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

sui_adapter_latest/
gas_meter.rs
