/
memory.go
319 lines (286 loc) · 8.43 KB
/
memory.go
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package storage
import (
"crypto/sha256"
"encoding/hex"
"fmt"
"sort"
"strconv"
"strings"
"sync"
"time"
"github.com/theupdateframework/notary/tuf/data"
)
type key struct {
algorithm string
public []byte
}
type ver struct {
version int
data []byte
createupdate time.Time
}
// we want to keep these sorted by version so that it's in increasing version
// order
type verList []ver
func (k verList) Len() int { return len(k) }
func (k verList) Swap(i, j int) { k[i], k[j] = k[j], k[i] }
func (k verList) Less(i, j int) bool {
return k[i].version < k[j].version
}
// MemStorage is really just designed for dev and testing. It is very
// inefficient in many scenarios
type MemStorage struct {
lock sync.Mutex
tufMeta map[string]verList
keys map[string]map[string]*key
checksums map[string]map[string]ver
changes []Change
}
// NewMemStorage instantiates a memStorage instance
func NewMemStorage() *MemStorage {
return &MemStorage{
tufMeta: make(map[string]verList),
keys: make(map[string]map[string]*key),
checksums: make(map[string]map[string]ver),
}
}
// UpdateCurrent updates the meta data for a specific role
func (st *MemStorage) UpdateCurrent(gun data.GUN, update MetaUpdate) error {
id := entryKey(gun, update.Role)
st.lock.Lock()
defer st.lock.Unlock()
if space, ok := st.tufMeta[id]; ok {
for _, v := range space {
if v.version >= update.Version {
return ErrOldVersion{}
}
}
}
version := ver{version: update.Version, data: update.Data, createupdate: time.Now()}
st.tufMeta[id] = append(st.tufMeta[id], version)
checksumBytes := sha256.Sum256(update.Data)
checksum := hex.EncodeToString(checksumBytes[:])
_, ok := st.checksums[gun.String()]
if !ok {
st.checksums[gun.String()] = make(map[string]ver)
}
st.checksums[gun.String()][checksum] = version
if update.Role == data.CanonicalTimestampRole {
st.writeChange(gun, update.Version, checksum)
}
return nil
}
// writeChange must only be called by a function already holding a lock on
// the MemStorage. Behaviour is undefined otherwise
func (st *MemStorage) writeChange(gun data.GUN, version int, checksum string) {
c := Change{
ID: strconv.Itoa(len(st.changes) + 1),
GUN: gun.String(),
Version: version,
SHA256: checksum,
CreatedAt: time.Now(),
Category: changeCategoryUpdate,
}
st.changes = append(st.changes, c)
}
// UpdateMany updates multiple TUF records
func (st *MemStorage) UpdateMany(gun data.GUN, updates []MetaUpdate) error {
st.lock.Lock()
defer st.lock.Unlock()
versioner := make(map[string]map[int]struct{})
constant := struct{}{}
// ensure that we only update in one transaction
for _, u := range updates {
id := entryKey(gun, u.Role)
// prevent duplicate versions of the same role
if _, ok := versioner[u.Role.String()][u.Version]; ok {
return ErrOldVersion{}
}
if _, ok := versioner[u.Role.String()]; !ok {
versioner[u.Role.String()] = make(map[int]struct{})
}
versioner[u.Role.String()][u.Version] = constant
if space, ok := st.tufMeta[id]; ok {
for _, v := range space {
if v.version >= u.Version {
return ErrOldVersion{}
}
}
}
}
for _, u := range updates {
id := entryKey(gun, u.Role)
version := ver{version: u.Version, data: u.Data, createupdate: time.Now()}
st.tufMeta[id] = append(st.tufMeta[id], version)
sort.Sort(st.tufMeta[id]) // ensure that it's sorted
checksumBytes := sha256.Sum256(u.Data)
checksum := hex.EncodeToString(checksumBytes[:])
_, ok := st.checksums[gun.String()]
if !ok {
st.checksums[gun.String()] = make(map[string]ver)
}
st.checksums[gun.String()][checksum] = version
if u.Role == data.CanonicalTimestampRole {
st.writeChange(gun, u.Version, checksum)
}
}
return nil
}
// GetCurrent returns the createupdate date metadata for a given role, under a GUN.
func (st *MemStorage) GetCurrent(gun data.GUN, role data.RoleName) (*time.Time, []byte, error) {
id := entryKey(gun, role)
st.lock.Lock()
defer st.lock.Unlock()
space, ok := st.tufMeta[id]
if !ok || len(space) == 0 {
return nil, nil, ErrNotFound{}
}
return &(space[len(space)-1].createupdate), space[len(space)-1].data, nil
}
// GetChecksum returns the createupdate date and metadata for a given role, under a GUN.
func (st *MemStorage) GetChecksum(gun data.GUN, role data.RoleName, checksum string) (*time.Time, []byte, error) {
st.lock.Lock()
defer st.lock.Unlock()
space, ok := st.checksums[gun.String()][checksum]
if !ok || len(space.data) == 0 {
return nil, nil, ErrNotFound{}
}
return &(space.createupdate), space.data, nil
}
// GetVersion gets a specific TUF record by its version
func (st *MemStorage) GetVersion(gun data.GUN, role data.RoleName, version int) (*time.Time, []byte, error) {
st.lock.Lock()
defer st.lock.Unlock()
id := entryKey(gun, role)
for _, ver := range st.tufMeta[id] {
if ver.version == version {
return &(ver.createupdate), ver.data, nil
}
}
return nil, nil, ErrNotFound{}
}
// Delete deletes all the metadata for a given GUN
func (st *MemStorage) Delete(gun data.GUN) error {
st.lock.Lock()
defer st.lock.Unlock()
l := len(st.tufMeta)
for k := range st.tufMeta {
if strings.HasPrefix(k, gun.String()) {
delete(st.tufMeta, k)
}
}
if l == len(st.tufMeta) {
// we didn't delete anything, don't write change.
return nil
}
delete(st.checksums, gun.String())
c := Change{
ID: strconv.Itoa(len(st.changes) + 1),
GUN: gun.String(),
Category: changeCategoryDeletion,
CreatedAt: time.Now(),
}
st.changes = append(st.changes, c)
return nil
}
// GetChanges returns a []Change starting from but excluding the record
// identified by changeID. In the context of the memory store, changeID
// is simply an index into st.changes. The ID of a change is its
// index+1, both to match the SQL implementations, and so that the first
// change can be retrieved by providing ID 0.
func (st *MemStorage) GetChanges(changeID string, records int, filterName string) ([]Change, error) {
var (
id int64
err error
)
if changeID == "" {
id = 0
} else {
id, err = strconv.ParseInt(changeID, 10, 32)
if err != nil {
return nil, ErrBadQuery{msg: fmt.Sprintf("change ID expected to be integer, provided ID was: %s", changeID)}
}
}
var (
start = int(id)
toInspect []Change
)
if err != nil {
return nil, err
}
reversed := id < 0
if records < 0 {
reversed = true
records = -records
}
if len(st.changes) <= int(id) && !reversed {
// no records to return as we're essentially trying to retrieve
// changes that haven't happened yet.
return nil, nil
}
// technically only -1 is a valid negative input, but we're going to be
// broad in what we accept here to reduce the need to error and instead
// act in a "do what I mean not what I say" fashion. Same logic for
// requesting changeID < 0 but not asking for reversed, we're just going
// to force it to be reversed.
if start < 0 {
// need to add one so we don't later slice off the last element
// when calculating toInspect.
start = len(st.changes) + 1
}
// reduce to only look at changes we're interested in
if reversed {
if start > len(st.changes) {
toInspect = st.changes
} else {
toInspect = st.changes[:start-1]
}
} else {
toInspect = st.changes[start:]
}
// if we're not doing any filtering
if filterName == "" {
// if the pageSize is larger than the total records
// that could be returned, return them all
if records >= len(toInspect) {
return toInspect, nil
}
// if we're going backwards, return the last pageSize records
if reversed {
return toInspect[len(toInspect)-records:], nil
}
// otherwise return pageSize records from front
return toInspect[:records], nil
}
return getFilteredChanges(toInspect, filterName, records, reversed), nil
}
func getFilteredChanges(toInspect []Change, filterName string, records int, reversed bool) []Change {
res := make([]Change, 0, records)
if reversed {
for i := len(toInspect) - 1; i >= 0; i-- {
if toInspect[i].GUN == filterName {
res = append(res, toInspect[i])
}
if len(res) == records {
break
}
}
// results are currently newest to oldest, should be oldest to newest
for i, j := 0, len(res)-1; i < j; i, j = i+1, j-1 {
res[i], res[j] = res[j], res[i]
}
} else {
for _, c := range toInspect {
if c.GUN == filterName {
res = append(res, c)
}
if len(res) == records {
break
}
}
}
return res
}
func entryKey(gun data.GUN, role data.RoleName) string {
return fmt.Sprintf("%s.%s", gun, role)
}