refactor trie package a bit

trie/gen_struct_step.go

@@ -0,0 +1,151 @@
+// Copyright 2019 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty off
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package trie
+
+// Experimental code for separating data and structural information
+// Each function corresponds to an opcode
+// DESCRIBED: docs/programmers_guide/guide.md#separation-of-keys-and-the-structure
+type structInfoReceiver interface {
+	leaf(length int) error
+	leafHash(length int) error
+	accountLeaf(length int, fieldset uint32) error
+	accountLeafHash(length int, fieldset uint32) error
+	extension(key []byte) error
+	extensionHash(key []byte) error
+	branch(set uint16) error
+	branchHash(set uint16) error
+	hash(number int) error
+}
+
+// GenStructStep is one step of the algorithm that generates the structural information based on the sequence of keys.
+// `fieldSet` parameter specifies whether the generated leaf should be a binary string (fieldSet==0), or
+// an account (in that case the opcodes `ACCOUNTLEAF`/`ACCOUNTLEAFHASH` are emitted instead of `LEAF`/`LEAFHASH`).
+// `hashOnly` parameter is the function that, called for a certain prefix, determines whether the trie node for that prefix needs to be
+// compressed into just hash (if `true` is returned), or constructed (if `false` is returned). Usually the `hashOnly` function is
+// implemented in such a way to guarantee that certain keys are always accessible in the resulting trie (see ResolveSet.HashOnly function).
+// `recursive` parameter is set to true if the algorithm's step is invoked recursively, i.e. not after a freshly provided leaf.
+// Recursive invocation is used to emit opcodes for non-leaf nodes.
+// `prec`, `curr`, `succ` are three full keys or prefixes that are currently visible to the algorithm. By comparing these, the algorithm
+// makes decisions about the local structure, i.e. the presense of the prefix groups.
+// `e` parameter is the trie builder, which uses the structure information to assemble trie on the stack and compute its hash.
+// `groups` parameter is the map of the stack. each element of the `groups` slice is a bitmask, one bit per element currently on the stack.
+// Whenever a `BRANCH` or `BRANCHHASH` opcode is emitted, the set of digits is taken from the corresponding `groups` item, which is
+// then removed from the slice. This signifies the usage of the number of the stack items by the `BRANCH` or `BRANCHHASH` opcode.
+// DESCRIBED: docs/programmers_guide/guide.md#separation-of-keys-and-the-structure
+func GenStructStep(
+	fieldSet uint32,
+	hashOnly func(prefix []byte) bool,
+	recursive bool,
+	prec, curr, succ []byte,
+	e structInfoReceiver,
+	groups []uint16,
+) ([]uint16, error) {
+	if !recursive && len(prec) == 0 {
+		prec = nil
+	}
+	// Calculate the prefix of the smallest prefix group containing curr
+	precLen := prefixLen(prec, curr)
+	succLen := prefixLen(succ, curr)
+	var maxLen int
+	if precLen > succLen {
+		maxLen = precLen
+	} else {
+		maxLen = succLen
+	}
+	//fmt.Printf("prec: %x, curr: %x, succ: %x, maxLen %d, prefix: %x\n", prec, curr, succ, maxLen, prefix)
+	// Add the digit immediately following the max common prefix and compute length of remainder length
+	extraDigit := curr[maxLen]
+	for maxLen >= len(groups) {
+		groups = append(groups, 0)
+	}
+	groups[maxLen] |= (uint16(1) << extraDigit)
+	//fmt.Printf("groups[%d] is now %b, len(groups) %d, prefix %x\n", maxLen, groups[maxLen], len(groups), prefix)
+	remainderStart := maxLen
+	if len(succ) > 0 || prec != nil {
+		remainderStart++
+	}
+	remainderLen := len(curr) - remainderStart
+	// Emit LEAF or EXTENSION based on the remainder
+	if recursive {
+		if remainderLen > 0 {
+			if hashOnly(curr[:maxLen]) {
+				if err := e.extensionHash(curr[remainderStart : remainderStart+remainderLen]); err != nil {
+					return nil, err
+				}
+			} else {
+				if err := e.extension(curr[remainderStart : remainderStart+remainderLen]); err != nil {
+					return nil, err
+				}
+			}
+		}
+	} else {
+		if hashOnly(curr[:maxLen]) {
+			if fieldSet == 0 {
+				if err := e.leafHash(remainderLen); err != nil {
+					return nil, err
+				}
+			} else {
+				if err := e.accountLeafHash(remainderLen, fieldSet); err != nil {
+					return nil, err
+				}
+			}
+		} else {
+			if fieldSet == 0 {
+				if err := e.leaf(remainderLen); err != nil {
+					return nil, err
+				}
+			} else {
+				if err := e.accountLeaf(remainderLen, fieldSet); err != nil {
+					return nil, err
+				}
+			}
+		}
+	}
+	// Check for the optional part
+	if precLen <= succLen && len(succ) > 0 {
+		return groups, nil
+	}
+	// Close the immediately encompassing prefix group, if needed
+	if len(succ) > 0 || prec != nil {
+		if hashOnly(curr[:maxLen]) {
+			if err := e.branchHash(groups[maxLen]); err != nil {
+				return nil, err
+			}
+		} else {
+			if err := e.branch(groups[maxLen]); err != nil {
+				return nil, err
+			}
+		}
+	}
+	groups = groups[:maxLen]
+	// Check the end of recursion
+	if precLen == 0 {
+		return groups, nil
+	}
+	// Identify preceding key for the recursive invocation
+	newCurr := curr[:precLen]
+	var newPrec []byte
+	for len(groups) > 0 && groups[len(groups)-1] == 0 {
+		groups = groups[:len(groups)-1]
+	}
+	if len(groups) >= 1 {
+		newPrec = curr[:len(groups)-1]
+	}
+
+	// Recursion
+	return GenStructStep(fieldSet, hashOnly, true, newPrec, newCurr, succ, e, groups)
+}

trie/hack.go

@@ -2,6 +2,7 @@ package trie
 
 import (
 	"fmt"
+
 	"github.com/ledgerwatch/turbo-geth/common"
 	"github.com/ledgerwatch/turbo-geth/rlp"
 )
@@ -78,12 +79,12 @@ func hashRoot(n node, title string) {
 	defer returnHasherToPool(h)
 	defer returnHasherToPool(h1)
 	var hash common.Hash
-	hLen := h.hash(n, true, hash[:])
+	hLen, _ := h.hash(n, true, hash[:])
 	if hLen < 32 {
 		panic("expected hashNode")
 	}
 	fmt.Printf("%s noencode: %x\n", title, hash[:])
-	hLen = h1.hash(n, true, hash[:])
+	hLen, _ = h1.hash(n, true, hash[:])
 	if hLen < 32 {
 		panic("expected hashNode")
 	}