Add interface

src/VecSim/algorithms/hnsw/graph_storage_interface.h

@@ -0,0 +1,92 @@
+#pragma once
+
+#include <utility>
+
+#include "VecSim/utils/vecsim_stl.h"
+#include "VecSim/vec_sim_common.h"
+
+typedef uint16_t linkListSize;
+using graphNodeType = std::pair<idType, unsigned short>; // represented as: (element_id, level)
+using WriteBatch = void *;
+
+class GraphStorageInterface {
+    /**
+     * Common struct to hold the outgoing edges of a node.
+     */
+    struct OutgoingEdges {
+        linkListSize numLinks;
+        idType links[];
+    };
+    /**
+     * @brief Common struct to hold the incoming *unudirectional* edges of a node.
+     */
+    struct IncomingUnidirectionalEdges {
+        vecsim_stl::vector<idType> incomingUnidirectionalEdges;
+    };
+
+public:
+    GraphStorageInterface() = default;
+    virtual ~GraphStorageInterface() = default;
+    /**
+     * @brief Initialize a new element in the graph storage.
+     */
+    virtual void intializeNewElement(idType node_id, size_t max_level) = 0;
+    /**
+     * @brief Add a new outgoing neighbor to the node.
+     */
+    virtual void addNeighbor(const graphNodeType &node, idType target, WriteBatch wb) = 0;
+    /**
+     * @brief Add a new incoming unidirectional neighbor to the node.
+     */
+    virtual std::vector<int> addIncomingUnidirectionalNeighbor(const graphNodeType &node,
+                                                               idType nodeId, WriteBatch wb) = 0;
+    /**
+     * @brief update all edges for node (perform mutuall updates).
+     */
+    virtual void setAllNeighbors(const graphNodeType &node, std::vector<idType> nodeId,
+                                 WriteBatch wb) = 0;
+    /**
+     * @brief get node's edges (read only).
+     */
+    virtual const OutgoingEdges &getEdges(const graphNodeType &node) = 0;
+    /**
+     * @brief get node's edges for update.
+     */
+    virtual OutgoingEdges &getEdgesForUpdate(const graphNodeType &node) = 0;
+    /**
+     * @brief get node's incoming unidirectional edges (read only).
+     */
+    virtual const IncomingUnidirectionalEdges &
+    getIncomingUnidirectionalEdges(const graphNodeType &node) = 0;
+    /**
+     * @brief get node's incoming unidirectional edges for update.
+     */
+    virtual IncomingUnidirectionalEdges &
+    getIncomingUnidirectionalEdgesForUpdate(const graphNodeType &node) = 0;
+    /**
+     * @brief mark element as permanently deleted from the graph storage when it has no longer
+     * outgoing and incoming edges
+     */
+    virtual void permanentDelete(idType node_id) = 0;
+    /**
+     * @brief Apply garbage collection for permanente deleted elements from the graph storage.
+     */
+    virtual void applyGC() = 0;
+    /**
+     * Create new write trnasaction.
+     */
+    virtual WriteBatch createWriteBatch() = 0;
+    /**
+     * Commit write operaiton that were collected in the write batch.
+     */
+    virtual int commitWriteBatch(WriteBatch *wb) = 0;
+
+    /**
+     * @brief Save the graph storage to a file.
+     */
+    virtual void saveGraph(std::ofstream &output) const = 0;
+    /**
+     * @brief Load the graph storage from a file.
+     */
+    virtual void loadGraph(const std::ifstream &input) const = 0;
+};