Line data Source code
1 : // Copyright (c) 2021-2022 The Bitcoin Core developers
2 : // Distributed under the MIT software license, see the accompanying
3 : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 :
5 : #ifndef BITCOIN_WALLET_SPEND_H
6 : #define BITCOIN_WALLET_SPEND_H
7 :
8 : #include <consensus/amount.h>
9 : #include <policy/fees.h> // for FeeCalculation
10 : #include <util/result.h>
11 : #include <wallet/coinselection.h>
12 : #include <wallet/transaction.h>
13 : #include <wallet/wallet.h>
14 :
15 : #include <optional>
16 :
17 : namespace wallet {
18 : /** Get the marginal bytes if spending the specified output from this transaction.
19 : * Use CoinControl to determine whether to expect signature grinding when calculating the size of the input spend. */
20 : int CalculateMaximumSignedInputSize(const CTxOut& txout, const CWallet* pwallet, const CCoinControl* coin_control);
21 : int CalculateMaximumSignedInputSize(const CTxOut& txout, const COutPoint outpoint, const SigningProvider* pwallet, bool can_grind_r, const CCoinControl* coin_control);
22 : struct TxSize {
23 : int64_t vsize{-1};
24 : int64_t weight{-1};
25 : };
26 :
27 : /** Calculate the size of the transaction using CoinControl to determine
28 : * whether to expect signature grinding when calculating the size of the input spend. */
29 : TxSize CalculateMaximumSignedTxSize(const CTransaction& tx, const CWallet* wallet, const std::vector<CTxOut>& txouts, const CCoinControl* coin_control = nullptr);
30 : TxSize CalculateMaximumSignedTxSize(const CTransaction& tx, const CWallet* wallet, const CCoinControl* coin_control = nullptr) EXCLUSIVE_LOCKS_REQUIRED(wallet->cs_wallet);
31 :
32 : /**
33 : * COutputs available for spending, stored by OutputType.
34 : * This struct is really just a wrapper around OutputType vectors with a convenient
35 : * method for concatenating and returning all COutputs as one vector.
36 : *
37 : * Size(), Clear(), Erase(), Shuffle(), and Add() methods are implemented to
38 : * allow easy interaction with the struct.
39 : */
40 0 : struct CoinsResult {
41 : std::map<OutputType, std::vector<COutput>> coins;
42 :
43 : /** Concatenate and return all COutputs as one vector */
44 : std::vector<COutput> All() const;
45 :
46 : /** The following methods are provided so that CoinsResult can mimic a vector,
47 : * i.e., methods can work with individual OutputType vectors or on the entire object */
48 : size_t Size() const;
49 : /** Return how many different output types this struct stores */
50 : size_t TypesCount() const { return coins.size(); }
51 : void Clear();
52 : void Erase(const std::unordered_set<COutPoint, SaltedOutpointHasher>& coins_to_remove);
53 : void Shuffle(FastRandomContext& rng_fast);
54 : void Add(OutputType type, const COutput& out);
55 :
56 0 : CAmount GetTotalAmount() { return total_amount; }
57 0 : std::optional<CAmount> GetEffectiveTotalAmount() {return total_effective_amount; }
58 :
59 : private:
60 : /** Sum of all available coins raw value */
61 0 : CAmount total_amount{0};
62 : /** Sum of all available coins effective value (each output value minus fees required to spend it) */
63 0 : std::optional<CAmount> total_effective_amount{0};
64 : };
65 :
66 0 : struct CoinFilterParams {
67 : // Outputs below the minimum amount will not get selected
68 0 : CAmount min_amount{1};
69 : // Outputs above the maximum amount will not get selected
70 0 : CAmount max_amount{MAX_MONEY};
71 : // Return outputs until the minimum sum amount is covered
72 0 : CAmount min_sum_amount{MAX_MONEY};
73 : // Maximum number of outputs that can be returned
74 0 : uint64_t max_count{0};
75 : // By default, return only spendable outputs
76 0 : bool only_spendable{true};
77 : // By default, do not include immature coinbase outputs
78 0 : bool include_immature_coinbase{false};
79 : // By default, skip locked UTXOs
80 0 : bool skip_locked{true};
81 : };
82 :
83 : /**
84 : * Populate the CoinsResult struct with vectors of available COutputs, organized by OutputType.
85 : */
86 : CoinsResult AvailableCoins(const CWallet& wallet,
87 : const CCoinControl* coinControl = nullptr,
88 : std::optional<CFeeRate> feerate = std::nullopt,
89 : const CoinFilterParams& params = {}) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
90 :
91 : /**
92 : * Wrapper function for AvailableCoins which skips the `feerate` and `CoinFilterParams::only_spendable` parameters. Use this function
93 : * to list all available coins (e.g. listunspent RPC) while not intending to fund a transaction.
94 : */
95 : CoinsResult AvailableCoinsListUnspent(const CWallet& wallet, const CCoinControl* coinControl = nullptr, CoinFilterParams params = {}) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
96 :
97 : /**
98 : * Find non-change parent output.
99 : */
100 : const CTxOut& FindNonChangeParentOutput(const CWallet& wallet, const COutPoint& outpoint) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
101 :
102 : /**
103 : * Return list of available coins and locked coins grouped by non-change output address.
104 : */
105 : std::map<CTxDestination, std::vector<COutput>> ListCoins(const CWallet& wallet) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
106 :
107 : struct SelectionFilter {
108 : CoinEligibilityFilter filter;
109 : bool allow_mixed_output_types{true};
110 : };
111 :
112 : /**
113 : * Group coins by the provided filters.
114 : */
115 : FilteredOutputGroups GroupOutputs(const CWallet& wallet,
116 : const CoinsResult& coins,
117 : const CoinSelectionParams& coin_sel_params,
118 : const std::vector<SelectionFilter>& filters);
119 :
120 : /**
121 : * Attempt to find a valid input set that preserves privacy by not mixing OutputTypes.
122 : * `ChooseSelectionResult()` will be called on each OutputType individually and the best
123 : * the solution (according to the waste metric) will be chosen. If a valid input cannot be found from any
124 : * single OutputType, fallback to running `ChooseSelectionResult()` over all available coins.
125 : *
126 : * param@[in] chain The chain interface to get information on unconfirmed UTXOs bump fees
127 : * param@[in] nTargetValue The target value
128 : * param@[in] groups The grouped outputs mapped by coin eligibility filters
129 : * param@[in] coin_selection_params Parameters for the coin selection
130 : * param@[in] allow_mixed_output_types Relax restriction that SelectionResults must be of the same OutputType
131 : * returns If successful, a SelectionResult containing the input set
132 : * If failed, returns (1) an empty error message if the target was not reached (general "Insufficient funds")
133 : * or (2) an specific error message if there was something particularly wrong (e.g. a selection
134 : * result that surpassed the tx max weight size).
135 : */
136 : util::Result<SelectionResult> AttemptSelection(interfaces::Chain& chain, const CAmount& nTargetValue, OutputGroupTypeMap& groups,
137 : const CoinSelectionParams& coin_selection_params, bool allow_mixed_output_types);
138 :
139 : /**
140 : * Attempt to find a valid input set that meets the provided eligibility filter and target.
141 : * Multiple coin selection algorithms will be run and the input set that produces the least waste
142 : * (according to the waste metric) will be chosen.
143 : *
144 : * param@[in] chain The chain interface to get information on unconfirmed UTXOs bump fees
145 : * param@[in] nTargetValue The target value
146 : * param@[in] groups The struct containing the outputs grouped by script and divided by (1) positive only outputs and (2) all outputs (positive + negative).
147 : * param@[in] coin_selection_params Parameters for the coin selection
148 : * returns If successful, a SelectionResult containing the input set
149 : * If failed, returns (1) an empty error message if the target was not reached (general "Insufficient funds")
150 : * or (2) an specific error message if there was something particularly wrong (e.g. a selection
151 : * result that surpassed the tx max weight size).
152 : */
153 : util::Result<SelectionResult> ChooseSelectionResult(interfaces::Chain& chain, const CAmount& nTargetValue, Groups& groups, const CoinSelectionParams& coin_selection_params);
154 :
155 : // User manually selected inputs that must be part of the transaction
156 0 : struct PreSelectedInputs
157 : {
158 : std::set<std::shared_ptr<COutput>> coins;
159 : // If subtract fee from outputs is disabled, the 'total_amount'
160 : // will be the sum of each output effective value
161 : // instead of the sum of the outputs amount
162 0 : CAmount total_amount{0};
163 :
164 0 : void Insert(const COutput& output, bool subtract_fee_outputs)
165 : {
166 0 : if (subtract_fee_outputs) {
167 0 : total_amount += output.txout.nValue;
168 0 : } else {
169 0 : total_amount += output.GetEffectiveValue();
170 : }
171 0 : coins.insert(std::make_shared<COutput>(output));
172 0 : }
173 : };
174 :
175 : /**
176 : * Fetch and validate coin control selected inputs.
177 : * Coins could be internal (from the wallet) or external.
178 : */
179 : util::Result<PreSelectedInputs> FetchSelectedInputs(const CWallet& wallet, const CCoinControl& coin_control,
180 : const CoinSelectionParams& coin_selection_params) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
181 :
182 : /**
183 : * Select a set of coins such that nTargetValue is met; never select unconfirmed coins if they are not ours
184 : * param@[in] wallet The wallet which provides data necessary to spend the selected coins
185 : * param@[in] available_coins The struct of coins, organized by OutputType, available for selection prior to filtering
186 : * param@[in] nTargetValue The target value
187 : * param@[in] coin_selection_params Parameters for this coin selection such as feerates, whether to avoid partial spends,
188 : * and whether to subtract the fee from the outputs.
189 : * returns If successful, a SelectionResult containing the selected coins
190 : * If failed, returns (1) an empty error message if the target was not reached (general "Insufficient funds")
191 : * or (2) an specific error message if there was something particularly wrong (e.g. a selection
192 : * result that surpassed the tx max weight size).
193 : */
194 : util::Result<SelectionResult> AutomaticCoinSelection(const CWallet& wallet, CoinsResult& available_coins, const CAmount& nTargetValue,
195 : const CoinSelectionParams& coin_selection_params) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
196 :
197 : /**
198 : * Select all coins from coin_control, and if coin_control 'm_allow_other_inputs=true', call 'AutomaticCoinSelection' to
199 : * select a set of coins such that nTargetValue - pre_set_inputs.total_amount is met.
200 : */
201 : util::Result<SelectionResult> SelectCoins(const CWallet& wallet, CoinsResult& available_coins, const PreSelectedInputs& pre_set_inputs,
202 : const CAmount& nTargetValue, const CCoinControl& coin_control,
203 : const CoinSelectionParams& coin_selection_params) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
204 :
205 : struct CreatedTransactionResult
206 : {
207 : CTransactionRef tx;
208 : CAmount fee;
209 : FeeCalculation fee_calc;
210 : int change_pos;
211 :
212 0 : CreatedTransactionResult(CTransactionRef _tx, CAmount _fee, int _change_pos, const FeeCalculation& _fee_calc)
213 0 : : tx(_tx), fee(_fee), fee_calc(_fee_calc), change_pos(_change_pos) {}
214 : };
215 :
216 : /**
217 : * Create a new transaction paying the recipients with a set of coins
218 : * selected by SelectCoins(); Also create the change output, when needed
219 : * @note passing change_pos as -1 will result in setting a random position
220 : */
221 : util::Result<CreatedTransactionResult> CreateTransaction(CWallet& wallet, const std::vector<CRecipient>& vecSend, int change_pos, const CCoinControl& coin_control, bool sign = true);
222 :
223 : /**
224 : * Insert additional inputs into the transaction by
225 : * calling CreateTransaction();
226 : */
227 : bool FundTransaction(CWallet& wallet, CMutableTransaction& tx, CAmount& nFeeRet, int& nChangePosInOut, bilingual_str& error, bool lockUnspents, const std::set<int>& setSubtractFeeFromOutputs, CCoinControl);
228 : } // namespace wallet
229 :
230 : #endif // BITCOIN_WALLET_SPEND_H
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