Implemented a fix for #1794 (giant meta info produces invalid GDS)

src/plugins/streamers/gds2/db_plugin/dbGDS2ReaderBase.cc

@@ -461,6 +461,7 @@ GDS2ReaderBase::read_context_info_cell ()
     if (valid_hook) {
 
       std::vector <std::string> &strings = m_context_info.insert (std::make_pair (cn, std::vector <std::string> ())).first->second;
+      std::map <size_t, std::vector<std::string> > strings_ex;
 
       size_t attr = 0;
 
@@ -474,16 +475,60 @@ GDS2ReaderBase::read_context_info_cell ()
           attr = size_t (get_ushort ());
         } else if (rec_id == sPROPVALUE) {
 
-          if (strings.size () <= attr) {
-            strings.resize (attr + 1, std::string ());
+          const char *str = get_string ();
+
+          //  To embed long strings and more than 64k attributes, a separate notation is used:
+          //    "#<n>,<p>:<string>"
+          //  where <n> is a string index and <p> is the part index (zero-based).
+          //  For such properties, the PROPATTR value is ignored. This means however, that the
+          //  attribute numbers may not be unique.
+          //  See issue #1794.
+
+          if (str[0] == '#') {
+
+            tl::Extractor ex (str + 1);
+            size_t n = 0, p = 0;
+            if (ex.try_read (n) && ex.test (",") && ex.try_read (p) && ex.test (":")) {
+              if (strings.size () <= n) {
+                strings.resize (n + 1, std::string ());
+              }
+              std::vector<std::string> &sv = strings_ex[n];
+              if (sv.size () <= p) {
+                sv.resize (p + 1, std::string ());
+              }
+              sv[p] = ex.get ();
+            }
+
+          } else {
+
+            if (strings.size () <= attr) {
+              strings.resize (attr + 1, std::string ());
+            }
+            strings [attr] = str;
+
           }
-          strings [attr] = get_string ();
 
         } else {
           error (tl::to_string (tr ("ENDEL, PROPATTR or PROPVALUE record expected")));
         }
 
-      } 
+      }
+
+      //  combine the multipart strings (#1794)
+      for (auto es = strings_ex.begin (); es != strings_ex.end (); ++es) {
+        if (es->first < strings.size ()) {
+          std::string &s = strings [es->first];
+          s.clear ();
+          size_t sz = 0;
+          for (auto i = es->second.begin (); i != es->second.end (); ++i) {
+            sz += i->size ();
+          }
+          s.reserve (sz);
+          for (auto i = es->second.begin (); i != es->second.end (); ++i) {
+            s += *i;
+          }
+        }
+      }
 
     } else {
       error (tl::to_string (tr ("Invalid record inside a context info cell")));

src/plugins/streamers/gds2/db_plugin/dbGDS2WriterBase.cc

@@ -72,6 +72,54 @@ inline int scale (double sf, int value)
   }
 }
 
+void
+GDS2WriterBase::write_context_string (size_t n, const std::string &s)
+{
+  //  max. size for GDS strings used as payload carrier
+  size_t chunk_size = 32000;
+  short max_short = std::numeric_limits<short>::max ();
+
+  if (n > size_t (max_short) || s.size () > chunk_size) {
+
+    //  Split strings and use a separate notation: "#<n>,<+p>:..." for the partial
+    //  strings. n is the string index and p the part index (zero based).
+    //  The property number is not defined in that case. There may be properties with
+    //  the same number. See issue #1794.
+
+    size_t nchunks = (s.size () + (chunk_size - 1)) / chunk_size;
+    while (nchunks > 0) {
+
+      --nchunks;
+
+      std::string partial;
+      partial.reserve (chunk_size + 100); // approx.
+      partial += "#";
+      partial += tl::to_string (n);
+      partial += ",";
+      partial += tl::to_string (nchunks);
+      partial += ":";
+      size_t pos = nchunks * chunk_size;
+      partial += std::string (s, pos, std::min (s.size (), pos + chunk_size) - pos);
+
+      write_record_size (6);
+      write_record (sPROPATTR);
+      write_short (n <= size_t (max_short) ? short (n) : max_short);
+
+      write_string_record (sPROPVALUE, partial);
+
+    }
+
+  } else {
+
+    write_record_size (6);
+    write_record (sPROPATTR);
+    write_short (short (n));
+
+    write_string_record (sPROPVALUE, s);
+
+  }
+}
+
 void
 GDS2WriterBase::write_context_cell (db::Layout &layout, const short *time_data, const std::vector<db::cell_index_type> &cells)
 {
@@ -112,15 +160,9 @@ GDS2WriterBase::write_context_cell (db::Layout &layout, const short *time_data,
       //  Hint: write in the reverse order since this way, the reader is more efficient (it knows how many strings
       //  will arrive)
       for (std::vector <std::string>::const_iterator s = context_prop_strings.end (); s != context_prop_strings.begin (); ) {
-
         --s;
-
-        write_record_size (6);
-        write_record (sPROPATTR);
-        write_short (short (std::distance (std::vector <std::string>::const_iterator (context_prop_strings.begin ()), s)));  //  = user string
-
-        write_string_record (sPROPVALUE, *s);
-
+        size_t n = std::distance (std::vector <std::string>::const_iterator (context_prop_strings.begin ()), s);
+        write_context_string (n, *s);
       }
 
     }
@@ -151,15 +193,9 @@ GDS2WriterBase::write_context_cell (db::Layout &layout, const short *time_data,
         //  Hint: write in the reverse order since this way, the reader is more efficient (it knows how many strings
         //  will arrive)
         for (std::vector <std::string>::const_iterator s = context_prop_strings.end (); s != context_prop_strings.begin (); ) {
-
           --s;
-
-          write_record_size (6);
-          write_record (sPROPATTR);
-          write_short (short (std::distance (std::vector <std::string>::const_iterator (context_prop_strings.begin ()), s)));  //  = user string
-
-          write_string_record (sPROPVALUE, *s);
-
+          size_t n = std::distance (std::vector <std::string>::const_iterator (context_prop_strings.begin ()), s);
+          write_context_string (n, *s);
         }
 
       }

src/plugins/streamers/gds2/db_plugin/dbGDS2WriterBase.h

@@ -169,6 +169,7 @@ class DB_PLUGIN_PUBLIC GDS2WriterBase
 
   void write_properties (const db::Layout &layout, db::properties_id_type prop_id);
   void write_context_cell (db::Layout &layout, const short *time_data, const std::vector<cell_index_type> &cells);
+  void write_context_string (size_t n, const std::string &s);
 };
 
 } // namespace db

src/plugins/streamers/gds2/unit_tests/dbGDS2WriterTests.cc

@@ -1196,7 +1196,7 @@ TEST(121)
 }
 
 //  Meta info
-TEST(130a)
+TEST(130)
 {
   db::Layout layout_org;
 
@@ -1312,6 +1312,113 @@ TEST(130a)
   EXPECT_EQ (layout_read.meta_info ("b").value.to_string (), "nil");
 }
 
+//  Giant meta info (issue #1794)
+TEST(131)
+{
+  db::Layout layout_org;
+
+  layout_org.add_cell ("U");
+  db::cell_index_type ci = layout_org.add_cell ("X");
+
+  std::vector<tl::Variant> ll1;
+  std::vector<tl::Variant> ll2;
+
+  for (unsigned int i = 0; i < 100000; ++i) {
+    ll1.push_back (tl::Variant (i));
+    ll2.push_back ("C" + tl::to_string (i));
+  }
+
+  layout_org.add_meta_info ("a", db::MetaInfo ("", ll1, true));
+  layout_org.add_meta_info ("b", db::MetaInfo ("", "value", true));
+
+  layout_org.add_meta_info (ci, "a", db::MetaInfo ("", ll2, true));
+  layout_org.add_meta_info (ci, "c", db::MetaInfo ("", -1, true));
+
+  std::string tmp_file = tl::TestBase::tmp_file ("tmp_GDS2Writer_131.gds");
+
+  {
+    tl::OutputStream out (tmp_file);
+    db::SaveLayoutOptions options;
+    db::Writer writer (options);
+    writer.write (layout_org, out);
+  }
+
+  db::Layout layout_read;
+
+  {
+    tl::InputStream in (tmp_file);
+    db::Reader reader (in);
+    reader.read (layout_read);
+  }
+
+  EXPECT_EQ (layout_read.has_meta_info ("x"), false);
+  EXPECT_EQ (layout_read.has_meta_info ("a"), true);
+  EXPECT_EQ (layout_read.meta_info ("x").value.to_string (), "nil");
+  EXPECT_EQ (layout_read.meta_info ("a").value == ll1, true);
+  EXPECT_EQ (layout_read.has_meta_info ("b"), true);
+  EXPECT_EQ (layout_read.meta_info ("b").value.to_string (), "value");
+
+  db::cell_index_type ci2 = layout_read.cell_by_name ("X").second;
+
+  EXPECT_EQ (layout_read.meta_info (ci2, "x").value.to_string (), "nil");
+  EXPECT_EQ (layout_read.meta_info (ci2, "a").value == ll2, true);
+  EXPECT_EQ (layout_read.meta_info (ci2, "c").value.to_string (), "-1");
+}
+
+//  Many meta info (issue #1794)
+TEST(132)
+{
+  db::Layout layout_org;
+
+  layout_org.add_cell ("U");
+  db::cell_index_type ci = layout_org.add_cell ("X");
+
+  for (unsigned int i = 0; i < 100000; ++i) {
+    layout_org.add_meta_info ("a" + tl::to_string (i), db::MetaInfo ("", i, true));
+  }
+  layout_org.add_meta_info ("b", db::MetaInfo ("", "value", true));
+
+  for (unsigned int i = 0; i < 100000; ++i) {
+    layout_org.add_meta_info (ci, "a" + tl::to_string (i * 2), db::MetaInfo ("", i * 2, true));
+  }
+  layout_org.add_meta_info (ci, "c", db::MetaInfo ("", -1, true));
+
+  std::string tmp_file = tl::TestBase::tmp_file ("tmp_GDS2Writer_132.gds");
+
+  {
+    tl::OutputStream out (tmp_file);
+    db::SaveLayoutOptions options;
+    db::Writer writer (options);
+    writer.write (layout_org, out);
+  }
+
+  db::Layout layout_read;
+
+  {
+    tl::InputStream in (tmp_file);
+    db::Reader reader (in);
+    reader.read (layout_read);
+  }
+
+  EXPECT_EQ (layout_read.has_meta_info ("x"), false);
+  EXPECT_EQ (layout_read.meta_info ("x").value.to_string (), "nil");
+  for (unsigned int i = 0; i < 10; ++i) {
+    EXPECT_EQ (layout_read.has_meta_info ("a" + tl::to_string (i)), true);
+    EXPECT_EQ (layout_read.meta_info ("a" + tl::to_string (i)).value.to_string (), tl::Variant (i).to_string ());
+  }
+  EXPECT_EQ (layout_read.has_meta_info ("b"), true);
+  EXPECT_EQ (layout_read.meta_info ("b").value.to_string (), "value");
+
+  db::cell_index_type ci2 = layout_read.cell_by_name ("X").second;
+
+  EXPECT_EQ (layout_read.meta_info (ci2, "x").value.to_string (), "nil");
+  for (unsigned int i = 0; i < 10; ++i) {
+    EXPECT_EQ (layout_read.has_meta_info (ci2, "a" + tl::to_string (i * 2)), true);
+    EXPECT_EQ (layout_read.meta_info (ci2, "a" + tl::to_string (i * 2)).value.to_string (), tl::Variant (i * 2).to_string ());
+  }
+  EXPECT_EQ (layout_read.meta_info (ci2, "c").value.to_string (), "-1");
+}
+
 //  Extreme fracturing by max. points
 TEST(166)
 {