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Diffstat (limited to 'doc/developer/cspf.rst')
| -rw-r--r-- | doc/developer/cspf.rst | 163 |
1 files changed, 82 insertions, 81 deletions
diff --git a/doc/developer/cspf.rst b/doc/developer/cspf.rst index 426553ff06..7a5a55ee31 100644 --- a/doc/developer/cspf.rst +++ b/doc/developer/cspf.rst @@ -24,59 +24,59 @@ to the cost of the cuurent path from the source up to the current node. The algorithm is as followed: -``` - cost = MAX_COST; - Priority_Queue.empty(); - Visited_Node.empty(); - Processed_Path.empty(); - src = new_path(source_address); - src.cost = 0; - dst = new_destinatio(destination_address); - dst.cost = MAX_COST; - Processed_Path.add(src); - Processed_Path.add(dst); - while (Priority_Queue.count != 0) { - current_path = Priority_Queue.pop(); - current_node = next_path.destination; - Visited_Node.add(current_node); - for (current_node.edges: edge) { - if (prune_edge(current_path, edge) - continue; - if (relax(current_path) && cost > current_path.cost) { - optim_path = current_path; - cost = current_path.cost; - } - } - } - - prune_edge(path, edge) { - // check that path + edge meet constraints e.g. - if (current_path.cost + edge.cost > constrained_cost) - return false; - else - return true; - } - - relax_edge(current_path, edge) { - next_node = edge.destination; - if (Visited_Node.get(next_node)) - return false; - next_path = Processed_Path.get(edge.destination); - if (!next_path) { - next_path = new path(edge.destination); - Processed_Path.add(next_path); - } - total_cost = current_path.cost + edge.cost; - if (total_cost < next_path.cost) { - next_path = current_path; - next_path.add_edge(edge); - next_path.cost = total_cost; - Priority_Queue.add(next_path); - } - return (next_path.destination == destination); - } - -``` +.. code-block:: c + + cost = MAX_COST; + Priority_Queue.empty(); + Visited_Node.empty(); + Processed_Path.empty(); + src = new_path(source_address); + src.cost = 0; + dst = new_destinatio(destination_address); + dst.cost = MAX_COST; + Processed_Path.add(src); + Processed_Path.add(dst); + while (Priority_Queue.count != 0) { + current_path = Priority_Queue.pop(); + current_node = next_path.destination; + Visited_Node.add(current_node); + for (current_node.edges: edge) { + if (prune_edge(current_path, edge) + continue; + if (relax(current_path) && cost > current_path.cost) { + optim_path = current_path; + cost = current_path.cost; + } + } + } + + prune_edge(path, edge) { + // check that path + edge meet constraints e.g. + if (current_path.cost + edge.cost > constrained_cost) + return false; + else + return true; + } + + relax_edge(current_path, edge) { + next_node = edge.destination; + if (Visited_Node.get(next_node)) + return false; + next_path = Processed_Path.get(edge.destination); + if (!next_path) { + next_path = new path(edge.destination); + Processed_Path.add(next_path); + } + total_cost = current_path.cost + edge.cost; + if (total_cost < next_path.cost) { + next_path = current_path; + next_path.add_edge(edge); + next_path.cost = total_cost; + Priority_Queue.add(next_path); + } + return (next_path.destination == destination); + } + Definition ---------- @@ -162,34 +162,35 @@ various metrics. Link State provides such Traffic Engineering Database. To perform a Path Computation with given constraints, proceed as follow: .. code-block:: c - struct cspf *algo; - struct ls_ted *ted; - struct in_addr src; - struct in_addr dst; - struct constraints csts; - struct c_path *path; - - // Create a new CSPF structure - algo = cspf_new(); - - // Initialize constraints - csts.cost = 100; - csts.ctype = CSPF_TE_METRIC; - csts.family = AF_INET; - csts.type = SR_TE; - csts.bw = 1000000; - csts.cos = 3; - - // Then, initialise th CSPF with source, destination and constraints - cspf_init_v4(algo, ted, src, dst, &csts); - - // Finally, got the Computed Path; - path = compute_p2p_path(ted, algo); - - if (path.status == SUCCESS) - zlog_info("Got a valid constraints path"); - else - zlog_info("Unable to compute constraints path. Got %d status", path->status); + + struct cspf *algo; + struct ls_ted *ted; + struct in_addr src; + struct in_addr dst; + struct constraints csts; + struct c_path *path; + + // Create a new CSPF structure + algo = cspf_new(); + + // Initialize constraints + csts.cost = 100; + csts.ctype = CSPF_TE_METRIC; + csts.family = AF_INET; + csts.type = SR_TE; + csts.bw = 1000000; + csts.cos = 3; + + // Then, initialise th CSPF with source, destination and constraints + cspf_init_v4(algo, ted, src, dst, &csts); + + // Finally, got the Computed Path; + path = compute_p2p_path(ted, algo); + + if (path.status == SUCCESS) + zlog_info("Got a valid constraints path"); + else + zlog_info("Unable to compute constraints path. Got %d status", path->status); If you would compute another path, you must call `cspf_init()` prior to |