sui_adapter_latest/
gas_meter.rs

1// Copyright (c) Mysten Labs, Inc.
2// SPDX-License-Identifier: Apache-2.0
3
4use std::ops::DerefMut;
5
6use move_binary_format::errors::PartialVMResult;
7use move_core_types::gas_algebra::{AbstractMemorySize, InternalGas, NumArgs, NumBytes};
8use move_vm_runtime::{
9    execution::Type,
10    shared::{
11        gas::{GasMeter, SimpleInstruction},
12        views::{SizeConfig, ValueView},
13    },
14};
15use sui_types::gas_model::{
16    gas_predicates::{
17        legacy_charge_native_pops_args, native_function_threshold_exceeded,
18        use_legacy_abstract_size,
19    },
20    tables::{GasStatus, REFERENCE_SIZE, STRUCT_SIZE, VEC_SIZE},
21};
22
23pub struct SuiGasMeter<G: DerefMut<Target = GasStatus>>(pub G);
24
25/// Returns a tuple of (<pops>, <pushes>, <stack_size_decrease>, <stack_size_increase>)
26fn get_simple_instruction_stack_change(
27    instr: SimpleInstruction,
28) -> PartialVMResult<(u64, u64, AbstractMemorySize, AbstractMemorySize)> {
29    use SimpleInstruction::*;
30
31    Ok(match instr {
32        // NB: The `Ret` pops are accounted for in `Call` instructions, so we say `Ret` has no pops.
33        Nop | Ret => (0, 0, 0.into(), 0.into()),
34        BrTrue | BrFalse => (1, 0, Type::Bool.size()?, 0.into()),
35        Branch => (0, 0, 0.into(), 0.into()),
36        LdU8 => (0, 1, 0.into(), Type::U8.size()?),
37        LdU16 => (0, 1, 0.into(), Type::U16.size()?),
38        LdU32 => (0, 1, 0.into(), Type::U32.size()?),
39        LdU64 => (0, 1, 0.into(), Type::U64.size()?),
40        LdU128 => (0, 1, 0.into(), Type::U128.size()?),
41        LdU256 => (0, 1, 0.into(), Type::U256.size()?),
42        LdTrue | LdFalse => (0, 1, 0.into(), Type::Bool.size()?),
43        FreezeRef => (1, 1, REFERENCE_SIZE, REFERENCE_SIZE),
44        ImmBorrowLoc | MutBorrowLoc => (0, 1, 0.into(), REFERENCE_SIZE),
45        ImmBorrowField | MutBorrowField | ImmBorrowFieldGeneric | MutBorrowFieldGeneric => {
46            (1, 1, REFERENCE_SIZE, REFERENCE_SIZE)
47        }
48        // Since we don't have the size of the value being cast here we take a conservative
49        // over-approximation: it is _always_ getting cast from the smallest integer type.
50        CastU8 => (1, 1, Type::U8.size()?, Type::U8.size()?),
51        CastU16 => (1, 1, Type::U8.size()?, Type::U16.size()?),
52        CastU32 => (1, 1, Type::U8.size()?, Type::U32.size()?),
53        CastU64 => (1, 1, Type::U8.size()?, Type::U64.size()?),
54        CastU128 => (1, 1, Type::U8.size()?, Type::U128.size()?),
55        CastU256 => (1, 1, Type::U8.size()?, Type::U256.size()?),
56        // NB: We don't know the size of what integers we're dealing with, so we conservatively
57        // over-approximate by popping the smallest integers, and push the largest.
58        Add | Sub | Mul | Mod | Div => (
59            2,
60            1,
61            Type::U8.size()? + Type::U8.size()?,
62            Type::U256.size()?,
63        ),
64        BitOr | BitAnd | Xor => (
65            2,
66            1,
67            Type::U8.size()? + Type::U8.size()?,
68            Type::U256.size()?,
69        ),
70        Shl | Shr => (
71            2,
72            1,
73            Type::U8.size()? + Type::U8.size()?,
74            Type::U256.size()?,
75        ),
76        Or | And => (
77            2,
78            1,
79            Type::Bool.size()? + Type::Bool.size()?,
80            Type::Bool.size()?,
81        ),
82        Lt | Gt | Le | Ge => (
83            2,
84            1,
85            Type::U8.size()? + Type::U8.size()?,
86            Type::Bool.size()?,
87        ),
88        Not => (1, 1, Type::Bool.size()?, Type::Bool.size()?),
89        Abort => (1, 0, Type::U64.size()?, 0.into()),
90    })
91}
92
93impl<G: DerefMut<Target = GasStatus>> GasMeter for SuiGasMeter<G> {
94    /// Charge an instruction and fail if not enough gas units are left.
95    fn charge_simple_instr(&mut self, instr: SimpleInstruction) -> PartialVMResult<()> {
96        let (pops, pushes, pop_size, push_size) = get_simple_instruction_stack_change(instr)?;
97        self.0
98            .charge(1, pushes, pops, push_size.into(), pop_size.into())
99    }
100
101    fn charge_pop(&mut self, popped_val: impl ValueView) -> PartialVMResult<()> {
102        let decr_size = abstract_memory_size(&self.0, popped_val)?;
103        self.0.charge(1, 0, 1, 0, decr_size.into())
104    }
105
106    fn charge_native_function(
107        &mut self,
108        amount: InternalGas,
109        ret_vals: Option<impl ExactSizeIterator<Item = impl ValueView>>,
110    ) -> PartialVMResult<()> {
111        // Charge for the number of pushes on to the stack that the return of this function is
112        // going to cause.
113        let pushes = ret_vals
114            .as_ref()
115            .map(|ret_vals| ret_vals.len())
116            .unwrap_or(0) as u64;
117        // Calculate the number of bytes that are getting pushed onto the stack.
118        let size_increase = match ret_vals {
119            Some(mut ret_vals) => ret_vals.try_fold(
120                AbstractMemorySize::zero(),
121                |acc, elem| -> PartialVMResult<_> {
122                    Ok(acc + abstract_memory_size(&self.0, elem)?)
123                },
124            )?,
125            None => AbstractMemorySize::zero(),
126        };
127        self.0.record_native_call();
128        if native_function_threshold_exceeded(self.0.gas_model_version, self.0.num_native_calls) {
129            // Charge for the stack operations. We don't count this as an "instruction" since we
130            // already accounted for the `Call` instruction in the
131            // `charge_native_function_before_execution` call.
132            // The amount returned by the native function is viewed as the "virtual" instruction cost
133            // for the native function, and will be charged and contribute to the overall cost tier of
134            // the transaction accordingly.
135            self.0
136                .charge(amount.into(), pushes, 0, size_increase.into(), 0)
137        } else {
138            // Charge for the stack operations. We don't count this as an "instruction" since we
139            // already accounted for the `Call` instruction in the
140            // `charge_native_function_before_execution` call.
141            self.0.charge(0, pushes, 0, size_increase.into(), 0)?;
142            // Now charge the gas that the native function told us to charge.
143            self.0.deduct_gas(amount)
144        }
145    }
146
147    fn charge_native_function_before_execution(
148        &mut self,
149        mut args: impl ExactSizeIterator<Item = impl ValueView>,
150    ) -> PartialVMResult<()> {
151        if legacy_charge_native_pops_args(self.0.gas_model_version) {
152            // Legacy: pop args again (double-pop, masked by saturating_sub).
153            let pops = args.len() as u64;
154            let stack_reduction_size = args.try_fold(
155                AbstractMemorySize::new(pops),
156                |acc, elem| -> PartialVMResult<_> {
157                    Ok(acc + abstract_memory_size(&self.0, elem)?)
158                },
159            )?;
160            self.0.charge(1, 0, pops, 0, stack_reduction_size.into())
161        } else {
162            // The args were already popped by charge_call/charge_call_generic.
163            // Only charge the instruction cost, not the pops.
164            self.0.charge(1, 0, 0, 0, 0)
165        }
166    }
167
168    fn charge_call(
169        &mut self,
170        mut args: impl ExactSizeIterator<Item = impl ValueView>,
171        _num_locals: NumArgs,
172    ) -> PartialVMResult<()> {
173        // We will have to perform this many pops for the call.
174        let pops = args.len() as u64;
175        // Size stays the same -- we're just moving it from the operand stack to the locals. But
176        // the size on the operand stack is reduced by sum_{args} arg.size()?.
177        let stack_reduction_size = args.try_fold(
178            AbstractMemorySize::new(0),
179            |acc, elem| -> PartialVMResult<_> { Ok(acc + abstract_memory_size(&self.0, elem)?) },
180        )?;
181        self.0.charge(1, 0, pops, 0, stack_reduction_size.into())
182    }
183
184    fn charge_call_generic(
185        &mut self,
186        mut args: impl ExactSizeIterator<Item = impl ValueView>,
187        _num_locals: NumArgs,
188    ) -> PartialVMResult<()> {
189        // We have to perform this many pops from the operand stack for this function call.
190        let pops = args.len() as u64;
191        // Calculate the size reduction on the operand stack.
192        let stack_reduction_size = args.try_fold(
193            AbstractMemorySize::new(0),
194            |acc, elem| -> PartialVMResult<_> { Ok(acc + abstract_memory_size(&self.0, elem)?) },
195        )?;
196        // Charge for the pops, no pushes, and account for the stack size decrease. Also track the
197        // `CallGeneric` instruction we must have encountered for this.
198        self.0.charge(1, 0, pops, 0, stack_reduction_size.into())
199    }
200
201    fn charge_ld_const(&mut self, size: NumBytes) -> PartialVMResult<()> {
202        // Charge for the load from the locals onto the stack.
203        self.0.charge(1, 1, 0, u64::from(size), 0)
204    }
205
206    fn charge_ld_const_after_deserialization(
207        &mut self,
208        _val: impl ValueView,
209    ) -> PartialVMResult<()> {
210        // We already charged for this based on the bytes that we're loading so don't charge again.
211        Ok(())
212    }
213
214    fn charge_copy_loc(&mut self, val: impl ValueView) -> PartialVMResult<()> {
215        // Charge for the copy of the local onto the stack.
216        let incr_size = abstract_memory_size(&self.0, val)?;
217        self.0.charge(1, 1, 0, incr_size.into(), 0)
218    }
219
220    fn charge_move_loc(&mut self, val: impl ValueView) -> PartialVMResult<()> {
221        if reweight_move_loc(self.0.gas_model_version) {
222            self.0.charge(1, 1, 0, REFERENCE_SIZE.into(), 0)
223        } else {
224            // Charge for the move of the local on to the stack. Note that we charge here since we
225            // aren't tracking the local size (at least not yet). If we were, this should be a net-zero
226            // operation in terms of memory usage.
227            let incr_size = abstract_memory_size(&self.0, val)?;
228            self.0.charge(1, 1, 0, incr_size.into(), 0)
229        }
230    }
231
232    fn charge_store_loc(&mut self, val: impl ValueView) -> PartialVMResult<()> {
233        // Charge for the storing of the value on the stack into a local. Note here that if we were
234        // also accounting for the size of the locals that this would be a net-zero operation in
235        // terms of memory.
236        let decr_size = abstract_memory_size(&self.0, val)?;
237        self.0.charge(1, 0, 1, 0, decr_size.into())
238    }
239
240    fn charge_pack(
241        &mut self,
242        _is_generic: bool,
243        args: impl ExactSizeIterator<Item = impl ValueView>,
244    ) -> PartialVMResult<()> {
245        // We perform `num_fields` number of pops.
246        let num_fields = args.len() as u64;
247        // The actual amount of memory on the stack is staying the same with the addition of some
248        // extra size for the struct, so the size doesn't really change much.
249        self.0.charge(1, 1, num_fields, STRUCT_SIZE.into(), 0)
250    }
251
252    fn charge_unpack(
253        &mut self,
254        _is_generic: bool,
255        args: impl ExactSizeIterator<Item = impl ValueView>,
256    ) -> PartialVMResult<()> {
257        // We perform `num_fields` number of pushes.
258        let num_fields = args.len() as u64;
259        self.0.charge(1, num_fields, 1, 0, STRUCT_SIZE.into())
260    }
261
262    fn charge_variant_switch(&mut self, val: impl ValueView) -> PartialVMResult<()> {
263        // We perform a single pop of a value from the stack.
264        let decr_size = abstract_memory_size(&self.0, val)?;
265        self.0.charge(1, 0, 1, 0, decr_size.into())
266    }
267
268    fn charge_read_ref(&mut self, ref_val: impl ValueView) -> PartialVMResult<()> {
269        // We read the reference so we are decreasing the size of the stack by the size of the
270        // reference, and adding to it the size of the value that has been read from that
271        // reference.
272        let size = if reweight_read_ref(self.0.gas_model_version) {
273            abstract_memory_size_with_traversal(&self.0, ref_val)?
274        } else {
275            abstract_memory_size(&self.0, ref_val)?
276        };
277        self.0.charge(1, 1, 1, size.into(), REFERENCE_SIZE.into())
278    }
279
280    fn charge_write_ref(
281        &mut self,
282        new_val: impl ValueView,
283        old_val: impl ValueView,
284    ) -> PartialVMResult<()> {
285        // TODO(tzakian): We should account for this elsewhere as the owner of data the
286        // reference points to won't be on the stack. For now though, we treat it as adding to the
287        // stack size.
288        let (pushes, pops) = if reduce_stack_size(self.0.gas_model_version) {
289            (0, 2)
290        } else {
291            (1, 2)
292        };
293        let incr_size = abstract_memory_size(&self.0, new_val)?;
294        let decr_size = abstract_memory_size(&self.0, old_val)?;
295        self.0
296            .charge(1, pushes, pops, incr_size.into(), decr_size.into())
297    }
298
299    fn charge_eq(&mut self, lhs: impl ValueView, rhs: impl ValueView) -> PartialVMResult<()> {
300        let size_reduction = abstract_memory_size_with_traversal(&self.0, lhs)?
301            + abstract_memory_size_with_traversal(&self.0, rhs)?;
302        self.0.charge(
303            1,
304            1,
305            2,
306            (Type::Bool.size()? + size_reduction).into(),
307            size_reduction.into(),
308        )
309    }
310
311    fn charge_neq(&mut self, lhs: impl ValueView, rhs: impl ValueView) -> PartialVMResult<()> {
312        let size_reduction = abstract_memory_size_with_traversal(&self.0, lhs)?
313            + abstract_memory_size_with_traversal(&self.0, rhs)?;
314        let size_increase = if enable_traverse_refs(self.0.gas_model_version) {
315            Type::Bool.size()? + size_reduction
316        } else {
317            Type::Bool.size()?
318        };
319        self.0
320            .charge(1, 1, 2, size_increase.into(), size_reduction.into())
321    }
322
323    fn charge_vec_pack<'a>(
324        &mut self,
325        args: impl ExactSizeIterator<Item = impl ValueView>,
326    ) -> PartialVMResult<()> {
327        // We will perform `num_args` number of pops.
328        let num_args = args.len() as u64;
329        // The amount of data on the stack stays constant except we have some extra metadata for
330        // the vector to hold the length of the vector.
331        self.0.charge(1, 1, num_args, VEC_SIZE.into(), 0)
332    }
333
334    fn charge_vec_len(&mut self) -> PartialVMResult<()> {
335        self.0
336            .charge(1, 1, 1, Type::U64.size()?.into(), REFERENCE_SIZE.into())
337    }
338
339    fn charge_vec_borrow(&mut self, _is_mut: bool, _is_success: bool) -> PartialVMResult<()> {
340        self.0.charge(
341            1,
342            1,
343            2,
344            REFERENCE_SIZE.into(),
345            (REFERENCE_SIZE + Type::U64.size()?).into(),
346        )
347    }
348
349    fn charge_vec_push_back(&mut self, _val: impl ValueView) -> PartialVMResult<()> {
350        // The value was already on the stack, so we aren't increasing the number of bytes on the stack.
351        self.0.charge(1, 0, 2, 0, REFERENCE_SIZE.into())
352    }
353
354    fn charge_vec_pop_back(&mut self, _val: Option<impl ValueView>) -> PartialVMResult<()> {
355        self.0.charge(1, 1, 1, 0, REFERENCE_SIZE.into())
356    }
357
358    fn charge_vec_unpack(
359        &mut self,
360        expect_num_elements: NumArgs,
361        _elems: impl ExactSizeIterator<Item = impl ValueView>,
362    ) -> PartialVMResult<()> {
363        // Charge for the pushes
364        let pushes = u64::from(expect_num_elements);
365        // The stack size stays pretty much the same modulo the additional vector size
366        self.0.charge(1, pushes, 1, 0, VEC_SIZE.into())
367    }
368
369    fn charge_vec_swap(&mut self) -> PartialVMResult<()> {
370        let size_decrease = REFERENCE_SIZE + Type::U64.size()? + Type::U64.size()?;
371        let (pushes, pops) = if reduce_stack_size(self.0.gas_model_version) {
372            (0, 3)
373        } else {
374            (1, 1)
375        };
376        self.0.charge(1, pushes, pops, 0, size_decrease.into())
377    }
378
379    fn charge_drop_frame(
380        &mut self,
381        _locals: impl Iterator<Item = impl ValueView>,
382    ) -> PartialVMResult<()> {
383        Ok(())
384    }
385
386    fn remaining_gas(&self) -> InternalGas {
387        if !self.0.charge {
388            return InternalGas::new(u64::MAX);
389        }
390        self.0.gas_left
391    }
392}
393
394fn abstract_memory_size(
395    status: &GasStatus,
396    val: impl ValueView,
397) -> PartialVMResult<AbstractMemorySize> {
398    let config = size_config_for_gas_model_version(status.gas_model_version, false);
399    val.abstract_memory_size(&config)
400}
401
402fn abstract_memory_size_with_traversal(
403    status: &GasStatus,
404    val: impl ValueView,
405) -> PartialVMResult<AbstractMemorySize> {
406    let config = size_config_for_gas_model_version(status.gas_model_version, true);
407    val.abstract_memory_size(&config)
408}
409
410fn enable_traverse_refs(gas_model_version: u64) -> bool {
411    gas_model_version > 9
412}
413
414fn reweight_read_ref(gas_model_version: u64) -> bool {
415    // Reweighting `ReadRef` is only done in gas model versions 10 and above.
416    gas_model_version > 10
417}
418
419fn reweight_move_loc(gas_model_version: u64) -> bool {
420    // Reweighting `MoveLoc` is only done in gas model versions 10 and above.
421    gas_model_version > 10
422}
423
424fn reduce_stack_size(gas_model_version: u64) -> bool {
425    // Reducing stack size is only done in gas model versions 10 and above.
426    gas_model_version > 10
427}
428
429fn size_config_for_gas_model_version(
430    gas_model_version: u64,
431    should_traverse_refs: bool,
432) -> SizeConfig {
433    if use_legacy_abstract_size(gas_model_version) {
434        SizeConfig {
435            traverse_references: false,
436            include_vector_size: false,
437        }
438    } else if should_traverse_refs {
439        SizeConfig {
440            traverse_references: enable_traverse_refs(gas_model_version),
441            include_vector_size: true,
442        }
443    } else {
444        SizeConfig {
445            traverse_references: false,
446            include_vector_size: true,
447        }
448    }
449}
sui_adapter_latest/gas_meter.rs

sui_adapter_latest/
gas_meter.rs
