Add data store implementation (not used yet)

Src/data_store.cpp

@@ -0,0 +1,104 @@
+#include <string.h>
+
+#include <data_store.hh>
+#include <utils.hh>
+
+DataStore::DataStore()
+{
+	this->registeredData = NULL;
+	this->n_registeredData = 0;
+
+	/* Convention: Odd numbers for the clients */
+	this->key_counter = 1;
+}
+
+DataStore::~DataStore()
+{
+	free(this->registeredData);
+}
+
+struct ds_data *DataStore::registerData(uint32_t key,
+		struct ds_data *data)
+{
+	int i;
+
+	/* Replacing an existing entry? */
+	for (i = 0; i < this->n_registeredData; i++)
+	{
+		if (this->registeredData[i] &&
+				this->registeredData[i]->key == key)
+		{
+			struct ds_data *old = this->registeredData[i];
+
+			this->registeredData[i] = data;
+			return old;
+		}
+	}
+
+	for (i = 0; i < this->n_registeredData; i++)
+	{
+		/* Found free spot? */
+		if (this->registeredData[i] == NULL)
+			break;
+	}
+
+	if (i >= this->n_registeredData)
+	{
+		this->n_registeredData++;
+		this->registeredData = (struct ds_data **)xrealloc(this->registeredData,
+				this->n_registeredData * sizeof(void*));
+	}
+	this->registeredData[i] = data;
+
+	return NULL;
+}
+
+struct ds_data *DataStore::embedData(void *data, size_t sz)
+{
+	struct ds_data *out;
+
+	out = (struct ds_data *)xmalloc(sizeof(struct ds_data) + sz);
+
+	out->key = this->key_counter;
+	out->metadata = 0; /* Setup by the embedder */
+	memcpy(out->data, data, sz);
+
+	panic_if(this->registerData(out->key, out) != NULL,
+			"Registering new data with key %u was non-NULL\n",
+			out->key);
+	out->key += 2;
+
+	return out;
+}
+
+struct ds_data *DataStore::unregisterData(uint32_t key)
+{
+	for (int i = 0; i < this->n_registeredData; i++)
+	{
+		if (this->registeredData[i] &&
+				this->registeredData[i]->key == key)
+		{
+			struct ds_data *old = this->registeredData[i];
+
+			this->registeredData[i] = NULL;
+
+			return old;
+		}
+	}
+
+	return NULL;
+}
+
+struct ds_data *DataStore::getData(uint32_t key)
+{
+	for (int i = 0; i < this->n_registeredData; i++)
+	{
+		if (this->registeredData[i] &&
+				this->registeredData[i]->key == key)
+			return this->registeredData[i];
+	}
+
+	return NULL;
+}
+
+DataStore *DataStore::ds = NULL;

Src/data_store.hh

@@ -0,0 +1,63 @@
+#ifndef __DATA_STORE_HH__
+#define __DATA_STORE_HH__
+
+#include <stdint.h>
+
+struct ds_data
+{
+	uint32_t key;
+	uint32_t metadata; /* Type etc */
+	uint8_t  data[];
+};
+
+class DataStore;
+
+class DataStore
+{
+public:
+	DataStore();
+
+	~DataStore();
+
+	/**
+	 * Register a new datum.
+	 *
+	 * @param key The key to register with
+	 * @param data The data to register
+	 *
+	 * @return the old datum with that key, or NULL
+	 */
+	struct ds_data *registerData(uint32_t key, struct ds_data *data);
+
+	/**
+	 * Embed existing data into a data store. The new data is reallocated,
+	 * but the old is not freed
+	 *
+	 * @param data The data to embed.
+	 * @param sz the size of the data
+	 *
+	 * @return the new data store data.
+	 */
+	struct ds_data *embedData(void *data, size_t sz);
+
+	/**
+	 * Unregister a datum.
+	 *
+	 * @param key The key to unregister
+	 *
+	 * @return the unregistered datum, or NULL if it didn't exist
+	 */
+	struct ds_data *unregisterData(uint32_t key);
+
+	struct ds_data *getData(uint32_t key);
+
+	static DataStore *ds;
+
+private:
+	struct ds_data **registeredData;
+	int n_registeredData;
+
+	uint32_t key_counter;
+};
+
+#endif /* __DATA_STORE_HH__ */