From 72347e2d4584633bf2bd8b83fc9021e0cf03ba2e Mon Sep 17 00:00:00 2001
From: tqchen <tianqi.tchen@gmail.com>
Date: Sun, 10 Jan 2016 22:27:26 -0800
Subject: [PATCH] [DATA] Make it fully compatible with rank

---
 amalgamation/xgboost-all0.cc |  2 ++
 src/data/data.cc             | 41 ++++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/amalgamation/xgboost-all0.cc b/amalgamation/xgboost-all0.cc
index 9e3dba90c..c0f004e40 100644
--- a/amalgamation/xgboost-all0.cc
+++ b/amalgamation/xgboost-all0.cc
@@ -30,6 +30,8 @@
 #include "../src/data/data.cc"
 #include "../src/data/simple_csr_source.cc"
 #include "../src/data/simple_dmatrix.cc"
+#include "../src/data/sparse_page_source.cc"
+#include "../src/data/sparse_page_dmatrix.cc"
 
 // tress
 #include "../src/tree/tree_model.cc"
diff --git a/src/data/data.cc b/src/data/data.cc
index 593ccf284..024b68c0d 100644
--- a/src/data/data.cc
+++ b/src/data/data.cc
@@ -51,6 +51,35 @@ void MetaInfo::LoadBinary(dmlc::Stream *fi) {
   CHECK(fi->Read(&base_margin)) << "MetaInfo: invalid format";
 }
 
+// try to load group information from file, if exists
+inline bool MetaTryLoadGroup(const std::string& fname,
+                             std::vector<unsigned>* group) {
+  std::unique_ptr<dmlc::Stream> fi(dmlc::Stream::Create(fname.c_str(), "r", true));
+  if (fi.get() == nullptr) return false;
+  dmlc::istream is(fi.get());
+  group->clear();
+  group->push_back(0);
+  unsigned nline;
+  while (is >> nline) {
+    group->push_back(group->back() + nline);
+  }
+  return true;
+}
+
+// try to load weight information from file, if exists
+inline bool MetaTryLoadFloatInfo(const std::string& fname,
+                                 std::vector<float>* data) {
+  std::unique_ptr<dmlc::Stream> fi(dmlc::Stream::Create(fname.c_str(), "r", true));
+  if (fi.get() == nullptr) return false;
+  dmlc::istream is(fi.get());
+  data->clear();
+  float value;
+  while (is >> value) {
+    data->push_back(value);
+  }
+  return true;
+}
+
 // macro to dispatch according to specified pointer types
 #define DISPATCH_CONST_PTR(dtype, old_ptr, cast_ptr, proc)              \
   switch (dtype) {                                                      \
@@ -143,6 +172,18 @@ DMatrix* DMatrix::Load(const std::string& uri,
     LOG(CONSOLE) << dmat->info().num_row << 'x' << dmat->info().num_col << " matrix with "
                  << dmat->info().num_nonzero << " entries loaded from " << uri;
   }
+  // backward compatiblity code.
+  if (!load_row_split) {
+    MetaInfo& info = dmat->info();
+    if (MetaTryLoadGroup(fname + ".group", &info.group_ptr) && !silent) {
+      LOG(CONSOLE) << info.group_ptr.size() - 1
+                   << " groups are loaded from " << fname << ".group";
+    }
+    if (MetaTryLoadFloatInfo(fname + ".base_margin", &info.base_margin) && !silent) {
+      LOG(CONSOLE) << info.base_margin.size()
+                   << " base_margin are loaded from " << fname << ".base_margin";
+    }
+  }
   return dmat;
 }