From 8fa4f1fb4f122ee1e27c6015479bcd883b4b0671 Mon Sep 17 00:00:00 2001
From: Jesse Morgan <jesse@jesterpm.net>
Date: Thu, 25 Sep 2014 08:11:56 -0700
Subject: Adding Support for Scan in DynamoDatabase.

Also added scan and scanf (filtered) options to DbTool.
---
 src/com/p4square/grow/backend/dynamo/DbTool.java   | 58 ++++++++++++++++++++++
 .../grow/backend/dynamo/DynamoDatabase.java        | 41 +++++++++++++++
 2 files changed, 99 insertions(+)

diff --git a/src/com/p4square/grow/backend/dynamo/DbTool.java b/src/com/p4square/grow/backend/dynamo/DbTool.java
index 581795d..1a6d5e9 100644
--- a/src/com/p4square/grow/backend/dynamo/DbTool.java
+++ b/src/com/p4square/grow/backend/dynamo/DbTool.java
@@ -45,6 +45,8 @@ public class DbTool {
         System.out.println("\t--get    <table> <key> <attribute>          Get a value");
         System.out.println("\t--put    <table> <key> <attribute> <value>  Put a value");
         System.out.println("\t--delete <table> <key> <attribute>          Delete a value");
+        System.out.println("\t--scan   <table>                            List all rows");
+        System.out.println("\t--scanf  <table> <attribute>                List all rows");
         System.out.println();
         System.out.println("Bootstrap Commands:");
         System.out.println("\t--bootstrap <data>          Create all tables and import all data");
@@ -103,6 +105,12 @@ public class DbTool {
                 } else if ("--delete".equals(args[offset])) {
                     offset = delete(args, ++offset);
 
+                } else if ("--scan".equals(args[offset])) {
+                    offset = scan(args, ++offset);
+
+                } else if ("--scanf".equals(args[offset])) {
+                    offset = scanf(args, ++offset);
+
                 /* Bootstrap Commands */
                 } else if ("--bootstrap".equals(args[offset])) {
                     if ("dev".equals(mConfig.getDomain())) {
@@ -221,6 +229,56 @@ public class DbTool {
         return offset;
     }
 
+    private static int scan(String[] args, int offset) {
+        String table     = args[offset++];
+
+        DynamoKey key = DynamoKey.newKey(table, null);
+
+        doScan(key);
+
+        return offset;
+    }
+
+    private static int scanf(String[] args, int offset) {
+        String table     = args[offset++];
+        String attribute = args[offset++];
+
+        DynamoKey key = DynamoKey.newAttributeKey(table, null, attribute);
+
+        doScan(key);
+
+        return offset;
+    }
+
+    private static void doScan(DynamoKey key) {
+        DynamoDatabase db = getDatabase();
+
+        String attributeFilter = key.getAttribute();
+
+        while (key != null) {
+            Map<DynamoKey, Map<String, String>> result = db.getAll(key);
+
+            key = null; // If there are no results, exit
+
+            for (Map.Entry<DynamoKey, Map<String, String>> entry : result.entrySet()) {
+                key = entry.getKey(); // Save the last key
+
+                for (Map.Entry<String, String> attribute : entry.getValue().entrySet()) {
+                    if (attributeFilter == null || attributeFilter.equals(attribute.getKey())) {
+                        String keyString = key.getHashKey();
+                        if (key.getRangeKey() != null) {
+                            keyString += "(" + key.getRangeKey() + ")";
+                        }
+                        System.out.printf("%s %s:%s\n%s\n\n",
+                                key.getTable(), keyString, attribute.getKey(),
+                                attribute.getValue());
+                    }
+                }
+            }
+        }
+    }
+
+
     private static int bootstrapTables(String[] args, int offset) {
         DynamoDatabase db = getDatabase();
 
diff --git a/src/com/p4square/grow/backend/dynamo/DynamoDatabase.java b/src/com/p4square/grow/backend/dynamo/DynamoDatabase.java
index 0c77c49..68a165d 100644
--- a/src/com/p4square/grow/backend/dynamo/DynamoDatabase.java
+++ b/src/com/p4square/grow/backend/dynamo/DynamoDatabase.java
@@ -4,6 +4,7 @@
 
 package com.p4square.grow.backend.dynamo;
 
+import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -31,6 +32,8 @@ import com.amazonaws.services.dynamodbv2.model.KeyType;
 import com.amazonaws.services.dynamodbv2.model.ProvisionedThroughput;
 import com.amazonaws.services.dynamodbv2.model.PutItemRequest;
 import com.amazonaws.services.dynamodbv2.model.PutItemResult;
+import com.amazonaws.services.dynamodbv2.model.ScanRequest;
+import com.amazonaws.services.dynamodbv2.model.ScanResult;
 import com.amazonaws.services.dynamodbv2.model.UpdateItemRequest;
 import com.amazonaws.services.dynamodbv2.model.UpdateItemResult;
 import com.amazonaws.services.dynamodbv2.model.UpdateTableRequest;
@@ -120,6 +123,44 @@ public class DynamoDatabase {
         DeleteTableResult result = mClient.deleteTable(deleteTableRequest);
     }
 
+    /**
+     * Get all rows from a table.
+     *
+     * The key parameter must specify a table. If hash/range key is specified,
+     * the scan will begin after that key.
+     *
+     * @param key Previous key to start with.
+     * @return An ordered map of all results.
+     */
+    public Map<DynamoKey, Map<String, String>> getAll(final DynamoKey key) {
+        ScanRequest scanRequest = new ScanRequest().withTableName(mTablePrefix + key.getTable());
+
+        if (key.getHashKey() != null) {
+            scanRequest.setExclusiveStartKey(generateKey(key));
+        }
+
+        ScanResult scanResult = mClient.scan(scanRequest);
+
+        Map<DynamoKey, Map<String, String>> result = new LinkedHashMap<>();
+        for (Map<String, AttributeValue> map : scanResult.getItems()) {
+            String id = null;
+            String range = null;
+            Map<String, String> row = new LinkedHashMap<>();
+            for (Map.Entry<String, AttributeValue> entry : map.entrySet()) {
+                if ("id".equals(entry.getKey())) {
+                    id = entry.getValue().getS();
+                } else if ("range".equals(entry.getKey())) {
+                    range = entry.getValue().getS();
+                } else {
+                    row.put(entry.getKey(), entry.getValue().getS());
+                }
+            }
+            result.put(DynamoKey.newRangeKey(key.getTable(), id, range), row);
+        }
+
+        return result;
+    }
+
     public Map<String, String> getKey(final DynamoKey key) {
         GetItemRequest getItemRequest = new GetItemRequest()
             .withTableName(mTablePrefix + key.getTable())
-- 
cgit v1.2.3