Implement Invalidator::Acknowledge

sync/internal_api/public/base/invalidation.cc

Index: sync/internal_api/public/base/invalidation.cc
diff --git a/sync/internal_api/public/base/invalidation.cc b/sync/internal_api/public/base/invalidation.cc
index 2ddaa63adea9d3fa91ea5afa4c01c12bd73826a4..002d700d569038888426cac5d5609ba8cd3fe89d 100644
--- a/sync/internal_api/public/base/invalidation.cc
+++ b/sync/internal_api/public/base/invalidation.cc
@@ -4,20 +4,51 @@
 
 #include "sync/internal_api/public/base/invalidation.h"
 
+#include <cstddef>
+#include "base/rand_util.h"
+#include "base/string_number_conversions.h"
 #include "base/values.h"
 
 namespace syncer {
 
+namespace {
+// Hopefully enough bytes for uniqueness.
+const size_t kBytesInHandle = 16;
+// This is not a valid handle name, since all valid handles are 16 bytes long.
+const char kInvalidHandleName[] = "INVALIDHANDLENAME";
+COMPILE_ASSERT(kBytesInHandle != arraysize(kInvalidHandleName),
+               invalid_handle_name_must_differ_in_length_from_valid_handles);
+}  // namespace
+
+AckHandle AckHandle::CreateUnique() {
+  // This isn't a valid UUID, so we don't attempt to format it like one.
+  uint8_t random_bytes[kBytesInHandle];
+  base::RandBytes(random_bytes, sizeof(random_bytes));
+  return AckHandle(base::HexEncode(random_bytes, sizeof(random_bytes)));
+}
+
+AckHandle AckHandle::InvalidAckHandle() {
+  return AckHandle(kInvalidHandleName);
+}
+
 bool AckHandle::Equals(const AckHandle& other) const {
-  return true;
+  return state_ == other.state_;
 }
 
 scoped_ptr<base::Value> AckHandle::ToValue() const {
-  return scoped_ptr<base::Value>(new DictionaryValue());
+  return scoped_ptr<base::Value>(new StringValue(state_));

[akalin, 2012/10/19 13:27:16]

more future-proof to have a dictionary with a single string field?

[dcheng, 2012/10/19 19:38:11]

Done.

 }
 
 bool AckHandle::ResetFromValue(const base::Value& value) {
-  return true;
+  // TODO(dcheng): Add debug mode sanity checking?
+  return value.GetAsString(&state_);
+}
+
+AckHandle::AckHandle(const std::string& state) : state_(state) {
+}
+
+Invalidation::Invalidation()
+    : ack_handle(AckHandle::InvalidAckHandle()) {
 }
 
 bool Invalidation::Equals(const Invalidation& other) const {