Function pruneblockchain

src/rpc/blockchain.cpp:1231–1289

}

static RPCHelpMan pruneblockchain()
{
    return RPCHelpMan{"pruneblockchain", "",
                {
                    {"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 RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
    if (!node::fPruneMode)
        throw JSONRPCError(RPC_MISC_ERROR, "Cannot prune blocks because node is not in prune mode.");

    ChainstateManager& chainman = EnsureAnyChainman(request.context);
    LOCK(cs_main);
    CChainState& active_chainstate = chainman.ActiveChainstate();
    CChain& active_chain = active_chainstate.m_chain;

    int heightParam = request.params[0].get_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
        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 < Params().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) {
        LogPrint(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);
    const CBlockIndex* block = active_chain.Tip();
    CHECK_NONFATAL(block);
    while (block->pprev && (block->pprev->nStatus & BLOCK_HAVE_DATA)) {
        block = block->pprev;
    }
    return uint64_t(block->nHeight);
},
    };