Prefix iterator

README.md

@@ -13,6 +13,7 @@ operations  | description
 **Multi delete keys** | Delete keys from DB
 **Check key exist** | Check key existing
 **Imcrement** | Imcrement value by key
+**Prefit** | Prefix iterator
 
 
 For more details see: [protocol description](protocol.md)

protocol.md

@@ -211,6 +211,16 @@ POST /tail
 Reply: same [multi get](https://github.com/valmat/RocksServer/blob/master/protocol.md#multi-get)
 
 
+###Get keys and values by key-prefix
+
+Request:
+```
+GET /prefit?<prefix>
+```
+
+Reply: same [multi get](https://github.com/valmat/RocksServer/blob/master/protocol.md#multi-get)
+
+
 ###Backup
 Backup database
 

src/Protocol/ProtocolInGetIterator.h

@@ -56,13 +56,8 @@ namespace RocksServer {
          */
         ProtocolInGetIterator operator++(int)
         {
-            // make a copy
             ProtocolInGetIterator copy(*this);
-
-            // increment current object
             ++(*this);
-
-            // return the original
             return copy;
         }
 

src/Protocol/ProtocolInPostKeysIterator.h

@@ -57,13 +57,8 @@ namespace RocksServer {
          */
         ProtocolInPostKeysIterator operator++(int)
         {
-            // make a copy
             ProtocolInPostKeysIterator copy(*this);
-
-            // increment current object
             ++(*this);
-
-            // return the original
             return copy;
         }
 

src/Protocol/ProtocolInPostPairsIterator.h

@@ -49,13 +49,8 @@ namespace RocksServer {
          */
         ProtocolInPostPairsIterator operator++(int)
         {
-            // make a copy
             ProtocolInPostPairsIterator copy(*this);
-
-            // increment current object
             ++(*this);
-
-            // return the original
             return copy;
         }
 

src/RocksServer.cpp

@@ -161,6 +161,7 @@ int main(int argc, char **argv)
     server.onRequest("/tail",   new RequestTailing(rdb));
     server.onRequest("/backup", new RequestBackup(rdb, cfg.get("backup_path", dfCfg.backup_path)));
     server.onRequest("/stats",  new RequestStats(rdb));
+    server.onRequest("/prefit", new RequestPrefIt(rdb));
 
 
     /**
@@ -169,7 +170,7 @@ int main(int argc, char **argv)
      *  
      */
     if (!server.dispatch()) {
-        std::cerr << "Failed to run messahe loop." << std::endl;
+        std::cerr << "Failed to run message loop." << std::endl;
         return 1;
     }
 

src/RocksServer.h

@@ -7,7 +7,7 @@
  *  @github https://github.com/valmat/rocksserver
  */
 
-#define ROCKSSERVER_VERSION "v.0.1.1"
+#define ROCKSSERVER_VERSION "v.0.1.2"
 
 // C++ headers
 #include <iostream>
@@ -81,6 +81,7 @@
 #include "listeners/RequestTailing.h"
 #include "listeners/RequestBackup.h"
 #include "listeners/RequestStats.h"
+#include "listeners/RequestPrefIt.h"
 
 
 #include "evhttp/EvServer.h"

src/listeners/RequestPrefIt.h

@@ -0,0 +1,50 @@
+/**
+ *  RequestPrefIt.h
+ *
+ *  Request listener for command "prefit"
+ *  Prefix iterator
+ *
+ *  @author valmat <[email protected]>
+ *  @github https://github.com/valmat/rocksserver
+ */
+
+
+namespace RocksServer {
+
+    class RequestPrefIt : public RequestBase<ProtocolInGet, ProtocolOut>
+    {
+    public:
+        RequestPrefIt(RocksDBWrapper &rdb) : _rdb(rdb) {}
+
+        /**
+         *  Runs request listener
+         *  @param       protocol in object
+         *  @param       protocol out object
+         */
+        virtual void run(const ProtocolInGet &in, const ProtocolOut &out) override
+        {
+            if(!in.check()) {
+                out.setFailValue();
+                return;
+            }
+
+            auto prefix = in.key();
+            std::unique_ptr<rocksdb::Iterator> iter(_rdb->NewIterator(rocksdb::ReadOptions()));
+
+            // filling buffer
+            for (iter->Seek(prefix); iter->Valid() && iter->key().starts_with(prefix); iter->Next()) {
+                if(iter->status().ok()) {
+                    out.setPair(iter->key(), iter->value());
+                } else {
+                    out.setFailPair(iter->key());
+                }
+            }
+
+        }
+
+        virtual ~RequestPrefIt() {}
+    private:
+        RocksDBWrapper& _rdb;
+    };
+
+}