From 01422903688c153437cf6368a58fde42b3125efd Mon Sep 17 00:00:00 2001
From: Ian Jackson <ian@liberator.relativity.greenend.org.uk>
Date: Sat, 17 Oct 2009 15:25:42 +0100
Subject: [PATCH 1/1] routesearch: permit approxiation by disregarding trivial
 trades

---
 yarrg/rscommon.h            |  2 +-
 yarrg/rsmain.c              |  4 +++-
 yarrg/rsvalue.c             | 36 ++++++++++++++++++++++++++----------
 yarrg/web/query_routesearch |  1 +
 4 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/yarrg/rscommon.h b/yarrg/rscommon.h
index 66e36d9..216fec3 100644
--- a/yarrg/rscommon.h
+++ b/yarrg/rscommon.h
@@ -135,7 +135,7 @@ void search(int start_isle, int final_isle /* -1 means any */,
 
 extern double max_mass, max_volu, max_capi;
 extern double distance_loss_factor_per_league;
-extern int max_dist;
+extern int max_dist, min_trade_maxprofit;
 
 #define LOSS_FACTOR_PER_DELAY_SLOT (1-1e-8)
 
diff --git a/yarrg/rsmain.c b/yarrg/rsmain.c
index f99f866..2a172c9 100644
--- a/yarrg/rsmain.c
+++ b/yarrg/rsmain.c
@@ -7,7 +7,7 @@
 int o_quiet= 0;
 double max_mass=-1, max_volu=-1, max_capi=-1;
 double distance_loss_factor_per_league;
-int max_dist= -1;
+int max_dist=-1, min_trade_maxprofit=0;
 
 FILE *debug_file;
 FILE *output;
@@ -90,6 +90,8 @@ int main(int argc, const char **argv) {
   double loss_per_league= atof(*argv++);
   distance_loss_factor_per_league= 1.0 - loss_per_league;
 
+  min_trade_maxprofit= atoi(*argv++);
+
   setup_sql(database);
   setup_value();
   setup_search();
diff --git a/yarrg/rsvalue.c b/yarrg/rsvalue.c
index 22b3d29..d3ffeeb 100644
--- a/yarrg/rsvalue.c
+++ b/yarrg/rsvalue.c
@@ -62,18 +62,22 @@ static void add_constraint(int row, double coefficient) {
   constraint_coeffs[nconstraint_rows]= coefficient;
 }
 
-static void avail_c(const Trade *t, IslandTradeEnd **trades,
-		    int price, const char *srcdst,
-		    int islandid, sqlite3_stmt *ss_ite) {
-  /* find row number of trade availability constraint */
+static IslandTradeEnd *get_ite(const Trade *t, IslandTradeEnd **trades,
+			       int price) {
   IslandTradeEnd *search;
-
+  
   for (search= *trades; search; search=search->next)
     if (search->commodid==t->commodid && search->price==price)
-      goto found;
+      return search;
   abort();
-  
- found:;
+}
+
+static void avail_c(const Trade *t, IslandTradeEnd *ite,
+		    int price, const char *srcdst,
+		    int islandid, sqlite3_stmt *ss_ite) {
+  /* find row number of trade availability constraint */
+  IslandTradeEnd *search= ite;
+
   if (search->generation != generation) {
     search->rownum= lpx_add_rows(lp, 1);
     lpx_set_row_bnds(lp, search->rownum, LPX_UP, 0, search->qty);
@@ -255,10 +259,22 @@ double value_route(int nislands, const int *islands, int exclude_arbitrage) {
 	  debugf("  TRADE i%d#%d..i%d#%d c%d %d-%d  ",
 		 si,s, di,d, t->commodid, t->src_price, t->dst_price);
 
+	  IslandTradeEnd
+	    *src_ite= get_ite(t, &itradeends[si].src, t->src_price),
+	    *dst_ite= get_ite(t, &itradeends[di].dst, t->dst_price);
+
+	  int qty= src_ite->qty < dst_ite->qty ? src_ite->qty : dst_ite->qty;
+	  int maxprofit= qty * (t->dst_price - t->src_price);
+	  debugf("maxprofit=%d ",maxprofit);
+	  if (maxprofit < min_trade_maxprofit) {
+	    debugf("trivial\n");
+	    continue;
+	  }
+
 	  nconstraint_rows=0;
 
-	  avail_c(t, &itradeends[si].src, t->src_price, "src", si,ss_ite_sell);
-	  avail_c(t, &itradeends[di].dst, t->dst_price, "dst", di,ss_ite_buy);
+	  avail_c(t, src_ite, t->src_price, "src", si,ss_ite_sell);
+	  avail_c(t, dst_ite, t->dst_price, "dst", di,ss_ite_buy);
 
 	  int leg;
 	  for (leg=s; leg<d; leg++) {
diff --git a/yarrg/web/query_routesearch b/yarrg/web/query_routesearch
index 6f05135..587a2b6 100644
--- a/yarrg/web/query_routesearch
+++ b/yarrg/web/query_routesearch
@@ -131,6 +131,7 @@ foreach my $k (qw(MaxMass MaxVolume MaxCapital)) {
 }
 push @rsargs, defined $routeparams->{LossPerLeaguePct}
 	? $routeparams->{LossPerLeaguePct}*0.01 : 1e-9;
+push @rsargs, '0';
 push @rsargs, 'search',$maxdist, $maxcountea,$maxcountea, 'any', @islandids;
 
 m/[^-.0-9a-zA-Z]/ and die "$_ $& ?" foreach @rsargs;
-- 
2.30.2