From aa6da2dce99c7e89063bd9722dcb0199452febb2 Mon Sep 17 00:00:00 2001
From: Dane Springmeyer <dane@dbsgeo.com>
Date: Mon, 23 Jan 2012 23:51:31 -0800
Subject: [PATCH] collect context before featureset creation in sqlite

---
 plugins/input/sqlite/sqlite_datasource.cpp | 23 +++++++++++++++++-----
 plugins/input/sqlite/sqlite_featureset.cpp |  7 ++-----
 plugins/input/sqlite/sqlite_featureset.hpp |  1 +
 3 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/plugins/input/sqlite/sqlite_datasource.cpp b/plugins/input/sqlite/sqlite_datasource.cpp
index 2cd3f11e0..7a7529584 100644
--- a/plugins/input/sqlite/sqlite_datasource.cpp
+++ b/plugins/input/sqlite/sqlite_datasource.cpp
@@ -547,19 +547,24 @@ featureset_ptr sqlite_datasource::features(query const& q) const
         mapnik::box2d<double> const& e = q.get_bbox();
 
         std::ostringstream s;
+        mapnik::context_ptr ctx = boost::make_shared<mapnik::context_type>();
 
         s << "SELECT " << geometry_field_;
         if (!key_field_.empty())
+        {
             s << "," << key_field_;
+            ctx->push(key_field_);
+        }
         std::set<std::string> const& props = q.property_names();
         std::set<std::string>::const_iterator pos = props.begin();
         std::set<std::string>::const_iterator end = props.end();
-        while (pos != end)
+
+        for ( ;pos != end;++pos)
         {
             // TODO - should we restrict duplicate key query?
             //if (*pos != key_field_)
             s << ",[" << *pos << "]";
-            ++pos;
+            ctx->push(*pos);
         }
 
         s << " FROM ";
@@ -601,6 +606,7 @@ featureset_ptr sqlite_datasource::features(query const& q) const
         boost::shared_ptr<sqlite_resultset> rs(dataset_->execute_query(s.str()));
 
         return boost::make_shared<sqlite_featureset>(rs,
+                                                     ctx,
                                                      desc_.get_encoding(),
                                                      format_,
                                                      using_subquery_);
@@ -619,20 +625,26 @@ featureset_ptr sqlite_datasource::features_at_point(coord2d const& pt) const
         mapnik::box2d<double> const e(pt.x, pt.y, pt.x, pt.y);
 
         std::ostringstream s;
+        mapnik::context_ptr ctx = boost::make_shared<mapnik::context_type>();
+
         s << "SELECT " << geometry_field_;
         if (!key_field_.empty())
+        {
             s << "," << key_field_;
+            ctx->push(key_field_);
+        }
+        
         std::vector<attribute_descriptor>::const_iterator itr = desc_.get_descriptors().begin();
         std::vector<attribute_descriptor>::const_iterator end = desc_.get_descriptors().end();
-        while (itr != end)
+
+        for ( ; itr != end; ++itr)
         {
             std::string fld_name = itr->get_name();
             if (fld_name != key_field_)
             {
                 s << ",[" << itr->get_name() << "]";
+                ctx->push(itr->get_name());
             }
-
-            ++itr;
         }
 
         s << " FROM ";
@@ -674,6 +686,7 @@ featureset_ptr sqlite_datasource::features_at_point(coord2d const& pt) const
         boost::shared_ptr<sqlite_resultset> rs(dataset_->execute_query(s.str()));
 
         return boost::make_shared<sqlite_featureset>(rs,
+                                                     ctx,
                                                      desc_.get_encoding(),
                                                      format_,
                                                      using_subquery_);
diff --git a/plugins/input/sqlite/sqlite_featureset.cpp b/plugins/input/sqlite/sqlite_featureset.cpp
index 4e7fbe6df..dc9aeb5d8 100644
--- a/plugins/input/sqlite/sqlite_featureset.cpp
+++ b/plugins/input/sqlite/sqlite_featureset.cpp
@@ -45,6 +45,7 @@ using mapnik::transcoder;
 using mapnik::feature_factory;
 
 sqlite_featureset::sqlite_featureset(boost::shared_ptr<sqlite_resultset> rs,
+                                     mapnik::context_ptr const& ctx,
                                      std::string const& encoding,
                                      mapnik::wkbFormat format,
                                      bool using_subquery)
@@ -52,12 +53,8 @@ sqlite_featureset::sqlite_featureset(boost::shared_ptr<sqlite_resultset> rs,
       tr_(new transcoder(encoding)),
       format_(format),
       using_subquery_(using_subquery),
-      ctx_(boost::make_shared<mapnik::context_type>())
+      ctx_(ctx)
 {
-    for (int i = 2; i < rs_->column_count(); ++i)
-    {
-        ctx_->push(rs_->column_name(i));
-    }
 }
 
 sqlite_featureset::~sqlite_featureset()
diff --git a/plugins/input/sqlite/sqlite_featureset.hpp b/plugins/input/sqlite/sqlite_featureset.hpp
index cddc5d89f..b7feb7386 100644
--- a/plugins/input/sqlite/sqlite_featureset.hpp
+++ b/plugins/input/sqlite/sqlite_featureset.hpp
@@ -40,6 +40,7 @@ class sqlite_featureset : public mapnik::Featureset
 {
 public:
     sqlite_featureset(boost::shared_ptr<sqlite_resultset> rs,
+                      mapnik::context_ptr const& ctx,
                       std::string const& encoding,
                       mapnik::wkbFormat format,
                       bool using_subquery);