requests
        if (deleted) {
          row.value.deleted = true;
          row.doc = null;
        } else if (opts.include_docs) {
          fetchDocAsynchronously(metadata, row, winningRev);
        }
      } else if (!deleted && skip-- <= 0) {
        results.push(row);
        if (opts.include_docs) {
          fetchDocAsynchronously(metadata, row, winningRev);
        }
        if (--limit === 0) {
          return;
        }
      }
      cursor.continue();
    }

    function onGetCursor(e) {
      docCount = api._meta.docCount; // do this within the txn for consistency
      var cursor = e.target.result;
      if (!cursor) {
        return;
      }
      var metadata = decodeMetadata(cursor.value);
      var winningRev = metadata.winningRev;

      allDocsInner(cursor, winningRev, metadata);
    }

    function onResultsReady() {
      callback(null, {
        total_rows: docCount,
        offset: opts.skip,
        rows: results
      });
    }

    function onTxnComplete() {
      if (opts.attachments) {
        postProcessAttachments(results, opts.binary).then(onResultsReady);
      } else {
        onResultsReady();
      }
    }

    txn.oncomplete = onTxnComplete;
    cursor.onsuccess = onGetCursor;
  }

  function allDocs(opts, callback) {

    if (opts.limit === 0) {
      return callback(null, {
        total_rows: api._meta.docCount,
        offset: opts.skip,
        rows: []
      });
    }
    allDocsQuery(opts, callback);
  }

  allDocs(opts, callback);
}

export default idbAllDocs;