ecoin/ecoin/src/db.h

// ECOin - Copyright (c) - 2014/2021 - GPLv3 - epsylon@riseup.net (https://03c8.net)
#ifndef ECOIN_DB_H
#define ECOIN_DB_H

#include "main.h"
#include <map>
#include <string>
#include <vector>
#include <db_cxx.h>

class CAddress;
class CAddrMan;
class CBlockLocator;
class CDiskBlockIndex;
class CDiskTxPos;
class CMasterKey;
class COutPoint;
class CTxIndex;
class CWallet;
class CWalletTx;

extern unsigned int nWalletDBUpdated;

void ThreadFlushWalletDB(void* parg);
bool BackupWallet(const CWallet& wallet, const std::string& strDest);

class CDBEnv
{
private:
    bool fDetachDB;
    bool fDbEnvInit;
    bool fMockDb;
    boost::filesystem::path pathEnv;
    std::string strPath;
    void EnvShutdown();

public:
    mutable CCriticalSection cs_db;
    DbEnv dbenv;
    std::map<std::string, int> mapFileUseCount;
    std::map<std::string, Db*> mapDb;
    CDBEnv();
    ~CDBEnv();
    void MakeMock();
    bool IsMock() { return fMockDb; };

    enum VerifyResult { VERIFY_OK, RECOVER_OK, RECOVER_FAIL };
    VerifyResult Verify(std::string strFile, bool (*recoverFunc)(CDBEnv& dbenv, std::string strFile));
    typedef std::pair<std::vector<unsigned char>, std::vector<unsigned char> > KeyValPair;
    bool Salvage(std::string strFile, bool fAggressive, std::vector<KeyValPair>& vResult);

    bool Open(boost::filesystem::path pathEnv_);
    void Close();
    void Flush(bool fShutdown);
    void CheckpointLSN(std::string strFile);
    void SetDetach(bool fDetachDB_) { fDetachDB = fDetachDB_; }
    bool GetDetach() { return fDetachDB; }

    void CloseDb(const std::string& strFile);
    bool RemoveDb(const std::string& strFile);

    DbTxn *TxnBegin(int flags=DB_TXN_WRITE_NOSYNC)
    {
        DbTxn* ptxn = NULL;
        int ret = dbenv.txn_begin(NULL, &ptxn, flags);
        if (!ptxn || ret != 0)
            return NULL;
        return ptxn;
    }
};

extern CDBEnv bitdb;

class CDB
{
protected:
    Db* pdb;
    std::string strFile;
    DbTxn *activeTxn;
    bool fReadOnly;
    explicit CDB(const char* pszFile, const char* pszMode="r+");
    ~CDB() { Close(); }
public:
    void Close();
private:
    CDB(const CDB&);
    void operator=(const CDB&);

protected:
    template<typename K, typename T>
    bool Read(const K& key, T& value)
    {
        if (!pdb)
            return false;

        CDataStream ssKey(SER_DISK, CLIENT_VERSION);
        ssKey.reserve(1000);
        ssKey << key;
        Dbt datKey(&ssKey[0], ssKey.size());

        Dbt datValue;
        datValue.set_flags(DB_DBT_MALLOC);
        int ret = pdb->get(activeTxn, &datKey, &datValue, 0);
        memset(datKey.get_data(), 0, datKey.get_size());
        if (datValue.get_data() == NULL)
            return false;

        try {
            CDataStream ssValue((char*)datValue.get_data(), (char*)datValue.get_data() + datValue.get_size(), SER_DISK, CLIENT_VERSION);
            ssValue >> value;
        }
        catch (std::exception &e) {
            return false;
        }

        memset(datValue.get_data(), 0, datValue.get_size());
        free(datValue.get_data());
        return (ret == 0);
    }

    template<typename K, typename T>
    bool Write(const K& key, const T& value, bool fOverwrite=true)
    {
        if (!pdb)
            return false;
        if (fReadOnly)
            assert(!"Write called on database in read-only mode");

        CDataStream ssKey(SER_DISK, CLIENT_VERSION);
        ssKey.reserve(1000);
        ssKey << key;
        Dbt datKey(&ssKey[0], ssKey.size());

        CDataStream ssValue(SER_DISK, CLIENT_VERSION);
        ssValue.reserve(10000);
        ssValue << value;
        Dbt datValue(&ssValue[0], ssValue.size());

        int ret = pdb->put(activeTxn, &datKey, &datValue, (fOverwrite ? 0 : DB_NOOVERWRITE));

        memset(datKey.get_data(), 0, datKey.get_size());
        memset(datValue.get_data(), 0, datValue.get_size());
        return (ret == 0);
    }

    template<typename K>
    bool Erase(const K& key)
    {
        if (!pdb)
            return false;
        if (fReadOnly)
            assert(!"Erase called on database in read-only mode");

        CDataStream ssKey(SER_DISK, CLIENT_VERSION);
        ssKey.reserve(1000);
        ssKey << key;
        Dbt datKey(&ssKey[0], ssKey.size());

        int ret = pdb->del(activeTxn, &datKey, 0);

        memset(datKey.get_data(), 0, datKey.get_size());
        return (ret == 0 || ret == DB_NOTFOUND);
    }

    template<typename K>
    bool Exists(const K& key)
    {
        if (!pdb)
            return false;

        CDataStream ssKey(SER_DISK, CLIENT_VERSION);
        ssKey.reserve(1000);
        ssKey << key;
        Dbt datKey(&ssKey[0], ssKey.size());

        int ret = pdb->exists(activeTxn, &datKey, 0);

        memset(datKey.get_data(), 0, datKey.get_size());
        return (ret == 0);
    }

    Dbc* GetCursor()
    {
        if (!pdb)
            return NULL;
        Dbc* pcursor = NULL;
        int ret = pdb->cursor(NULL, &pcursor, 0);
        if (ret != 0)
            return NULL;
        return pcursor;
    }

    int ReadAtCursor(Dbc* pcursor, CDataStream& ssKey, CDataStream& ssValue, unsigned int fFlags=DB_NEXT)
    {
        Dbt datKey;
        if (fFlags == DB_SET || fFlags == DB_SET_RANGE || fFlags == DB_GET_BOTH || fFlags == DB_GET_BOTH_RANGE)
        {
            datKey.set_data(&ssKey[0]);
            datKey.set_size(ssKey.size());
        }
        Dbt datValue;
        if (fFlags == DB_GET_BOTH || fFlags == DB_GET_BOTH_RANGE)
        {
            datValue.set_data(&ssValue[0]);
            datValue.set_size(ssValue.size());
        }
        datKey.set_flags(DB_DBT_MALLOC);
        datValue.set_flags(DB_DBT_MALLOC);
        int ret = pcursor->get(&datKey, &datValue, fFlags);
        if (ret != 0)
            return ret;
        else if (datKey.get_data() == NULL || datValue.get_data() == NULL)
            return 99999;

        ssKey.SetType(SER_DISK);
        ssKey.clear();
        ssKey.write((char*)datKey.get_data(), datKey.get_size());
        ssValue.SetType(SER_DISK);
        ssValue.clear();
        ssValue.write((char*)datValue.get_data(), datValue.get_size());

        memset(datKey.get_data(), 0, datKey.get_size());
        memset(datValue.get_data(), 0, datValue.get_size());
        free(datKey.get_data());
        free(datValue.get_data());
        return 0;
    }

public:
    bool TxnBegin()
    {
        if (!pdb || activeTxn)
            return false;
        DbTxn* ptxn = bitdb.TxnBegin();
        if (!ptxn)
            return false;
        activeTxn = ptxn;
        return true;
    }

    bool TxnCommit()
    {
        if (!pdb || !activeTxn)
            return false;
        int ret = activeTxn->commit(0);
        activeTxn = NULL;
        return (ret == 0);
    }

    bool TxnAbort()
    {
        if (!pdb || !activeTxn)
            return false;
        int ret = activeTxn->abort();
        activeTxn = NULL;
        return (ret == 0);
    }

    bool ReadVersion(int& nVersion)
    {
        nVersion = 0;
        return Read(std::string("version"), nVersion);
    }

    bool WriteVersion(int nVersion)
    {
        return Write(std::string("version"), nVersion);
    }

    bool static Rewrite(const std::string& strFile, const char* pszSkip = NULL);
};

class CAddrDB
{
private:
    boost::filesystem::path pathAddr;
public:
    CAddrDB();
    bool Write(const CAddrMan& addr);
    bool Read(CAddrMan& addr);
};

#endif // ECOIN_DB_H