Add persist module

This commit is contained in:
lash 2023-04-12 23:42:36 +01:00
parent 15c64a46e6
commit 064418cb83
Signed by untrusted user who does not match committer: lash
GPG Key ID: 21D2E7BB88C2A746
8 changed files with 260 additions and 80 deletions

2
asm/doc.go Normal file
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@ -0,0 +1,2 @@
// Package asm parses and compiles festive assembly code to bytecode.
package asm

12
cache/cache.go vendored
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@ -10,14 +10,14 @@ type Cache struct {
CacheSize uint32 // Total allowed cumulative size of values (not code) in cache
CacheUseSize uint32 // Currently used bytes by all values (not code) in cache
Cache []map[string]string // All loaded cache items
sizes map[string]uint16 // Size limits for all loaded symbols.
Sizes map[string]uint16 // Size limits for all loaded symbols.
}
// NewCache creates a new ready-to-use cache object
func NewCache() *Cache {
ca := &Cache{
Cache: []map[string]string{make(map[string]string)},
sizes: make(map[string]uint16),
Sizes: make(map[string]uint16),
}
return ca
}
@ -58,13 +58,13 @@ func(ca *Cache) Add(key string, value string, sizeLimit uint16) error {
log.Printf("add key %s value size %v limit %v", key, sz, sizeLimit)
ca.Cache[len(ca.Cache)-1][key] = value
ca.CacheUseSize += sz
ca.sizes[key] = sizeLimit
ca.Sizes[key] = sizeLimit
return nil
}
// ReservedSize returns the maximum byte size available for the given symbol.
func(ca *Cache) ReservedSize(key string) (uint16, error) {
v, ok := ca.sizes[key]
v, ok := ca.Sizes[key]
if !ok {
return 0, fmt.Errorf("unknown symbol: %s", key)
}
@ -80,8 +80,8 @@ func(ca *Cache) ReservedSize(key string) (uint16, error) {
// - value is longer than size limit
// - replacing value exceeds cumulative cache capacity
func(ca *Cache) Update(key string, value string) error {
sizeLimit := ca.sizes[key]
if ca.sizes[key] > 0 {
sizeLimit := ca.Sizes[key]
if ca.Sizes[key] > 0 {
l := uint16(len(value))
if l > sizeLimit {
return fmt.Errorf("update value length %v exceeds value size limit %v", l, sizeLimit)

3
go.mod
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@ -4,5 +4,8 @@ go 1.20
require (
github.com/alecthomas/participle/v2 v2.0.0
github.com/fxamacker/cbor/v2 v2.4.0
github.com/peteole/testdata-loader v0.3.0
)
require github.com/x448/float16 v0.8.4 // indirect

61
persist/fs.go Normal file
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@ -0,0 +1,61 @@
package persist
import (
"io/ioutil"
"path"
"path/filepath"
"github.com/fxamacker/cbor/v2"
"git.defalsify.org/festive/cache"
"git.defalsify.org/festive/state"
)
type FsPersister struct {
State *state.State
Memory *cache.Cache
dir string
}
func NewFsPersister(dir string) *FsPersister {
fp, err := filepath.Abs(dir)
if err != nil {
panic(err)
}
return &FsPersister{
dir: fp,
}
}
func(p *FsPersister) WithContent(st *state.State, ca *cache.Cache) *FsPersister {
p.State = st
p.Memory = ca
return p
}
func(p *FsPersister) Serialize() ([]byte, error) {
return cbor.Marshal(p)
}
func(p *FsPersister) Deserialize(b []byte) error {
err := cbor.Unmarshal(b, p)
return err
}
func(p *FsPersister) Save(key string) error {
b, err := p.Serialize()
if err != nil {
return err
}
fp := path.Join(p.dir, key)
return ioutil.WriteFile(fp, b, 0600)
}
func(p *FsPersister) Load(key string) error {
fp := path.Join(p.dir, key)
b, err := ioutil.ReadFile(fp)
if err != nil {
return err
}
err = p.Deserialize(b)
return err
}

106
persist/fs_test.go Normal file
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@ -0,0 +1,106 @@
package persist
import (
"bytes"
"io/ioutil"
"log"
"reflect"
"testing"
"git.defalsify.org/festive/cache"
"git.defalsify.org/festive/state"
"git.defalsify.org/festive/vm"
)
func TestSerializeState(t *testing.T) {
st := state.NewState(12)
st.Down("foo")
st.Down("bar")
st.Down("baz")
st.Next()
st.Next()
b := vm.NewLine(nil, vm.LOAD, []string{"foo"}, []byte{42}, nil)
b = vm.NewLine(b, vm.HALT, nil, nil, nil)
st.SetCode(b)
ca := cache.NewCache().WithCacheSize(1024)
ca.Add("inky", "pinky", 13)
ca.Add("blinky", "clyde", 42)
pr := NewFsPersister(".").WithContent(&st, ca)
v, err := pr.Serialize()
if err != nil {
t.Error(err)
}
log.Printf("v %b", v)
prnew := NewFsPersister(".")
err = prnew.Deserialize(v)
if err != nil {
t.Fatal(err)
}
if !reflect.DeepEqual(prnew.State.ExecPath, pr.State.ExecPath) {
t.Fatalf("expected %s, got %s", prnew.State.ExecPath, pr.State.ExecPath)
}
if !bytes.Equal(prnew.State.Code, pr.State.Code) {
t.Fatalf("expected %x, got %x", prnew.State.Code, pr.State.Code)
}
if prnew.State.BitSize != pr.State.BitSize {
t.Fatalf("expected %v, got %v", prnew.State.BitSize, pr.State.BitSize)
}
if prnew.State.SizeIdx != pr.State.SizeIdx {
t.Fatalf("expected %v, got %v", prnew.State.SizeIdx, pr.State.SizeIdx)
}
if !reflect.DeepEqual(prnew.Memory, pr.Memory) {
t.Fatalf("expected %v, got %v", prnew.Memory, pr.Memory)
}
}
func TestSaveLoad(t *testing.T) {
st := state.NewState(12)
st.Down("foo")
st.Down("bar")
st.Down("baz")
st.Next()
st.Next()
b := vm.NewLine(nil, vm.LOAD, []string{"foo"}, []byte{42}, nil)
b = vm.NewLine(b, vm.HALT, nil, nil, nil)
st.SetCode(b)
ca := cache.NewCache().WithCacheSize(1024)
ca.Add("inky", "pinky", 13)
ca.Add("blinky", "clyde", 42)
dir, err := ioutil.TempDir("", "festive_persist")
if err != nil {
t.Error(err)
}
pr := NewFsPersister(dir).WithContent(&st, ca)
err = pr.Save("xyzzy")
if err != nil {
t.Error(err)
}
prnew := NewFsPersister(dir)
err = prnew.Load("xyzzy")
if err != nil {
t.Error(err)
}
if !reflect.DeepEqual(prnew.State.ExecPath, pr.State.ExecPath) {
t.Fatalf("expected %s, got %s", prnew.State.ExecPath, pr.State.ExecPath)
}
if !bytes.Equal(prnew.State.Code, pr.State.Code) {
t.Fatalf("expected %x, got %x", prnew.State.Code, pr.State.Code)
}
if prnew.State.BitSize != pr.State.BitSize {
t.Fatalf("expected %v, got %v", prnew.State.BitSize, pr.State.BitSize)
}
if prnew.State.SizeIdx != pr.State.SizeIdx {
t.Fatalf("expected %v, got %v", prnew.State.SizeIdx, pr.State.SizeIdx)
}
if !reflect.DeepEqual(prnew.Memory, pr.Memory) {
t.Fatalf("expected %v, got %v", prnew.Memory, pr.Memory)
}
}

9
persist/persist.go Normal file
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@ -0,0 +1,9 @@
package persist
type Persister interface {
Serialize() ([]byte, error)
Deserialize(b []byte) error
Save(key string) error
Load(key string) error
}

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@ -29,25 +29,24 @@ func(err *IndexError) Error() string {
//
// 8 first flags are reserved.
type State struct {
Flags []byte // Error state
Code []byte // Pending bytecode to execute
ExecPath []string // Command symbols stack
BitSize uint32 // size of (32-bit capacity) bit flag byte array
SizeIdx uint16
flags []byte // Error state
input []byte // Last input
code []byte // Pending bytecode to execute
execPath []string // Command symbols stack
arg *string // Optional argument. Nil if not set.
bitSize uint32 // size of (32-bit capacity) bit flag byte array
sizeIdx uint16
}
// number of bytes necessary to represent a bitfield of the given size.
func toByteSize(bitSize uint32) uint8 {
if bitSize == 0 {
func toByteSize(BitSize uint32) uint8 {
if BitSize == 0 {
return 0
}
n := bitSize % 8
n := BitSize % 8
if n > 0 {
bitSize += (8 - n)
BitSize += (8 - n)
}
return uint8(bitSize / 8)
return uint8(BitSize / 8)
}
// Retrieve the state of a state flag
@ -58,16 +57,16 @@ func getFlag(bitIndex uint32, bitField []byte) bool {
return (b & (1 << localBitIndex)) > 0
}
// NewState creates a new State object with bitSize number of error condition states in ADDITION to the 8 builtin flags.
func NewState(bitSize uint32) State {
// NewState creates a new State object with BitSize number of error condition states in ADDITION to the 8 builtin flags.
func NewState(BitSize uint32) State {
st := State{
bitSize: bitSize + 8,
BitSize: BitSize + 8,
}
byteSize := toByteSize(bitSize + 8)
byteSize := toByteSize(BitSize + 8)
if byteSize > 0 {
st.Flags = make([]byte, byteSize)
st.flags = make([]byte, byteSize)
} else {
st.Flags = []byte{}
st.flags = []byte{}
}
return st
}
@ -78,17 +77,17 @@ func NewState(bitSize uint32) State {
//
// Fails if bitindex is out of range.
func(st *State) SetFlag(bitIndex uint32) (bool, error) {
if bitIndex + 1 > st.bitSize {
return false, fmt.Errorf("bit index %v is out of range of bitfield size %v", bitIndex, st.bitSize)
if bitIndex + 1 > st.BitSize {
return false, fmt.Errorf("bit index %v is out of range of bitfield size %v", bitIndex, st.BitSize)
}
r := getFlag(bitIndex, st.Flags)
r := getFlag(bitIndex, st.flags)
if r {
return false, nil
}
byteIndex := bitIndex / 8
localBitIndex := bitIndex % 8
b := st.Flags[byteIndex]
st.Flags[byteIndex] = b | (1 << localBitIndex)
b := st.flags[byteIndex]
st.flags[byteIndex] = b | (1 << localBitIndex)
return true, nil
}
@ -99,17 +98,17 @@ func(st *State) SetFlag(bitIndex uint32) (bool, error) {
//
// Fails if bitindex is out of range.
func(st *State) ResetFlag(bitIndex uint32) (bool, error) {
if bitIndex + 1 > st.bitSize {
return false, fmt.Errorf("bit index %v is out of range of bitfield size %v", bitIndex, st.bitSize)
if bitIndex + 1 > st.BitSize {
return false, fmt.Errorf("bit index %v is out of range of bitfield size %v", bitIndex, st.BitSize)
}
r := getFlag(bitIndex, st.Flags)
r := getFlag(bitIndex, st.flags)
if !r {
return false, nil
}
byteIndex := bitIndex / 8
localBitIndex := bitIndex % 8
b := st.Flags[byteIndex]
st.Flags[byteIndex] = b & (^(1 << localBitIndex))
b := st.flags[byteIndex]
st.flags[byteIndex] = b & (^(1 << localBitIndex))
return true, nil
}
@ -117,20 +116,20 @@ func(st *State) ResetFlag(bitIndex uint32) (bool, error) {
//
// Fails if bit field index is out of range.
func(st *State) GetFlag(bitIndex uint32) (bool, error) {
if bitIndex + 1 > st.bitSize {
return false, fmt.Errorf("bit index %v is out of range of bitfield size %v", bitIndex, st.bitSize)
if bitIndex + 1 > st.BitSize {
return false, fmt.Errorf("bit index %v is out of range of bitfield size %v", bitIndex, st.BitSize)
}
return getFlag(bitIndex, st.Flags), nil
return getFlag(bitIndex, st.flags), nil
}
// FlagBitSize reports the amount of bits available in the bit field index.
func(st *State) FlagBitSize() uint32 {
return st.bitSize
return st.BitSize
}
// FlagBitSize reports the amount of bits available in the bit field index.
func(st *State) FlagByteSize() uint8 {
return uint8(len(st.Flags))
return uint8(len(st.flags))
}
// MatchFlag matches the current state of the given flag.
@ -158,7 +157,7 @@ func(st *State) MatchFlag(sig uint32, invertMatch bool) (bool, error) {
// If the given byte slice is too small for the bit field bitsize, the check will terminate at end-of-data without error.
func(st *State) GetIndex(flags []byte) bool {
var globalIndex uint32
if st.bitSize == 0 {
if st.BitSize == 0 {
return false
}
if len(flags) == 0 {
@ -168,9 +167,9 @@ func(st *State) GetIndex(flags []byte) bool {
var localIndex uint8
l := uint8(len(flags))
var i uint32
for i = 0; i < st.bitSize; i++ {
for i = 0; i < st.BitSize; i++ {
testVal := flags[byteIndex] & (1 << localIndex)
if (testVal & st.Flags[byteIndex]) > 0 {
if (testVal & st.flags[byteIndex]) > 0 {
return true
}
globalIndex += 1
@ -189,50 +188,50 @@ func(st *State) GetIndex(flags []byte) bool {
// Where returns the current active rendering symbol.
func(st *State) Where() (string, uint16) {
if len(st.execPath) == 0 {
if len(st.ExecPath) == 0 {
return "", 0
}
l := len(st.execPath)
return st.execPath[l-1], st.sizeIdx
l := len(st.ExecPath)
return st.ExecPath[l-1], st.SizeIdx
}
// Next moves to the next sink page index.
func(st *State) Next() (uint16, error) {
if len(st.execPath) == 0 {
if len(st.ExecPath) == 0 {
return 0, fmt.Errorf("state root node not yet defined")
}
st.sizeIdx += 1
st.SizeIdx += 1
s, idx := st.Where()
log.Printf("next page for %s: %v", s, idx)
return st.sizeIdx, nil
return st.SizeIdx, nil
}
// Previous moves to the next sink page index.
//
// Fails if try to move beyond index 0.
func(st *State) Previous() (uint16, error) {
if len(st.execPath) == 0 {
if len(st.ExecPath) == 0 {
return 0, fmt.Errorf("state root node not yet defined")
}
if st.sizeIdx == 0 {
if st.SizeIdx == 0 {
return 0, &IndexError{} // ("already at first index")
}
st.sizeIdx -= 1
st.SizeIdx -= 1
s, idx := st.Where()
log.Printf("previous page for %s: %v", s, idx)
return st.sizeIdx, nil
return st.SizeIdx, nil
}
// Sides informs the caller which index page options will currently succeed.
//
// Two values are returned, for the "next" and "previous" options in that order. A false value means the option is not available in the current state.
func(st *State) Sides() (bool, bool) {
if len(st.execPath) == 0 {
if len(st.ExecPath) == 0 {
return false, false
}
next := true
log.Printf("sides %v", st.sizeIdx)
if st.sizeIdx == 0 {
log.Printf("sides %v", st.SizeIdx)
if st.SizeIdx == 0 {
return next, false
}
return next, true
@ -242,18 +241,18 @@ func(st *State) Sides() (bool, bool) {
//
// Fails if first Down() was never called.
func(st *State) Top() (bool, error) {
if len(st.execPath) == 0 {
if len(st.ExecPath) == 0 {
return false, fmt.Errorf("state root node not yet defined")
}
return len(st.execPath) == 1, nil
return len(st.ExecPath) == 1, nil
}
// Down adds the given symbol to the command stack.
//
// Clears mapping and sink.
func(st *State) Down(input string) error {
st.execPath = append(st.execPath, input)
st.sizeIdx = 0
st.ExecPath = append(st.ExecPath, input)
st.SizeIdx = 0
return nil
}
@ -265,29 +264,29 @@ func(st *State) Down(input string) error {
//
// Fails if called at top frame.
func(st *State) Up() (string, error) {
l := len(st.execPath)
l := len(st.ExecPath)
if l == 0 {
return "", fmt.Errorf("exit called beyond top frame")
}
log.Printf("execpath before %v", st.execPath)
st.execPath = st.execPath[:l-1]
log.Printf("execpath before %v", st.ExecPath)
st.ExecPath = st.ExecPath[:l-1]
sym := ""
if len(st.execPath) > 0 {
sym = st.execPath[len(st.execPath)-1]
if len(st.ExecPath) > 0 {
sym = st.ExecPath[len(st.ExecPath)-1]
}
st.sizeIdx = 0
log.Printf("execpath after %v", st.execPath)
st.SizeIdx = 0
log.Printf("execpath after %v", st.ExecPath)
return sym, nil
}
// Depth returns the current call stack depth.
func(st *State) Depth() uint8 {
return uint8(len(st.execPath)-1)
return uint8(len(st.ExecPath)-1)
}
// Appendcode adds the given bytecode to the end of the existing code.
func(st *State) AppendCode(b []byte) error {
st.code = append(st.code, b...)
st.Code = append(st.Code, b...)
log.Printf("code changed to 0x%x", b)
return nil
}
@ -295,13 +294,13 @@ func(st *State) AppendCode(b []byte) error {
// SetCode replaces the current bytecode with the given bytecode.
func(st *State) SetCode(b []byte) {
log.Printf("code set to 0x%x", b)
st.code = b
st.Code = b
}
// Get the remaning cached bytecode
func(st *State) GetCode() ([]byte, error) {
b := st.code
st.code = []byte{}
b := st.Code
st.Code = []byte{}
return b, nil
}
@ -328,5 +327,5 @@ func(st *State) Reset() error {
}
func(st State) String() string {
return fmt.Sprintf("path: %s", strings.Join(st.execPath, "/"))
return fmt.Sprintf("idx %v path: %s", st.SizeIdx, strings.Join(st.ExecPath, "/"))
}

View File

@ -8,20 +8,20 @@ import (
// Check creation
func TestNewState(t *testing.T) {
st := NewState(5)
if len(st.Flags) != 2 {
t.Fatalf("invalid state flag length: %v", len(st.Flags))
if len(st.flags) != 2 {
t.Fatalf("invalid state flag length: %v", len(st.flags))
}
st = NewState(8)
if len(st.Flags) != 2 {
t.Fatalf("invalid state flag length: %v", len(st.Flags))
if len(st.flags) != 2 {
t.Fatalf("invalid state flag length: %v", len(st.flags))
}
st = NewState(17)
if len(st.Flags) != 4 {
t.Fatalf("invalid state flag length: %v", len(st.Flags))
if len(st.flags) != 4 {
t.Fatalf("invalid state flag length: %v", len(st.flags))
}
}
func TestStateFlags(t *testing.T) {
func TestStateflags(t *testing.T) {
st := NewState(9)
v, err := st.GetFlag(2)
if err != nil {
@ -98,8 +98,8 @@ func TestStateFlags(t *testing.T) {
if err == nil {
t.Fatalf("Expected out of range for bit index 17")
}
if !bytes.Equal(st.Flags[:3], []byte{0x04, 0x04, 0x01}) {
t.Fatalf("Expected 0x040401, got %v", st.Flags[:3])
if !bytes.Equal(st.flags[:3], []byte{0x04, 0x04, 0x01}) {
t.Fatalf("Expected 0x040401, got %v", st.flags[:3])
}
}