Index: TODO
===================================================================
diff -u -rcef0608bea97458e5dcd87615c9b8ca3fe7b464c -r2fbf1bf87402e8639e772781c5719164e7e55555
--- TODO	(.../TODO)	(revision cef0608bea97458e5dcd87615c9b8ca3fe7b464c)
+++ TODO	(.../TODO)	(revision 2fbf1bf87402e8639e772781c5719164e7e55555)
@@ -3000,8 +3000,17 @@
   * use "-withObj" in mongodb interface
   * adapted regression test
 
+- mongodb interface:
+  * mongo::gridfile::seek: added a seek command for gridfiles
+  * added example for the low-level interface to shwo how 
+    to access gridfs via the plain mongodb interface, how
+    to add some additional metadata (e.g. dublin core meta
+    data) and how to retrieve this via the gridfile interface
 
 TODO:
+- extend mongo::gridfs::store_file with a switch -metadata to
+  pass metadata together at gridfs file creation time
+
 - do we have to adjust the documentation in xotcl2 for object initialization?
 - maybe optional arg (true) to ::nsf::object::initialized 
   to generalize -noinit
Index: library/mongodb/example-nsf-gridfs.tcl
===================================================================
diff -u -rdf67ed7db2b0cda881c4a9e704379a2a02d415b6 -r2fbf1bf87402e8639e772781c5719164e7e55555
--- library/mongodb/example-nsf-gridfs.tcl	(.../example-nsf-gridfs.tcl)	(revision df67ed7db2b0cda881c4a9e704379a2a02d415b6)
+++ library/mongodb/example-nsf-gridfs.tcl	(.../example-nsf-gridfs.tcl)	(revision 2fbf1bf87402e8639e772781c5719164e7e55555)
@@ -14,12 +14,16 @@
 #    $ mongo
 #    > use myfs
 #    > show collections
+#    > db.fs.files.find()
 #
 # or via the mongofiles interface:
 #
 #    $ mongofiles -d myfs list
 #
 
+#
+# First, as usual, open the connection to the mongo db
+#
 set mongoConn [::mongo::connect]
 
 #
@@ -29,12 +33,18 @@
 set gridFS [::mongo::gridfs::open $mongoConn myfs fs]
 
 #
-# The current version of gridfs_store_file() is quite unfriendly,
-# since it assumes that the file exists, and aborts otherwise. So, we
-# perform the existance test here. 
+# gridfs::remove_file removes all files with the specified name
+# multiple store operations create "revisions" with different uploadDates
+::mongo::gridfs::remove_file $gridFS README
+
 #
+# ::mongo::gridfs::store_file $gridFS $inputFileName $storeFileName text/plain
 # Note that the input file name can be "-" for reading from stdin.
 #
+# The current version of gridfs_store_file() is quite unfriendly,
+# since it assumes that the file exists, and aborts otherwise. So, we
+# perform the existence test here. 
+#
 # Store a known file:
 #
 set fn README
@@ -45,29 +55,63 @@
   puts stderr "no such file: $fn"
 }
 
-# unknown file
-set fn unknown-file
-if {[file readable $fn]} {
-  set r [::mongo::gridfs::store_file $gridFS $fn $fn text/plain]
-  puts stderr r=$r
-} else {
-  puts stderr "no such file: $fn"
-}
-
+#
+# Open a grid file, get some of its properties, and read it in chunks
+# of 500 bytes, and close it finally.
+#
 set f [mongo::gridfile::open $gridFS README]
-puts stderr "opened file $f"
-puts stderr meta=[mongo::gridfile::get_metadata $f]
-puts stderr contentlength=[mongo::gridfile::get_contentlength $f]
-puts stderr contenttype=[mongo::gridfile::get_contenttype $f]
+puts stderr "\nOpened grid file $f"
+puts stderr "Metadata: [mongo::gridfile::get_metadata $f]"
+puts stderr "ContentLength: [mongo::gridfile::get_contentlength $f]"
+puts stderr "ContentType: [mongo::gridfile::get_contenttype $f]"
 while {1} {
   set chunk [mongo::gridfile::read $f 500]
   puts stderr "read chunk-len [string length $chunk] content [string range $chunk 0 10]..."
-  if {[string length $chunk] < 500} break;
+  if {[string length $chunk] < 500} {
+    break
+  }
 }
 mongo::gridfile::close $f
-puts stderr OK
 
 #
+# Access the files stored in the gridfs via plain query interface
+#
+puts "\nAll Files:\n[join [::mongo::query $mongoConn myfs.fs.files {}] \n]\n"
+
+#
+# Get the file named README from the gridfs via plain query interface
+#
+set atts [lindex [::mongo::query $mongoConn myfs.fs.files \
+		      [list \$query object {filename string README}] \
+		      -limit 1] 0]
+puts "Attributes of file README:\n$atts\n"
+
+#
+# Extract the oid from the bson attributes
+#
+foreach {name type value} $atts {
+  if {$name eq "_id"} {
+    set oid $value
+    break
+  }
+}
+
+#
+# Add a dc:creator to the bson attributes ...
+#
+lappend atts metadata object {dc:creator string "Gustaf Neumann"}
+# .. and update the entry in the gridfs
+::mongo::update $mongoConn myfs.fs.files [list _id oid $oid] $atts
+
+#
+# Now we can use the gridfs interface to obtain the additional
+# metadata as well
+#
+set f [mongo::gridfile::open $gridFS README]
+puts stderr "Metadata: [mongo::gridfile::get_metadata $f]"
+mongo::gridfile::close $f
+
+#
 # close everything
 #
 ::mongo::gridfs::close $gridFS
Index: library/mongodb/mongoAPI.decls
===================================================================
diff -u -rcef0608bea97458e5dcd87615c9b8ca3fe7b464c -r2fbf1bf87402e8639e772781c5719164e7e55555
--- library/mongodb/mongoAPI.decls	(.../mongoAPI.decls)	(revision cef0608bea97458e5dcd87615c9b8ca3fe7b464c)
+++ library/mongodb/mongoAPI.decls	(.../mongoAPI.decls)	(revision 2fbf1bf87402e8639e772781c5719164e7e55555)
@@ -95,24 +95,28 @@
 # GridFile
 #
 
-cmd gridfile::close NsfMongoGridFileClose {
+cmd "gridfile::close" NsfMongoGridFileClose {
   {-argName "file" -required 1 -type gridfile -withObj 1}
 }
 
-cmd gridfile::get_contentlength NsfMongoGridFileGetContentlength {
+cmd "gridfile::get_contentlength" NsfMongoGridFileGetContentlength {
   {-argName "file" -required 1 -type gridfile}
 }
-cmd gridfile::get_contenttype NsfMongoGridFileGetContentType {
+cmd "gridfile::get_contenttype" NsfMongoGridFileGetContentType {
   {-argName "file" -required 1 -type gridfile}
 }
-cmd gridfile::get_metadata NsfMongoGridFileGetMetaData {
+cmd "gridfile::get_metadata" NsfMongoGridFileGetMetaData {
   {-argName "file" -required 1 -type gridfile}
 }
-cmd gridfile::open NsfMongoGridFileOpen {
+cmd "gridfile::open" NsfMongoGridFileOpen {
   {-argName "fs" -required 1 -type gridfs}
   {-argName "filename" -required 1}
 }
-cmd gridfile::read NsfMongoGridFileRead {
+cmd "gridfile::read" NsfMongoGridFileRead {
   {-argName "file" -required 1 -type gridfile}
   {-argName "size" -required 1 -type int32}
 }
+cmd "gridfile::seek" NsfMongoGridFileSeek {
+  {-argName "file" -required 1 -type gridfile}
+  {-argName "offset" -required 1 -type int32}
+}
\ No newline at end of file
Index: library/mongodb/mongoAPI.h
===================================================================
diff -u -rcef0608bea97458e5dcd87615c9b8ca3fe7b464c -r2fbf1bf87402e8639e772781c5719164e7e55555
--- library/mongodb/mongoAPI.h	(.../mongoAPI.h)	(revision cef0608bea97458e5dcd87615c9b8ca3fe7b464c)
+++ library/mongodb/mongoAPI.h	(.../mongoAPI.h)	(revision 2fbf1bf87402e8639e772781c5719164e7e55555)
@@ -19,6 +19,7 @@
 static int NsfMongoGridFileGetMetaDataStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfMongoGridFileOpenStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfMongoGridFileReadStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
+static int NsfMongoGridFileSeekStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfMongoIndexStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfMongoInsertStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfMongoQueryStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
@@ -38,6 +39,7 @@
 static int NsfMongoGridFileGetMetaData(Tcl_Interp *interp, gridfile *filePtr);
 static int NsfMongoGridFileOpen(Tcl_Interp *interp, gridfs *fsPtr, CONST char *filename);
 static int NsfMongoGridFileRead(Tcl_Interp *interp, gridfile *filePtr, int size);
+static int NsfMongoGridFileSeek(Tcl_Interp *interp, gridfile *filePtr, int size);
 static int NsfMongoIndex(Tcl_Interp *interp, mongo_connection *connPtr, CONST char *namespace, Tcl_Obj *attributes, int withDropdups, int withUnique);
 static int NsfMongoInsert(Tcl_Interp *interp, mongo_connection *connPtr, CONST char *namespace, Tcl_Obj *values);
 static int NsfMongoQuery(Tcl_Interp *interp, mongo_connection *connPtr, CONST char *namespace, Tcl_Obj *query, Tcl_Obj *withAtts, int withLimit, int withSkip);
@@ -58,6 +60,7 @@
  NsfMongoGridFileGetMetaDataIdx,
  NsfMongoGridFileOpenIdx,
  NsfMongoGridFileReadIdx,
+ NsfMongoGridFileSeekIdx,
  NsfMongoIndexIdx,
  NsfMongoInsertIdx,
  NsfMongoQueryIdx,
@@ -325,6 +328,26 @@
 }
 
 static int
+NsfMongoGridFileSeekStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) {
+  ParseContext pc;
+  (void)clientData;
+
+  if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
+                     method_definitions[NsfMongoGridFileSeekIdx].paramDefs, 
+                     method_definitions[NsfMongoGridFileSeekIdx].nrParameters, 1,
+                     &pc) != TCL_OK) {
+    return TCL_ERROR;
+  } else {
+    gridfile *filePtr = (gridfile *)pc.clientData[0];
+    int size = (int )PTR2INT(pc.clientData[1]);
+
+    assert(pc.status == 0);
+    return NsfMongoGridFileSeek(interp, filePtr, size);
+
+  }
+}
+
+static int
 NsfMongoIndexStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) {
   ParseContext pc;
   (void)clientData;
@@ -488,6 +511,10 @@
   {"file", NSF_ARG_REQUIRED, 1, Nsf_ConvertToPointer, NULL,NULL,"gridfile",NULL,NULL,NULL,NULL,NULL},
   {"size", NSF_ARG_REQUIRED, 1, Nsf_ConvertToInt32, NULL,NULL,"int32",NULL,NULL,NULL,NULL,NULL}}
 },
+{"::mongo::gridfile::seek", NsfMongoGridFileSeekStub, 2, {
+  {"file", NSF_ARG_REQUIRED, 1, Nsf_ConvertToPointer, NULL,NULL,"gridfile",NULL,NULL,NULL,NULL,NULL},
+  {"size", NSF_ARG_REQUIRED, 1, Nsf_ConvertToInt32, NULL,NULL,"int32",NULL,NULL,NULL,NULL,NULL}}
+},
 {"::mongo::index", NsfMongoIndexStub, 5, {
   {"conn", NSF_ARG_REQUIRED, 1, Nsf_ConvertToPointer, NULL,NULL,"mongo_connection",NULL,NULL,NULL,NULL,NULL},
   {"namespace", NSF_ARG_REQUIRED, 1, Nsf_ConvertToString, NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL},
Index: library/mongodb/nsfmongo.c
===================================================================
diff -u -rcef0608bea97458e5dcd87615c9b8ca3fe7b464c -r2fbf1bf87402e8639e772781c5719164e7e55555
--- library/mongodb/nsfmongo.c	(.../nsfmongo.c)	(revision cef0608bea97458e5dcd87615c9b8ca3fe7b464c)
+++ library/mongodb/nsfmongo.c	(.../nsfmongo.c)	(revision 2fbf1bf87402e8639e772781c5719164e7e55555)
@@ -887,6 +887,9 @@
 
 /***********************************************************************
  * GridFile interface
+ *
+ * Currently offsets and sizes are limited to 32bit integers, we should
+ * relax this later.
  ***********************************************************************/
 
 /*
@@ -993,6 +996,22 @@
   return TCL_OK;
 }
 
+/*
+cmd "gridfile::seek" NsfMongoGridFileSeek {
+  {-argName "file" -required 1 -type gridfile}
+  {-argName "offset" -required 1 -type int32}
+}
+*/
+static int 
+NsfMongoGridFileSeek(Tcl_Interp *interp, gridfile *gridFilePtr, int offset) {
+  int pos;
+
+  pos = gridfile_seek(gridFilePtr, offset);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(pos));
+
+  return TCL_OK;
+}
+
 /***********************************************************************
  * Finally, provide the necessary Tcl package interface.
  ***********************************************************************/