Consolidate Stylus Params

arbos/programs/memory.go

@@ -21,16 +21,6 @@ func NewMemoryModel(freePages uint16, pageGas uint16) *MemoryModel {
 	}
 }
 
-func (p Programs) memoryModel() (*MemoryModel, error) {
-	freePages, err := p.FreePages()
-	if err != nil {
-		return nil, err
-	}
-	pageGas, err := p.PageGas()
-
-	return NewMemoryModel(freePages, pageGas), err
-}
-
 // Determines the gas cost of allocating `new` pages given `open` are active and `ever` have ever been.
 func (model *MemoryModel) GasCost(new, open, ever uint16) uint64 {
 	newOpen := arbmath.SaturatingUAdd(open, new)

arbos/programs/params.go

@@ -0,0 +1,126 @@
+// Copyright 2022-2024, Offchain Labs, Inc.
+// For license information, see https://github.com/OffchainLabs/nitro/blob/master/LICENSE
+
+package programs
+
+import (
+	"errors"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/params"
+	"github.com/offchainlabs/nitro/arbos/storage"
+	am "github.com/offchainlabs/nitro/util/arbmath"
+)
+
+const MaxWasmSize = 128 * 1024      // max decompressed wasm size (programs are also bounded by compressed size)
+const initialStackDepth = 4 * 65536 // 4 page stack.
+const InitialFreePages = 2          // 2 pages come free (per tx).
+const InitialPageGas = 1000         // linear cost per allocation.
+const initialPageRamp = 620674314   // targets 8MB costing 32 million gas, minus the linear term.
+const initialPageLimit = 128        // reject wasms with memories larger than 8MB.
+const initialInkPrice = 10000       // 1 evm gas buys 10k ink.
+const initialMinInitGas = 0         // assume pricer is correct (update in case of emergency)
+const initialExpiryDays = 365       // deactivate after 1 year.
+const initialKeepaliveDays = 31     // wait a month before allowing reactivation
+const initialInitTableBits = 7      // cache the last 128 programs
+const initialTrieTableBits = 11     // cache the hottest 1024 slots
+
+// This struct exists to collect the many Stylus configuration parameters into a single word.
+// The items here must only be modified in ArbOwner precompile methods (or in ArbOS upgrades).
+type StylusParams struct {
+	backingStorage *storage.Storage
+	Version        uint16 // must only be changed during ArbOS upgrades
+	InkPrice       uint24
+	MaxStackDepth  uint32
+	FreePages      uint16
+	PageGas        uint16
+	PageRamp       uint64
+	PageLimit      uint16
+	MinInitGas     uint16
+	ExpiryDays     uint16
+	KeepaliveDays  uint16
+	InitTableBits  uint8
+	TrieTableBits  uint8
+}
+
+// Provides a view of the Stylus parameters. Call Save() to persist.
+// Note: this method never returns nil.
+func (p Programs) Params() (*StylusParams, error) {
+	sto := p.backingStorage.OpenSubStorage(paramsKey)
+
+	// assume read is warm due to the frequency of access
+	if err := sto.Burner().Burn(params.WarmStorageReadCostEIP2929); err != nil {
+		return &StylusParams{}, err
+	}
+
+	// paid for the read above
+	word := sto.GetFree(common.Hash{})
+	data := word[:]
+	take := func(count int) []byte {
+		value := data[:count]
+		data = data[count:]
+		return value
+	}
+
+	return &StylusParams{
+		backingStorage: sto,
+		Version:        am.BytesToUint16(take(2)),
+		InkPrice:       am.BytesToUint24(take(3)),
+		MaxStackDepth:  am.BytesToUint32(take(4)),
+		FreePages:      am.BytesToUint16(take(2)),
+		PageGas:        am.BytesToUint16(take(2)),
+		PageRamp:       am.BytesToUint(take(8)),
+		PageLimit:      am.BytesToUint16(take(2)),
+		MinInitGas:     am.BytesToUint16(take(2)),
+		ExpiryDays:     am.BytesToUint16(take(2)),
+		KeepaliveDays:  am.BytesToUint16(take(2)),
+		InitTableBits:  am.BytesToUint8(take(1)),
+		TrieTableBits:  am.BytesToUint8(take(1)),
+	}, nil
+}
+
+// Writes the params to permanent storage.
+func (p *StylusParams) Save() error {
+	if p.backingStorage == nil {
+		log.Error("tried to Save invalid StylusParams")
+		return errors.New("invalid StylusParams")
+	}
+
+	data := am.ConcatByteSlices(
+		am.Uint16ToBytes(p.Version),
+		am.Uint24ToBytes(p.InkPrice),
+		am.Uint32ToBytes(p.MaxStackDepth),
+		am.Uint16ToBytes(p.FreePages),
+		am.Uint16ToBytes(p.PageGas),
+		am.UintToBytes(p.PageRamp),
+		am.Uint16ToBytes(p.PageLimit),
+		am.Uint16ToBytes(p.MinInitGas),
+		am.Uint16ToBytes(p.ExpiryDays),
+		am.Uint16ToBytes(p.KeepaliveDays),
+		am.Uint8ToBytes(p.InitTableBits),
+		am.Uint8ToBytes(p.TrieTableBits),
+	)
+	word := common.Hash{}
+	copy(word[:], data) // right-pad with zeros
+	return p.backingStorage.SetByUint64(0, word)
+}
+
+func initStylusParams(sto *storage.Storage) {
+	params := &StylusParams{
+		backingStorage: sto,
+		Version:        1,
+		InkPrice:       initialInkPrice,
+		MaxStackDepth:  initialStackDepth,
+		FreePages:      InitialFreePages,
+		PageGas:        InitialPageGas,
+		PageRamp:       initialPageRamp,
+		PageLimit:      initialPageLimit,
+		MinInitGas:     initialMinInitGas,
+		ExpiryDays:     initialExpiryDays,
+		KeepaliveDays:  initialKeepaliveDays,
+		InitTableBits:  initialInitTableBits,
+		TrieTableBits:  initialTrieTableBits,
+	}
+	_ = params.Save()
+}