filters: add cross-reference comments to keep bloom and compact filter extraction in sync

PastaPastaPasta · PastaPastaPasta · commit 1c9809f1c6b9 · 2025-08-20T10:11:26.000-05:00
Add maintenance notes in ExtractSpecialTxFilterElements and CBloomFilter::CheckSpecialTransactionMatchesAndUpdate to ensure future changes update both implementations together.
diff --git a/src/common/bloom.cpp b/src/common/bloom.cpp
@@ -119,6 +119,11 @@ bool CBloomFilter::CheckScript(const CScript &script) const
 // Filter is updated only if it has BLOOM_UPDATE_ALL flag to be able to have
 // simple SPV wallets that doesn't work with DIP2 transactions (multicoin
 // wallets, etc.)
+// NOTE(maintenance): Keep this implementation in sync with
+// ExtractSpecialTxFilterElements in src/evo/specialtx_filter.cpp.
+// Both routines must handle the same set of special-transaction fields.
+// If you modify one, update the other to prevent mismatches between
+// bloom filter relevance and compact filter element extraction.
 bool CBloomFilter::CheckSpecialTransactionMatchesAndUpdate(const CTransaction &tx)
 {
     if (!tx.HasExtraPayloadField()) {
diff --git a/src/evo/specialtx_filter.cpp b/src/evo/specialtx_filter.cpp
@@ -49,6 +49,11 @@ static void AddHashElement(const T& hash,
     addElement(std::vector<unsigned char>(hash.begin(), hash.end()));
 }
 
+// NOTE(maintenance): Keep this in sync with
+// CBloomFilter::CheckSpecialTransactionMatchesAndUpdate in
+// src/common/bloom.cpp. If you add or remove fields for a special
+// transaction type here, update the bloom filter routine accordingly
+// (and vice versa) to avoid compact-filter vs bloom-filter divergence.
 void ExtractSpecialTxFilterElements(const CTransaction& tx,
                                    const std::function<void(const std::vector<unsigned char>&)>& addElement)
 {

Original file line number	Diff line number	Diff line change
`@@ -49,6 +49,11 @@ static void AddHashElement(const T& hash,`
`49`	`49`	`addElement(std::vector<unsigned char>(hash.begin(), hash.end()));`
`50`	`50`	`}`
`51`	`51`
	`52`	`+// NOTE(maintenance): Keep this in sync with`
	`53`	`+// CBloomFilter::CheckSpecialTransactionMatchesAndUpdate in`
	`54`	`+// src/common/bloom.cpp. If you add or remove fields for a special`
	`55`	`+// transaction type here, update the bloom filter routine accordingly`
	`56`	`+// (and vice versa) to avoid compact-filter vs bloom-filter divergence.`
`52`	`57`	`void ExtractSpecialTxFilterElements(const CTransaction& tx,`
`53`	`58`	`const std::function<void(const std::vector<unsigned char>&)>& addElement)`
`54`	`59`	`{`