Prepare user comparator

README.md

@@ -40,7 +40,7 @@ What is to be verified and implemented
 --------------------
 There are some operations not linked with C++ [API](http://code.google.com/p/leveldb/source/browse/#svn%2Ftrunk%2Finclude%2Fleveldb) : 
 
-* [Comparator](http://code.google.com/p/leveldb/source/browse/trunk/include/leveldb/comparator.h) - important enough (callback)
+* [Comparator](http://code.google.com/p/leveldb/source/browse/trunk/include/leveldb/comparator.h) - important enough. But require callback from C to Java which is difficult to do in SWIG. 
 * [TableBuilder](http://code.google.com/p/leveldb/source/browse/trunk/include/leveldb/table_builder.h) and [Table](http://code.google.com/p/leveldb/source/browse/trunk/include/leveldb/table.h) - should be properly tested. There is no default API to read Table from middle of file but it can be implemented. 
 
 

db.i

@@ -5,13 +5,49 @@
 #include "leveldb/write_batch.h"
 #include "leveldb/db.h"
 #include "leveldb/env.h"
+#include "leveldb/comparator.h"
 #include "leveldb/table_builder.h"
 #include "leveldb/table.h"
 #include "leveldb/options.h"
 %}
 
+
+%{
+ namespace leveldb {
+   class UserComparator : private Comparator {
+     private : 
+        std::string comparatorName; 
+        int (*comparatorFunc)(const std::string& a, const std::string& b);
+     public :   
+        UserComparator(std::string name, int (*c)(const std::string& a, const std::string& b)) : comparatorName(name){
+            this-> comparatorFunc = c;
+        }
+
+        // If *start < limit, changes *start to a short string in [start,limit).
+   	    void FindShortestSeparator(std::string* start, const Slice& limit) {
+   	      // Does nothing that's correct to allow optimization 
+   	    }
+
+   	    // Changes *key to a short string >= *key.
+   	    void FindShortSuccessor(std::string* key) {
+   	      // Does nothing that's correct to allow optimization
+   	    }
+   	    int Compare(const leveldb::Slice& a, const leveldb::Slice& b) const {
+           return 0; 
+        }
+
+
+        const char* Name() const {
+           return comparatorName.c_str();
+        }
+   };
+  }
+%}
+
+
 namespace leveldb {
 
+  %nodefaultctor;
   %nodefaultdtor Snapshot;
   class Snapshot {
   };
@@ -30,7 +66,6 @@ namespace leveldb {
     // DB::ReleaseSnapshot(*post_write_snapshotsnapshot) when the
     // snapshot is no longer needed.
     // Default: NULL
-
     %rename(postWriteSnapshot) post_write_snapshot;
     const Snapshot** post_write_snapshot;
 
@@ -90,6 +125,9 @@ namespace leveldb {
     int block_restart_interval;
 
     CompressionType compression;
+
+    // const Comparator* comparator;
+
   };
 
 
@@ -115,7 +153,8 @@ namespace leveldb {
 
 %inline %{
  namespace leveldb {
-
+
+
    class DBWriteBatch {
       friend class DBAccessor;
       private : 
@@ -208,6 +247,7 @@ namespace leveldb {
          long long approximateOffsetOf(const std::string& key) { table -> ApproximateOffsetOf(Slice(key)); }
    };
 
+
    class DBTableBuilder {
        TableBuilder* tableBuilder;
        WritableFile* wf;

src/com/anvisics/jleveldb/ext/LeveldbJNI.java

@@ -9,7 +9,6 @@
 package com.anvisics.jleveldb.ext;
 
 class LeveldbJNI {
-  public final static native long new_Snapshot();
   public final static native long new_WriteOptions();
   public final static native void WriteOptions_sync_set(long jarg1, WriteOptions jarg1_, boolean jarg2);
   public final static native boolean WriteOptions_sync_get(long jarg1, WriteOptions jarg1_);

src/com/anvisics/jleveldb/ext/Snapshot.java

@@ -31,8 +31,4 @@ public synchronized void delete() {
     }
   }
 
-  public Snapshot() {
-    this(LeveldbJNI.new_Snapshot(), true);
-  }
-
 }