Copy certifiers from light-client

certifiers/memprovider.go

@@ -0,0 +1,78 @@
+package certifiers
+
+import (
+	"encoding/hex"
+	"sort"
+
+	certerr "github.com/tendermint/tendermint/certifiers/errors"
+)
+
+type memStoreProvider struct {
+	// byHeight is always sorted by Height... need to support range search (nil, h]
+	// btree would be more efficient for larger sets
+	byHeight fullCommits
+	byHash   map[string]FullCommit
+}
+
+// fullCommits just exists to allow easy sorting
+type fullCommits []FullCommit
+
+func (s fullCommits) Len() int      { return len(s) }
+func (s fullCommits) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
+func (s fullCommits) Less(i, j int) bool {
+	return s[i].Height() < s[j].Height()
+}
+
+func NewMemStoreProvider() Provider {
+	return &memStoreProvider{
+		byHeight: fullCommits{},
+		byHash:   map[string]FullCommit{},
+	}
+}
+
+func (m *memStoreProvider) encodeHash(hash []byte) string {
+	return hex.EncodeToString(hash)
+}
+
+func (m *memStoreProvider) StoreCommit(fc FullCommit) error {
+	// make sure the fc is self-consistent before saving
+	err := fc.ValidateBasic(fc.Commit.Header.ChainID)
+	if err != nil {
+		return err
+	}
+
+	// store the valid fc
+	key := m.encodeHash(fc.ValidatorsHash())
+	m.byHash[key] = fc
+	m.byHeight = append(m.byHeight, fc)
+	sort.Sort(m.byHeight)
+	return nil
+}
+
+func (m *memStoreProvider) GetByHeight(h int) (FullCommit, error) {
+	// search from highest to lowest
+	for i := len(m.byHeight) - 1; i >= 0; i-- {
+		fc := m.byHeight[i]
+		if fc.Height() <= h {
+			return fc, nil
+		}
+	}
+	return FullCommit{}, certerr.ErrCommitNotFound()
+}
+
+func (m *memStoreProvider) GetByHash(hash []byte) (FullCommit, error) {
+	var err error
+	fc, ok := m.byHash[m.encodeHash(hash)]
+	if !ok {
+		err = certerr.ErrCommitNotFound()
+	}
+	return fc, err
+}
+
+func (m *memStoreProvider) LatestCommit() (FullCommit, error) {
+	l := len(m.byHeight)
+	if l == 0 {
+		return FullCommit{}, certerr.ErrCommitNotFound()
+	}
+	return m.byHeight[l-1], nil
+}