diff options
Diffstat (limited to 'common/indexeddb.js')
| -rw-r--r-- | common/indexeddb.js | 66 |
1 files changed, 44 insertions, 22 deletions
diff --git a/common/indexeddb.js b/common/indexeddb.js index 096391a..e54d1ca 100644 --- a/common/indexeddb.js +++ b/common/indexeddb.js @@ -62,7 +62,8 @@ const stores = [ ["files", {keyPath: "hash_key"}], ["file_uses", {keyPath: "hash_key"}], ["resources", {keyPath: "identifier"}], - ["mappings", {keyPath: "identifier"}] + ["mappings", {keyPath: "identifier"}], + ["settings", {keyPath: "name"}] ]; let db = null; @@ -207,7 +208,7 @@ async function incr_file_uses(context, file_ref, by=1) const decr_file_uses = (ctx, file_ref) => incr_file_uses(ctx, file_ref, -1); -async function finalize_items_transaction(context) +async function finalize_transaction(context) { for (const uses of Object.values(context.file_uses)) { if (uses.uses < 0) @@ -248,7 +249,7 @@ async function finalize_items_transaction(context) return context.result; } -#EXPORT finalize_items_transaction +#EXPORT finalize_transaction /* * How a sample data argument to the function below might look like: @@ -304,7 +305,7 @@ async function _save_items(resources, mappings, context) for (const item of resources.concat(mappings)) await save_item(item, context); - await finalize_items_transaction(context); + await finalize_transaction(context); } /* @@ -314,9 +315,9 @@ async function _save_items(resources, mappings, context) * object with keys being of the form `sha256-<file's-sha256-sum>`. * * context should be one returned from start_items_transaction() and should be - * later passed to finalize_items_transaction() so that files depended on are - * added to IndexedDB and files that are no longer depended on after this - * operation are removed from IndexedDB. + * later passed to finalize_transaction() so that files depended on are added to + * IndexedDB and files that are no longer depended on after this operation are + * removed from IndexedDB. */ async function save_item(item, context) { @@ -346,9 +347,9 @@ async function _remove_item(store_name, identifier, context) * Remove definition of a resource/mapping from IndexedDB. * * context should be one returned from start_items_transaction() and should be - * later passed to finalize_items_transaction() so that files depended on are - * added to IndexedDB and files that are no longer depended on after this - * operation are removed from IndexedDB. + * later passed to finalize_transaction() so that files depended on are added to + * IndexedDB and files that are no longer depended on after this operation are + * removed from IndexedDB. */ async function remove_item(store_name, identifier, context) { @@ -363,26 +364,49 @@ const remove_resource = (id, ctx) => remove_item("resources", id, ctx); const remove_mapping = (id, ctx) => remove_item("mappings", id, ctx); #EXPORT remove_mapping +/* A simplified kind of transaction for modifying just the "settings" store. */ +async function start_settings_transaction() +{ + const db = await get_db(); + return make_context(db.transaction("settings", "readwrite"), {}); +} + +async function set_setting(name, value) +{ + const context = await start_settings_transaction(); + broadcast.prepare(context.sender, `idb_changes_settings`, name); + await idb_put(context.transaction, "settings", {name, value}); + return finalize_transaction(context); +} +#EXPORT set_setting + +async function get_setting(name) +{ + const transaction = (await get_db()).transaction("settings"); + return ((await idb_get(transaction, "settings", name)) || {}).value; +} +#EXPORT get_setting + /* Callback used when listening to broadcasts while tracking db changes. */ -async function track_change(tracking, identifier) +async function track_change(tracking, key) { const transaction = (await get_db()).transaction([tracking.store_name]); - const new_val = await idb_get(transaction, tracking.store_name, identifier); + const new_val = await idb_get(transaction, tracking.store_name, key); - tracking.onchange({identifier, new_val}); + tracking.onchange({key, new_val}); } /* * Monitor changes to `store_name` IndexedDB object store. * - * `store_name` should be either "resources" or "mappings". + * `store_name` should be either "resources", "mappings" or "settings". * * `onchange` should be a callback that will be called when an item is added, * modified or removed from the store. The callback will be passed an object * representing the change as its first argument. This object will have the * form: * { - * identifier: "the identifier of modified resource/mapping", + * key: "the identifier of modified resource/mapping or settings key", * new_val: undefined // `undefined` if item removed, item object otherwise * } * @@ -395,7 +419,7 @@ async function track_change(tracking, identifier) * actually modified or that it only gets called once after multiple quick * changes to an item. */ -async function track(store_name, onchange) +async function start_tracking(store_name, onchange) { const tracking = {store_name, onchange}; tracking.listener = @@ -408,12 +432,10 @@ async function track(store_name, onchange) return [tracking, (await wait_request(all_req)).target.result]; } -const track_resources = onchange => track("resources", onchange); -#EXPORT track_resources - -const track_mappings = onchange => track("mappings", onchange); -#EXPORT track_mappings +const track = {}; +for (const store_name of ["resources", "mappings", "settings"]) + track[store_name] = onchange => start_tracking(store_name, onchange); +#EXPORT track const untrack = tracking => broadcast.close(tracking.listener); #EXPORT untrack - |