optimize weighted_partial match

5 files changed, 84 insertions, 13 deletions

diff --git a/app.js b/app.js
index c0392e6..b5fd29b 100644
--- a/app.js
+++ b/app.js
@@ -2,6 +2,8 @@
 
 const Koa = require('koa');
 // const { koaBody } = require('koa-body');
+
+// load parameters
 require('dotenv').config();
 
 // define app
@@ -10,7 +12,7 @@ const app = new Koa();
 // middleware
 // app.use(koaBody());
 
-// Require routes
+// load routes
 let _r = require('./routes');
 app.use(_r.routes()).use(_r.allowedMethods());
 
diff --git a/pieces/prepare-streams.js b/pieces/prepare.js
index ee7ba8e..65ccee1 100644
--- a/pieces/prepare-streams.js
+++ b/pieces/prepare.js
@@ -31,6 +31,8 @@ const kb = require('../utils/kb-util.js');
 
 
 /** create entity file from url
+ * used for entities like 'linked-words', 'synonyms', etc.
+ * 
  * @param {string} entity: use the entity name 
  * @param {string} url: prepared entity json-file in remote server
  */
@@ -50,6 +52,14 @@ function create(entity, url) {
     );
 }
 
+function get_data_structure() {
+    // data structure is an array of `{ url:.., expiration:.., path:.. }` objects
+}
+
+function set_data_structure(node) {
+
+}
+
 
 function load_products(url) {
     request(url,
@@ -58,6 +68,15 @@ function load_products(url) {
                 // body is a ready json-string; no need to parse and (re-)stringify
                 json = JSON.parse(body);
                 newJson = [];
+
+                // TODO:
+                // + attach handle synonyms
+                // + mark brand-names
+                // + attach category-names and SAP-categories
+                // + construct combo words
+                // + remove non-important words
+                // + normalize popularity
+
                 json.forEach( p => {
                     newJson.push({
                         id: p.id,
@@ -65,11 +84,19 @@ function load_products(url) {
                         kb: kb.keyboardize(kb.clean(p.w))
                     });
                 });
+                
                 try {
-                    fs.writeFileSync(`${__dirname}/../data/products.json`, JSON.stringify(newJson), 'utf-8');
-                    // file written successfully
+
+                    fs.writeFileSync(
+                        `${__dirname}/../data/products.json`,
+                        JSON.stringify(newJson),
+                        'utf-8'
+                    );
+                    return true;    // file written successfully
+
                 } catch (err) {
                     console.error(err);
+                    return false;
                 }
             }
         }
diff --git a/routes/dev.js b/routes/dev.js
index 3f142d0..cd40822 100644
--- a/routes/dev.js
+++ b/routes/dev.js
@@ -6,7 +6,7 @@
 const Router = require('koa-router');
 const urler = require('../utils/url-util.js'); 
 
-const data = require('../pieces/prepare-streams.js');
+const data = require('../pieces/prepare.js');
 
 const bench = require('../benchmark/find.js');
 const matchStr = require('../benchmark/match-str.js');
diff --git a/routes/v1.js b/routes/v1.js
index 859f7b0..9690973 100644
--- a/routes/v1.js
+++ b/routes/v1.js
@@ -3,6 +3,7 @@
  */
 
 const Router = require('koa-router');
+const prepare = require('../pieces/prepare.js');
 
 
 // Prefix all routes with: /items
@@ -14,10 +15,25 @@ const router = new Router({
 
 // Routes
 
+router.get('/prepare/:title', (ctx) => {
+    let result = false;
+    switch (ctx.params.title) {
+        case 'products': 
+            result = prepare.load_products(
+                'https://storage.googleapis.com/pythia-files/uploads/json/emarket-products.json'
+            );
+            break;
+        
+        default:
+            break;
+            
+    }
+    return { success: result };
+})
 
 
 router.get('/search', (ctx) => {
-	ctx.body = { success: true, results: [] };
+	ctx.body = [];
 });
 
 router.get('/search/:title', (ctx) => {
diff --git a/utils/match-util.js b/utils/match-util.js
index b6b9fc0..5e8c648 100644
--- a/utils/match-util.js
+++ b/utils/match-util.js
@@ -1,3 +1,13 @@
+/**
+ * match utility;
+ * includes fuzzy and partial match functions too;
+ * many of them return a match-rate
+ */
+
+
+// fuzzy match
+////////////////////////////////////////////////////////////////////////////////
+
 /** Ngram fuzzy match algorithm
  * (simple and fast)
  */
@@ -63,13 +73,16 @@ const resemblance = (a, b, n) => {
 }
 
 
+// exact and partial match
+////////////////////////////////////////////////////////////////////////////////
+
 /** is_exact_match
  * check if a searching string -> query (string/latin in kb-format)
  * matches exactly an item of the array of synonyms -> chkArr (array of utf-8/strings)
  * 
- * @param query (string): searching string; string/latin in kb-format
- * @param chkArr (array): array of synonyms; (array of utf-8/strings)
- * @return (boolean): true|false
+ * @param {string} query: searching string; string/latin in kb-format
+ * @param {array} chkArr: array of synonyms; (array of utf-8/strings)
+ * @return {boolean}: true|false
  */
 function exact( query, chkArr ) {
     found = false;
@@ -89,11 +102,10 @@ function partial( query, chkArr ) {
 function weighted_exact( query, chkArr ) {
     let weight = 0;   // closer to left/begin rating
     let len = chkArr.length;
-    for(let i = 0; i < len ; i++) {
+    for(let i = 0; i < len ; i++) {     // i ~ depth
         if (chkArr[i] == query) {
-            // rating weights array depth
+            // weights array depth
             weight = (len - i + 1.0) / len;
-            // console.log(i, weight, query);
             break;
         }
     }
@@ -102,22 +114,36 @@ function weighted_exact( query, chkArr ) {
 
 
 /** is partial match + weight rating
+ * 
+ * @param query (string): searching string; string/latin in kb-format
+ * @param chkArr (array): array of synonyms; (array of utf-8/strings)
  * @returns {float} weight rates both match position and depth of match
+ * 
+ * (*) optimization NOTE:
+ * Given the weight `W` and the depth `i`,
+ * the best weight for next `i` shall be: `(L - (i+1)) / L`
+ * To be imposibbe to have a better weight, should:
+ * W > (L - (i+1)) / L  => ... =>  i > (L - L*W - 1)
  */
 function weighted_partial( query, chkArr ) {
     let rate = 0;
     let weight = 0;
     let len = chkArr.length;
-    for(let i = 0; i < len ; i++) {
+    for( let i = 0 ; i < len ; i++ ) {
         let chk = chkArr[i].indexOf(query)
         if (chk != -1) {
-            rate = (len -i +1.0) / (len + 2.0 * chk);
+            rate = (len - i) / (len + 2.0 * chk);
             weight = rate > weight ? rate : weight;
         }
+        if (i > (len - len * weight - 1)) {
+            break;      // better rating is not possible (*)
+        }
     }
     return weight;
 }
 
+
+// exports
 module.exports = {
     exact,
     partial,