Function cbm_gbuf_merge

src/graph_buffer/graph_buffer.c:1373–1413

}

int cbm_gbuf_merge(cbm_gbuf_t *dst, cbm_gbuf_t *src) {
    if (!dst || !src) {
        return CBM_NOT_FOUND;
    }
    if (src->nodes.count == 0 && src->edges.count == 0) {
        return 0;
    }

    /* ID remap for QN-colliding nodes: "src_id" → (int64_t*) dst_id.
     * Only populated when a src node's QN already exists in dst. */
    CBMHashTable *remap = NULL;

    for (int i = 0; i < src->nodes.count; i++) {
        cbm_gbuf_node_t *sn = src->nodes.items[i];
        if (!sn->qualified_name) {
            continue;
        }

        /* Skip nodes deleted from QN index */
        if (!cbm_ht_get(src->node_by_qn, sn->qualified_name)) {
            continue;
        }

        cbm_gbuf_node_t *existing = cbm_ht_get(dst->node_by_qn, sn->qualified_name);
        if (existing) {
            merge_update_existing(dst, existing, sn, &remap);
        } else {
            merge_copy_new_node(dst, sn);
        }
    }

    /* Merge edges with optional ID remapping */
    merge_remap_edges(dst, src, remap);

    if (remap) {
        cbm_ht_foreach(remap, free_remap_entry, NULL);
        cbm_ht_free(remap);
    }

    return 0;
}

/* ── Dump / Flush ────────────────────────────────────────────────── */