Add stylus programSize and programMemoryFootprint precompiles

arbos/programs/programs.go

@@ -333,6 +333,17 @@ func (p Programs) CodehashVersion(codeHash common.Hash) (uint16, error) {
 	return program.version, err
 }
 
+func (p Programs) CodehashSize(codeHash common.Hash) (uint32, error) {
+	program, err := p.deserializeProgram(codeHash)
+	// wasmSize represents the number of half kb units, return as bytes
+	return uint32(program.wasmSize) * 512, err
+}
+
+func (p Programs) CodehashMemoryFootprint(codeHash common.Hash) (uint16, error) {
+	program, err := p.deserializeProgram(codeHash)
+	return program.footprint, err
+}
+
 type goParams struct {
 	version   uint16
 	maxDepth  uint32

precompiles/ArbWasm.go

@@ -71,6 +71,24 @@ func (con ArbWasm) ProgramVersion(c ctx, evm mech, program addr) (uint16, error)
 	return con.CodehashVersion(c, evm, codehash)
 }
 
+// ProgramSize returns the uncompressed size of program at addr
+func (con ArbWasm) ProgramSize(c ctx, _ mech, program addr) (uint32, error) {
+	codehash, err := c.GetCodeHash(program)
+	if err != nil {
+		return 0, err
+	}
+	return c.State.Programs().CodehashSize(codehash)
+}
+
+// ProgramMemoryFootprint returns the footprint of program at addr
+func (con ArbWasm) ProgramMemoryFootprint(c ctx, _ mech, program addr) (uint16, error) {
+	codehash, err := c.GetCodeHash(program)
+	if err != nil {
+		return 0, err
+	}
+	return c.State.Programs().CodehashMemoryFootprint(codehash)
+}
+
 // Gets the added wasm call cost paid per half kb uncompressed wasm
 func (con ArbWasm) CallScalar(c ctx, _ mech) (uint16, error) {
 	return c.State.Programs().CallScalar()

system_tests/program_test.go

@@ -84,6 +84,16 @@ func keccakTest(t *testing.T, jit bool) {
 	if otherVersion != programVersion {
 		Fatal(t, "mismatched versions", stylusVersion, programVersion)
 	}
+	programSize, err := arbWasm.ProgramSize(nil, programAddress)
+	Require(t, err)
+	if programSize < 5000 || programSize > 20000 {
+		Fatal(t, "unexpected size", programSize)
+	}
+	programMemoryFootprint, err := arbWasm.ProgramMemoryFootprint(nil, programAddress)
+	Require(t, err)
+	if programMemoryFootprint != 1 {
+		Fatal(t, "unexpected memory footprint", programMemoryFootprint)
+	}
 
 	preimage := []byte("°º¤ø,¸,ø¤°º¤ø,¸,ø¤°º¤ø,¸ nyan nyan ~=[,,_,,]:3 nyan nyan")
 	correct := crypto.Keccak256Hash(preimage)