multi: interface filter header store

Author: mohamedawnallah

blockmanager.go

@@ -84,7 +84,7 @@ type blockManagerCfg struct {
 
 	// RegFilterHeaders is the store where filter headers for the regular
 	// compact filters are persistently stored.
-	RegFilterHeaders *headerfs.FilterHeaderStore
+	RegFilterHeaders headerfs.FilterHeaderStore
 
 	// TimeSource is used to access a time estimate based on the clocks of
 	// the connected peers.
@@ -702,7 +702,7 @@ waitForHeaders:
 // network, if it can, and resolves any conflicts between them. It then writes
 // any verified headers to the store.
 func (b *blockManager) getUncheckpointedCFHeaders(
-	store *headerfs.FilterHeaderStore, fType wire.FilterType) error {
+	store headerfs.FilterHeaderStore, fType wire.FilterType) error {
 
 	// Get the filter header store's chain tip.
 	filterTip, filtHeight, err := store.ChainTip()
@@ -928,7 +928,7 @@ func (c *checkpointedCFHeadersQuery) handleResponse(req, resp wire.Message,
 // checkpoints we got from the network. It assumes that the filter header store
 // matches the checkpoints up to the tip of the store.
 func (b *blockManager) getCheckpointedCFHeaders(checkpoints []*chainhash.Hash,
-	store *headerfs.FilterHeaderStore, fType wire.FilterType) {
+	store headerfs.FilterHeaderStore, fType wire.FilterType) {
 
 	// We keep going until we've caught up the filter header store with the
 	// latest known checkpoint.
@@ -1174,7 +1174,7 @@ func (b *blockManager) getCheckpointedCFHeaders(checkpoints []*chainhash.Hash,
 // filter header field in the next message range before writing to disk, and
 // the current height after writing the headers.
 func (b *blockManager) writeCFHeadersMsg(msg *wire.MsgCFHeaders,
-	store *headerfs.FilterHeaderStore) (*chainhash.Hash, uint32, error) {
+	store headerfs.FilterHeaderStore) (*chainhash.Hash, uint32, error) {
 
 	// Check that the PrevFilterHeader is the same as the last stored so we
 	// can prevent misalignment.
@@ -1364,7 +1364,7 @@ func verifyCheckpoint(prevCheckpoint, nextCheckpoint *chainhash.Hash,
 // information.
 func (b *blockManager) resolveConflict(
 	checkpoints map[string][]*chainhash.Hash,
-	store *headerfs.FilterHeaderStore, fType wire.FilterType) (
+	store headerfs.FilterHeaderStore, fType wire.FilterType) (
 	[]*chainhash.Hash, error) {
 
 	// First check the served checkpoints against the hardcoded ones.
@@ -1913,7 +1913,7 @@ func (b *blockManager) getCheckpts(lastHash *chainhash.Hash,
 // existing store up to the tip of the store. If all of the peers match but
 // the store doesn't, the height at which the mismatch occurs is returned.
 func checkCFCheckptSanity(cp map[string][]*chainhash.Hash,
-	headerStore *headerfs.FilterHeaderStore) (int, error) {
+	headerStore headerfs.FilterHeaderStore) (int, error) {
 
 	// Get the known best header to compare against checkpoints.
 	_, storeTip, err := headerStore.ChainTip()

blockmanager_test.go

@@ -55,7 +55,7 @@ func (m *mockDispatcher) Query(requests []*query.Request,
 
 // setupBlockManager initialises a blockManager to be used in tests.
 func setupBlockManager(t *testing.T) (*blockManager, headerfs.BlockHeaderStore,
-	*headerfs.FilterHeaderStore, error) {
+	headerfs.FilterHeaderStore, error) {
 
 	// Set up the block and filter header stores.
 	tempDir := t.TempDir()

headerfs/file.go

@@ -140,7 +140,7 @@ func (h *blockHeaderStore) readHeader(height uint32) (wire.BlockHeader, error) {
 
 // readHeader reads a single filter header at the specified height from the
 // flat files on disk.
-func (f *FilterHeaderStore) readHeader(height uint32) (*chainhash.Hash, error) {
+func (f *filterHeaderStore) readHeader(height uint32) (*chainhash.Hash, error) {
 	seekDistance := uint64(height) * 32
 
 	rawHeader, err := f.readRaw(seekDistance)
@@ -158,7 +158,7 @@ func (f *FilterHeaderStore) readHeader(height uint32) (*chainhash.Hash, error) {
 //
 // NOTE: The end height is _inclusive_ so we'll fetch all headers from the
 // startHeight up to the end height, including the final header.
-func (f *FilterHeaderStore) readHeaderRange(startHeight uint32,
+func (f *filterHeaderStore) readHeaderRange(startHeight uint32,
 	endHeight uint32) ([]chainhash.Hash, error) {
 
 	// Based on the defined header type, we'll determine the number of

headerfs/store.go

@@ -613,22 +613,52 @@ func (h *blockHeaderStore) ChainTip() (*wire.BlockHeader, uint32, error) {
 	return &latestHeader, tipHeight, nil
 }
 
-// FilterHeaderStore is an implementation of a fully fledged database for any
-// variant of filter headers.  The FilterHeaderStore combines a flat file to
+// FilterHeaderStore defines the interface for storing and retrieving filter
+// headers.
+type FilterHeaderStore interface {
+	// ChainTip returns the hash and height of the latest filter header.
+	ChainTip() (*chainhash.Hash, uint32, error)
+
+	// FetchHeader fetches the filter header for a specific block hash.
+	FetchHeader(hash *chainhash.Hash) (*chainhash.Hash, error)
+
+	// FetchHeaderAncestors fetches the given number of headers starting
+	// from the specified stop hash and working backwards.
+	FetchHeaderAncestors(numHeaders uint32,
+		stopHash *chainhash.Hash) ([]chainhash.Hash, uint32, error)
+
+	// FetchHeaderByHeight fetches the filter header for a specific block
+	// height.
+	FetchHeaderByHeight(height uint32) (*chainhash.Hash, error)
+
+	// WriteHeaders writes a set of filter headers to the store.
+	WriteHeaders(hdrs ...FilterHeader) error
+
+	// RollbackLastBlock rolls back the last block, returning the new tip
+	// after rollback.
+	RollbackLastBlock(newTip *chainhash.Hash) (*BlockStamp, error)
+}
+
+// filterHeaderStore is an implementation of a fully fledged database for any
+// variant of filter headers. The filterHeaderStore combines a flat file to
 // store the block headers with a database instance for managing the index into
 // the set of flat files.
-type FilterHeaderStore struct {
+type filterHeaderStore struct {
 	*headerStore
 }
 
+// Compile-time assertion to ensure filterHeaderStore implements
+// FilterHeaderStore interface.
+var _ FilterHeaderStore = (*filterHeaderStore)(nil)
+
 // NewFilterHeaderStore returns a new instance of the FilterHeaderStore based
 // on a target file path, filter type, and target net parameters. These
 // parameters are required as if this is the initial start up of the
 // FilterHeaderStore, then the initial genesis filter header will need to be
 // inserted.
 func NewFilterHeaderStore(filePath string, db walletdb.DB,
 	filterType HeaderType, netParams *chaincfg.Params,
-	headerStateAssertion *FilterHeader) (*FilterHeaderStore, error) {
+	headerStateAssertion *FilterHeader) (FilterHeaderStore, error) {
 
 	fStore, err := newHeaderStore(db, filePath, filterType)
 	if err != nil {
@@ -642,7 +672,7 @@ func NewFilterHeaderStore(filePath string, db walletdb.DB,
 		return nil, err
 	}
 
-	fhs := &FilterHeaderStore{
+	fhs := &filterHeaderStore{
 		fStore,
 	}
 
@@ -746,7 +776,7 @@ func NewFilterHeaderStore(filePath string, db walletdb.DB,
 // maybeResetHeaderState will reset the header state if the header assertion
 // fails, but only if the target height is found. The boolean returned indicates
 // that header state was reset.
-func (f *FilterHeaderStore) maybeResetHeaderState(
+func (f *filterHeaderStore) maybeResetHeaderState(
 	headerStateAssertion *FilterHeader) (bool, error) {
 
 	// First, we'll attempt to locate the header at this height. If no such
@@ -781,7 +811,11 @@ func (f *FilterHeaderStore) maybeResetHeaderState(
 
 // FetchHeader returns the filter header that corresponds to the passed block
 // height.
-func (f *FilterHeaderStore) FetchHeader(hash *chainhash.Hash) (*chainhash.Hash, error) {
+//
+// NOTE: Part of the FilterHeaderStore interface.
+func (f *filterHeaderStore) FetchHeader(
+	hash *chainhash.Hash) (*chainhash.Hash, error) {
+
 	// Lock store for read.
 	f.mtx.RLock()
 	defer f.mtx.RUnlock()
@@ -795,7 +829,11 @@ func (f *FilterHeaderStore) FetchHeader(hash *chainhash.Hash) (*chainhash.Hash,
 }
 
 // FetchHeaderByHeight returns the filter header for a particular block height.
-func (f *FilterHeaderStore) FetchHeaderByHeight(height uint32) (*chainhash.Hash, error) {
+//
+// NOTE: Part of the FilterHeaderStore interface.
+func (f *filterHeaderStore) FetchHeaderByHeight(
+	height uint32) (*chainhash.Hash, error) {
+
 	// Lock store for read.
 	f.mtx.RLock()
 	defer f.mtx.RUnlock()
@@ -809,7 +847,9 @@ func (f *FilterHeaderStore) FetchHeaderByHeight(height uint32) (*chainhash.Hash,
 // then return the final header specified by the stop hash. We'll also return
 // the starting height of the header range as well so callers can compute the
 // height of each header without knowing the height of the stop hash.
-func (f *FilterHeaderStore) FetchHeaderAncestors(numHeaders uint32,
+//
+// NOTE: Part of the FilterHeaderStore interface.
+func (f *filterHeaderStore) FetchHeaderAncestors(numHeaders uint32,
 	stopHash *chainhash.Hash) ([]chainhash.Hash, uint32, error) {
 
 	// First, we'll find the final header in the range, this will be the
@@ -855,7 +895,9 @@ func (f *FilterHeader) toIndexEntry() headerEntry {
 // WriteHeaders writes a batch of filter headers to persistent storage. The
 // headers themselves are appended to the flat file, and then the index updated
 // to reflect the new entries.
-func (f *FilterHeaderStore) WriteHeaders(hdrs ...FilterHeader) error {
+//
+// NOTE: Part of the FilterHeaderStore interface.
+func (f *filterHeaderStore) WriteHeaders(hdrs ...FilterHeader) error {
 	// Lock store for write.
 	f.mtx.Lock()
 	defer f.mtx.Unlock()
@@ -896,7 +938,9 @@ func (f *FilterHeaderStore) WriteHeaders(hdrs ...FilterHeader) error {
 
 // ChainTip returns the latest filter header and height known to the
 // FilterHeaderStore.
-func (f *FilterHeaderStore) ChainTip() (*chainhash.Hash, uint32, error) {
+//
+// NOTE: Part of the FilterHeaderStore interface.
+func (f *filterHeaderStore) ChainTip() (*chainhash.Hash, uint32, error) {
 	// Lock store for read.
 	f.mtx.RLock()
 	defer f.mtx.RUnlock()
@@ -919,7 +963,11 @@ func (f *FilterHeaderStore) ChainTip() (*chainhash.Hash, uint32, error) {
 // re-org which disconnects the latest filter header from the end of the main
 // chain. The information about the latest header tip after truncation is
 // returned.
-func (f *FilterHeaderStore) RollbackLastBlock(newTip *chainhash.Hash) (*BlockStamp, error) {
+//
+// NOTE: Part of the FilterHeaderStore interface.
+func (f *filterHeaderStore) RollbackLastBlock(
+	newTip *chainhash.Hash) (*BlockStamp, error) {
+
 	// Lock store for write.
 	f.mtx.Lock()
 	defer f.mtx.Unlock()