prepare 5.6.0 release (launchdarkly#128)

caching_store_wrapper.js

@@ -0,0 +1,143 @@
+var NodeCache = require('node-cache'),
+    dataKind = require('./versioned_data_kind'),
+    UpdateQueue = require('./update_queue');
+
+function cacheKey(kind, key) {
+  return kind.namespace + ":" + key;
+}
+
+function allCacheKey(kind) {
+  return "$all:" + kind.namespace;
+}
+
+var initializedKey = "$checkedInit";
+
+/*
+  CachingStoreWrapper provides commonly needed functionality for implementations of an
+  SDK feature store. The underlyingStore must implement a simplified interface for
+  querying and updating the data store (see redis_feature_store.js for an example)
+  while CachingStoreWrapper adds optional caching of stored items and of the
+  initialized state, and ensures that asynchronous operations are serialized correctly.
+*/
+function CachingStoreWrapper(underlyingStore, ttl) {
+  var cache = ttl ? new NodeCache({ stdTTL: ttl }) : null;
+  var queue = new UpdateQueue();
+  var initialized = false;
+
+  this.underlyingStore = underlyingStore;
+
+  this.init = function(allData, cb) {
+    queue.enqueue(function(cb) {
+      underlyingStore.initInternal(allData, function() {
+        initialized = true;
+
+        if (cache) {
+          cache.del(initializedKey);
+          cache.flushAll();
+
+          // populate cache with initial data
+          for (var kindNamespace in allData) {
+            if (Object.hasOwnProperty.call(allData, kindNamespace)) {
+              var kind = dataKind[kindNamespace];
+              var items = allData[kindNamespace];
+              cache.set(allCacheKey(kind), items);
+              for (var key in items) {
+                cache.set(cacheKey(kind, key), items[key]);
+              }
+            }
+          }
+        }
+
+        cb();
+      });
+    }, [], cb);
+  };
+
+  this.initialized = function(cb) {
+    if (initialized) {
+      cb(true);
+    } else if (cache && cache.get(initializedKey)) {
+      cb(false);
+    } else {
+      underlyingStore.initializedInternal(function(inited) {
+        initialized = inited;
+        if (!initialized) {
+          cache && cache.set(initializedKey, true);
+        }
+        cb(initialized);
+      });
+    }
+  };
+
+  this.all = function(kind, cb) {
+    var items = cache && cache.get(allCacheKey(kind));
+    if (items) {
+      cb(items);
+      return;
+    }
+
+    underlyingStore.getAllInternal(kind, function(items) {
+      var filteredItems = {};
+      Object.keys(items).forEach(function(key) {
+        var item = items[key];
+        if (item && !item.deleted) {
+          filteredItems[key] = item;
+        }
+      });
+      cache && cache.set(allCacheKey(kind), filteredItems);
+      cb(filteredItems);
+    });
+  };
+
+  this.get = function(kind, key, cb) {
+    if (cache) {
+      var item = cache.get(cacheKey(kind, key));
+      if (item !== undefined) {
+        cb(itemOnlyIfNotDeleted(item));
+        return;
+      }
+    }
+
+    underlyingStore.getInternal(kind, key, function(item) {
+      cache && cache.set(cacheKey(kind, key), item);
+      cb(itemOnlyIfNotDeleted(item));
+    });
+  };
+
+  function itemOnlyIfNotDeleted(item) { 
+    return (!item || item.deleted) ? null : item;
+  }
+
+  this.upsert = function(kind, newItem, cb) {
+    queue.enqueue(function (cb) {
+      flushAllCaches();
+      underlyingStore.upsertInternal(kind, newItem, function(err, updatedItem) {
+        if (!err) {
+          cache && cache.set(cacheKey(kind, newItem.key), updatedItem);
+        }
+        cb();
+      });
+    }, [], cb);
+  };
+
+  this.delete = function(kind, key, version, cb) {
+    this.upsert(kind, { key: key, version: version, deleted: true }, cb);
+  };
+
+  this.close = function() {
+    cache.close();
+    underlyingStore.close();
+  };
+
+  function flushAllCaches() {
+    if (!cache) {
+      return;
+    }
+    for (var kindNamespace in dataKind) {
+      cache.del(allCacheKey(dataKind[kindNamespace]));
+    }
+  }
+}
+
+module.exports = CachingStoreWrapper;
+

package.json

@@ -33,7 +33,7 @@
     "request": "2.87.0",
     "request-etag": "^2.0.3",
     "semver": "5.5.0",
-    "tunnel": "https://github.com/launchdarkly/node-tunnel/tarball/d860e57650cce1ea655d00854c81babe6b47e02c",
+    "tunnel": "0.0.6",
     "winston": "2.4.1"
   },
   "engines": {