1 files changed, 101 insertions, 0 deletions
diff --git a/src/com/p4square/grow/backend/db/CassandraCollectionProvider.java b/src/com/p4square/grow/backend/db/CassandraCollectionProvider.java
new file mode 100644
index 0000000..cc11828
--- /dev/null
+++ b/src/com/p4square/grow/backend/db/CassandraCollectionProvider.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.backend.db;
+
+import java.io.IOException;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import com.netflix.astyanax.model.Column;
+import com.netflix.astyanax.model.ColumnList;
+
+import com.p4square.grow.provider.CollectionProvider;
+import com.p4square.grow.provider.JsonEncodedProvider;
+
+/**
+ * CollectionProvider implementation backed by a Cassandra ColumnFamily.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public class CassandraCollectionProvider<V> implements CollectionProvider<String, String, V> {
+    private final CassandraDatabase mDb;
+    private final String mCF;
+    private final Class<V> mClazz;
+
+    public CassandraCollectionProvider(CassandraDatabase db, String columnFamily, Class<V> clazz) {
+        mDb = db;
+        mCF = columnFamily;
+        mClazz = clazz;
+    }
+
+    @Override
+    public V get(String collection, String key) throws IOException {
+        String blob = mDb.getKey(mCF, collection, key);
+        return decode(blob);
+    }
+
+    @Override
+    public Map<String, V> query(String collection) throws IOException {
+        return query(collection, -1);
+    }
+
+    @Override
+    public Map<String, V> query(String collection, int limit) throws IOException {
+        Map<String, V> result = new HashMap<>();
+
+        ColumnList<String> row = mDb.getRow(mCF, collection);
+        if (!row.isEmpty()) {
+            int count = 0;
+            for (Column<String> c : row) {
+                String key = c.getName();
+                String blob = c.getStringValue();
+                V obj = decode(blob);
+
+                result.put(key, obj);
+
+                if (limit >= 0 && ++count > limit) {
+                    break; // Limit reached.
+                }
+            }
+        }
+
+        return Collections.unmodifiableMap(result);
+    }
+
+    @Override
+    public void put(String collection, String key, V obj) throws IOException {
+        String blob = encode(obj);
+        mDb.putKey(mCF, collection, key, blob);
+    }
+
+    /**
+     * Encode the object as JSON.
+     *
+     * @param obj The object to encode.
+     * @return The JSON encoding of obj.
+     * @throws IOException if the object cannot be encoded.
+     */
+    protected String encode(V obj) throws IOException {
+        return JsonEncodedProvider.MAPPER.writeValueAsString(obj);
+    }
+
+    /**
+     * Decode the JSON string as an object.
+     *
+     * @param blob The JSON data to decode.
+     * @return The decoded object or null if blob is null.
+     * @throws IOException If an object cannot be decoded.
+     */
+    protected V decode(String blob) throws IOException {
+        if (blob == null) {
+            return null;
+        }
+
+        V obj = JsonEncodedProvider.MAPPER.readValue(blob, mClazz);
+        return obj;
+    }
+}