Compute distance for identities

Signed-off-by: James Ketrenos <james.p.ketrenos@intel.com>

server/routes/identities.js

@@ -1,6 +1,7 @@
 "use strict";
 
-const express = require("express");
+const express = require("express"),
+  Promise = require("bluebird");
 
 let photoDB;
 
@@ -84,9 +85,23 @@ router.post("/", (req, res) => {
   });
 });
 
+function bufferToFloat32Array(buffer) {
+  return new Float32Array(buffer.buffer, buffer.byteOffset, buffer.byteLength / Float32Array.BYTES_PER_ELEMENT);
+}
+
+function euclideanDistance(a, b) {
+  let A = bufferToFloat32Array(a);
+  let B = bufferToFloat32Array(b);
+  let sum = 0;
+  for (let i = 0; i < 128; i++) {
+    let delta = A[i] - B[i];
+    sum += delta * delta;
+  }
+  return Math.sqrt(sum);
+}
+
 router.get("/:id?", (req, res) => {
   let id;
-  console.log("here");
 
   if (req.params.id) {
     id = parseInt(req.params.id);
@@ -111,7 +126,6 @@ router.get("/:id?", (req, res) => {
     type: photoDB.Sequelize.QueryTypes.SELECT,
     raw: true
   }).then((identities) => {
-    console.log("asdf");
     identities.forEach((identity) => {
       const relatedFaces = identity.relatedFaceIds.split(","),
         relatedFacePhotos = identity.relatedFacePhotoIds.split(",");
@@ -132,24 +146,40 @@ router.get("/:id?", (req, res) => {
       console.log("No score request.");
       return identities;
     }
-    console.log("Looking up scores.");
+    console.log("Looking up score against: " + req.query.withScore);
 
-    return photoDB.sequelize.query("SELECT * FROM facedescriptor WHERE faceId IN (:faceIds)", {
+    return Promise.map(identities, (identity) => {
+      return photoDB.sequelize.query("SELECT * FROM facedescriptors WHERE faceId IN (:id,:faceIds)", {
         replacements: {
-        faceIds: relatedFaces
+          id: parseInt(req.query.withScore),
+          faceIds: identity.relatedFaces.map(face => face.faceId)
         },
         type: photoDB.Sequelize.QueryTypes.SELECT,
         raw: true
       }).then((descriptors) => {
+        let target;
+        for (let i = 0; i < descriptors.length; i++) {
+          if (descriptors[i].faceId == req.query.withScore) {
+            target = descriptors[i].descriptors;
+            break;
+          }
+        }
+        if (!target) {
+          console.warn("Could not find descriptor for requested face: " + req.query.withScore);
+          return;
+        }
+
         descriptors.forEach((descriptor) => {
           for (let i = 0; i < identity.relatedFaces.length; i++) {
             if (identity.relatedFaces[i].faceId == descriptor.faceId) {
+              identity.relatedFaces[i].distance = euclideanDistance(target, descriptor.descriptors)
               identity.relatedFaces[i].descriptors = descriptor.descriptors;
               return;
             }
           }
         });
-
+      });
+    }).then(() => {
       return identities;
     });
   }).then((identities) => {