From 9e134e5caf9f96e2d19f2b1793d04f6194a7cfdc Mon Sep 17 00:00:00 2001
From: Ryuichi Inagaki <ryuichi.inagaki.24@googlemail.com>
Date: Fri, 16 Feb 2018 22:27:50 +1100
Subject: [PATCH] ref #5 Extracted collection management logic

---
 lib/decoration-registry.js        | 36 ++++++++++++++++--------------
 lib/text-decoration-collection.js | 37 +++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 17 deletions(-)
 create mode 100644 lib/text-decoration-collection.js

diff --git a/lib/decoration-registry.js b/lib/decoration-registry.js
index 568b604..6890bf9 100644
--- a/lib/decoration-registry.js
+++ b/lib/decoration-registry.js
@@ -1,6 +1,7 @@
 
 const _ = require('lodash');
 const OverviewRulerLane = require('vscode').OverviewRulerLane;
+const TextDecorationCollection = require('./text-decoration-collection');
 
 const OVERVIEW_RULER_COLOUR = 'violet';
 
@@ -11,7 +12,7 @@ class DecorationRegistry {
         this._window = params.window;
         this._generateUuid = params.generateUuid;
 
-        this._textDecorationMap = {};
+        this._textDecorationMap = new TextDecorationCollection();
     }
 
     inquireById(decorationId) {
@@ -19,18 +20,20 @@ class DecorationRegistry {
     }
 
     inquireByPattern(pattern) {
-        const decorationId = _.findKey(
-            this._textDecorationMap,
-            decoration => decoration && decoration.pattern.equalTo(pattern)
-        );
-        return decorationId ? this._buildDecorationFromId(decorationId) : null;
+        const isSamePattern = decoration => decoration.pattern.equalTo(pattern);
+        const decoration = this._textDecorationMap.find(isSamePattern);
+        return decoration && this._buildDecorationInfo(decoration);
     }
 
-    _buildDecorationFromId(decorationId) {
-        const decoration = Object.assign({id: decorationId}, this._textDecorationMap[decorationId]);
+    _buildDecorationInfo(decoration) {
         return _.pick(decoration, ['id', 'decorationType', 'pattern']);
     }
 
+    _buildDecorationFromId(decorationId) {
+        const decoration = this._textDecorationMap.get(decorationId);
+        return decoration && this._buildDecorationInfo(decoration);
+    }
+
     issue(pattern) {
         const decoration = this.inquireByPattern(pattern);
         if (decoration) return null;
@@ -38,26 +41,25 @@ class DecorationRegistry {
         const colour = this._colourRegistry.issue();
         const id = this._generateUuid();
         const decorationType = this._generateDecorationType(colour);
-        this._textDecorationMap[id] = {pattern, colour, decorationType};
+        this._textDecorationMap.add({id, pattern, colour, decorationType});
         return this._buildDecorationFromId(id);
     }
 
     updatePattern(decorationId, newPattern) {
-        this._textDecorationMap[decorationId].pattern = newPattern;
-        return this._buildDecorationFromId(decorationId);
+        const decoration = this._textDecorationMap.get(decorationId);
+        decoration.pattern = newPattern;
+        return this._buildDecorationInfo(decoration);
     }
 
     revoke(decorationId) {
-        const decoration = this._textDecorationMap[decorationId];
+        const decoration = this._textDecorationMap.get(decorationId);
         this._colourRegistry.revoke(decoration.colour);
-        this._textDecorationMap[decorationId] = null;
+        this._textDecorationMap.remove(decorationId);
     }
 
     retrieveAll() {
-        return _.reduce(this._textDecorationMap,
-            (result, value, key) => value ? result.concat(this._buildDecorationFromId(key)) : result,
-            []
-        );
+        return this._textDecorationMap.toList()
+            .map(this._buildDecorationInfo);
     }
 
     _generateDecorationType(colour) {
diff --git a/lib/text-decoration-collection.js b/lib/text-decoration-collection.js
new file mode 100644
index 0000000..5d26224
--- /dev/null
+++ b/lib/text-decoration-collection.js
@@ -0,0 +1,37 @@
+
+const _ = require('lodash');
+
+class TextDecorationCollection {
+
+    constructor() {
+        this._map = Object.create(null);
+    }
+
+    add({id, pattern, colour, decorationType}) {
+        this._map[id] = {pattern, colour, decorationType};
+    }
+
+    get(id) {
+        const value = this._map[id];
+        return value ? Object.assign({id}, value) : null;
+    }
+
+    remove(id) {
+        this._map[id] = null;
+    }
+
+    find(predicate) {
+        const id = _.findKey(this._map, decoration => decoration && predicate(decoration));
+        return id ? Object.assign({id}, this._map[id]) : null;
+    }
+
+    toList() {
+        return _.reduce(this._map,
+            (result, value, key) => value ? [...result, Object.assign({id: key}, value)] : result,
+            []
+        );
+    }
+
+}
+
+module.exports = TextDecorationCollection;