feat: persist and transfer script command payloads

internal/client/agent/script.go

@@ -0,0 +1,47 @@
+package agent
+
+import (
+	"context"
+	"crypto/sha256"
+	"errors"
+
+	rvboxv1 "github.com/rvbox/rvbox/gen/go/rvbox/v1"
+	"github.com/rvbox/rvbox/internal/agentproto"
+	"github.com/rvbox/rvbox/internal/client/spool"
+	"github.com/rvbox/rvbox/internal/domain"
+)
+
+var ErrInvalidScriptTransfer = errors.New("invalid script transfer")
+
+// ApplyScriptChunk validates one server script frame and appends it to the
+// durable client spool. The spool accepts only the next contiguous range or
+// an exact replay, so reconnects cannot create holes or duplicate bytes.
+func ApplyScriptChunk(ctx context.Context, store *spool.Store, session Session, chunk *rvboxv1.ScriptChunk, limits agentproto.Limits) (spool.ScriptStatus, error) {
+	if store == nil || session.Generation == 0 || chunk == nil || chunk.GetOffset() > limits.MaxScriptBytes || uint64(len(chunk.GetData())) > limits.MaxRawChunkBytes || len(chunk.GetSha256()) != sha256.Size {
+		return spool.ScriptStatus{}, ErrInvalidScriptTransfer
+	}
+	issue, err := domain.ParseUUIDv7(chunk.GetIssueUuid())
+	if err != nil || sha256.Sum256(chunk.GetData()) != bytesToDigest(chunk.GetSha256()) {
+		return spool.ScriptStatus{}, ErrInvalidScriptTransfer
+	}
+	return store.AppendScriptChunk(ctx, issue, chunk.GetOffset(), chunk.GetData(), bytesToDigest(chunk.GetSha256()))
+}
+
+// ApplyScriptCommit marks a fully received script launch-eligible only after
+// the spool verifies the declared size and whole-body SHA-256.
+func ApplyScriptCommit(ctx context.Context, store *spool.Store, session Session, commit *rvboxv1.ScriptCommit, limits agentproto.Limits) (spool.ScriptStatus, error) {
+	if store == nil || session.Generation == 0 || commit == nil || commit.GetSizeBytes() > limits.MaxScriptBytes || len(commit.GetSha256()) != sha256.Size {
+		return spool.ScriptStatus{}, ErrInvalidScriptTransfer
+	}
+	issue, err := domain.ParseUUIDv7(commit.GetIssueUuid())
+	if err != nil {
+		return spool.ScriptStatus{}, ErrInvalidScriptTransfer
+	}
+	return store.CommitScript(ctx, issue, spool.ScriptDescriptor{SizeBytes: commit.GetSizeBytes(), SHA256: bytesToDigest(commit.GetSha256())})
+}
+
+func bytesToDigest(value []byte) [sha256.Size]byte {
+	var digest [sha256.Size]byte
+	copy(digest[:], value)
+	return digest
+}