renaming files and moving around

1 files changed, 42 insertions, 0 deletions

diff --git a/utils_state.go b/utils_state.go
new file mode 100644
index 0000000..2273c24
--- /dev/null
+++ b/utils_state.go
@@ -0,0 +1,42 @@
+package main
+
+import (
+	"crypto/sha256"
+	"encoding/json"
+	"fmt"
+	"os"
+
+	ct "github.com/google/certificate-transparency-go"
+)
+
+type treeHead struct {
+	TreeSize int64             `json:"tree_size"`
+	RootHash [sha256.Size]byte `json:root_hash"`
+}
+
+func readState(opts options, logID []byte) (treeHead, error) {
+	if _, err := os.Stat(fmt.Sprintf("%s/%x/%s", opts.logDirectory, logID, opts.stateFile)); err != nil {
+		return treeHead{0, sha256.Sum256(nil)}, nil
+	}
+	b, err := os.ReadFile(fmt.Sprintf("%s/%x/%s", opts.logDirectory, logID, opts.stateFile))
+	if err != nil {
+		return treeHead{}, err
+	}
+	var th treeHead
+	if err := json.Unmarshal(b, &th); err != nil {
+		return treeHead{}, err
+	}
+	return th, nil
+}
+
+func readSnapshot(opts options, logID []byte) (ct.SignedTreeHead, error) {
+	b, err := os.ReadFile(fmt.Sprintf("%s/%x/%s", opts.logDirectory, logID, opts.sthFile))
+	if err != nil {
+		return ct.SignedTreeHead{}, err
+	}
+	var sth ct.SignedTreeHead
+	if err := json.Unmarshal(b, &sth); err != nil {
+		return ct.SignedTreeHead{}, err
+	}
+	return sth, nil
+}