optimized filtering

README.md

@@ -72,6 +72,7 @@ The exported property contains an array of definitions, each linking a match to
   - `options.ignoreFromSelf`: Don't inform about changes that originated from the microservice to be informed (based on the hostname).
   - `options.retry`: (experimental) How many times the request is sent again on failure.  Defaults to 0. Warning: in case of retries, deltas may be received out of order!
   - `options.retryTimeout`: (experimental) How much time is left in between retries (in ms).  Currently defaults to 250ms.
+  - `options.sendMatchesOnly`: Only send triples that match, removing the other triples from the changes.
 
 ### Modifying quads
 #### Normalize datetime

app.js

@@ -2,22 +2,47 @@ import { app } from 'mu';
 import services from './config/rules';
 import normalizeQuad from './config/normalize-quad';
 import bodyParser from 'body-parser';
-import dns from 'dns';
 import { foldChangeSets } from './folding';
 import { sendRequest } from './send-request';
 import { sendBundledRequest } from './bundle-requests';
+import {
+  filterChangesetsOnPattern,
+  tripleMatchesSpec,
+  filterMatchesForOrigin,
+  hostnameForEntry
+} from './matching';
+import {
+  DEBUG_DELTA_MATCH,
+  DEBUG_DELTA_SEND,
+  DEBUG_TRIPLE_MATCHES_SPEC,
+  LOG_REQUESTS,
+  LOG_SERVER_CONFIGURATION,
+} from './env';
 
 // Log server config if requested
-if( process.env["LOG_SERVER_CONFIGURATION"] )
+if(LOG_SERVER_CONFIGURATION)
   console.log(JSON.stringify( services ));
 
+let index = 0;
+const groupedServices = services.reduce((acc, service) => {
+  // Create a unique key for the match pattern
+  const matchKey = `${normalizeObject(service.match)}${service.options.sendMatchesOnly || false}`;
+  if (!acc[matchKey]) {
+    acc[matchKey] = [];
+  }
+  service.index = index++;
+  acc[matchKey].push(service);
+  return acc;
+}, {});
+
+
 app.get( '/', function( req, res ) {
   res.status(200);
   res.send("Hello, delta notification is running");
 } );
 
 app.post( '/', bodyParser.json({limit: '500mb'}), function( req, res ) {
-  if( process.env["LOG_REQUESTS"] ) {
+  if( LOG_REQUESTS ) {
     console.log("Logging request body");
     console.log(req.body);
   }
@@ -44,98 +69,69 @@ app.post( '/', bodyParser.json({limit: '500mb'}), function( req, res ) {
 } );
 
 async function informWatchers( changeSets, res, muCallIdTrail, muSessionId ){
-  services.map( async (entry, index) => {
-    entry.index = index;
-    // for each entity
-    if( process.env["DEBUG_DELTA_MATCH"] )
-      console.log(`Checking if we want to send to ${entry.callback.url}`);
-
-    const matchSpec = entry.match;
-
-    const originFilteredChangeSets = await filterMatchesForOrigin( changeSets, entry );
-    if( process.env["DEBUG_TRIPLE_MATCHES_SPEC"] && entry.options.ignoreFromSelf )
-      console.log(`There are ${originFilteredChangeSets.length} changes sets not from ${hostnameForEntry( entry )}`);
+  // Iterate over each unique match pattern
+  for (const matchKey in groupedServices) {
+    const firstEntry = groupedServices[matchKey][0];
+    // can use first entry since it's part of grouping
+    const sendMatchesOnly = firstEntry.options.sendMatchesOnly;
+    let maybePatternFilteredChangesets = changeSets;
+    if (sendMatchesOnly) {
+      maybePatternFilteredChangesets = filterChangesetsOnPattern(changeSets, firstEntry);
+    }
 
     let allInserts = [];
     let allDeletes = [];
-
-    originFilteredChangeSets.forEach( (change) => {
+    maybePatternFilteredChangesets.forEach( (change) => {
       allInserts = [...allInserts, ...change.insert];
       allDeletes = [...allDeletes, ...change.delete];
     } );
-
     const changedTriples = [...allInserts, ...allDeletes];
-
     const someTripleMatchedSpec =
-        changedTriples
-        .some( (triple) => tripleMatchesSpec( triple, matchSpec ) );
-
-    if( process.env["DEBUG_TRIPLE_MATCHES_SPEC"] )
-      console.log(`Triple matches spec? ${someTripleMatchedSpec}`);
-
-    if( someTripleMatchedSpec ) {
-      // inform matching entities
-      if( process.env["DEBUG_DELTA_SEND"] )
-        console.log(`Going to send ${entry.callback.method} to ${entry.callback.url}`);
-
-      if( entry.options && entry.options.gracePeriod ) {
-        sendBundledRequest(entry, originFilteredChangeSets, muCallIdTrail, muSessionId);
-      } else {
-        const foldedChangeSets = foldChangeSets( entry, originFilteredChangeSets );
-        sendRequest( entry, foldedChangeSets, muCallIdTrail, muSessionId );
+          changedTriples
+          .some( (triple) => tripleMatchesSpec( triple, firstEntry.match ) );
+    const matchingServices = groupedServices[matchKey];
+    matchingServices.forEach( async (entry) => {
+      if( DEBUG_TRIPLE_MATCHES_SPEC )
+        console.log(`Triple matches spec? ${someTripleMatchedSpec}`);
+
+      if( someTripleMatchedSpec ) {
+        // for each entity
+        if( DEBUG_DELTA_MATCH )
+          console.log(`Checking if we want to send to ${entry.callback.url}`);
+        const matchSpec = entry.match;
+        const originFilteredChangeSets = await filterMatchesForOrigin( maybePatternFilteredChangesets, entry );
+
+        if ( originFilteredChangeSets.length > 0 ) {
+          if( DEBUG_TRIPLE_MATCHES_SPEC && entry.options.ignoreFromSelf )
+            console.log(`There are ${originFilteredChangeSets.length} changes sets not from ${hostnameForEntry( entry )}`);
+
+          // inform matching entities
+          if( DEBUG_DELTA_SEND )
+            console.log(`Going to send ${entry.callback.method} to ${entry.callback.url}`);
+
+          if( entry.options?.gracePeriod ) {
+            sendBundledRequest(entry, originFilteredChangeSets, muCallIdTrail, muSessionId);
+          } else {
+            const foldedChangeSets = foldChangeSets( entry, originFilteredChangeSets );
+            sendRequest( entry, foldedChangeSets, muCallIdTrail, muSessionId );
+          }
+        }
       }
-    }
-  } );
-}
-
-function tripleMatchesSpec( triple, matchSpec ) {
-  // form of triple is {s, p, o}, same as matchSpec
-  if( process.env["DEBUG_TRIPLE_MATCHES_SPEC"] )
-    console.log(`Does ${JSON.stringify(triple)} match ${JSON.stringify(matchSpec)}?`);
-
-  for( let key in matchSpec ){
-    // key is one of s, p, o
-    const subMatchSpec = matchSpec[key];
-    const subMatchValue = triple[key];
-
-    if( subMatchSpec && !subMatchValue )
-      return false;
-
-    for( let subKey in subMatchSpec )
-      // we're now matching something like {type: "url", value: "http..."}
-      if( subMatchSpec[subKey] !== subMatchValue[subKey] )
-        return false;
-  }
-  return true; // no false matches found, let's send a response
-}
-
-async function filterMatchesForOrigin( changeSets, entry ) {
-  if( ! entry.options || !entry.options.ignoreFromSelf ) {
-    return changeSets;
-  } else {
-    try {
-      const originIpAddress = await getServiceIp( entry );
-      return changeSets.filter( (changeSet) => changeSet.origin != originIpAddress );
-    } catch(e) {
-      console.error(`Could not filter changeset because an error was returned while looking up ip for ${entry.callback.url}`);
-      console.error(e);
-      return changeSets;
-    }
+    } );
   }
 }
 
-function hostnameForEntry( entry ) {
-  return (new URL(entry.callback.url)).hostname;
+/**
+ * Normalizes an object by sorting its keys and converting it to a string.
+ *
+ * @param {Object} obj - The object to normalize.
+ * @returns {string} A string representation of the normalized object.
+ */
+function normalizeObject(obj) {
+  return JSON.stringify(Object.keys(obj)
+                        .sort()
+                        .reduce((acc, key) => {
+                          acc[key] = obj[key];
+                          return acc;
+                        }, {}));
 }
-
-async function getServiceIp(entry) {
-  const hostName = hostnameForEntry( entry );
-  return new Promise( (resolve, reject) => {
-    dns.lookup( hostName, { family: 4 }, ( err, address) => {
-      if( err )
-        reject( err );
-      else
-        resolve( address );
-    } );
-  } );
-};

bundle-requests.js

@@ -1,5 +1,6 @@
 import { foldChangeSets } from './folding';
 import { sendRequest } from "./send-request.js";
+import { DEBUG_DELTA_SEND } from './env';
 
 // map from bundle key to bundle object
 const bundles = {};
@@ -58,13 +59,13 @@ export const sendBundledRequest = (
     existingBundle.bundledCallIdTrails.push(muCallIdTrail);
     // since an existing bundle exists, we don't need to send it after timeout,
     // the existing bundle will send us too
-    if (process.env["DEBUG_DELTA_SEND"]) {
+    if (DEBUG_DELTA_SEND) {
       console.log(
         `Adding to bundle for key ${bundleKey}, now contains ${existingBundle.changeSets.length} change sets`
       );
     }
   } else {
-    if (process.env["DEBUG_DELTA_SEND"]) {
+    if (DEBUG_DELTA_SEND) {
       console.log(
         `Creating bundle for key ${bundleKey}, sending in ${entry.options.gracePeriod}ms`
       );

config/normalize-quad.js

@@ -1,4 +1,4 @@
-const normalizeDate = process.env["NORMALIZE_DATETIME_IN_QUAD"];
+import { NORMALIZE_DATETIME_IN_QUAD as normalizeDate} from './env';
 
 export default function(quad) {
   if (normalizeDate && quad.object.datatype == 'http://www.w3.org/2001/XMLSchema#dateTime') {

env.js

@@ -0,0 +1,8 @@
+export const DEBUG_DELTA_FOLD = process.env["DEBUG_DELTA_FOLD"];
+export const DEBUG_DELTA_MATCH = process.env["DEBUG_DELTA_MATCH"];
+export const DEBUG_DELTA_NOT_SENDING_EMPTY = process.env["DEBUG_DELTA_NOT_SENDING_EMPTY"];
+export const DEBUG_DELTA_SEND = process.env["DEBUG_DELTA_SEND"];
+export const DEBUG_TRIPLE_MATCHES_SPEC = process.env["DEBUG_TRIPLE_MATCHES_SPEC"];
+export const LOG_REQUESTS =  process.env["LOG_REQUESTS"];
+export const LOG_SERVER_CONFIGURATION = process.env["LOG_SERVER_CONFIGURATION"];
+export const NORMALIZE_DATETIME_IN_QUAD = process.env["NORMALIZE_DATETIME_IN_QUAD"];

folding.js

@@ -1,3 +1,4 @@
+import { DEBUG_DELTA_FOLD } from './env';
 /**
  * Quads may be folded if
  * - a quad is deleted after it has been inserted
@@ -44,7 +45,7 @@ export function foldChangeSets(entry, changeSets) {
     if (foldedInsertQuads.length)
       foldedChangeSets.push({ delete: [], insert: foldedInsertQuads });
 
-    if (process.env["DEBUG_DELTA_FOLD"])
+    if (DEBUG_DELTA_FOLD)
       console.log(`Folded changeset from:\n ${JSON.stringify(changeSets)}\nto:\n ${JSON.stringify(foldedChangeSets)}`);
 
     return foldedChangeSets;

matching.js

@@ -0,0 +1,79 @@
+import dns from 'dns';
+import { DEBUG_TRIPLE_MATCHES_SPEC } from './env';
+/**
+ * Filters the change sets based on a specified pattern.
+ *
+ * @param {Array<Object>} changeSets - An array of change set objects,
+ * each containing `insert` and `delete` properties.
+ * @param {Object} entry - An object containing the matching criteria.
+ * @param {Array} entry.match - The pattern used to filter the triples
+ * in the `insert` and `delete` arrays.
+ * @returns {Array<Object>} A new array of change set objects with
+ * filtered `insert` and `delete` properties.
+ */
+export function filterChangesetsOnPattern(changeSets, entry) {
+  const filteredChangesets = [];
+  for (const changeSet of changeSets) {
+    const { insert, delete: deleteSet } = changeSet;
+    const clonedChangeSet = {
+      ...changeSet,
+      insert: insert.filter((triple) => tripleMatchesSpec(triple, entry.match)),
+      delete: deleteSet.filter((triple) => tripleMatchesSpec(triple, entry.match))
+    };
+    filteredChangesets.push(clonedChangeSet);
+  };
+  return filteredChangesets;
+}
+
+export function tripleMatchesSpec( triple, matchSpec ) {
+  // form of triple is {s, p, o}, same as matchSpec
+  if(DEBUG_TRIPLE_MATCHES_SPEC)
+    console.log(`Does ${JSON.stringify(triple)} match ${JSON.stringify(matchSpec)}?`);
+
+  for( let key in matchSpec ){
+    // key is one of s, p, o
+    const subMatchSpec = matchSpec[key];
+    const subMatchValue = triple[key];
+
+    if( subMatchSpec && !subMatchValue )
+      return false;
+
+    for( let subKey in subMatchSpec )
+      // we're now matching something like {type: "url", value: "http..."}
+      if( subMatchSpec[subKey] !== subMatchValue[subKey] )
+        return false;
+  }
+  return true; // no false matches found, let's send a response
+}
+
+
+export async function filterMatchesForOrigin( changeSets, entry ) {
+  if( ! entry.options || !entry.options.ignoreFromSelf ) {
+    return changeSets;
+  } else {
+    try {
+      const originIpAddress = await getServiceIp( entry );
+      return changeSets.filter( (changeSet) => changeSet.origin != originIpAddress );
+    } catch(e) {
+      console.error(`Could not filter changeset because an error was returned while looking up ip for ${entry.callback.url}`);
+      console.error(e);
+      return changeSets;
+    }
+  }
+}
+
+export function hostnameForEntry( entry ) {
+  return (new URL(entry.callback.url)).hostname;
+}
+
+async function getServiceIp(entry) {
+  const hostName = hostnameForEntry( entry );
+  return new Promise( (resolve, reject) => {
+    dns.lookup( hostName, { family: 4 }, ( err, address) => {
+      if( err )
+        reject( err );
+      else
+        resolve( address );
+    } );
+  } );
+};

send-request.js

@@ -2,6 +2,8 @@ import http from "http";
 import { uuid } from "mu";
 
 const DEFAULT_RETRY_TIMEOUT = 250;
+const DEBUG_DELTA_SEND = process.env["DEBUG_DELTA_SEND"];
+const DEBUG_DELTA_NOT_SENDING_EMPTY = process.env["DEBUG_DELTA_NOT_SENDING_EMPTY"];
 
 function formatChangesetBody(changeSets, options) {
   if (options.resourceFormat == "v0.0.1") {
@@ -115,7 +117,7 @@ export async function sendRequest(
       // we should send contents
       body = formatChangesetBody(changeSets, entry.options);
     }
-    if (process.env["DEBUG_DELTA_SEND"])
+    if (DEBUG_DELTA_SEND)
       console.log(`Executing send ${method} to ${url}`);
     try {
       const keepAliveAgent = new http.Agent({
@@ -137,10 +139,10 @@ export async function sendRequest(
         retriesLeft
       );
     } catch (error) {
-      console.log(error);
+      console.error(`Error sending delta to ${url}`, error);
     }
   } else {
-    if (process.env["DEBUG_DELTA_SEND"] || process.env["DEBUG_DELTA_NOT_SENDING_EMPTY"])
+    if (DEBUG_DELTA_SEND || DEBUG_DELTA_NOT_SENDING_EMPTY)
       console.log(`Changeset empty. Not sending to ${entry.callback.method} ${entry.callback.url}`);
   }
 }