eth,core: add api debug_getTrieFlushInterval (#27303)

* core,eth: add api debug_getTrieFlushInterval
Signed-off-by: jsvisa <delweng@gmail.com>

* eth/api_debug: comment of SetTrieFlushInterval
Signed-off-by: jsvisa <delweng@gmail.com>

* Apply suggestions from code review

---------
Signed-off-by: jsvisa <delweng@gmail.com>
Co-authored-by: Martin Holst Swende <martin@swende.se>

core/blockchain.go

@@ -2492,3 +2492,8 @@ func (bc *BlockChain) SetBlockValidatorAndProcessorForTesting(v Validator, p Pro
 func (bc *BlockChain) SetTrieFlushInterval(interval time.Duration) {
 	bc.flushInterval.Store(int64(interval))
 }
+
+// GetTrieFlushInterval gets the in-memroy tries flush interval
+func (bc *BlockChain) GetTrieFlushInterval() time.Duration {
+	return time.Duration(bc.flushInterval.Load())
+}

eth/api_debug.go

@@ -406,6 +406,8 @@ func (api *DebugAPI) GetAccessibleState(from, to rpc.BlockNumber) (uint64, error
 
 // SetTrieFlushInterval configures how often in-memory tries are persisted
 // to disk. The value is in terms of block processing time, not wall clock.
+// If the value is shorter than the block generation time, or even 0 or negative,
+// the node will flush trie after processing each block (effectively archive mode).
 func (api *DebugAPI) SetTrieFlushInterval(interval string) error {
 	t, err := time.ParseDuration(interval)
 	if err != nil {
@@ -414,3 +416,8 @@ func (api *DebugAPI) SetTrieFlushInterval(interval string) error {
 	api.eth.blockchain.SetTrieFlushInterval(t)
 	return nil
 }
+
+// GetTrieFlushInterval gets the current value of in-memory trie flush interval
+func (api *DebugAPI) GetTrieFlushInterval() string {
+	return api.eth.blockchain.GetTrieFlushInterval().String()
+}

internal/web3ext/web3ext.go

@@ -495,6 +495,11 @@ web3._extend({
 			call: 'debug_setTrieFlushInterval',
 			params: 1
 		}),
+		new web3._extend.Method({
+			name: 'getTrieFlushInterval',
+			call: 'debug_getTrieFlushInterval',
+			params: 0
+		}),
 	],
 	properties: []
 });