experimenting with username <-> uid mapping.

might be useful to implement twitter translation apis requiring user_id.

src/bitcoinrpc.cpp

@@ -285,6 +285,8 @@ static const CRPCCommand vRPCCommands[] =
     { "getpieceavailability",   &getpieceavailability,   false,     true,       true },
     { "getpiecemaxseen",        &getpiecemaxseen,        false,     true,       true },
     { "peekpost",               &peekpost,               false,     true,       true },
+    { "usernametouid",          &usernametouid,          false,     true,       true },
+    { "uidtousername",          &uidtousername,          false,     true,       true },
 };
 
 CRPCTable::CRPCTable()
@@ -1365,6 +1367,8 @@ Array RPCConvertValues(const std::string &strMethod, const std::vector<std::stri
     if (strMethod == "getpiecemaxseen"        && n > 1) ConvertTo<boost::int64_t>(params[1]);
     if (strMethod == "peekpost"               && n > 1) ConvertTo<boost::int64_t>(params[1]);
     if (strMethod == "peekpost"               && n > 3) ConvertTo<boost::int64_t>(params[3]);
+    if (strMethod == "uidtousername"          && n > 0) ConvertTo<boost::int64_t>(params[0]);
+    if (strMethod == "usernametouid"          && n > 1) ConvertTo<bool>(params[1]);;
 
     return params;
 }

src/bitcoinrpc.h

@@ -237,5 +237,7 @@ extern json_spirit::Value leavegroup(const json_spirit::Array& params, bool fHel
 extern json_spirit::Value getpieceavailability(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value getpiecemaxseen(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value peekpost(const json_spirit::Array& params, bool fHelp);
+extern json_spirit::Value uidtousername(const json_spirit::Array& params, bool fHelp);
+extern json_spirit::Value usernametouid(const json_spirit::Array& params, bool fHelp);
 
 #endif

src/main.cpp

@@ -406,6 +406,77 @@ bool CheckUsername(const std::string &userName, CValidationState &state)
     return true;
 }
 
+
+bool TxNumToUsername(unsigned int txNum, string &username)
+{
+    username = "";
+
+    if( txNum >= pindexBest->nChainTx )
+        return error("TxNumToUsername : txNum out of range");
+
+    int begin=0; 
+    int end=nBestHeight;
+    CBlockIndex *pindex;
+    do {
+        pindex = FindBlockByHeight((begin+end)/2);
+        if( txNum < pindex->nChainTx - pindex->nTx ) {
+            end = pindex->nHeight;
+        } else if ( txNum < pindex->nChainTx ) {
+            break;
+        } else {
+            begin = pindex->nHeight;
+        }
+    } while( 1 );
+
+    unsigned int txIdx = txNum - (pindex->nChainTx - pindex->nTx);
+
+    CBlock block;
+    if (!ReadBlockFromDisk(block, pindex))
+        return false;
+
+    CTransaction &tx = block.vtx[txIdx];
+    username = tx.GetUsername();
+    return true;
+}
+
+bool UsernameToTxNum(const string &username, int *txNum, bool last)
+{
+    CTransaction tx;
+    uint256 hashBlock;
+    if( !last ) {
+        return error("UsernameToTxNum : first not implemented");
+    } else {
+        int maxHeight = -1;
+        if( !GetTransaction( username, tx, hashBlock, maxHeight) ) {
+            return false;
+        }
+    }
+
+    if (!mapBlockIndex.count(hashBlock))
+        return error("UsernameToTxNum : mapBlockIndex error");
+
+    CBlockIndex* pindex = mapBlockIndex[hashBlock];
+    CBlock block;
+    if (!ReadBlockFromDisk(block, pindex))
+        return false;
+
+    unsigned int txIdx = 0;
+    while( txIdx < block.vtx.size() &&
+           block.vtx[txIdx].GetUsername() != username ) {
+           txIdx++;
+    }
+
+    if( txIdx >= block.vtx.size() )
+        return error("UsernameToTxNum : username not found in block.vtx");
+
+    //printf("username: %s block: %d txIdx:%d nTx: %d chainTx:%d\n", 
+    //        username.c_str(), pindex->nHeight, txIdx, pindex->nTx, pindex->nChainTx);
+
+    *txNum = (pindex->nChainTx - pindex->nTx) + txIdx;
+    return true;
+}
+
+
 bool DoTxProofOfWork(CTransaction& tx)
 {
   CBigNum bnTarget;

src/main.h

@@ -269,6 +269,10 @@ inline bool AllowFree(double dPriority)
 
 bool CheckUsername(const std::string &userName, CValidationState &state);
 
+bool TxNumToUsername(unsigned int txNum, string &username);
+
+bool UsernameToTxNum(const string &username, int *txNum, bool last = true);
+
 bool DoTxProofOfWork(CTransaction& tx);
 
 // Context-independent validity checks

src/twister.cpp

@@ -4188,3 +4188,35 @@ Value peekpost(const Array& params, bool fHelp)
     return ret;
 }
 
+Value uidtousername(const Array& params, bool fHelp)
+{
+    if (fHelp || params.size() < 1 || params.size() > 1 )
+        throw runtime_error(
+            "uidtousername <uid>\n"
+            "convert uid to username");
+
+    int uid               = params[0].get_int();
+
+    string strUsername;
+    if( !TxNumToUsername(uid, strUsername) )
+        throw JSONRPCError(RPC_INTERNAL_ERROR, "TxNumToUsername failed");
+
+    return Value(strUsername);
+}
+
+Value usernametouid(const Array& params, bool fHelp)
+{
+    if (fHelp || params.size() < 1 || params.size() > 2 )
+        throw runtime_error(
+            "uidtousername <username> [last=true]\n"
+            "convert username to uid");
+
+    string strUsername    = params[0].get_str();
+    bool last             = (params.size() > 1) ? params[1].get_bool() : true;
+
+    int uid;
+    if( !UsernameToTxNum(strUsername, &uid, last) )
+        throw JSONRPCError(RPC_INTERNAL_ERROR, "UsernameToTxNum failed");
+
+    return Value(uid);
+}