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Change LinkGraph::EdgeMatrix to a sparse storage format

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Use a btree_map instead of a SmallMatrix.
This avoids excessive storage requirements for large graphs,
and overly expensive edge matrix resize operations.
Remove next_edge iteration mechanism.
This commit is contained in:
Jonathan G Rennison
2022-12-05 18:17:25 +00:00
parent c457dc680b
commit e647075870
16 changed files with 353 additions and 470 deletions
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53
src/saveload/linkgraph_sl.cpp
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@@ -130,7 +130,7 @@ static const SaveLoad _edge_desc[] = {
SLE_VAR(Edge, last_unrestricted_update, SLE_INT32),
SLE_CONDVAR(Edge, last_restricted_update, SLE_INT32, SLV_187, SL_MAX_VERSION),
SLE_CONDVAR_X(Edge, last_aircraft_update, SLE_INT32, SL_MIN_VERSION, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_LINKGRAPH_AIRCRAFT)),
SLE_VAR(Edge, next_edge, SLE_UINT16),
// SLE_VAR(Edge, next_edge, SLE_UINT16), // Removed since XSLFI_LINKGRAPH_SPARSE_EDGES
};
std::vector<SaveLoad> _filtered_node_desc;
@@ -151,13 +151,19 @@ static void FilterDescs()
void Save_LinkGraph(LinkGraph &lg)
{
uint16 size = lg.Size();
auto edge_iter = lg.edges.begin();
auto edge_end = lg.edges.end();
for (NodeID from = 0; from < size; ++from) {
Node *node = &lg.nodes[from];
SlObjectSaveFiltered(node, _filtered_node_desc);
/* ... but as that wasted a lot of space we save a sparse matrix now. */
for (NodeID to = from; to != INVALID_NODE; to = lg.edges[from][to].next_edge) {
SlObjectSaveFiltered(&lg.edges[from][to], _filtered_edge_desc);
while (edge_iter != edge_end && edge_iter->first.first == from) {
SlWriteUint16(edge_iter->first.second);
Edge *edge = &edge_iter->second;
SlObjectSaveFiltered(edge, _filtered_edge_desc);
++edge_iter;
}
SlWriteUint16(INVALID_NODE);
}
}
@@ -168,19 +174,42 @@ void Save_LinkGraph(LinkGraph &lg)
void Load_LinkGraph(LinkGraph &lg)
{
uint size = lg.Size();
for (NodeID from = 0; from < size; ++from) {
Node *node = &lg.nodes[from];
SlObjectLoadFiltered(node, _filtered_node_desc);
if (IsSavegameVersionBefore(SLV_191)) {
if (SlXvIsFeaturePresent(XSLFI_LINKGRAPH_SPARSE_EDGES)) {
for (NodeID from = 0; from < size; ++from) {
Node *node = &lg.nodes[from];
SlObjectLoadFiltered(node, _filtered_node_desc);
while (true) {
NodeID to = SlReadUint16();
if (to == INVALID_NODE) break;
SlObjectLoadFiltered(&lg.edges[std::make_pair(from, to)], _filtered_edge_desc);
}
}
} else if (IsSavegameVersionBefore(SLV_191)) {
std::vector<Edge> temp_edges;
std::vector<NodeID> temp_next_edges;
temp_edges.resize(size);
temp_next_edges.resize(size);
for (NodeID from = 0; from < size; ++from) {
Node *node = &lg.nodes[from];
SlObjectLoadFiltered(node, _filtered_node_desc);
/* We used to save the full matrix ... */
for (NodeID to = 0; to < size; ++to) {
SlObjectLoadFiltered(&lg.edges[from][to], _filtered_edge_desc);
SlObjectLoadFiltered(&temp_edges[to], _filtered_edge_desc);
temp_next_edges[to] = SlReadUint16();
}
} else {
for (NodeID to = from; to != INVALID_NODE; to = temp_next_edges[to]) {
lg.edges[std::make_pair(from, to)] = temp_edges[to];
}
}
} else {
for (NodeID from = 0; from < size; ++from) {
Node *node = &lg.nodes[from];
SlObjectLoadFiltered(node, _filtered_node_desc);
/* ... but as that wasted a lot of space we save a sparse matrix now. */
for (NodeID to = from; to != INVALID_NODE; to = lg.edges[from][to].next_edge) {
for (NodeID to = from; to != INVALID_NODE;) {
if (to >= size) SlErrorCorrupt("Link graph structure overflow");
SlObjectLoadFiltered(&lg.edges[from][to], _filtered_edge_desc);
SlObjectLoadFiltered(&lg.edges[std::make_pair(from, to)], _filtered_edge_desc);
to = SlReadUint16();
}
}
}