Function pruneblockchain

src/rpc/blockchain.cpp:918–975

}

static RPCMethod pruneblockchain()
{
    return RPCMethod{"pruneblockchain",
                "Attempts to delete block and undo data up to a specified height or timestamp, if eligible for pruning.\n"
                "Requires `-prune` to be enabled at startup. While pruned data may be re-fetched in some cases (e.g., via `getblockfrompeer`), local deletion is irreversible.\n",
                {
                    {"height", RPCArg::Type::NUM, RPCArg::Optional::NO, "The block height to prune up to. May be set to a discrete height, or to a " + UNIX_EPOCH_TIME + "\n"
            "                  to prune blocks whose block time is at least 2 hours older than the provided timestamp."},
                },
                RPCResult{
                    RPCResult::Type::NUM, "", "Height of the last block pruned"},
                RPCExamples{
                    HelpExampleCli("pruneblockchain", "1000")
            + HelpExampleRpc("pruneblockchain", "1000")
                },
        [](const RPCMethod& self, const JSONRPCRequest& request) -> UniValue
{
    ChainstateManager& chainman = EnsureAnyChainman(request.context);
    if (!chainman.m_blockman.IsPruneMode()) {
        throw JSONRPCError(RPC_MISC_ERROR, "Cannot prune blocks because node is not in prune mode.");
    }

    LOCK(cs_main);
    Chainstate& active_chainstate = chainman.ActiveChainstate();
    CChain& active_chain = active_chainstate.m_chain;

    int heightParam = request.params[0].getInt<int>();
    if (heightParam < 0) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Negative block height.");
    }

    // Height value more than a billion is too high to be a block height, and
    // too low to be a block time (corresponds to timestamp from Sep 2001).
    if (heightParam > 1000000000) {
        // Add a 2 hour buffer to include blocks which might have had old timestamps
        const CBlockIndex* pindex = active_chain.FindEarliestAtLeast(heightParam - TIMESTAMP_WINDOW, 0);
        if (!pindex) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Could not find block with at least the specified timestamp.");
        }
        heightParam = pindex->nHeight;
    }

    unsigned int height = (unsigned int) heightParam;
    unsigned int chainHeight = (unsigned int) active_chain.Height();
    if (chainHeight < chainman.GetParams().PruneAfterHeight()) {
        throw JSONRPCError(RPC_MISC_ERROR, "Blockchain is too short for pruning.");
    } else if (height > chainHeight) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Blockchain is shorter than the attempted prune height.");
    } else if (height > chainHeight - MIN_BLOCKS_TO_KEEP) {
        LogDebug(BCLog::RPC, "Attempt to prune blocks close to the tip.  Retaining the minimum number of blocks.\n");
        height = chainHeight - MIN_BLOCKS_TO_KEEP;
    }

    PruneBlockFilesManual(active_chainstate, height);
    return GetPruneHeight(chainman.m_blockman, active_chain).value_or(-1);
},
    };
}