diff options
| -rw-r--r-- | background/storage.js | 24 | ||||
| -rw-r--r-- | common/observable.js | 36 |
2 files changed, 46 insertions, 14 deletions
diff --git a/background/storage.js b/background/storage.js index 682f933..c2160b0 100644 --- a/background/storage.js +++ b/background/storage.js @@ -16,6 +16,7 @@ * IMPORT make_once * IMPORT browser * IMPORT is_chrome + * IMPORT observables * IMPORTS_END */ @@ -98,7 +99,8 @@ async function list(prefix) for (let item of await get_list_var(name)) map.set(item, await get(prefix + item)); - return {map, prefix, name, listeners : new Set(), lock : make_lock()}; + return {map, prefix, name, observable: observables.make(), + lock: make_lock()}; } var list_by_prefix = {}; @@ -121,7 +123,7 @@ exports.add_change_listener = function (cb, prefixes=list_prefixes) prefixes = [prefixes]; for (let prefix of prefixes) - list_by_prefix[prefix].listeners.add(cb); + observables.subscribe(list_by_prefix[prefix].observable, cb); } exports.remove_change_listener = function (cb, prefixes=list_prefixes) @@ -130,13 +132,7 @@ exports.remove_change_listener = function (cb, prefixes=list_prefixes) prefixes = [prefixes]; for (let prefix of prefixes) - list_by_prefix[prefix].listeners.delete(cb); -} - -function broadcast_change(change, list) -{ - for (let listener_callback of list.listeners) - listener_callback(change); + observables.unsubscribe(list_by_prefix[prefix].observable, cb); } /* Prepare some hepler functions to get elements of a list */ @@ -198,7 +194,7 @@ async function _set_item(item, value, list) new_val : value }; - broadcast_change(change, list); + observables.broadcast(list.observable, change); return old_val; } @@ -236,7 +232,7 @@ async function _remove_item(item, list) new_val : undefined }; - broadcast_change(change, list); + observables.broadcast(list.observable, change); return old_val; } @@ -282,7 +278,7 @@ async function _replace_item(old_item, new_item, list, new_val=undefined) new_val : undefined }; - broadcast_change(change, list); + observables.broadcast(list.observable, change); list.map.set(new_item, new_val); @@ -290,7 +286,7 @@ async function _replace_item(old_item, new_item, list, new_val=undefined) change.old_val = undefined; change.new_val = new_val; - broadcast_change(change, list); + observables.broadcast(list.observable, change); return old_val; } @@ -375,7 +371,7 @@ exports.clear = async function () for (let [item, val] of list_entries_it(list)) { change.item = item; change.old_val = val; - broadcast_change(change, list); + observables.broadcast(list.observable, change); } list.map = new Map(); diff --git a/common/observable.js b/common/observable.js new file mode 100644 index 0000000..1fb0b0a --- /dev/null +++ b/common/observable.js @@ -0,0 +1,36 @@ +/** + * part of Hachette + * Facilitate listening to events + * + * Copyright (C) 2021 Wojtek Kosior + * Redistribution terms are gathered in the `copyright' file. + */ + +function make() +{ + return new Set(); +} + +function subscribe(observable, cb) +{ + observable.add(cb); +} + +function unsubscribe(observable, cb) +{ + observable.delete(cb); +} + +function broadcast(observable, event) +{ + for (const callback of observable) + callback(event); +} + +const observables = {make, subscribe, unsubscribe, broadcast}; + +/* + * EXPORTS_START + * EXPORT observables + * EXPORTS_END + */ |