run_block_generator()

src/gen/conditions.rs

@@ -348,7 +348,10 @@ pub struct SpendBundleConditions {
     // Unsafe Agg Sig conditions (i.e. not tied to the spend generating it)
     pub agg_sig_unsafe: Vec<(NodePtr, NodePtr)>,
 
-    // the total cost of the spend bundle
+    // the cost of conditions (when returned by parse_spends())
+    // run_generator() will include the CLVM cost
+    // run_block_generator() will include CLVM cost and byte cost (making this
+    // the total cost)
     pub cost: u64,
 }
 

src/gen/mod.rs

@@ -4,5 +4,6 @@ pub mod conditions;
 pub mod flags;
 pub mod get_puzzle_and_solution;
 pub mod opcodes;
+pub mod run_block_generator;
 mod sanitize_int;
 pub mod validation_error;

src/gen/run_block_generator.rs

@@ -0,0 +1,57 @@
+use crate::gen::conditions::{parse_spends, SpendBundleConditions};
+use crate::gen::validation_error::ValidationErr;
+use crate::generator_rom::{COST_PER_BYTE, GENERATOR_ROM};
+use clvmr::allocator::Allocator;
+use clvmr::chia_dialect::ChiaDialect;
+use clvmr::reduction::Reduction;
+use clvmr::run_program::run_program;
+use clvmr::serde::node_from_bytes;
+
+// Runs the generator ROM and passes in the program (transactions generator).
+// The program is expected to return a list of spends. Each item being:
+
+// (parent-coin-id puzzle-reveal amount solution)
+
+// The puzzle-reveals are then executed with the corresponding solution being
+// passed as the argument. The output from those puzzles are lists of
+// conditions. The conditions are parsed and returned in the
+// SpendBundleConditions. Some conditions are validated, and if invalid may
+// cause the function to return an error.
+
+// the only reason we need to pass in the allocator is because the returned
+// SpendBundleConditions contains NodePtr fields. If that's changed, we could
+// create the allocator inside this functions as well.
+pub fn run_block_generator<GenBuf: AsRef<[u8]>>(
+    a: &mut Allocator,
+    program: &[u8],
+    block_refs: &[GenBuf],
+    max_cost: u64,
+    flags: u32,
+) -> Result<SpendBundleConditions, ValidationErr> {
+    let byte_cost = program.len() as u64 * COST_PER_BYTE;
+
+    let generator_rom = node_from_bytes(a, &GENERATOR_ROM)?;
+    let program = node_from_bytes(a, program)?;
+
+    // iterate in reverse order since we're building a linked list from
+    // the tail
+    let mut args = a.null();
+    for g in block_refs.iter().rev() {
+        let ref_gen = a.new_atom(g.as_ref())?;
+        args = a.new_pair(ref_gen, args)?;
+    }
+
+    args = a.new_pair(args, a.null())?;
+    let args = a.new_pair(args, a.null())?;
+    let args = a.new_pair(program, args)?;
+
+    let dialect = ChiaDialect::new(flags);
+    let Reduction(clvm_cost, generator_output) =
+        run_program(a, &dialect, generator_rom, args, max_cost - byte_cost)?;
+
+    // we pass in what's left of max_cost here, to fail early in case the
+    // cost of a condition brings us over the cost limit
+    let mut result = parse_spends(a, generator_output, max_cost - clvm_cost - byte_cost, flags)?;
+    result.cost += clvm_cost + byte_cost;
+    Ok(result)
+}

src/gen/validation_error.rs

@@ -1,7 +1,9 @@
 use clvmr::allocator::{Allocator, NodePtr, SExp};
+use clvmr::reduction::EvalErr;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum ErrorCode {
+    GeneratorRuntimeError,
     NegativeAmount,
     AmountExceedsMaximum,
     InvalidConditionOpcode,
@@ -33,6 +35,18 @@ pub enum ErrorCode {
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct ValidationErr(pub NodePtr, pub ErrorCode);
 
+impl From<EvalErr> for ValidationErr {
+    fn from(v: EvalErr) -> Self {
+        ValidationErr(v.0, ErrorCode::GeneratorRuntimeError)
+    }
+}
+
+impl From<std::io::Error> for ValidationErr {
+    fn from(_: std::io::Error) -> Self {
+        ValidationErr(-1, ErrorCode::GeneratorRuntimeError)
+    }
+}
+
 // helper functions that fail with ValidationErr
 pub fn first(a: &Allocator, n: NodePtr) -> Result<NodePtr, ValidationErr> {
     match a.sexp(n) {
@@ -45,6 +59,7 @@ pub fn first(a: &Allocator, n: NodePtr) -> Result<NodePtr, ValidationErr> {
 impl From<ErrorCode> for u32 {
     fn from(err: ErrorCode) -> u32 {
         match err {
+            ErrorCode::GeneratorRuntimeError => 117,
             ErrorCode::NegativeAmount => 124,
             ErrorCode::AmountExceedsMaximum => 16,
             ErrorCode::InvalidPuzzleHash => 10,

src/generator_rom.rs

@@ -0,0 +1,55 @@
+// the generator ROM from:
+// https://github.com/Chia-Network/chia-blockchain/blob/main/chia/wallet/puzzles/rom_bootstrap_generator.clvm.hex
+pub const GENERATOR_ROM: [u8; 737] = [
+    0xff, 0x02, 0xff, 0xff, 0x01, 0xff, 0x02, 0xff, 0x0c, 0xff, 0xff, 0x04, 0xff, 0x02, 0xff, 0xff,
+    0x04, 0xff, 0xff, 0x02, 0xff, 0x05, 0xff, 0xff, 0x04, 0xff, 0x08, 0xff, 0xff, 0x04, 0xff, 0x13,
+    0xff, 0x80, 0x80, 0x80, 0x80, 0xff, 0x80, 0x80, 0x80, 0x80, 0xff, 0xff, 0x04, 0xff, 0xff, 0x01,
+    0xff, 0xff, 0xff, 0x02, 0xff, 0xff, 0x01, 0xff, 0x05, 0xff, 0xff, 0x02, 0xff, 0x3e, 0xff, 0xff,
+    0x04, 0xff, 0x02, 0xff, 0xff, 0x04, 0xff, 0x05, 0xff, 0x80, 0x80, 0x80, 0x80, 0x80, 0xff, 0xff,
+    0x04, 0xff, 0xff, 0x01, 0xff, 0xff, 0xff, 0x81, 0xff, 0x7f, 0xff, 0x81, 0xdf, 0x81, 0xbf, 0xff,
+    0xff, 0xff, 0x02, 0xff, 0xff, 0x03, 0xff, 0xff, 0x09, 0xff, 0x0b, 0xff, 0xff, 0x01, 0x81, 0x80,
+    0x80, 0xff, 0xff, 0x01, 0xff, 0x04, 0xff, 0x80, 0xff, 0xff, 0x04, 0xff, 0x05, 0xff, 0x80, 0x80,
+    0x80, 0xff, 0xff, 0x01, 0xff, 0x02, 0xff, 0xff, 0x03, 0xff, 0xff, 0x0a, 0xff, 0x0b, 0xff, 0x18,
+    0x80, 0xff, 0xff, 0x01, 0xff, 0x02, 0xff, 0x1a, 0xff, 0xff, 0x04, 0xff, 0x02, 0xff, 0xff, 0x04,
+    0xff, 0xff, 0x02, 0xff, 0xff, 0x03, 0xff, 0xff, 0x0a, 0xff, 0x0b, 0xff, 0x1c, 0x80, 0xff, 0xff,
+    0x01, 0xff, 0x02, 0xff, 0xff, 0x03, 0xff, 0xff, 0x0a, 0xff, 0x0b, 0xff, 0x14, 0x80, 0xff, 0xff,
+    0x01, 0xff, 0x08, 0x80, 0xff, 0xff, 0x01, 0xff, 0x04, 0xff, 0xff, 0x0e, 0xff, 0xff, 0x18, 0xff,
+    0xff, 0x01, 0x1f, 0xff, 0x0b, 0x80, 0xff, 0xff, 0x0c, 0xff, 0x05, 0xff, 0x80, 0xff, 0xff, 0x01,
+    0x01, 0x80, 0x80, 0xff, 0xff, 0x04, 0xff, 0xff, 0x0c, 0xff, 0x05, 0xff, 0xff, 0x01, 0x01, 0x80,
+    0xff, 0x80, 0x80, 0x80, 0x80, 0xff, 0x01, 0x80, 0xff, 0xff, 0x01, 0xff, 0x04, 0xff, 0xff, 0x18,
+    0xff, 0xff, 0x01, 0x3f, 0xff, 0x0b, 0x80, 0xff, 0xff, 0x04, 0xff, 0x05, 0xff, 0x80, 0x80, 0x80,
+    0x80, 0xff, 0x01, 0x80, 0xff, 0x80, 0x80, 0x80, 0x80, 0xff, 0xff, 0x01, 0xff, 0x04, 0xff, 0x0b,
+    0xff, 0xff, 0x04, 0xff, 0x05, 0xff, 0x80, 0x80, 0x80, 0x80, 0xff, 0x01, 0x80, 0x80, 0xff, 0x01,
+    0x80, 0xff, 0x04, 0xff, 0xff, 0x0c, 0xff, 0x15, 0xff, 0x80, 0xff, 0x09, 0x80, 0xff, 0xff, 0x04,
+    0xff, 0xff, 0x0c, 0xff, 0x15, 0xff, 0x09, 0x80, 0xff, 0x80, 0x80, 0x80, 0xff, 0xff, 0x04, 0xff,
+    0xff, 0x04, 0xff, 0x05, 0xff, 0x13, 0x80, 0xff, 0xff, 0x04, 0xff, 0x2b, 0xff, 0x80, 0x80, 0x80,
+    0xff, 0xff, 0x02, 0xff, 0x16, 0xff, 0xff, 0x04, 0xff, 0x02, 0xff, 0xff, 0x04, 0xff, 0x09, 0xff,
+    0xff, 0x04, 0xff, 0xff, 0x02, 0xff, 0x3e, 0xff, 0xff, 0x04, 0xff, 0x02, 0xff, 0xff, 0x04, 0xff,
+    0x15, 0xff, 0x80, 0x80, 0x80, 0x80, 0xff, 0x80, 0x80, 0x80, 0x80, 0x80, 0xff, 0x02, 0xff, 0xff,
+    0x03, 0xff, 0xff, 0x09, 0xff, 0xff, 0x0c, 0xff, 0x05, 0xff, 0x80, 0xff, 0xff, 0x01, 0x01, 0x80,
+    0xff, 0x10, 0x80, 0xff, 0xff, 0x01, 0xff, 0x02, 0xff, 0x2e, 0xff, 0xff, 0x04, 0xff, 0x02, 0xff,
+    0xff, 0x04, 0xff, 0xff, 0x02, 0xff, 0x3e, 0xff, 0xff, 0x04, 0xff, 0x02, 0xff, 0xff, 0x04, 0xff,
+    0xff, 0x0c, 0xff, 0x05, 0xff, 0xff, 0x01, 0x01, 0x80, 0xff, 0x80, 0x80, 0x80, 0x80, 0xff, 0x80,
+    0x80, 0x80, 0x80, 0xff, 0xff, 0x01, 0xff, 0x02, 0xff, 0x12, 0xff, 0xff, 0x04, 0xff, 0x02, 0xff,
+    0xff, 0x04, 0xff, 0xff, 0x0c, 0xff, 0x05, 0xff, 0xff, 0x01, 0x01, 0x80, 0xff, 0xff, 0x04, 0xff,
+    0xff, 0x0c, 0xff, 0x05, 0xff, 0x80, 0xff, 0xff, 0x01, 0x01, 0x80, 0xff, 0x80, 0x80, 0x80, 0x80,
+    0x80, 0x80, 0xff, 0x01, 0x80, 0xff, 0x01, 0x80, 0x80, 0xff, 0x04, 0xff, 0xff, 0x02, 0xff, 0x16,
+    0xff, 0xff, 0x04, 0xff, 0x02, 0xff, 0xff, 0x04, 0xff, 0x09, 0xff, 0x80, 0x80, 0x80, 0x80, 0xff,
+    0x0d, 0x80, 0xff, 0xff, 0x04, 0xff, 0x09, 0xff, 0xff, 0x04, 0xff, 0xff, 0x02, 0xff, 0x1e, 0xff,
+    0xff, 0x04, 0xff, 0x02, 0xff, 0xff, 0x04, 0xff, 0x15, 0xff, 0x80, 0x80, 0x80, 0x80, 0xff, 0xff,
+    0x04, 0xff, 0x2d, 0xff, 0xff, 0x04, 0xff, 0xff, 0x02, 0xff, 0x15, 0xff, 0x5d, 0x80, 0xff, 0x7d,
+    0x80, 0x80, 0x80, 0x80, 0xff, 0xff, 0x02, 0xff, 0xff, 0x03, 0xff, 0x05, 0xff, 0xff, 0x01, 0xff,
+    0x04, 0xff, 0xff, 0x02, 0xff, 0x0a, 0xff, 0xff, 0x04, 0xff, 0x02, 0xff, 0xff, 0x04, 0xff, 0x09,
+    0xff, 0x80, 0x80, 0x80, 0x80, 0xff, 0xff, 0x02, 0xff, 0x16, 0xff, 0xff, 0x04, 0xff, 0x02, 0xff,
+    0xff, 0x04, 0xff, 0x0d, 0xff, 0x80, 0x80, 0x80, 0x80, 0x80, 0xff, 0x80, 0x80, 0xff, 0x01, 0x80,
+    0xff, 0x02, 0xff, 0xff, 0x03, 0xff, 0xff, 0x07, 0xff, 0x05, 0x80, 0xff, 0xff, 0x01, 0xff, 0x0b,
+    0xff, 0xff, 0x01, 0x02, 0xff, 0xff, 0x02, 0xff, 0x1e, 0xff, 0xff, 0x04, 0xff, 0x02, 0xff, 0xff,
+    0x04, 0xff, 0x09, 0xff, 0x80, 0x80, 0x80, 0x80, 0xff, 0xff, 0x02, 0xff, 0x1e, 0xff, 0xff, 0x04,
+    0xff, 0x02, 0xff, 0xff, 0x04, 0xff, 0x0d, 0xff, 0x80, 0x80, 0x80, 0x80, 0x80, 0xff, 0xff, 0x01,
+    0xff, 0x0b, 0xff, 0xff, 0x01, 0x01, 0xff, 0x05, 0x80, 0x80, 0xff, 0x01, 0x80, 0xff, 0x01, 0x80,
+    0x80,
+];
+
+// constant from the main chia blockchain:
+// https://github.com/Chia-Network/chia-blockchain/blob/main/chia/consensus/default_constants.py
+pub const COST_PER_BYTE: u64 = 12000;

src/lib.rs

@@ -1,5 +1,6 @@
 pub mod compression;
 pub mod gen;
+pub mod generator_rom;
 pub mod merkle_set;
 
 #[cfg(fuzzing)]

tests/run_gen.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 
-from chia_rs import run_generator
+from chia_rs import run_block_generator
 from time import time
 from clvm_tools import binutils
 from clvm.serialize import atom_to_byte_iterator
@@ -16,70 +16,27 @@ def serialize_atom(blob: bytes) -> bytes:
 
 def run_gen(fn: str, flags: int = 0, args: Optional[str] = None):
 
-    # the generator ROM from:
-    # https://github.com/Chia-Network/chia-blockchain/blob/main/chia/wallet/puzzles/rom_bootstrap_generator.clvm.hex
-    program_data = bytes.fromhex(
-        "ff02ffff01ff02ff0cffff04ff02ffff04ffff02ff05ffff04ff08ffff04ff13"
-        "ff80808080ff80808080ffff04ffff01ffffff02ffff01ff05ffff02ff3effff"
-        "04ff02ffff04ff05ff8080808080ffff04ffff01ffffff81ff7fff81df81bfff"
-        "ffff02ffff03ffff09ff0bffff01818080ffff01ff04ff80ffff04ff05ff8080"
-        "80ffff01ff02ffff03ffff0aff0bff1880ffff01ff02ff1affff04ff02ffff04"
-        "ffff02ffff03ffff0aff0bff1c80ffff01ff02ffff03ffff0aff0bff1480ffff"
-        "01ff0880ffff01ff04ffff0effff18ffff011fff0b80ffff0cff05ff80ffff01"
-        "018080ffff04ffff0cff05ffff010180ff80808080ff0180ffff01ff04ffff18"
-        "ffff013fff0b80ffff04ff05ff80808080ff0180ff80808080ffff01ff04ff0b"
-        "ffff04ff05ff80808080ff018080ff0180ff04ffff0cff15ff80ff0980ffff04"
-        "ffff0cff15ff0980ff808080ffff04ffff04ff05ff1380ffff04ff2bff808080"
-        "ffff02ff16ffff04ff02ffff04ff09ffff04ffff02ff3effff04ff02ffff04ff"
-        "15ff80808080ff8080808080ff02ffff03ffff09ffff0cff05ff80ffff010180"
-        "ff1080ffff01ff02ff2effff04ff02ffff04ffff02ff3effff04ff02ffff04ff"
-        "ff0cff05ffff010180ff80808080ff80808080ffff01ff02ff12ffff04ff02ff"
-        "ff04ffff0cff05ffff010180ffff04ffff0cff05ff80ffff010180ff80808080"
-        "8080ff0180ff018080ff04ffff02ff16ffff04ff02ffff04ff09ff80808080ff"
-        "0d80ffff04ff09ffff04ffff02ff1effff04ff02ffff04ff15ff80808080ffff"
-        "04ff2dffff04ffff02ff15ff5d80ff7d80808080ffff02ffff03ff05ffff01ff"
-        "04ffff02ff0affff04ff02ffff04ff09ff80808080ffff02ff16ffff04ff02ff"
-        "ff04ff0dff8080808080ff8080ff0180ff02ffff03ffff07ff0580ffff01ff0b"
-        "ffff0102ffff02ff1effff04ff02ffff04ff09ff80808080ffff02ff1effff04"
-        "ff02ffff04ff0dff8080808080ffff01ff0bffff0101ff058080ff0180ff0180"
-        "80")
-
     # constants from the main chia blockchain:
     # https://github.com/Chia-Network/chia-blockchain/blob/main/chia/consensus/default_constants.py
     max_cost = 11000000000
     cost_per_byte = 12000
 
-    env_data = binutils.assemble(open(fn, "r").read()).as_bin()
-
-    byte_cost = len(env_data) * cost_per_byte
-
-    # we don't charge for the size of the generator ROM. However, we do charge
-    # cost for the operations it executes
-    max_cost -= len(env_data) * cost_per_byte
+    generator = binutils.assemble(open(fn, "r").read()).as_bin()
 
     # add the block program arguments
-    block_program_args = b"\x80"
+    block_refs = []
     if args and args != "":
         with open(args, "r") as f:
-            block_ref = bytes.fromhex(f.read())
-        block_program_args = b"\xff" + serialize_atom(block_ref) + block_program_args
-    env_data = b"\xff" + env_data + b"\xff\xff" + block_program_args  + b"\x80\x80"
+            block_refs = [bytes.fromhex(f.read())]
 
     try:
-        err, result = run_generator(
-            program_data,
-            env_data,
-            max_cost,
-            flags,
-        )
-        cost = 0 if result is None else result.cost + byte_cost
-        return (err, result, cost)
+        return run_block_generator(generator, block_refs, max_cost, flags)
     except Exception as e:
         # GENERATOR_RUNTIME_ERROR
-        return (117, None, 0)
+        return (117, None)
 
 
-def print_spend_bundle_conditions(result, cost: int) -> str:
+def print_spend_bundle_conditions(result) -> str:
     ret = ""
     if result.reserve_fee > 0:
         ret += f"RESERVE_FEE: {result.reserve_fee}\n"
@@ -104,14 +61,14 @@ def print_spend_bundle_conditions(result, cost: int) -> str:
                 ret += f"  CREATE_COIN: ph: {a[0].hex()} amount: {a[1]}\n"
         for a in sorted(s.agg_sig_me):
             ret += f"  AGG_SIG_ME pk: {a[0].hex()} msg: {a[1].hex()}\n"
-    ret += f"cost: {cost}\n"
+    ret += f"cost: {result.cost}\n"
     return ret
 
 
 if __name__ == "__main__":
     try:
         start_time = time()
-        error_code, result, cost = run_gen(sys.argv[1],
+        error_code, result = run_gen(sys.argv[1],
             0 if len(sys.argv) < 3 else int(sys.argv[2]),
             None if len(sys.argv) < 4 else sys.argv[3])
         run_time = time() - start_time
@@ -121,7 +78,7 @@ def print_spend_bundle_conditions(result, cost: int) -> str:
             sys.exit(1)
         start_time = time()
         print("Spend bundle:")
-        print(print_spend_bundle_conditions(result, cost))
+        print(print_spend_bundle_conditions(result))
         print_time = time() - start_time
         print(f"run-time: {run_time:.2f}s")
         print(f"print-time: {print_time:.2f}s")

tests/test-generators.py

@@ -18,26 +18,26 @@ def compare_output(output, expected, title):
         failed = 1
 
 
-def parse_output(result, error_code, cost) -> str:
+def parse_output(result, error_code) -> str:
     if error_code:
         return f"FAILED: {error_code}\n"
     else:
-        return print_spend_bundle_conditions(result, cost)
+        return print_spend_bundle_conditions(result)
 
 for g in sorted(glob.glob('generators/*.clvm')):
     print(f"{g}")
     sys.stdout.write("running generator...\r")
     start_time = perf_counter()
-    error_code, result, cost = run_gen(g, LIMIT_STACK, "generators/block-834752.hex")
+    error_code, result = run_gen(g, LIMIT_STACK, "generators/block-834752.hex")
     run_time = perf_counter() - start_time
-    output = parse_output(result, error_code, cost)
+    output = parse_output(result, error_code)
 
     sys.stdout.write("running generator (mempool mode) ...\r")
     sys.stdout.flush()
     start_time = perf_counter()
-    error_code2, result2, cost = run_gen(g, MEMPOOL_MODE, "generators/block-834752.hex")
+    error_code2, result2 = run_gen(g, MEMPOOL_MODE, "generators/block-834752.hex")
     run_time2 = perf_counter() - start_time
-    output2 = parse_output(result2, error_code2, cost)
+    output2 = parse_output(result2, error_code2)
 
     with open(g) as f:
         expected = f.read().split('\n', 1)[1]

wheel/chia_rs.pyi

@@ -14,6 +14,10 @@ def run_generator(
     program: bytes, args: bytes, max_cost: int, flags: int
 ) -> Tuple[Optional[int], Optional[SpendBundleConditions]]: ...
 
+def run_block_generator(
+    program: bytes, args: List[bytes], max_cost: int, flags: int
+) -> Tuple[Optional[int], Optional[SpendBundleConditions]]: ...
+
 COND_ARGS_NIL: int = ...
 NO_UNKNOWN_CONDS: int = ...
 STRICT_ARGS_COUNT: int = ...

wheel/generate_type_stubs.py

@@ -158,6 +158,10 @@ def run_generator(
     program: bytes, args: bytes, max_cost: int, flags: int
 ) -> Tuple[Optional[int], Optional[SpendBundleConditions]]: ...
 
+def run_block_generator(
+    program: bytes, args: List[bytes], max_cost: int, flags: int
+) -> Tuple[Optional[int], Optional[SpendBundleConditions]]: ...
+
 COND_ARGS_NIL: int = ...
 NO_UNKNOWN_CONDS: int = ...
 STRICT_ARGS_COUNT: int = ...

wheel/src/api.rs

@@ -1,5 +1,5 @@
 use crate::compression;
-use crate::run_generator::{PySpend, PySpendBundleConditions, __pyo3_get_function_run_generator};
+use crate::run_generator::{PySpend, PySpendBundleConditions, __pyo3_get_function_run_generator, __pyo3_get_function_run_block_generator};
 use chia::gen::flags::COND_ARGS_NIL;
 use chia::gen::flags::NO_UNKNOWN_CONDS;
 use chia::gen::flags::STRICT_ARGS_COUNT;
@@ -112,6 +112,7 @@ pub fn get_puzzle_and_solution_for_coin<'py>(
 pub fn chia_rs(py: Python, m: &PyModule) -> PyResult<()> {
     // generator functions
     m.add_function(wrap_pyfunction!(run_generator, m)?)?;
+    m.add_function(wrap_pyfunction!(run_block_generator, m)?)?;
     m.add_class::<PySpendBundleConditions>()?;
     m.add("ELIGIBLE_FOR_DEDUP", chia::gen::conditions::ELIGIBLE_FOR_DEDUP)?;
     m.add_class::<PySpend>()?;