From 6e097d3cdf38543414e0d5b4528f1763f0a49018 Mon Sep 17 00:00:00 2001
From: Wei Dong <wdong@wdong.org>
Date: Fri, 16 Mar 2018 19:52:54 -0400
Subject: [PATCH] expose save_text

---
 kgraph.cpp          | 15 +++++++++++++++
 kgraph.h            |  3 ++-
 python/pykgraph.cpp |  8 ++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/kgraph.cpp b/kgraph.cpp
index d486f9a..965175b 100644
--- a/kgraph.cpp
+++ b/kgraph.cpp
@@ -334,6 +334,21 @@ namespace kgraph {
         }
 
         virtual void save (char const *path, int format) const {
+            if (format == FORMAT_TEXT) {
+                std::cerr << "Saving to text file; you won't be able to load text file." << std::endl;
+                ofstream os(path);
+                os << graph.size() << endl;
+                for (unsigned i = 0; i < graph.size(); ++i) {
+                    auto const &knn = graph[i];
+                    uint32_t K = knn.size();
+                    os << K;
+                    for (unsigned k = 0; k < K; ++k) {
+                        os << ' ' << knn[k].id << ' ' << knn[k].dist;
+                    }
+                    os << endl;
+                }
+                return;
+            }
             ofstream os(path, ios::binary);
             uint32_t N = graph.size();
             os.write(KGRAPH_MAGIC, KGRAPH_MAGIC_SIZE);
diff --git a/kgraph.h b/kgraph.h
index 2138cd9..a3e5aaf 100644
--- a/kgraph.h
+++ b/kgraph.h
@@ -127,7 +127,8 @@ namespace kgraph {
 
         enum {
             FORMAT_DEFAULT = 0,
-            FORMAT_NO_DIST = 1
+            FORMAT_NO_DIST = 1,
+            FORMAT_TEXT = 128
         };
 
         /// Information and statistics of the indexing algorithm.
diff --git a/python/pykgraph.cpp b/python/pykgraph.cpp
index cd08a9e..8b16a00 100644
--- a/python/pykgraph.cpp
+++ b/python/pykgraph.cpp
@@ -269,6 +269,9 @@ namespace {
         void save (char const *path) const {
             index->save(path);
         }
+        void save_text (char const *path) const {
+            index->save(path, kgraph::KGraph::FORMAT_TEXT);
+        }
     };
 
     template <typename DATA_TYPE, typename METRIC_TYPE>
@@ -400,6 +403,10 @@ class KGraph {
         impl->save(path);
     }
 
+    void save_text (char const *path) const {
+        impl->save_text(path);
+    }
+
     void build (unsigned iterations,
                unsigned L,
                unsigned K,
@@ -468,6 +475,7 @@ BOOST_PYTHON_MODULE(pykgraph)
             //  (python::arg("data"), python::arg("metric") = "euclidean")))
         .def("load", &KGraph::load)
         .def("save", &KGraph::save)
+        .def("save_text", &KGraph::save_text)
         .def("build", &KGraph::build,
              (python::arg("data"),
               python::arg("iterations") = kgraph::default_iterations,