From 629ba4f692ac39aeeb760ce279a74bf8838c83dd Mon Sep 17 00:00:00 2001
From: Davide Ricci <majindageta@gmail.com>
Date: Wed, 8 Apr 2020 10:08:05 +0200
Subject: [PATCH] add onDemand capacity to backup and restore functions

dynamo-backup: add another property to use `onDemandReadCapacity`, the default value is 25, user need to update it when using function.
If table is onDemand will se the new onDemandReadCapacity value (instead of 0)

dynamo-restore: when creating the new table user can specify via `onDemandTable` to use onDemand (pay_per_request) mode
---
 lib/dynamo-backup.js  | 35 +++++++++++++++++++----------------
 lib/dynamo-restore.js | 16 +++++++++++-----
 2 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/lib/dynamo-backup.js b/lib/dynamo-backup.js
index a81e469..dbb81ea 100644
--- a/lib/dynamo-backup.js
+++ b/lib/dynamo-backup.js
@@ -26,6 +26,7 @@ function DynamoBackup(options) {
     this.awsSecretKey = options.awsSecretKey;
     this.awsRegion = options.awsRegion;
     this.debug = Boolean(options.debug);
+    this.onDemandReadCapacity = options.onDemandReadCapacity || 25;
 
     if (this.awsRegion) {
         params.region = this.awsRegion;
@@ -54,21 +55,21 @@ DynamoBackup.prototype.backupTable = function (tableName, backupPath, callback)
         backupPath = self._getBackupPath();
     }
 
-   var params = {};
-   if (self.awsRegion) {
-       params.region = self.awsRegion;
-   }
-   if (self.awsAccessKey && self.awsSecretKey) {
+    var params = {};
+    if (self.awsRegion) {
+        params.region = self.awsRegion;
+    }
+    if (self.awsAccessKey && self.awsSecretKey) {
         params.accessKey = self.awsAccessKey;
         params.secretKey = self.awsSecretKey;
     }
 
-   params.bucket = self.bucket;
-   params.objectName = path.join(backupPath, tableName + '.json');
-   params.stream = stream;
-   params.debug = self.debug;
+    params.bucket = self.bucket;
+    params.objectName = path.join(backupPath, tableName + '.json');
+    params.stream = stream;
+    params.debug = self.debug;
 
-   var upload = new Uploader(params);
+    var upload = new Uploader(params);
 
     var startTime = moment.utc();
     self.emit('start-backup', tableName, startTime);
@@ -87,7 +88,7 @@ DynamoBackup.prototype.backupTable = function (tableName, backupPath, callback)
 
     self._copyTable(
         tableName,
-        function (items) {
+        function (items) { //itemsReceived
             items.forEach(function (item) {
                 if (self.base64Binary) {
                     _.each(item, function (value, key) {
@@ -114,7 +115,7 @@ DynamoBackup.prototype.backupTable = function (tableName, backupPath, callback)
                 });
             }
         }
-        );
+    );
 };
 
 DynamoBackup.prototype.backupAllTables = function (callback) {
@@ -141,7 +142,7 @@ DynamoBackup.prototype.backupAllTables = function (callback) {
                 })
             },
             callback
-            );
+        );
     });
 };
 
@@ -161,7 +162,9 @@ DynamoBackup.prototype._copyTable = function (tableName, itemsReceived, callback
 
         var readPercentage = self.readPercentage;
         var limit = Math.max((data.Table.ProvisionedThroughput.ReadCapacityUnits * readPercentage) | 0, 1);
-
+        if (data.Table.BillingModeSummary.BillingMode === 'PAY_PER_REQUEST') {
+            limit = self.onDemandReadCapacity;
+        }
         self._streamItems(tableName, null, limit, itemsReceived, callback);
     });
 };
@@ -229,8 +232,8 @@ DynamoBackup.prototype._formatForDataPipeline = function (item) {
             value[dataPipelineValueKey] = v;
             value[k] = undefined;
             // for MAps and Lists, recurse until the elements are created with the correct case
-            if(k === 'M' || k === 'L') {
-              self._formatForDataPipeline(v);
+            if (k === 'M' || k === 'L') {
+                self._formatForDataPipeline(v);
             }
         });
     });
diff --git a/lib/dynamo-restore.js b/lib/dynamo-restore.js
index b341fb8..94bec4c 100755
--- a/lib/dynamo-restore.js
+++ b/lib/dynamo-restore.js
@@ -24,6 +24,7 @@ function DynamoRestore(options) {
     options.awsKey = options.awsKey || process.env.AWS_ACCESS_KEY_ID;
     options.awsSecret = options.awsSecret || process.env.AWS_SECRET_ACCESS_KEY;
     options.awsRegion = options.awsRegion || process.env.AWS_DEFAULT_REGION || 'ap-southeast-2';
+    options.onDemandTable = options.onDemandTable || false;
 
     AWS.config.update({
         accessKeyId: options.awsKey,
@@ -244,12 +245,17 @@ DynamoRestore.prototype._createTable = function(callback) {
         KeySchema: [{
             AttributeName: options.partitionkey,
             KeyType: 'HASH'
-        }],
-        ProvisionedThroughput: {
+        }],    
+    };
+    if (options.onDemandTable) {
+        params['BillingMode'] = 'PAY_PER_REQUEST';
+    } else {
+        params['ProvisionedThroughput'] = {
             ReadCapacityUnits: options.readcapacity,
             WriteCapacityUnits: options.concurrency // Need this high for pumping data, but will reduce it later.
         }
-    };
+    }
+
     if (options.sortkey) {
         params.AttributeDefinitions.push({
             AttributeName: options.sortkey,
@@ -291,8 +297,8 @@ DynamoRestore.prototype._sendBatch = function() {
     // Prepare
     var params = { RequestItems: {} },
         dynamo = this.dynamodb,
-        options = this.options;
-    batch = this.batches.shift();
+        options = this.options,
+        batch = this.batches.shift();
     params.RequestItems[options.table] = batch.items;
 
     // Send